android_kernel_samsung_sm8650-modules/smcinvoke/smcinvoke.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016-2021, The Linux Foundation. All rights reserved.
 * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
 */

#define pr_fmt(fmt) "smcinvoke: %s: " fmt, __func__

#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
#include <linux/hashtable.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/dma-buf.h>
#include <linux/delay.h>
#include <linux/kref.h>
#include <linux/signal.h>
#include <linux/msm_ion.h>
#include <linux/mem-buf.h>
#include <linux/of_platform.h>
#include <linux/firmware.h>
#include <linux/qcom_scm.h>
#include <linux/freezer.h>
#include <linux/ratelimit.h>
#include <asm/cacheflush.h>
#include <linux/qtee_shmbridge.h>
#include <linux/kthread.h>
#include "smcinvoke.h"
#include "smcinvoke_object.h"
#include "IClientEnv.h"
#if IS_ENABLED(CONFIG_QSEECOM_PROXY)
#include <linux/qseecom_kernel.h>
#include "misc/qseecom_priv.h"
#else
#include "misc/qseecom_kernel.h"
#endif
#include "misc/qseecomi.h"

#define CREATE_TRACE_POINTS
#include "trace_smcinvoke.h"

#define SMCINVOKE_DEV				"smcinvoke"
#define SMCINVOKE_TZ_ROOT_OBJ			1
#define SMCINVOKE_TZ_OBJ_NULL			0
#define SMCINVOKE_ARGS_ALIGN_SIZE		(sizeof(uint64_t))
#define SMCINVOKE_NEXT_AVAILABLE_TXN		0
#define SMCINVOKE_REQ_PLACED			1
#define SMCINVOKE_REQ_PROCESSING		2
#define SMCINVOKE_REQ_PROCESSED			3
#define SMCINVOKE_INCREMENT			1
#define SMCINVOKE_DECREMENT			0
#define SMCINVOKE_OBJ_TYPE_TZ_OBJ		0
#define SMCINVOKE_OBJ_TYPE_SERVER		1
#define SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL	2
#define SMCINVOKE_MEM_MAP_OBJ			0
#define SMCINVOKE_MEM_RGN_OBJ			1
#define SMCINVOKE_MEM_PERM_RW			6
#define SMCINVOKE_SCM_EBUSY_WAIT_MS		30
#define SMCINVOKE_SCM_EBUSY_MAX_RETRY		200
#define TZCB_ERR_RATELIMIT_INTERVAL		(1*HZ)
#define TZCB_ERR_RATELIMIT_BURST		1

//print tzcb err per sec
#define tzcb_err_ratelimited(fmt, ...) 	do {		\
	static DEFINE_RATELIMIT_STATE(_rs, 		\
			TZCB_ERR_RATELIMIT_INTERVAL,	\
			TZCB_ERR_RATELIMIT_BURST);	\
	if (__ratelimit(&_rs))				\
		pr_err(fmt, ##__VA_ARGS__);		\
} while(0)



/* TZ defined values - Start */
#define SMCINVOKE_INVOKE_PARAM_ID		0x224
#define SMCINVOKE_CB_RSP_PARAM_ID		0x22
#define SMCINVOKE_INVOKE_CMD_LEGACY		0x32000600
#define SMCINVOKE_INVOKE_CMD			0x32000602
#define SMCINVOKE_CB_RSP_CMD			0x32000601
#define SMCINVOKE_RESULT_INBOUND_REQ_NEEDED	3
/* TZ defined values - End */

/* Asynchronous protocol values */
/* Driver async version is set to match the minimal TZ version that supports async memory object */
#define SMCINVOKE_ASYNC_VERSION          (0x00010002)
#define SMCINVOKE_ASYNC_OP_MEMORY_OBJECT (0x00000003)

/*
 * This is the state when server FD has been closed but
 * TZ still has refs of CBOBjs served by this server
 */
#define SMCINVOKE_SERVER_STATE_DEFUNCT		1

#define CBOBJ_MAX_RETRIES 50
#define FOR_ARGS(ndxvar, counts, section) \
	for (ndxvar = OBJECT_COUNTS_INDEX_##section(counts); \
		ndxvar < (OBJECT_COUNTS_INDEX_##section(counts) \
		+ OBJECT_COUNTS_NUM_##section(counts)); \
		++ndxvar)

#define TZCB_BUF_OFFSET(tzcb_req) (sizeof(tzcb_req->result) + \
			sizeof(struct smcinvoke_msg_hdr) + \
			sizeof(union smcinvoke_tz_args) * \
			OBJECT_COUNTS_TOTAL(tzcb_req->hdr.counts))

/*
 * +ve uhandle : either remote obj or mem obj, decided by f_ops
 * -ve uhandle : either Obj NULL or CBObj
 *	- -1: OBJ NULL
 *	- < -1: CBObj
 */
#define UHANDLE_IS_FD(h) ((h) >= 0)
#define UHANDLE_IS_NULL(h) ((h) == SMCINVOKE_USERSPACE_OBJ_NULL)
#define UHANDLE_IS_CB_OBJ(h) (h < SMCINVOKE_USERSPACE_OBJ_NULL)
#define UHANDLE_NULL (SMCINVOKE_USERSPACE_OBJ_NULL)
/*
 * MAKE => create handle for other domain i.e. TZ or userspace
 * GET => retrieve obj from incoming handle
 */
#define UHANDLE_GET_CB_OBJ(h) (-2-(h))
#define UHANDLE_MAKE_CB_OBJ(o) (-2-(o))
#define UHANDLE_GET_FD(h) (h)

/*
 * +ve tzhandle : remote object i.e. owned by TZ
 * -ve tzhandle : local object i.e. owned by linux
 * --------------------------------------------------
 *| 1 (1 bit) | Obj Id (15 bits) | srvr id (16 bits) |
 * ---------------------------------------------------
 * Server ids are defined below for various local objects
 * server id 0 : Kernel Obj
 * server id 1 : Memory region Obj
 * server id 2 : Memory map Obj
 * server id 3-15: Reserverd
 * server id 16 & up: Callback Objs
 */
#define KRNL_SRVR_ID 0
#define MEM_RGN_SRVR_ID 1
#define MEM_MAP_SRVR_ID 2
#define CBOBJ_SERVER_ID_START 0x10
#define CBOBJ_SERVER_ID_END ((1<<16) - 1)
/* local obj id is represented by 15 bits */
#define MAX_LOCAL_OBJ_ID ((1<<15) - 1)
/* CBOBJs will be served by server id 0x10 onwards */
#define TZHANDLE_GET_SERVER(h) ((uint16_t)((h) & 0xFFFF))
#define TZHANDLE_GET_OBJID(h) (((h) >> 16) & 0x7FFF)
#define TZHANDLE_MAKE_LOCAL(s, o) (((0x8000 | (o)) << 16) | s)
#define SET_BIT(s,b) (s | (1 << b))
#define UNSET_BIT(s,b) (s & (~ (1 << b)))

#define TZHANDLE_IS_NULL(h) ((h) == SMCINVOKE_TZ_OBJ_NULL)
#define TZHANDLE_IS_LOCAL(h) ((h) & 0x80000000)
#define TZHANDLE_IS_REMOTE(h) (!TZHANDLE_IS_NULL(h) && !TZHANDLE_IS_LOCAL(h))

#define TZHANDLE_IS_KERNEL_OBJ(h) (TZHANDLE_IS_LOCAL(h) && \
				TZHANDLE_GET_SERVER(h) == KRNL_SRVR_ID)
#define TZHANDLE_IS_MEM_RGN_OBJ(h) (TZHANDLE_IS_LOCAL(h) && \
				TZHANDLE_GET_SERVER(h) == MEM_RGN_SRVR_ID)
#define TZHANDLE_IS_MEM_MAP_OBJ(h) (TZHANDLE_IS_LOCAL(h) && \
				TZHANDLE_GET_SERVER(h) == MEM_MAP_SRVR_ID)
#define TZHANDLE_IS_MEM_OBJ(h) (TZHANDLE_IS_MEM_RGN_OBJ(h) || \
				TZHANDLE_IS_MEM_MAP_OBJ(h))
#define TZHANDLE_IS_CB_OBJ(h) (TZHANDLE_IS_LOCAL(h) && \
				TZHANDLE_GET_SERVER(h) >= CBOBJ_SERVER_ID_START)

#define FILE_IS_REMOTE_OBJ(f) ((f)->f_op && (f)->f_op == &g_smcinvoke_fops)

static DEFINE_MUTEX(g_smcinvoke_lock);
#define NO_LOCK 0
#define TAKE_LOCK 1
#define MUTEX_LOCK(x) { if (x) mutex_lock(&g_smcinvoke_lock); }
#define MUTEX_UNLOCK(x) { if (x) mutex_unlock(&g_smcinvoke_lock); }

#define POST_KT_SLEEP           0
#define POST_KT_WAKEUP          1
#define MAX_CHAR_NAME           50

enum worker_thread_type {
	SHMB_WORKER_THREAD      = 0,
	OBJECT_WORKER_THREAD,
	ADCI_WORKER_THREAD,
	MAX_THREAD_NUMBER
};

static DEFINE_HASHTABLE(g_cb_servers, 8);
static LIST_HEAD(g_mem_objs);
static uint16_t g_last_cb_server_id = CBOBJ_SERVER_ID_START;
static uint16_t g_last_mem_rgn_id, g_last_mem_map_obj_id;
static size_t g_max_cb_buf_size = SMCINVOKE_TZ_MIN_BUF_SIZE;
static unsigned int cb_reqs_inflight;
static bool legacy_smc_call;
static int invoke_cmd;

static long smcinvoke_ioctl(struct file *, unsigned int, unsigned long);
static int smcinvoke_open(struct inode *, struct file *);
static int smcinvoke_release(struct inode *, struct file *);
static int release_cb_server(uint16_t);

static const struct file_operations g_smcinvoke_fops = {
	.owner		= THIS_MODULE,
	.unlocked_ioctl	= smcinvoke_ioctl,
	.compat_ioctl	= smcinvoke_ioctl,
	.open		= smcinvoke_open,
	.release	= smcinvoke_release,
};

static dev_t smcinvoke_device_no;
static struct cdev smcinvoke_cdev;
static struct class *driver_class;
struct device *class_dev;
static struct platform_device *smcinvoke_pdev;

/* We disable async memory object support by default,
 * until we receive the first message from TZ over the
 * async channel and can determine TZ async version.
 */
static bool mem_obj_async_support = false;
static uint32_t tz_async_version = 0x0;

struct smcinvoke_buf_hdr {
	uint32_t offset;
	uint32_t size;
};

union smcinvoke_tz_args {
	struct smcinvoke_buf_hdr b;
	int32_t handle;
};

struct smcinvoke_msg_hdr {
	uint32_t tzhandle;
	uint32_t op;
	uint32_t counts;
};

/* Inbound reqs from TZ */
struct smcinvoke_tzcb_req {
	int32_t result;
	struct smcinvoke_msg_hdr hdr;
	union smcinvoke_tz_args args[0];
};

struct smcinvoke_file_data {
	uint32_t context_type;
	union {
		uint32_t tzhandle;
		uint16_t server_id;
	};
};

struct smcinvoke_piggyback_msg {
	uint32_t version;
	uint32_t op;
	uint32_t counts;
	int32_t objs[0];
};

/* Mapped memory object data
 *
 * memObjRef		Handle reference for the memory object
 * mapObjRef		Handle reference for the map object
 * addr				Mapped memory address
 * size				Size of mapped memory
 * perm				Access rights for the memory
 */
struct smcinvoke_mem_obj_info {
	uint32_t memObjRef;
	uint32_t mapObjRef;
	uint64_t addr;
	uint64_t size;
	uint32_t perm;
};

/* Memory object info to be written into the async buffer
 *
 * version		Async protocol version
 * op			Async protocol operation
 * count		Number of memory objects passed
 * mo			Mapped memory object data
 */
struct smcinvoke_mem_obj_msg {
	uint32_t version;
	uint32_t op;
	uint32_t count;
	struct smcinvoke_mem_obj_info mo[];
};

struct smcinvoke_mem_obj_pending_async {
	struct smcinvoke_mem_obj *mem_obj;
	struct list_head list;
};

/* Data structure to hold request coming from TZ */
struct smcinvoke_cb_txn {
	uint32_t txn_id;
	int32_t state;
	struct smcinvoke_tzcb_req *cb_req;
	size_t cb_req_bytes;
	struct file **filp_to_release;
	struct hlist_node hash;
	struct kref ref_cnt;
};

struct smcinvoke_server_info {
	uint16_t server_id;
	uint16_t state;
	uint32_t txn_id;
	struct kref ref_cnt;
	wait_queue_head_t req_wait_q;
	wait_queue_head_t rsp_wait_q;
	size_t cb_buf_size;
	DECLARE_HASHTABLE(reqs_table, 4);
	DECLARE_HASHTABLE(responses_table, 4);
	struct hlist_node hash;
	struct list_head pending_cbobjs;
	uint8_t is_server_suspended;
};

struct smcinvoke_cbobj {
	uint16_t cbobj_id;
	struct kref ref_cnt;
	struct smcinvoke_server_info *server;
	struct list_head list;
};

/*
 * We require couple of objects, one for mem region & another
 * for mapped mem_obj once mem region has been mapped. It is
 * possible that TZ can release either independent of other.
 */
struct smcinvoke_mem_obj {
	/* these ids are objid part of tzhandle */
	uint16_t mem_region_id;
	uint16_t mem_map_obj_id;
	struct dma_buf *dma_buf;
	struct dma_buf_attachment *buf_attach;
	struct sg_table *sgt;
	struct kref mem_regn_ref_cnt;
	struct kref mem_map_obj_ref_cnt;
	uint64_t p_addr;
	size_t p_addr_len;
	struct list_head list;
	uint64_t shmbridge_handle;
	struct smcinvoke_server_info *server;
	int32_t mem_obj_user_fd;
};

static LIST_HEAD(g_bridge_postprocess);
DEFINE_MUTEX(bridge_postprocess_lock);

static LIST_HEAD(g_object_postprocess);
DEFINE_MUTEX(object_postprocess_lock);

struct bridge_deregister {
	uint64_t shmbridge_handle;
	struct dma_buf *dmabuf_to_free;
};

struct object_release {
	uint32_t tzhandle;
	uint32_t context_type;
};


struct smcinvoke_shmbridge_deregister_pending_list {
	struct list_head list;
	struct bridge_deregister data;
};

struct smcinvoke_object_release_pending_list {
	struct list_head list;
	struct object_release data;
};

struct smcinvoke_worker_thread {
	enum worker_thread_type type;
	atomic_t postprocess_kthread_state;
	wait_queue_head_t postprocess_kthread_wq;
	struct task_struct *postprocess_kthread_task;
};

static struct smcinvoke_worker_thread smcinvoke[MAX_THREAD_NUMBER];
static const char thread_name[MAX_THREAD_NUMBER][MAX_CHAR_NAME] = {
	"smcinvoke_shmbridge_postprocess", "smcinvoke_object_postprocess", "smcinvoke_adci_thread"};
static struct Object adci_rootEnv = Object_NULL;
extern int get_root_obj(struct Object *rootObj);

static int prepare_send_scm_msg(const uint8_t *in_buf, phys_addr_t in_paddr,
		size_t in_buf_len,
		uint8_t *out_buf, phys_addr_t out_paddr,
		size_t out_buf_len,
		struct smcinvoke_cmd_req *req,
		union smcinvoke_arg *args_buf,
		bool *tz_acked, uint32_t context_type,
		struct qtee_shm *in_shm, struct qtee_shm *out_shm, bool retry);

static void process_piggyback_data(void *buf, size_t buf_size);
static void add_mem_obj_info_to_async_side_channel_locked(void *buf, size_t buf_size, struct list_head *l_pending_mem_obj);
static void delete_pending_async_list_locked(struct list_head *l_pending_mem_obj);

static void destroy_cb_server(struct kref *kref)
{
	struct smcinvoke_server_info *server = container_of(kref,
			struct smcinvoke_server_info, ref_cnt);
	if (server) {
		hash_del(&server->hash);
		kfree(server);
	}
}

/*
 *  A separate find func is reqd mainly for couple of cases:
 *  next_cb_server_id_locked which checks if server id had been utilized or not.
 *      - It would be overhead if we do ref_cnt for this case
 *  smcinvoke_release: which is called when server is closed from userspace.
 *      - During server creation we init ref count, now put it back
 */
static struct smcinvoke_server_info *find_cb_server_locked(uint16_t server_id)
{
	struct smcinvoke_server_info *data = NULL;

	hash_for_each_possible(g_cb_servers, data, hash, server_id) {
		if (data->server_id == server_id)
			return data;
	}
	return NULL;
}

static struct smcinvoke_server_info *get_cb_server_locked(uint16_t server_id)
{
	struct smcinvoke_server_info *server = find_cb_server_locked(server_id);

	if (server)
		kref_get(&server->ref_cnt);

	return server;
}

static uint16_t next_cb_server_id_locked(void)
{
	if (g_last_cb_server_id == CBOBJ_SERVER_ID_END)
		g_last_cb_server_id = CBOBJ_SERVER_ID_START;

	while (find_cb_server_locked(++g_last_cb_server_id))
		;

	return g_last_cb_server_id;
}

static inline void release_filp(struct file **filp_to_release, size_t arr_len)
{
	size_t i = 0;

	for (i = 0; i < arr_len; i++) {
		if (filp_to_release[i]) {
			fput(filp_to_release[i]);
			filp_to_release[i] = NULL;
		}
	}
}

static struct smcinvoke_mem_obj *find_mem_obj_locked(uint16_t mem_obj_id,
							bool is_mem_rgn_obj)
{
	struct smcinvoke_mem_obj *mem_obj = NULL;

	if (list_empty(&g_mem_objs))
		return NULL;

	list_for_each_entry(mem_obj, &g_mem_objs, list) {
		if ((is_mem_rgn_obj &&
				(mem_obj->mem_region_id == mem_obj_id)) ||
				(!is_mem_rgn_obj &&
				(mem_obj->mem_map_obj_id == mem_obj_id)))
				return mem_obj;
	}
	return NULL;
}

static uint32_t next_mem_region_obj_id_locked(void)
{
	if (g_last_mem_rgn_id == MAX_LOCAL_OBJ_ID)
		g_last_mem_rgn_id = 0;

	while (find_mem_obj_locked(++g_last_mem_rgn_id, SMCINVOKE_MEM_RGN_OBJ))
		;

	return g_last_mem_rgn_id;
}

static uint32_t next_mem_map_obj_id_locked(void)
{
	if (g_last_mem_map_obj_id == MAX_LOCAL_OBJ_ID)
		g_last_mem_map_obj_id = 0;

	while (find_mem_obj_locked(++g_last_mem_map_obj_id,
			SMCINVOKE_MEM_MAP_OBJ))
		;

	return g_last_mem_map_obj_id;
}

static void smcinvoke_shmbridge_post_process(void)
{
	struct smcinvoke_shmbridge_deregister_pending_list *entry = NULL;
	struct list_head *pos;
	int ret = 0;
	uint64_t handle = 0;
	struct dma_buf *dmabuf_to_free = NULL;

	do {
		mutex_lock(&bridge_postprocess_lock);
		if (list_empty(&g_bridge_postprocess)) {
			mutex_unlock(&bridge_postprocess_lock);
			break;
		}
		pos = g_bridge_postprocess.next;
		entry = list_entry(pos,
				struct smcinvoke_shmbridge_deregister_pending_list,
				list);
		if (entry) {
			handle = entry->data.shmbridge_handle;
			dmabuf_to_free = entry->data.dmabuf_to_free;
		} else {
			pr_err("entry is NULL, pos:%#llx\n", (uint64_t)pos);
		}
		list_del(pos);
		kfree_sensitive(entry);
		mutex_unlock(&bridge_postprocess_lock);

		if (entry) {
			do {
				ret = qtee_shmbridge_deregister(handle);
				if (unlikely(ret)) {
					pr_err_ratelimited("SHM failed: ret:%d ptr:0x%x h:%#llx\n",
							ret,
							dmabuf_to_free,
							handle);
				} else {
					pr_debug("SHM deletion: Handle:%#llx\n",
							handle);
					dma_buf_put(dmabuf_to_free);
				}
			} while (-EBUSY == ret);
		}
	} while (1);
}

static int smcinvoke_release_tz_object(struct qtee_shm *in_shm, struct qtee_shm *out_shm,
		uint32_t tzhandle, uint32_t context_type)
{
	int ret = 0;
	bool release_handles;
	uint8_t *in_buf = NULL;
        uint8_t *out_buf = NULL;
	struct smcinvoke_msg_hdr hdr = {0};
	struct smcinvoke_cmd_req req = {0};

	in_buf = in_shm->vaddr;
	out_buf = out_shm->vaddr;
	hdr.tzhandle = tzhandle;
	hdr.op = OBJECT_OP_RELEASE;
	hdr.counts = 0;
	*(struct smcinvoke_msg_hdr *)in_buf = hdr;

	ret = prepare_send_scm_msg(in_buf, in_shm->paddr,
			SMCINVOKE_TZ_MIN_BUF_SIZE, out_buf, out_shm->paddr,
			SMCINVOKE_TZ_MIN_BUF_SIZE, &req, NULL,
			&release_handles, context_type, in_shm, out_shm, false);
	process_piggyback_data(out_buf, SMCINVOKE_TZ_MIN_BUF_SIZE);
	if (ret) {
		pr_err_ratelimited("Failed to release object(0x%x), ret:%d\n",
				hdr.tzhandle, ret);
	} else {
		pr_debug("Released object(0x%x) successfully.\n",
				hdr.tzhandle);
	}

	return ret;
}


static int smcinvoke_object_post_process(void)
{
	struct smcinvoke_object_release_pending_list *entry = NULL;
	struct list_head *pos;
	int ret = 0;
	struct qtee_shm in_shm = {0}, out_shm = {0};

	ret = qtee_shmbridge_allocate_shm(SMCINVOKE_TZ_MIN_BUF_SIZE, &in_shm);
	if (ret) {
		ret = -ENOMEM;
		pr_err("shmbridge alloc failed for in msg in object release\n");
		goto out;
	}

	ret = qtee_shmbridge_allocate_shm(SMCINVOKE_TZ_MIN_BUF_SIZE, &out_shm);
	if (ret) {
		ret = -ENOMEM;
		pr_err("shmbridge alloc failed for out msg in object release\n");
		goto out;
	}

	do {
		mutex_lock(&object_postprocess_lock);
		if (list_empty(&g_object_postprocess)) {
			mutex_unlock(&object_postprocess_lock);
			break;
		}
		pos = g_object_postprocess.next;
		entry = list_entry(pos, struct smcinvoke_object_release_pending_list, list);

		list_del(pos);
		mutex_unlock(&object_postprocess_lock);

		if (entry) {
			do {
				ret = smcinvoke_release_tz_object(&in_shm, &out_shm,
					       	entry->data.tzhandle,  entry->data.context_type);
			} while (-EBUSY == ret);
		} else {
			pr_err("entry is NULL, pos:%#llx\n", (uint64_t)pos);
		}
		kfree_sensitive(entry);
	} while (1);

out:
	qtee_shmbridge_free_shm(&in_shm);
	qtee_shmbridge_free_shm(&out_shm);

	return ret;
}

static void smcinvoke_start_adci_thread(void)
{

	int32_t  ret = OBJECT_ERROR;
	int retry_count = 0;

	ret = get_root_obj(&adci_rootEnv);
	if (ret) {
		pr_err("failed to get rootEnv for ADCI invoke thread. ret = %d\n", ret);
		/* Marking it Object_NULL in case of failure scenario in order to avoid
		 * undefined behavior while relasing garbage adci_rootEnv object. */
		adci_rootEnv = Object_NULL;
		goto out;
	}
	/* Invoke call to QTEE which should never return if ADCI is supported */
	pr_debug("Invoking adciAccept method in QTEE\n");
	do {
		ret = IClientEnv_adciAccept(adci_rootEnv);
		if (ret == OBJECT_ERROR_BUSY) {
			pr_err_ratelimited("Secure side is busy,will retry after 5 ms, retry_count = %d\n",retry_count);
			msleep(SMCINVOKE_INTERFACE_BUSY_WAIT_MS);
		}
	} while ((ret == OBJECT_ERROR_BUSY) && (retry_count++ < SMCINVOKE_INTERFACE_MAX_RETRY));

	if (ret == OBJECT_ERROR_INVALID)
		pr_err("ADCI feature is not supported on this chipsets, ret = %d\n", ret);
	else
		pr_debug("Received response from QTEE, ret = %d\n", ret);
out:
	/* Control should reach to this point only if ADCI feature is not supported by QTEE
	  (or) ADCI thread held in QTEE is released. */
	Object_ASSIGN_NULL(adci_rootEnv);
}

static void __wakeup_postprocess_kthread(struct smcinvoke_worker_thread *smcinvoke)
{
	if (smcinvoke) {
		atomic_set(&smcinvoke->postprocess_kthread_state,
				POST_KT_WAKEUP);
		wake_up_interruptible(&smcinvoke->postprocess_kthread_wq);
	} else {
		pr_err("Invalid smcinvoke pointer.\n");
	}
}


static int smcinvoke_postprocess_kthread_func(void *data)
{
	struct smcinvoke_worker_thread *smcinvoke_wrk_trd = data;
	static const char *const tag[] = {"shmbridge","object","adci","invalid"};

	if (!smcinvoke_wrk_trd) {
		pr_err("Bad input.\n");
		return -EINVAL;
	}

	while (!kthread_should_stop()) {
		wait_event_interruptible(
			smcinvoke_wrk_trd->postprocess_kthread_wq,
			kthread_should_stop() ||
			(atomic_read(&smcinvoke_wrk_trd->postprocess_kthread_state)
			== POST_KT_WAKEUP));
		switch (smcinvoke_wrk_trd->type) {
		case SHMB_WORKER_THREAD:
			pr_debug("kthread to %s postprocess is called %d\n",
			tag[SHMB_WORKER_THREAD], atomic_read(&smcinvoke_wrk_trd->postprocess_kthread_state));
			smcinvoke_shmbridge_post_process();
			break;
		case OBJECT_WORKER_THREAD:
			pr_debug("kthread to %s postprocess is called %d\n",
			tag[OBJECT_WORKER_THREAD], atomic_read(&smcinvoke_wrk_trd->postprocess_kthread_state));
			smcinvoke_object_post_process();
			break;
		case ADCI_WORKER_THREAD:
			pr_debug("kthread to %s postprocess is called %d\n",
			tag[ADCI_WORKER_THREAD], atomic_read(&smcinvoke_wrk_trd->postprocess_kthread_state));
			smcinvoke_start_adci_thread();
			break;
		default:
			pr_err("Invalid thread type(%d), do nothing.\n",
					(int)smcinvoke_wrk_trd->type);
			break;
		}
		/* For ADCI thread, if control reaches here, that indicates either ADCI
		 * thread is not supported (or) released by QTEE. Since ADCI thread is
		 * getting signaled only during the smcinvoke driver initialization,
		 * there is no point of putting the thread into sleep state again. All the
		 * required post-processing will be taken care by object and shmbridge threads.
		 */
		if(smcinvoke_wrk_trd->type == ADCI_WORKER_THREAD) {
			break;
		  }
		atomic_set(&smcinvoke_wrk_trd->postprocess_kthread_state,
			POST_KT_SLEEP);
	}
	pr_warn("kthread(worker_thread) processed, worker_thread type is %d \n", smcinvoke_wrk_trd->type);

	return 0;
}


static int smcinvoke_create_kthreads(void)
{
	int i, rc = 0;
	const enum worker_thread_type thread_type[MAX_THREAD_NUMBER] = {
		SHMB_WORKER_THREAD, OBJECT_WORKER_THREAD, ADCI_WORKER_THREAD};

	for (i = 0; i < MAX_THREAD_NUMBER; i++) {
		init_waitqueue_head(&smcinvoke[i].postprocess_kthread_wq);
		smcinvoke[i].type = thread_type[i];
		smcinvoke[i].postprocess_kthread_task = kthread_run(
				smcinvoke_postprocess_kthread_func,
				&smcinvoke[i], thread_name[i]);
		if (IS_ERR(smcinvoke[i].postprocess_kthread_task)) {
			rc = PTR_ERR(smcinvoke[i].postprocess_kthread_task);
			pr_err("fail to create kthread to postprocess, rc = %x\n",
					rc);
			return rc;
		}
		atomic_set(&smcinvoke[i].postprocess_kthread_state,
				POST_KT_SLEEP);
	}

	return rc;
}

static void smcinvoke_destroy_kthreads(void)
{
	int i;
	int32_t  ret = OBJECT_ERROR;
	int retry_count = 0;

	if (!Object_isNull(adci_rootEnv)) {
		pr_debug("Invoking adciShutdown method in QTEE\n");
		do {
			ret = IClientEnv_adciShutdown(adci_rootEnv);
			if (ret == OBJECT_ERROR_BUSY) {
				pr_err_ratelimited("Secure side is busy,will retry after 5 ms, retry_count = %d\n",retry_count);
				msleep(SMCINVOKE_INTERFACE_BUSY_WAIT_MS);
			}
		} while ((ret == OBJECT_ERROR_BUSY) && (retry_count++ < SMCINVOKE_INTERFACE_MAX_RETRY));
		if (OBJECT_isERROR(ret)) {
			pr_err("adciShutdown in QTEE failed with error = %d\n", ret);
		}
		Object_ASSIGN_NULL(adci_rootEnv);
	}

	for (i = 0; i < MAX_THREAD_NUMBER; i++) {
		kthread_stop(smcinvoke[i].postprocess_kthread_task);
	}
}

/* Queue newly created memory object to l_pending_mem_obj list.
 * Later, the mapping information for objects in this list will be sent to TZ
 * over the async side channel.
 *
 * No return value as TZ is always able to explicitly ask for this information
 * in case this function fails and the memory object is not added to this list.
 */
static void queue_mem_obj_pending_async_locked(struct smcinvoke_mem_obj *mem_obj, struct list_head *l_pending_mem_obj)
{
	struct smcinvoke_mem_obj_pending_async *t_mem_obj_pending =
			kzalloc(sizeof(*t_mem_obj_pending), GFP_KERNEL);

	/*
	 * We are not failing execution in case of a failure here,
	 * since TZ can always ask for this information explicitly
	 * if it's not available in the side channel.
	 */
	if (!t_mem_obj_pending) {
		pr_err("Unable to allocate memory\n");
		return;
	}

	t_mem_obj_pending->mem_obj = mem_obj;
	list_add(&t_mem_obj_pending->list, l_pending_mem_obj);
}

static inline void free_mem_obj_locked(struct smcinvoke_mem_obj *mem_obj)
{
	int ret = 0;
	struct dma_buf *dmabuf_to_free = mem_obj->dma_buf;
	uint64_t shmbridge_handle = mem_obj->shmbridge_handle;
	struct smcinvoke_shmbridge_deregister_pending_list *entry = NULL;

	list_del(&mem_obj->list);
	kfree(mem_obj->server);
	kfree(mem_obj);
	mem_obj = NULL;
	mutex_unlock(&g_smcinvoke_lock);

	if (shmbridge_handle)
		ret = qtee_shmbridge_deregister(shmbridge_handle);
	if (ret) {
		pr_err("Error:%d delete bridge failed leaking memory 0x%x\n",
				ret, dmabuf_to_free);
		if (ret == -EBUSY) {
			pr_err("EBUSY: we postpone it 0x%x\n",
					dmabuf_to_free);
			entry = kzalloc(sizeof(*entry), GFP_KERNEL);
			if (entry) {
				entry->data.shmbridge_handle = shmbridge_handle;
				entry->data.dmabuf_to_free = dmabuf_to_free;
				mutex_lock(&bridge_postprocess_lock);
				list_add_tail(&entry->list, &g_bridge_postprocess);
				mutex_unlock(&bridge_postprocess_lock);
				pr_debug("SHMBridge list: added a Handle:%#llx\n",
						shmbridge_handle);
				__wakeup_postprocess_kthread(
						&smcinvoke[SHMB_WORKER_THREAD]);
			}
		}
	} else {
		dma_buf_put(dmabuf_to_free);
	}

	mutex_lock(&g_smcinvoke_lock);
}

static void del_mem_regn_obj_locked(struct kref *kref)
{
	struct smcinvoke_mem_obj *mem_obj = container_of(kref,
			struct smcinvoke_mem_obj, mem_regn_ref_cnt);

	/*
	 * mem_regn obj and mem_map obj are held into mem_obj structure which
	 * can't be released until both kinds of objs have been released.
	 * So check whether mem_map iobj has ref 0 and only then release mem_obj
	 */
	if (kref_read(&mem_obj->mem_map_obj_ref_cnt) == 0)
		free_mem_obj_locked(mem_obj);
}

static void del_mem_map_obj_locked(struct kref *kref)
{
	struct smcinvoke_mem_obj *mem_obj = container_of(kref,
			struct smcinvoke_mem_obj, mem_map_obj_ref_cnt);

	mem_obj->p_addr_len = 0;
	mem_obj->p_addr = 0;
	if (mem_obj->sgt)
		dma_buf_unmap_attachment(mem_obj->buf_attach,
				mem_obj->sgt, DMA_BIDIRECTIONAL);
	if (mem_obj->buf_attach)
		dma_buf_detach(mem_obj->dma_buf, mem_obj->buf_attach);

	/*
	 * mem_regn obj and mem_map obj are held into mem_obj structure which
	 * can't be released until both kinds of objs have been released.
	 * So check if mem_regn obj has ref 0 and only then release mem_obj
	 */
	if (kref_read(&mem_obj->mem_regn_ref_cnt) == 0)
		free_mem_obj_locked(mem_obj);
}

static int release_mem_obj_locked(int32_t tzhandle)
{
	int is_mem_regn_obj = TZHANDLE_IS_MEM_RGN_OBJ(tzhandle);
	struct smcinvoke_mem_obj *mem_obj = find_mem_obj_locked(
			TZHANDLE_GET_OBJID(tzhandle), is_mem_regn_obj);

	if (!mem_obj) {
		pr_err("memory object not found\n");
		return OBJECT_ERROR_BADOBJ;
	}

	if (is_mem_regn_obj)
		kref_put(&mem_obj->mem_regn_ref_cnt, del_mem_regn_obj_locked);
	else
		kref_put(&mem_obj->mem_map_obj_ref_cnt, del_mem_map_obj_locked);
	return OBJECT_OK;
}

static void free_pending_cbobj_locked(struct kref *kref)
{
	struct smcinvoke_server_info *server = NULL;
	struct smcinvoke_cbobj *obj = container_of(kref,
			struct smcinvoke_cbobj, ref_cnt);
	list_del(&obj->list);
	server = obj->server;
	kfree(obj);
	if (server)
		kref_put(&server->ref_cnt, destroy_cb_server);
}

static int get_pending_cbobj_locked(uint16_t srvr_id, int16_t obj_id)
{
	int ret = 0;
	bool release_server = true;
	struct list_head *head = NULL;
	struct smcinvoke_cbobj *cbobj = NULL;
	struct smcinvoke_cbobj *obj = NULL;
	struct smcinvoke_server_info *server = get_cb_server_locked(srvr_id);

	if (!server) {
		pr_err("%s, server id : %u not found\n", __func__, srvr_id);
		return OBJECT_ERROR_BADOBJ;
	}

	head = &server->pending_cbobjs;
	list_for_each_entry(cbobj, head, list)
		if (cbobj->cbobj_id == obj_id) {
			kref_get(&cbobj->ref_cnt);
			goto out;
		}

	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
	if (!obj) {
		ret = OBJECT_ERROR_KMEM;
		goto out;
	}

	obj->cbobj_id = obj_id;
	kref_init(&obj->ref_cnt);
	obj->server = server;
	/*
	 * we are holding server ref in cbobj; we will
	 * release server ref when cbobj is destroyed
	 */
	release_server = false;
	list_add_tail(&obj->list, head);
out:
	if (release_server)
		kref_put(&server->ref_cnt, destroy_cb_server);
	return ret;
}

static int put_pending_cbobj_locked(uint16_t srvr_id, int16_t obj_id)
{
	int ret = -EINVAL;
	struct smcinvoke_server_info *srvr_info =
			get_cb_server_locked(srvr_id);
	struct list_head *head = NULL;
	struct smcinvoke_cbobj *cbobj = NULL;

	if (!srvr_info) {
		pr_err("%s, server id : %u not found\n", __func__, srvr_id);
		return ret;
	}

	trace_put_pending_cbobj_locked(srvr_id, obj_id);

	head = &srvr_info->pending_cbobjs;
	list_for_each_entry(cbobj, head, list)
		if (cbobj->cbobj_id == obj_id) {
			kref_put(&cbobj->ref_cnt, free_pending_cbobj_locked);
			ret = 0;
			break;
		}
	kref_put(&srvr_info->ref_cnt, destroy_cb_server);
	return ret;
}

static int release_tzhandle_locked(int32_t tzhandle)
{
	if (TZHANDLE_IS_MEM_OBJ(tzhandle))
		return release_mem_obj_locked(tzhandle);
	else if (TZHANDLE_IS_CB_OBJ(tzhandle))
		return put_pending_cbobj_locked(TZHANDLE_GET_SERVER(tzhandle),
				TZHANDLE_GET_OBJID(tzhandle));
	return OBJECT_ERROR;
}

static void release_tzhandles(const int32_t *tzhandles, size_t len)
{
	size_t i;

	mutex_lock(&g_smcinvoke_lock);
	for (i = 0; i < len; i++)
		release_tzhandle_locked(tzhandles[i]);
	mutex_unlock(&g_smcinvoke_lock);
}

static void delete_cb_txn_locked(struct kref *kref)
{
	struct smcinvoke_cb_txn *cb_txn = container_of(kref,
			struct smcinvoke_cb_txn, ref_cnt);

	if (OBJECT_OP_METHODID(cb_txn->cb_req->hdr.op) == OBJECT_OP_RELEASE)
		release_tzhandle_locked(cb_txn->cb_req->hdr.tzhandle);

	kfree(cb_txn->cb_req);
	hash_del(&cb_txn->hash);
	kfree(cb_txn);
}

static struct smcinvoke_cb_txn *find_cbtxn_locked(
		struct smcinvoke_server_info *server,
		uint32_t txn_id, int32_t state)
{
	int i = 0;
	struct smcinvoke_cb_txn *cb_txn = NULL;

	/*
	 * Since HASH_BITS() does not work on pointers, we can't select hash
	 * table using state and loop over it.
	 */
	if (state == SMCINVOKE_REQ_PLACED) {
		/* pick up 1st req */
		hash_for_each(server->reqs_table, i, cb_txn, hash) {
			kref_get(&cb_txn->ref_cnt);
			hash_del(&cb_txn->hash);
			return cb_txn;
		}
	} else if (state == SMCINVOKE_REQ_PROCESSING) {
		hash_for_each_possible(
				server->responses_table, cb_txn, hash, txn_id) {
			if (cb_txn->txn_id == txn_id) {
				kref_get(&cb_txn->ref_cnt);
				hash_del(&cb_txn->hash);
				return cb_txn;
			}
		}
	}
	return NULL;
}

/*
 * size_add_ saturates at SIZE_MAX. If integer overflow is detected,
 * this function would return SIZE_MAX otherwise normal a+b is returned.
 */
static inline size_t size_add_(size_t a, size_t b)
{
	return (b > (SIZE_MAX - a)) ? SIZE_MAX : a + b;
}
/*
 * pad_size is used along with size_align to define a buffer overflow
 * protected version of ALIGN
 */
static inline size_t pad_size(size_t a, size_t b)
{
	return (~a + 1) % b;
}

/*
 * size_align saturates at SIZE_MAX. If integer overflow is detected, this
 * function would return SIZE_MAX otherwise next aligned size is returned.
 */
static inline size_t size_align(size_t a, size_t b)
{
	return size_add_(a, pad_size(a, b));
}

static uint16_t get_server_id(int cb_server_fd)
{
	uint16_t server_id = 0;
	struct smcinvoke_file_data *svr_cxt = NULL;
	struct file *tmp_filp = fget(cb_server_fd);

	if (!tmp_filp || !FILE_IS_REMOTE_OBJ(tmp_filp))
		return server_id;

	svr_cxt = tmp_filp->private_data;
	if (svr_cxt && svr_cxt->context_type == SMCINVOKE_OBJ_TYPE_SERVER)
		server_id = svr_cxt->server_id;
	fput(tmp_filp);

	return server_id;
}

static bool is_dma_fd(int32_t uhandle, struct dma_buf **dma_buf)
{
	*dma_buf = dma_buf_get(uhandle);
	return IS_ERR_OR_NULL(*dma_buf) ? false : true;
}

static bool is_remote_obj(int32_t uhandle, struct smcinvoke_file_data **tzobj,
		struct file **filp)
{
	bool ret = false;
	struct file *tmp_filp = fget(uhandle);

	if (!tmp_filp)
		return ret;

	if (FILE_IS_REMOTE_OBJ(tmp_filp)) {
		*tzobj = tmp_filp->private_data;
		if ((*tzobj)->context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ) {
			*filp = tmp_filp;
			tmp_filp = NULL;
			ret = true;
		}
	}

	if (tmp_filp)
		fput(tmp_filp);
	return ret;
}

static int smcinvoke_create_bridge(struct smcinvoke_mem_obj *mem_obj)
{
  int ret = 0;
  int tz_perm = PERM_READ|PERM_WRITE;
  uint32_t *vmid_list;
  uint32_t *perms_list;
  uint32_t nelems = 0;
  struct dma_buf *dmabuf = mem_obj->dma_buf;
  phys_addr_t phys = mem_obj->p_addr;
  size_t size = mem_obj->p_addr_len;

  if (!qtee_shmbridge_is_enabled())
    return 0;

  ret = mem_buf_dma_buf_copy_vmperm(dmabuf, (int **)&vmid_list,
      (int **)&perms_list, (int *)&nelems);
  if (ret) {
    pr_err("mem_buf_dma_buf_copy_vmperm failure, err=%d\n", ret);
    return ret;
  }

  if (mem_buf_dma_buf_exclusive_owner(dmabuf))
    perms_list[0] = PERM_READ | PERM_WRITE;

  ret = qtee_shmbridge_register(phys, size, vmid_list, perms_list, nelems,
      tz_perm, &mem_obj->shmbridge_handle);

  if (ret) {
	  pr_err("creation of shm bridge for mem_region_id %d failed ret %d\n",
			  mem_obj->mem_region_id, ret);
	  goto exit;
  }

  trace_smcinvoke_create_bridge(mem_obj->shmbridge_handle, mem_obj->mem_region_id);
exit:
  kfree(perms_list);
  kfree(vmid_list);
  return ret;
}

/* Map memory region for a given memory object.
 * Mapping information will be saved as part of the memory object structure.
 */
static int32_t smcinvoke_map_mem_region_locked(struct smcinvoke_mem_obj* mem_obj)
{
	int ret = OBJECT_OK;
	struct dma_buf_attachment *buf_attach = NULL;
	struct sg_table *sgt = NULL;

	if (!mem_obj) {
		pr_err("Invalid memory object\n");
		return OBJECT_ERROR_BADOBJ;
	}

	if (!mem_obj->p_addr) {
		kref_init(&mem_obj->mem_map_obj_ref_cnt);
		buf_attach = dma_buf_attach(mem_obj->dma_buf,
				&smcinvoke_pdev->dev);
		if (IS_ERR(buf_attach)) {
			ret = OBJECT_ERROR_KMEM;
			pr_err("dma buf attach failed, ret: %d\n", ret);
			goto out;
		}
		mem_obj->buf_attach = buf_attach;

		sgt = dma_buf_map_attachment(buf_attach, DMA_BIDIRECTIONAL);
		if (IS_ERR(sgt)) {
			pr_err("mapping dma buffers failed, ret: %d\n",
					PTR_ERR(sgt));
			ret = OBJECT_ERROR_KMEM;
			goto out;
		}
		mem_obj->sgt = sgt;

		/* contiguous only => nents=1 */
		if (sgt->nents != 1) {
			ret = OBJECT_ERROR_INVALID;
			pr_err("sg enries are not contigous, ret: %d\n", ret);
			goto out;
		}
		mem_obj->p_addr = sg_dma_address(sgt->sgl);
		mem_obj->p_addr_len = sgt->sgl->length;
		if (!mem_obj->p_addr) {
			ret = OBJECT_ERROR_INVALID;
			pr_err("invalid physical address, ret: %d\n", ret);
			goto out;
		}

		/* Increase reference count as we are feeding the memobj to
		 * smcinvoke and unlock the mutex. No need to hold the mutex in
		 * case of shmbridge creation.
		 */
		kref_get(&mem_obj->mem_map_obj_ref_cnt);
		mutex_unlock(&g_smcinvoke_lock);

		ret = smcinvoke_create_bridge(mem_obj);

		/* Take lock again and decrease the reference count which we
		 * increased for shmbridge but before proceeding further we
		 * have to check again if the memobj is still valid or not
		 * after decreasing the reference.
		 */
		mutex_lock(&g_smcinvoke_lock);
		kref_put(&mem_obj->mem_map_obj_ref_cnt, del_mem_map_obj_locked);

		if (ret) {
			ret = OBJECT_ERROR_INVALID;
			pr_err("Unable to create shm bridge, ret: %d\n", ret);
			goto out;
		}

		if (!find_mem_obj_locked(mem_obj->mem_region_id,
				SMCINVOKE_MEM_RGN_OBJ)) {
			mutex_unlock(&g_smcinvoke_lock);
			pr_err("Memory object not found\n");
			return OBJECT_ERROR_BADOBJ;
		}

		mem_obj->mem_map_obj_id = next_mem_map_obj_id_locked();
	}

out:
	if (ret != OBJECT_OK)
		kref_put(&mem_obj->mem_map_obj_ref_cnt, del_mem_map_obj_locked);
	return ret;
}

static int create_mem_obj(struct dma_buf *dma_buf, int32_t *tzhandle,
			struct smcinvoke_mem_obj **mem_obj, int32_t server_id, int32_t user_handle)
{
	struct smcinvoke_mem_obj *t_mem_obj = NULL;
	struct smcinvoke_server_info *server_i = NULL;

	t_mem_obj = kzalloc(sizeof(struct smcinvoke_mem_obj), GFP_KERNEL);
	if (!t_mem_obj) {
		dma_buf_put(dma_buf);
		return -ENOMEM;
	}
	server_i = kzalloc(sizeof(struct smcinvoke_server_info),GFP_KERNEL);
	if (!server_i) {
		kfree(t_mem_obj);
		dma_buf_put(dma_buf);
		return -ENOMEM;
	}
	kref_init(&t_mem_obj->mem_regn_ref_cnt);
	t_mem_obj->dma_buf = dma_buf;
	mutex_lock(&g_smcinvoke_lock);
	t_mem_obj->mem_region_id = next_mem_region_obj_id_locked();
	server_i->server_id = server_id;
	t_mem_obj->server = server_i;
	t_mem_obj->mem_obj_user_fd = user_handle;
	list_add_tail(&t_mem_obj->list, &g_mem_objs);
	mutex_unlock(&g_smcinvoke_lock);
	*mem_obj = t_mem_obj;
	*tzhandle = TZHANDLE_MAKE_LOCAL(MEM_RGN_SRVR_ID,
			t_mem_obj->mem_region_id);
	return 0;
}

/*
 * This function retrieves file pointer corresponding to FD provided. It stores
 * retrieved file pointer until IOCTL call is concluded. Once call is completed,
 * all stored file pointers are released. file pointers are stored to prevent
 * other threads from releasing that FD while IOCTL is in progress.
 */
static int get_tzhandle_from_uhandle(int32_t uhandle, int32_t server_fd,
		struct file **filp, uint32_t *tzhandle, struct list_head *l_pending_mem_obj)
{
	int ret = -EBADF;
	uint16_t server_id = 0;
	struct smcinvoke_mem_obj *mem_obj = NULL;

	if (UHANDLE_IS_NULL(uhandle)) {
		*tzhandle = SMCINVOKE_TZ_OBJ_NULL;
		ret = 0;
	} else if (UHANDLE_IS_CB_OBJ(uhandle)) {
		server_id = get_server_id(server_fd);
		if (server_id < CBOBJ_SERVER_ID_START)
			goto out;

		mutex_lock(&g_smcinvoke_lock);
		ret = get_pending_cbobj_locked(server_id,
					UHANDLE_GET_CB_OBJ(uhandle));
		mutex_unlock(&g_smcinvoke_lock);
		if (ret)
			goto out;
		*tzhandle = TZHANDLE_MAKE_LOCAL(server_id,
				UHANDLE_GET_CB_OBJ(uhandle));
		ret = 0;
	} else if (UHANDLE_IS_FD(uhandle)) {
		struct dma_buf *dma_buf = NULL;
		struct smcinvoke_file_data *tzobj = NULL;

		if (is_dma_fd(UHANDLE_GET_FD(uhandle), &dma_buf)) {
			server_id = get_server_id(server_fd);
			ret = create_mem_obj(dma_buf, tzhandle, &mem_obj, server_id, uhandle);
			if (!ret && mem_obj_async_support && l_pending_mem_obj) {
				mutex_lock(&g_smcinvoke_lock);
				/* Map the newly created memory object and add it
				 * to l_pending_mem_obj list.
				 * Before returning to TZ, add the mapping data
				 * to the async side channel so it's available to TZ
				 * together with the memory object.
				 */
				if (!smcinvoke_map_mem_region_locked(mem_obj)) {
					queue_mem_obj_pending_async_locked(mem_obj, l_pending_mem_obj);
				} else {
					pr_err("Failed to map memory region\n");
				}
				mutex_unlock(&g_smcinvoke_lock);
			}

		} else if (is_remote_obj(UHANDLE_GET_FD(uhandle),
				&tzobj, filp)) {
			*tzhandle = tzobj->tzhandle;
			ret = 0;
		}
	}
out:
	return ret;
}

static int get_fd_for_obj(uint32_t obj_type, uint32_t obj, int32_t *fd)
{
	int unused_fd = -1, ret = -EINVAL;
	struct file *f = NULL;
	struct smcinvoke_file_data *cxt = NULL;

	cxt = kzalloc(sizeof(*cxt), GFP_KERNEL);
	if (!cxt) {
		ret = -ENOMEM;
		goto out;
	}
	if (obj_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ ||
		obj_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL) {
		cxt->context_type = obj_type;
		cxt->tzhandle = obj;
	} else if (obj_type == SMCINVOKE_OBJ_TYPE_SERVER) {
		cxt->context_type = SMCINVOKE_OBJ_TYPE_SERVER;
		cxt->server_id = obj;
	} else {
		goto out;
	}

	unused_fd = get_unused_fd_flags(O_RDWR);
	if (unused_fd < 0)
		goto out;

	if (fd == NULL)
		goto out;

	f = anon_inode_getfile(SMCINVOKE_DEV, &g_smcinvoke_fops, cxt, O_RDWR);
	if (IS_ERR(f))
		goto out;

	*fd = unused_fd;
	fd_install(*fd, f);
	return 0;
out:
	if (unused_fd >= 0)
		put_unused_fd(unused_fd);
	kfree(cxt);

	return ret;
}

static int get_uhandle_from_tzhandle(int32_t tzhandle, int32_t srvr_id,
		int32_t *uhandle, bool lock, uint32_t context_type)
{
	int ret = -1;

	if (TZHANDLE_IS_NULL(tzhandle)) {
		*uhandle = UHANDLE_NULL;
		ret = 0;
	} else if (TZHANDLE_IS_CB_OBJ(tzhandle)) {
		if (srvr_id != TZHANDLE_GET_SERVER(tzhandle))
			goto out;
		*uhandle = UHANDLE_MAKE_CB_OBJ(TZHANDLE_GET_OBJID(tzhandle));
		MUTEX_LOCK(lock)
		ret = get_pending_cbobj_locked(TZHANDLE_GET_SERVER(tzhandle),
				TZHANDLE_GET_OBJID(tzhandle));
		MUTEX_UNLOCK(lock)
	} else if (TZHANDLE_IS_MEM_RGN_OBJ(tzhandle)) {
		struct smcinvoke_mem_obj *mem_obj = NULL;

		MUTEX_LOCK(lock)
		mem_obj = find_mem_obj_locked(TZHANDLE_GET_OBJID(tzhandle),
				SMCINVOKE_MEM_RGN_OBJ);

		if (mem_obj != NULL) {
			int fd;

			fd = mem_obj->mem_obj_user_fd;
			if (fd < 0)
				goto exit_lock;
			*uhandle = fd;
			ret = 0;
		}
exit_lock:
		MUTEX_UNLOCK(lock)
	} else if (TZHANDLE_IS_REMOTE(tzhandle)) {
		/* if execution comes here => tzhandle is an unsigned int */
		ret = get_fd_for_obj(context_type,
				(uint32_t)tzhandle, uhandle);
	}
out:
	return ret;
}

static int32_t smcinvoke_release_mem_obj_locked(void *buf, size_t buf_len)
{
	struct smcinvoke_tzcb_req *msg = buf;

	if (msg->hdr.counts != OBJECT_COUNTS_PACK(0, 0, 0, 0)) {
		pr_err("Invalid object count in %s\n", __func__);
		return OBJECT_ERROR_INVALID;
	}

	trace_release_mem_obj_locked(msg->hdr.tzhandle, buf_len);

	return release_tzhandle_locked(msg->hdr.tzhandle);
}

static int32_t smcinvoke_process_map_mem_region_req(void *buf, size_t buf_len)
{
	int ret = OBJECT_OK;
	struct smcinvoke_tzcb_req *msg = buf;
	struct {
		uint64_t p_addr;
		uint64_t len;
		uint32_t perms;
	} *ob = NULL;
	int32_t *oo = NULL;
	struct smcinvoke_mem_obj *mem_obj = NULL;

	if (msg->hdr.counts != OBJECT_COUNTS_PACK(0, 1, 1, 1) ||
			(buf_len - msg->args[0].b.offset < msg->args[0].b.size)) {
		pr_err("Invalid counts received for mapping mem obj\n");
		return OBJECT_ERROR_INVALID;
	}
	/* args[0] = BO, args[1] = OI, args[2] = OO */
	ob = buf + msg->args[0].b.offset;
	oo = &msg->args[2].handle;

	mutex_lock(&g_smcinvoke_lock);
	mem_obj = find_mem_obj_locked(TZHANDLE_GET_OBJID(msg->args[1].handle),
			SMCINVOKE_MEM_RGN_OBJ);
	if (!mem_obj) {
		mutex_unlock(&g_smcinvoke_lock);
		pr_err("Memory object not found\n");
		return OBJECT_ERROR_BADOBJ;
	}

	if (!mem_obj->p_addr) {
		ret = smcinvoke_map_mem_region_locked(mem_obj);
	} else {
		kref_get(&mem_obj->mem_map_obj_ref_cnt);
	}

	if (!ret) {
		ob->p_addr = mem_obj->p_addr;
		ob->len = mem_obj->p_addr_len;
		ob->perms = SMCINVOKE_MEM_PERM_RW;
		*oo = TZHANDLE_MAKE_LOCAL(MEM_MAP_SRVR_ID, mem_obj->mem_map_obj_id);
	}

	mutex_unlock(&g_smcinvoke_lock);

	return ret;
}

static int32_t smcinvoke_sleep(void *buf, size_t buf_len)
{
    struct smcinvoke_tzcb_req *msg = buf;
    uint32_t sleepTimeMs_val = 0;

    if (msg->hdr.counts != OBJECT_COUNTS_PACK(1, 0, 0, 0) ||
       (buf_len - msg->args[0].b.offset < msg->args[0].b.size)) {
         pr_err("Invalid counts received for sleeping in hlos\n");
         return OBJECT_ERROR_INVALID;
    }

    /* Time in miliseconds is expected from tz */
    sleepTimeMs_val = *((uint32_t *)(buf + msg->args[0].b.offset));
    msleep(sleepTimeMs_val);
    return OBJECT_OK;
}

static void process_kernel_obj(void *buf, size_t buf_len)
{
	struct smcinvoke_tzcb_req *cb_req = buf;

	switch (cb_req->hdr.op) {
	case OBJECT_OP_MAP_REGION:
		if (mem_obj_async_support) {
			/* Mapping requests are not supposed to come
			 * from TZ once memory object async support
			 * is enabled.
			 * If they are still coming, we would like to
			 * know about it.
			 */
			pr_info("Received a request to map memory region\n");
		}
		cb_req->result = smcinvoke_process_map_mem_region_req(buf, buf_len);
		break;
	case OBJECT_OP_YIELD:
		cb_req->result = OBJECT_OK;
		break;
	case OBJECT_OP_SLEEP:
		cb_req->result = smcinvoke_sleep(buf, buf_len);
		break;
	default:
		pr_err(" invalid operation for tz kernel object\n");
		cb_req->result = OBJECT_ERROR_INVALID;
		break;
	}
}

static void process_mem_obj(void *buf, size_t buf_len)
{
	struct smcinvoke_tzcb_req *cb_req = buf;

	mutex_lock(&g_smcinvoke_lock);
	cb_req->result = (cb_req->hdr.op == OBJECT_OP_RELEASE) ?
			smcinvoke_release_mem_obj_locked(buf, buf_len) :
			OBJECT_ERROR_INVALID;
	mutex_unlock(&g_smcinvoke_lock);
}

static int invoke_cmd_handler(int cmd, phys_addr_t in_paddr, size_t in_buf_len,
		uint8_t *out_buf, phys_addr_t out_paddr,
		size_t out_buf_len, int32_t *result, u64 *response_type,
		unsigned int *data, struct qtee_shm *in_shm,
		struct qtee_shm *out_shm)
{
	int ret = 0;

	switch (cmd) {
	case SMCINVOKE_INVOKE_CMD_LEGACY:
		qtee_shmbridge_flush_shm_buf(in_shm);
		qtee_shmbridge_flush_shm_buf(out_shm);
		ret = qcom_scm_invoke_smc_legacy(in_paddr, in_buf_len, out_paddr, out_buf_len,
				result, response_type, data);
		qtee_shmbridge_inv_shm_buf(in_shm);
		qtee_shmbridge_inv_shm_buf(out_shm);
		break;

	case SMCINVOKE_INVOKE_CMD:
		ret = qcom_scm_invoke_smc(in_paddr, in_buf_len, out_paddr, out_buf_len,
				result, response_type, data);
		break;

	case SMCINVOKE_CB_RSP_CMD:
		if (legacy_smc_call)
			qtee_shmbridge_flush_shm_buf(out_shm);
		ret = qcom_scm_invoke_callback_response(virt_to_phys(out_buf), out_buf_len,
				result, response_type, data);
		if (legacy_smc_call) {
			qtee_shmbridge_inv_shm_buf(in_shm);
			qtee_shmbridge_inv_shm_buf(out_shm);
		}
		break;

	default:
		ret = -EINVAL;
		break;
	}

	trace_invoke_cmd_handler(cmd, *response_type, *result, ret);
	return ret;
}
/*
 * Buf should be aligned to struct smcinvoke_tzcb_req
 */
static void process_tzcb_req(void *buf, size_t buf_len, struct file **arr_filp)
{
	/* ret is going to TZ. Provide values from OBJECT_ERROR_<> */
	int ret = OBJECT_ERROR_DEFUNCT;
	int cbobj_retries = 0;
	long timeout_jiff;
	bool wait_interrupted = false;
	struct smcinvoke_cb_txn *cb_txn = NULL;
	struct smcinvoke_tzcb_req *cb_req = NULL, *tmp_cb_req = NULL;
	struct smcinvoke_server_info *srvr_info = NULL;
	struct smcinvoke_mem_obj *mem_obj = NULL;
	uint16_t server_id = 0;

	if (buf_len < sizeof(struct smcinvoke_tzcb_req)) {
		pr_err("smaller buffer length : %u\n", buf_len);
		return;
	}

	cb_req = buf;

	/* check whether it is to be served by kernel or userspace */
	if (TZHANDLE_IS_KERNEL_OBJ(cb_req->hdr.tzhandle)) {
		return process_kernel_obj(buf, buf_len);
	} else if (TZHANDLE_IS_MEM_MAP_OBJ(cb_req->hdr.tzhandle)) {
		/*
		 * MEM_MAP memory object is created and owned by kernel,
		 * hence its processing(handling deletion) is done in
		 * kernel context.
		 */
		return process_mem_obj(buf, buf_len);
	} else if(TZHANDLE_IS_MEM_RGN_OBJ(cb_req->hdr.tzhandle)) {
		/*
		 * MEM_RGN memory objects are created and owned by userspace,
		 * and hence their deletion/handling requires going back to the
		 * userspace, similar to that of callback objects. If we enter
		 * this 'if' condition, its no-op here, and proceed similar to
		 * case of callback objects.
		 */
	} else if (!TZHANDLE_IS_CB_OBJ(cb_req->hdr.tzhandle)) {
		pr_err("Request object is not a callback object %x\n",
			cb_req->hdr.tzhandle);
		cb_req->result = OBJECT_ERROR_INVALID;
		return;
	}

	/*
	 * We need a copy of req that could be sent to server. Otherwise, if
	 * someone kills invoke caller, buf would go away and server would be
	 * working on already freed buffer, causing a device crash.
	 */
	tmp_cb_req = kmemdup(buf, buf_len, GFP_KERNEL);
	if (!tmp_cb_req) {
		/* we need to return error to caller so fill up result */
		cb_req->result = OBJECT_ERROR_KMEM;
		pr_err("failed to create copy of request, set result: %d\n",
				cb_req->result);
		return;
	}

	cb_txn = kzalloc(sizeof(*cb_txn), GFP_KERNEL);
	if (!cb_txn) {
		cb_req->result = OBJECT_ERROR_KMEM;
		pr_err("failed to allocate memory for request, result: %d\n",
				cb_req->result);
		kfree(tmp_cb_req);
		return;
	}
	/* no need for memcpy as we did kmemdup() above */
	cb_req = tmp_cb_req;

	trace_process_tzcb_req_handle(cb_req->hdr.tzhandle, cb_req->hdr.op, cb_req->hdr.counts);

	cb_txn->state = SMCINVOKE_REQ_PLACED;
	cb_txn->cb_req = cb_req;
	cb_txn->cb_req_bytes = buf_len;
	cb_txn->filp_to_release = arr_filp;
	kref_init(&cb_txn->ref_cnt);

	mutex_lock(&g_smcinvoke_lock);
	++cb_reqs_inflight;

	if(TZHANDLE_IS_MEM_RGN_OBJ(cb_req->hdr.tzhandle)) {
		mem_obj= find_mem_obj_locked(TZHANDLE_GET_OBJID(cb_req->hdr.tzhandle),SMCINVOKE_MEM_RGN_OBJ);
		if(!mem_obj) {
			pr_err("mem obj with tzhandle : %d not found",cb_req->hdr.tzhandle);
			mutex_unlock(&g_smcinvoke_lock);
			goto out;
		}
		server_id = mem_obj->server->server_id;
	} else {
		server_id = TZHANDLE_GET_SERVER(cb_req->hdr.tzhandle);
	}

	srvr_info = get_cb_server_locked(server_id);
	if (!srvr_info || srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT) {
		/* ret equals Object_ERROR_DEFUNCT, at this point go to out */
		if (!srvr_info)
			pr_err("server is invalid\n");
		else {
			pr_err("server is defunct, state= %d tzhandle = %d\n",
					srvr_info->state, cb_req->hdr.tzhandle);
		}
		mutex_unlock(&g_smcinvoke_lock);
		goto out;
	}

	cb_txn->txn_id = ++srvr_info->txn_id;
	hash_add(srvr_info->reqs_table, &cb_txn->hash, cb_txn->txn_id);
	mutex_unlock(&g_smcinvoke_lock);

	trace_process_tzcb_req_wait(cb_req->hdr.tzhandle, cbobj_retries, cb_txn->txn_id,
			current->pid, current->tgid, srvr_info->state, srvr_info->server_id,
			cb_reqs_inflight);
	/*
	 * we need not worry that server_info will be deleted because as long
	 * as this CBObj is served by this server, srvr_info will be valid.
	 */
	wake_up_interruptible_all(&srvr_info->req_wait_q);
	/* timeout before 1s otherwise tzbusy would come */
	timeout_jiff = msecs_to_jiffies(100);

	while (cbobj_retries < CBOBJ_MAX_RETRIES) {
		if (wait_interrupted) {
			ret = wait_event_timeout(srvr_info->rsp_wait_q,
					(cb_txn->state == SMCINVOKE_REQ_PROCESSED) ||
					(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT),
					timeout_jiff);
		} else {
			ret = wait_event_interruptible_timeout(srvr_info->rsp_wait_q,
					(cb_txn->state == SMCINVOKE_REQ_PROCESSED) ||
					(srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT),
					timeout_jiff);
		}
		if (ret == 0) {
			if (srvr_info->is_server_suspended == 0) {
				tzcb_err_ratelimited("CBobj timed out waiting on cbtxn :%d,cb-tzhandle:%d, retry:%d, op:%d counts :%d\n",
						cb_txn->txn_id,cb_req->hdr.tzhandle, cbobj_retries,
						cb_req->hdr.op, cb_req->hdr.counts);
				tzcb_err_ratelimited("CBobj %d timedout pid %x,tid %x, srvr state=%d, srvr id:%u\n",
						cb_req->hdr.tzhandle, current->pid,
						current->tgid, srvr_info->state,
						srvr_info->server_id);
			}
		} else {
			/* wait_event returned due to a signal */
			if (srvr_info->state != SMCINVOKE_SERVER_STATE_DEFUNCT &&
					cb_txn->state != SMCINVOKE_REQ_PROCESSED) {
				wait_interrupted = true;
			} else {
				break;
			}
		}
		/*
		 * If bit corresponding to any accept thread is set, invoke threads
		 * should wait infinitely for the accept thread to come back with
		 * response.
		 */
		if (srvr_info->is_server_suspended > 0) {
			cbobj_retries = 0;
		} else {
			cbobj_retries++;
		}
	}

out:
	/*
	 * we could be here because of either:
	 * a. Req is PROCESSED
	 * b. Server was killed
	 * c. Invoke thread is killed
	 * sometime invoke thread and server are part of same process.
	 */
	mutex_lock(&g_smcinvoke_lock);
	hash_del(&cb_txn->hash);
	if (ret == 0) {
		pr_err("CBObj timed out! No more retries\n");
		cb_req->result = Object_ERROR_TIMEOUT;
	} else if (ret == -ERESTARTSYS) {
		pr_err("wait event interruped, ret: %d\n", ret);
		cb_req->result = OBJECT_ERROR_ABORT;
	} else {
		if (cb_txn->state == SMCINVOKE_REQ_PROCESSED) {
			/*
			 * it is possible that server was killed immediately
			 * after CB Req was processed but who cares now!
			 */
		} else if (!srvr_info ||
			srvr_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT) {
			cb_req->result = OBJECT_ERROR_DEFUNCT;
			pr_err("server invalid, res: %d\n", cb_req->result);
		} else {
			pr_err("%s: unexpected event happened, ret:%d\n", __func__, ret);
			cb_req->result = OBJECT_ERROR_ABORT;
		}
	}
	--cb_reqs_inflight;

	trace_process_tzcb_req_result(cb_req->result, cb_req->hdr.tzhandle, cb_req->hdr.op,
			cb_req->hdr.counts, cb_reqs_inflight);

	memcpy(buf, cb_req, buf_len);

	kref_put(&cb_txn->ref_cnt, delete_cb_txn_locked);
	if (srvr_info)
		kref_put(&srvr_info->ref_cnt, destroy_cb_server);
	mutex_unlock(&g_smcinvoke_lock);
}

static int marshal_out_invoke_req(const uint8_t *buf, uint32_t buf_size,
		struct smcinvoke_cmd_req *req,
		union smcinvoke_arg *args_buf,
		uint32_t context_type)
{
	int ret = -EINVAL, i = 0;
	int32_t temp_fd = UHANDLE_NULL;
	union smcinvoke_tz_args *tz_args = NULL;
	size_t offset = sizeof(struct smcinvoke_msg_hdr) +
			OBJECT_COUNTS_TOTAL(req->counts) *
			sizeof(union smcinvoke_tz_args);

	if (offset > buf_size)
		goto out;

	tz_args = (union smcinvoke_tz_args *)
			(buf + sizeof(struct smcinvoke_msg_hdr));

	tz_args += OBJECT_COUNTS_NUM_BI(req->counts);

	if (args_buf == NULL)
		return 0;

	FOR_ARGS(i, req->counts, BO) {
		args_buf[i].b.size = tz_args->b.size;
		if ((buf_size - tz_args->b.offset < tz_args->b.size) ||
				tz_args->b.offset > buf_size) {
			pr_err("%s: buffer overflow detected\n", __func__);
			goto out;
		}
		if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ) {
			if (copy_to_user((void __user *)
					(uintptr_t)(args_buf[i].b.addr),
					(uint8_t *)(buf) + tz_args->b.offset,
					tz_args->b.size)) {
				pr_err("Error %d copying ctxt to user\n", ret);
				goto out;
			}
		} else {
			memcpy((uint8_t *)(args_buf[i].b.addr),
					(uint8_t *)(buf) + tz_args->b.offset,
					tz_args->b.size);
		}
		tz_args++;
	}
	tz_args += OBJECT_COUNTS_NUM_OI(req->counts);

	FOR_ARGS(i, req->counts, OO) {
		/*
		 * create a new FD and assign to output object's context.
		 * We are passing cb_server_fd from output param in case OO
		 * is a CBObj. For CBObj, we have to ensure that it is sent
		 * to server who serves it and that info comes from USpace.
		 */
		temp_fd = UHANDLE_NULL;

		ret = get_uhandle_from_tzhandle(tz_args->handle,
				TZHANDLE_GET_SERVER(tz_args->handle),
				&temp_fd, NO_LOCK, context_type);

		args_buf[i].o.fd = temp_fd;

		if (ret)
			goto out;

		trace_marshal_out_invoke_req(i, tz_args->handle,
				TZHANDLE_GET_SERVER(tz_args->handle), temp_fd);

		tz_args++;
	}
	ret = 0;
out:
	return ret;
}

static bool is_inbound_req(int val)
{
	return (val == SMCINVOKE_RESULT_INBOUND_REQ_NEEDED ||
		val == QSEOS_RESULT_INCOMPLETE ||
		val == QSEOS_RESULT_BLOCKED_ON_LISTENER);
}

static int prepare_send_scm_msg(const uint8_t *in_buf, phys_addr_t in_paddr,
		size_t in_buf_len,
		uint8_t *out_buf, phys_addr_t out_paddr,
		size_t out_buf_len,
		struct smcinvoke_cmd_req *req,
		union smcinvoke_arg *args_buf,
		bool *tz_acked, uint32_t context_type,
		struct qtee_shm *in_shm, struct qtee_shm *out_shm,
		bool retry)
{
	int ret = 0, cmd, retry_count = 0;
	u64 response_type;
	unsigned int data;
	struct file *arr_filp[OBJECT_COUNTS_MAX_OO] = {NULL};

	*tz_acked = false;
	/* buf size should be page aligned */
	if ((in_buf_len % PAGE_SIZE) != 0 || (out_buf_len % PAGE_SIZE) != 0)
		return -EINVAL;

	cmd = invoke_cmd;

	while (1) {
		do {
			ret = invoke_cmd_handler(cmd, in_paddr, in_buf_len, out_buf,
					out_paddr, out_buf_len, &req->result,
					&response_type, &data, in_shm, out_shm);

			if (ret == -EBUSY) {
				pr_err_ratelimited("Secure side is busy,will retry after 30 ms, retry_count = %d\n",retry_count);
				msleep(SMCINVOKE_SCM_EBUSY_WAIT_MS);
			}

		} while (retry && (ret == -EBUSY) &&
				(retry_count++ < SMCINVOKE_SCM_EBUSY_MAX_RETRY));

		if (!ret && !is_inbound_req(response_type)) {
			/* dont marshal if Obj returns an error */
			if (!req->result) {
				if (args_buf != NULL)
					ret = marshal_out_invoke_req(in_buf,
							in_buf_len, req, args_buf,
							context_type);
			}
			*tz_acked = true;
		}

		if (cmd == SMCINVOKE_CB_RSP_CMD)
			release_filp(arr_filp, OBJECT_COUNTS_MAX_OO);

		if (ret || !is_inbound_req(response_type))
			break;

		/* process listener request */
		if (response_type == QSEOS_RESULT_INCOMPLETE ||
				response_type == QSEOS_RESULT_BLOCKED_ON_LISTENER) {
			ret = qseecom_process_listener_from_smcinvoke(
					&req->result, &response_type, &data);

			trace_prepare_send_scm_msg(response_type, req->result);

			if (!req->result &&
			response_type != SMCINVOKE_RESULT_INBOUND_REQ_NEEDED) {
				ret = marshal_out_invoke_req(in_buf,
						in_buf_len, req, args_buf,
						context_type);
			}
			*tz_acked = true;
		}

		/*
		 * qseecom does not understand smcinvoke's callback object &&
		 * erringly sets ret value as -EINVAL :( We need to handle it.
		 */
		if (response_type != SMCINVOKE_RESULT_INBOUND_REQ_NEEDED)
			break;

		if (response_type == SMCINVOKE_RESULT_INBOUND_REQ_NEEDED) {
			trace_status(__func__, "looks like inbnd req reqd");
			process_tzcb_req(out_buf, out_buf_len, arr_filp);
			cmd = SMCINVOKE_CB_RSP_CMD;
		}
	}
	return ret;
}
/*
 * SMC expects arguments in following format
 * ---------------------------------------------------------------------------
 * | cxt | op | counts | ptr|size |ptr|size...|ORef|ORef|...| rest of payload |
 * ---------------------------------------------------------------------------
 * cxt: target, op: operation, counts: total arguments
 * offset: offset is from beginning of buffer i.e. cxt
 * size: size is 8 bytes aligned value
 */
static size_t compute_in_msg_size(const struct smcinvoke_cmd_req *req,
		const union smcinvoke_arg *args_buf)
{
	uint32_t i = 0;

	size_t total_size = sizeof(struct smcinvoke_msg_hdr) +
			OBJECT_COUNTS_TOTAL(req->counts) *
			sizeof(union smcinvoke_tz_args);

	/* Computed total_size should be 8 bytes aligned from start of buf */
	total_size = ALIGN(total_size, SMCINVOKE_ARGS_ALIGN_SIZE);

	/* each buffer has to be 8 bytes aligned */
	while (i < OBJECT_COUNTS_NUM_buffers(req->counts))
		total_size = size_add_(total_size,
				size_align(args_buf[i++].b.size,
				SMCINVOKE_ARGS_ALIGN_SIZE));

	return PAGE_ALIGN(total_size);
}

static int marshal_in_invoke_req(const struct smcinvoke_cmd_req *req,
		const union smcinvoke_arg *args_buf, uint32_t tzhandle,
		uint8_t *buf, size_t buf_size, struct file **arr_filp,
		int32_t *tzhandles_to_release, uint32_t context_type,
		struct list_head *l_pending_mem_obj)
{
	int ret = -EINVAL, i = 0, j = 0, k = 0;
	const struct smcinvoke_msg_hdr msg_hdr = {
			tzhandle, req->op, req->counts};
	uint32_t offset = sizeof(struct smcinvoke_msg_hdr) +
			sizeof(union smcinvoke_tz_args) *
			OBJECT_COUNTS_TOTAL(req->counts);
	union smcinvoke_tz_args *tz_args = NULL;

	if (buf_size < offset)
		goto out;

	*(struct smcinvoke_msg_hdr *)buf = msg_hdr;
	tz_args = (union smcinvoke_tz_args *)(buf +
			sizeof(struct smcinvoke_msg_hdr));

	if (args_buf == NULL)
		return 0;

	FOR_ARGS(i, req->counts, BI) {
		offset = size_align(offset, SMCINVOKE_ARGS_ALIGN_SIZE);
		if ((offset > buf_size) ||
			(args_buf[i].b.size > (buf_size - offset)))
			goto out;

		tz_args[i].b.offset = offset;
		tz_args[i].b.size = args_buf[i].b.size;
		if (context_type != SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL) {
			if (copy_from_user(buf + offset,
					(void __user *)(uintptr_t)(args_buf[i].b.addr),
					args_buf[i].b.size))
				goto out;
		} else {
			memcpy(buf + offset, (void *)(args_buf[i].b.addr),
					args_buf[i].b.size);
		}
		offset += args_buf[i].b.size;
	}
	FOR_ARGS(i, req->counts, BO) {
		offset = size_align(offset, SMCINVOKE_ARGS_ALIGN_SIZE);
		if ((offset > buf_size) ||
				(args_buf[i].b.size > (buf_size - offset)))
			goto out;

		tz_args[i].b.offset = offset;
		tz_args[i].b.size = args_buf[i].b.size;
		offset += args_buf[i].b.size;
	}
	FOR_ARGS(i, req->counts, OI) {
		ret = get_tzhandle_from_uhandle(args_buf[i].o.fd,
				args_buf[i].o.cb_server_fd, &arr_filp[j++],
				&(tz_args[i].handle), l_pending_mem_obj);
		if (ret)
			goto out;

		trace_marshal_in_invoke_req(i, args_buf[i].o.fd,
				args_buf[i].o.cb_server_fd, tz_args[i].handle);

		tzhandles_to_release[k++] = tz_args[i].handle;
	}
	ret = 0;
out:
	return ret;
}

static int marshal_in_tzcb_req(const struct smcinvoke_cb_txn *cb_txn,
				struct smcinvoke_accept *user_req, int srvr_id)
{
	int ret = 0, i = 0;
	int32_t temp_fd = UHANDLE_NULL;
	union smcinvoke_arg tmp_arg;
	struct smcinvoke_tzcb_req *tzcb_req = cb_txn->cb_req;
	union smcinvoke_tz_args *tz_args = tzcb_req->args;
	size_t tzcb_req_len = cb_txn->cb_req_bytes;
	size_t tz_buf_offset = TZCB_BUF_OFFSET(tzcb_req);
	size_t user_req_buf_offset = sizeof(union smcinvoke_arg) *
			OBJECT_COUNTS_TOTAL(tzcb_req->hdr.counts);

	if (tz_buf_offset > tzcb_req_len) {
		ret = -EINVAL;
		goto out;
	}

	user_req->txn_id = cb_txn->txn_id;
	if (get_uhandle_from_tzhandle(tzcb_req->hdr.tzhandle, srvr_id,
			(int32_t*)(&user_req->cbobj_id), TAKE_LOCK,
			SMCINVOKE_OBJ_TYPE_TZ_OBJ)) {
		ret = -EINVAL;
		goto out;
	}
	user_req->op = tzcb_req->hdr.op;
	user_req->counts = tzcb_req->hdr.counts;
	user_req->argsize = sizeof(union smcinvoke_arg);

	trace_marshal_in_tzcb_req_handle(tzcb_req->hdr.tzhandle, srvr_id,
			user_req->cbobj_id, user_req->op, user_req->counts);

	FOR_ARGS(i, tzcb_req->hdr.counts, BI) {
		user_req_buf_offset = size_align(user_req_buf_offset,
				SMCINVOKE_ARGS_ALIGN_SIZE);
		tmp_arg.b.size = tz_args[i].b.size;
		if ((tz_args[i].b.offset > tzcb_req_len) ||
				(tz_args[i].b.size > tzcb_req_len - tz_args[i].b.offset) ||
				(user_req_buf_offset > user_req->buf_len) ||
				(tmp_arg.b.size >
				user_req->buf_len - user_req_buf_offset)) {
			ret = -EINVAL;
			pr_err("%s: buffer overflow detected\n", __func__);
			goto out;
		}
		tmp_arg.b.addr = user_req->buf_addr + user_req_buf_offset;

		if (copy_to_user(u64_to_user_ptr
				(user_req->buf_addr + i * sizeof(tmp_arg)),
				&tmp_arg, sizeof(tmp_arg)) ||
				copy_to_user(u64_to_user_ptr(tmp_arg.b.addr),
				(uint8_t *)(tzcb_req) + tz_args[i].b.offset,
				tz_args[i].b.size)) {
			ret = -EFAULT;
			goto out;
		}
		user_req_buf_offset += tmp_arg.b.size;
	}
	FOR_ARGS(i, tzcb_req->hdr.counts, BO) {
		user_req_buf_offset = size_align(user_req_buf_offset,
				SMCINVOKE_ARGS_ALIGN_SIZE);

		tmp_arg.b.size = tz_args[i].b.size;
		if ((user_req_buf_offset > user_req->buf_len) ||
				(tmp_arg.b.size >
				user_req->buf_len - user_req_buf_offset)) {
			ret = -EINVAL;
			pr_err("%s: buffer overflow detected\n", __func__);
			goto out;
		}
		tmp_arg.b.addr = user_req->buf_addr + user_req_buf_offset;

		if (copy_to_user(u64_to_user_ptr
				(user_req->buf_addr + i * sizeof(tmp_arg)),
				&tmp_arg, sizeof(tmp_arg))) {
			ret = -EFAULT;
			goto out;
		}
		user_req_buf_offset += tmp_arg.b.size;
	}
	FOR_ARGS(i, tzcb_req->hdr.counts, OI) {
		/*
		 * create a new FD and assign to output object's
		 * context
		 */
		temp_fd = UHANDLE_NULL;

		ret = get_uhandle_from_tzhandle(tz_args[i].handle, srvr_id,
				&temp_fd, TAKE_LOCK, SMCINVOKE_OBJ_TYPE_TZ_OBJ);

		tmp_arg.o.fd = temp_fd;

		if (ret) {
			ret = -EINVAL;
			goto out;
		}
		if (copy_to_user(u64_to_user_ptr
				(user_req->buf_addr + i * sizeof(tmp_arg)),
				&tmp_arg, sizeof(tmp_arg))) {
			ret = -EFAULT;
			goto out;
		}

		trace_marshal_in_tzcb_req_fd(i, tz_args[i].handle, srvr_id, temp_fd);
	}
out:
	return ret;
}

static int marshal_out_tzcb_req(const struct smcinvoke_accept *user_req,
		struct smcinvoke_cb_txn *cb_txn,
		struct file **arr_filp)
{
	int ret = -EINVAL, i = 0;
	int32_t tzhandles_to_release[OBJECT_COUNTS_MAX_OO] = {0};
	struct smcinvoke_tzcb_req *tzcb_req = cb_txn->cb_req;
	union smcinvoke_tz_args *tz_args = tzcb_req->args;
	size_t tz_buf_offset = TZCB_BUF_OFFSET(tzcb_req);
	LIST_HEAD(l_mem_objs_pending_async);    /* Holds new memory objects, to be later sent to TZ */
	uint32_t max_offset = 0;
	uint32_t buffer_size_max_offset = 0;
	void* async_buf_begin;
	size_t async_buf_size;
	uint32_t offset = 0;

	/* We assume 'marshal_in_tzcb_req' increases the ref-count of the CBOBJs.
	 * It should be the case for mem-obj as well. However, it does not do that.
	 * It is easier to filter out the 'release_tzhandles' for mem-obj here rather
	 * than increases its ref-count on 'marshal_in_tzcb_req'. Because, there is no
	 * reliable error handling and cleanup in 'marshal_in_tzcb_req'. So if it fails
	 * mem-obj may not get released.  **/

	if (!TZHANDLE_IS_MEM_OBJ(cb_txn->cb_req->hdr.tzhandle))
		release_tzhandles(&cb_txn->cb_req->hdr.tzhandle, 1);

	tzcb_req->result = user_req->result;
        /* Return without marshaling user args if destination callback invocation was
           unsuccessful. */
        if (tzcb_req->result != 0) {
                ret = 0;
                goto out;
        }

	FOR_ARGS(i, tzcb_req->hdr.counts, BI) {

		/* Find the max offset and the size of the buffer in that offset */
		if (tz_args[i].b.offset > max_offset) {
			max_offset = tz_args[i].b.offset;
			buffer_size_max_offset = tz_args[i].b.size;
		}
	}

	FOR_ARGS(i, tzcb_req->hdr.counts, BO) {
		union smcinvoke_arg tmp_arg;

		if (copy_from_user((uint8_t *)&tmp_arg, u64_to_user_ptr(
				user_req->buf_addr + i * sizeof(union smcinvoke_arg)),
				sizeof(union smcinvoke_arg))) {
			ret = -EFAULT;
			goto out;
		}
		if (tmp_arg.b.size > tz_args[i].b.size)
			goto out;
		if (copy_from_user((uint8_t *)(tzcb_req) + tz_args[i].b.offset,
				u64_to_user_ptr(tmp_arg.b.addr),
				tmp_arg.b.size)) {
			ret = -EFAULT;
			goto out;
		}

		/* Find the max offset and the size of the buffer in that offset */
		if (tz_args[i].b.offset > max_offset) {
			max_offset = tz_args[i].b.offset;
			buffer_size_max_offset = tz_args[i].b.size;
		}
	}

	FOR_ARGS(i, tzcb_req->hdr.counts, OO) {
		union smcinvoke_arg tmp_arg;

		if (copy_from_user((uint8_t *)&tmp_arg, u64_to_user_ptr(
				user_req->buf_addr + i * sizeof(union smcinvoke_arg)),
				sizeof(union smcinvoke_arg))) {
			ret = -EFAULT;
			goto out;
		}
		ret = get_tzhandle_from_uhandle(tmp_arg.o.fd,
				tmp_arg.o.cb_server_fd, &arr_filp[i],
				&(tz_args[i].handle), &l_mem_objs_pending_async);

		if (ret)
			goto out;
		tzhandles_to_release[i] = tz_args[i].handle;

		trace_marshal_out_tzcb_req(i, tmp_arg.o.fd,
				tmp_arg.o.cb_server_fd, tz_args[i].handle);
	}
	ret = 0;
out:
	FOR_ARGS(i, tzcb_req->hdr.counts, OI) {
		if (TZHANDLE_IS_CB_OBJ(tz_args[i].handle))
			release_tzhandles(&tz_args[i].handle, 1);
	}

	do {
		if (mem_obj_async_support) {
		/* We will be able to add the async information to the buffer beyond the data in the max offset, if exists.
		 * If doesn't exist, we can add the async information after the header and the args. */
		offset = (max_offset ? (max_offset + buffer_size_max_offset) : tz_buf_offset);
		offset = size_align(offset, SMCINVOKE_ARGS_ALIGN_SIZE);
		async_buf_begin = (uint8_t *)tzcb_req + offset;

		if (async_buf_begin - (void *)tzcb_req > g_max_cb_buf_size) {
			pr_err("Unable to add memory object info to the async channel\n");
			break;
		} else {
			async_buf_size = g_max_cb_buf_size - (async_buf_begin - (void *)tzcb_req);
		}

		mutex_lock(&g_smcinvoke_lock);
		add_mem_obj_info_to_async_side_channel_locked(async_buf_begin, async_buf_size, &l_mem_objs_pending_async);
		delete_pending_async_list_locked(&l_mem_objs_pending_async);
		mutex_unlock(&g_smcinvoke_lock);
		}
	} while (0);

	if (ret)
		release_tzhandles(tzhandles_to_release, OBJECT_COUNTS_MAX_OO);

	return ret;
}

static void set_tz_version (uint32_t tz_version)
{

	tz_async_version = tz_version;

	/* We enable async memory object support when TZ async
	 * version is equal or larger than the driver version.
	 * It is expected that if the protocol changes in later
	 * TZ versions, TZ will support backward compatibility
	 * so this condition should still be valid.
	 */
	if (tz_version >= SMCINVOKE_ASYNC_VERSION) {
		mem_obj_async_support = true;
		pr_debug("Enabled asynchronous memory object support\n");
	}
}

static void process_piggyback_data(void *buf, size_t buf_size)
{
	int i;
	struct smcinvoke_tzcb_req req = {0};
	struct smcinvoke_piggyback_msg *msg = buf;
	int32_t *objs = msg->objs;

	if (msg->version == 0) {
		/* QTEE reset the buffer if it is unused. */
		return;
	}

	for (i = 0; i < msg->counts; i++) {
		if (msg->op != OBJECT_OP_RELEASE) {
			/* We only support release handler. */
			break;
		}

		req.hdr.op = msg->op;
		req.hdr.counts = 0; /* release op does not require any args */
		req.hdr.tzhandle = objs[i];
		if (tz_async_version == 0)
			set_tz_version(msg->version);
		process_tzcb_req(&req, sizeof(struct smcinvoke_tzcb_req), NULL);
		/* cbobjs_in_flight will be adjusted during CB processing */
	}

	/* Reset output buffer after processing.*/
	memset(buf, 0, buf_size);
}


/* Add memory object mapped data to the async side channel, so it's available to TZ
 * together with the memory object.
 *
 * No return value as TZ is always able to explicitly ask for this information
 * in case this function fails.
 */
static void add_mem_obj_info_to_async_side_channel_locked(void *buf, size_t buf_size, struct list_head *l_pending_mem_obj)
{
	struct smcinvoke_mem_obj_msg *msg = buf;
	struct smcinvoke_mem_obj_pending_async *mem_obj_pending = NULL;
	size_t header_size = 0;
	size_t mo_size = 0;
	size_t used = 0;
	size_t index = 0;

	if (list_empty(l_pending_mem_obj))
		return;

	header_size = sizeof(struct smcinvoke_mem_obj_msg);
	mo_size = sizeof(struct smcinvoke_mem_obj_info);

	/* Minimal size required is the header data + one mem obj info */
	if (buf_size < header_size + mo_size) {
		pr_err("Unable to add memory object info to async channel\n");
		return;
	}

	msg->version = SMCINVOKE_ASYNC_VERSION;
	msg->op = SMCINVOKE_ASYNC_OP_MEMORY_OBJECT;
	msg->count = 0;

	used = header_size;
	index = 0;

	list_for_each_entry(mem_obj_pending, l_pending_mem_obj, list) {
		if (NULL == mem_obj_pending->mem_obj) {
			pr_err("Memory object is no longer valid\n");
			continue;
		}

		if (used + mo_size > buf_size) {
			pr_err("Not all memory object info was added to the async channel\n");
			break;
		}

		msg->mo[index].memObjRef = TZHANDLE_MAKE_LOCAL(MEM_RGN_SRVR_ID, mem_obj_pending->mem_obj->mem_region_id);
		msg->mo[index].mapObjRef = TZHANDLE_MAKE_LOCAL(MEM_MAP_SRVR_ID, mem_obj_pending->mem_obj->mem_map_obj_id);
		msg->mo[index].addr = mem_obj_pending->mem_obj->p_addr;
		msg->mo[index].size = mem_obj_pending->mem_obj->p_addr_len;
		msg->mo[index].perm = SMCINVOKE_MEM_PERM_RW;

		used += sizeof(msg->mo[index]);
		index++;
	}

	msg->count = index;

	pr_debug("Added %d memory objects to the side channel, total size = %d\n", index, used);

	return;
}

/*
 * Delete entire pending async list.
 */
static void delete_pending_async_list_locked(struct list_head *l_pending_mem_obj)
{
	struct smcinvoke_mem_obj_pending_async *mem_obj_pending = NULL;
	struct smcinvoke_mem_obj_pending_async *temp = NULL;

	if (list_empty(l_pending_mem_obj))
		return;

	list_for_each_entry_safe(mem_obj_pending, temp, l_pending_mem_obj, list) {
		mem_obj_pending->mem_obj = NULL;
		list_del(&mem_obj_pending->list);
		kfree(mem_obj_pending);
	}
}


/*
 * Unmap/release the mapped objects from  pending async list.
 */
static void release_map_obj_pending_async_list_locked(struct list_head *l_pending_mem_obj)
{
	struct smcinvoke_mem_obj_pending_async *mem_obj_pending = NULL;
	struct smcinvoke_mem_obj_pending_async *temp = NULL;

	if (list_empty(l_pending_mem_obj))
		return;

	list_for_each_entry_safe(mem_obj_pending, temp, l_pending_mem_obj, list) {
		kref_put(&mem_obj_pending->mem_obj->mem_map_obj_ref_cnt, del_mem_map_obj_locked);
	}
}

static long process_ack_local_obj(struct file *filp, unsigned int cmd,
						unsigned long arg)
{
	int ret = -1;
	int32_t local_obj = SMCINVOKE_USERSPACE_OBJ_NULL;
	struct smcinvoke_file_data *filp_data = filp->private_data;

	if (_IOC_SIZE(cmd) != sizeof(int32_t))
		return -EINVAL;

	ret = copy_from_user(&local_obj, (void __user *)(uintptr_t)arg,
			sizeof(int32_t));
	if (ret)
		return -EFAULT;

	mutex_lock(&g_smcinvoke_lock);
	if (UHANDLE_IS_CB_OBJ(local_obj))
		ret = put_pending_cbobj_locked(filp_data->server_id,
				UHANDLE_GET_CB_OBJ(local_obj));
	mutex_unlock(&g_smcinvoke_lock);

	return ret;
}

static long process_server_req(struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	int ret = -1;
	int32_t server_fd = -1;
	struct smcinvoke_server server_req = {0};
	struct smcinvoke_server_info *server_info = NULL;

	if (_IOC_SIZE(cmd) != sizeof(server_req)) {
		pr_err("invalid command size received for server request\n");
		return -EINVAL;
	}
	ret = copy_from_user(&server_req, (void __user *)(uintptr_t)arg,
					sizeof(server_req));
	if (ret) {
		pr_err("copying server request from user failed\n");
		return -EFAULT;
	}
	server_info = kzalloc(sizeof(*server_info), GFP_KERNEL);
	if (!server_info)
		return -ENOMEM;

	kref_init(&server_info->ref_cnt);
	init_waitqueue_head(&server_info->req_wait_q);
	init_waitqueue_head(&server_info->rsp_wait_q);
	server_info->cb_buf_size = server_req.cb_buf_size;
	hash_init(server_info->reqs_table);
	hash_init(server_info->responses_table);
	INIT_LIST_HEAD(&server_info->pending_cbobjs);
	server_info->is_server_suspended = 0;

	mutex_lock(&g_smcinvoke_lock);

	server_info->server_id = next_cb_server_id_locked();
	hash_add(g_cb_servers, &server_info->hash,
			server_info->server_id);
	if (g_max_cb_buf_size < server_req.cb_buf_size)
		g_max_cb_buf_size = server_req.cb_buf_size;

	mutex_unlock(&g_smcinvoke_lock);
	ret = get_fd_for_obj(SMCINVOKE_OBJ_TYPE_SERVER,
			server_info->server_id, &server_fd);

	if (ret)
		release_cb_server(server_info->server_id);

	return server_fd;
}

static long process_accept_req(struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	int ret = -1;
	struct smcinvoke_file_data *server_obj = filp->private_data;
	struct smcinvoke_accept user_args = {0};
	struct smcinvoke_cb_txn *cb_txn = NULL;
	struct smcinvoke_server_info *server_info = NULL;

	if (_IOC_SIZE(cmd) != sizeof(struct smcinvoke_accept)) {
		pr_err("command size invalid for accept request\n");
		return -EINVAL;
	}

	if (copy_from_user(&user_args, (void __user *)arg,
			sizeof(struct smcinvoke_accept))) {
		pr_err("copying accept request from user failed\n");
		return -EFAULT;
	}

	if (user_args.argsize != sizeof(union smcinvoke_arg)) {
		pr_err("arguments size is invalid for accept thread\n");
		return -EINVAL;
	}

	/* ACCEPT is available only on server obj */
	if (server_obj->context_type != SMCINVOKE_OBJ_TYPE_SERVER) {
		pr_err("invalid object type received for accept req\n");
		return -EPERM;
	}

	mutex_lock(&g_smcinvoke_lock);
	server_info = get_cb_server_locked(server_obj->server_id);

	if (!server_info) {
		pr_err("No matching server with server id : %u found\n",
				server_obj->server_id);
		mutex_unlock(&g_smcinvoke_lock);
		return -EINVAL;
	}

	if (server_info->state == SMCINVOKE_SERVER_STATE_DEFUNCT)
		server_info->state = 0;

	server_info->is_server_suspended = UNSET_BIT(server_info->is_server_suspended,
				(current->pid)%DEFAULT_CB_OBJ_THREAD_CNT);

	mutex_unlock(&g_smcinvoke_lock);

	/* First check if it has response otherwise wait for req */
	if (user_args.has_resp) {
		trace_process_accept_req_has_response(current->pid, current->tgid);

		mutex_lock(&g_smcinvoke_lock);
		cb_txn = find_cbtxn_locked(server_info, user_args.txn_id,
				SMCINVOKE_REQ_PROCESSING);
		mutex_unlock(&g_smcinvoke_lock);
		/*
		 * cb_txn can be null if userspace provides wrong txn id OR
		 * invoke thread died while server was processing cb req.
		 * if invoke thread dies, it would remove req from Q. So
		 * no matching cb_txn would be on Q and hence NULL cb_txn.
		 * In this case, we want this thread to start waiting
		 * new cb requests.
		 */
		if (!cb_txn) {
			pr_err_ratelimited("%s txn %d either invalid or removed from Q\n",
					__func__, user_args.txn_id);
			goto start_waiting_for_requests;
		}
		ret = marshal_out_tzcb_req(&user_args, cb_txn,
				cb_txn->filp_to_release);
		/*
		 * if client did not set error and we get error locally,
		 * we return local error to TA
		 */
		if (ret && cb_txn->cb_req->result == 0)
			cb_txn->cb_req->result = OBJECT_ERROR_UNAVAIL;

		cb_txn->state = SMCINVOKE_REQ_PROCESSED;
		mutex_lock(&g_smcinvoke_lock);

		kref_put(&cb_txn->ref_cnt, delete_cb_txn_locked);
		mutex_unlock(&g_smcinvoke_lock);
		wake_up(&server_info->rsp_wait_q);
		/*
		 * if marshal_out fails, we should let userspace release
		 * any ref/obj it created for CB processing
		 */
		if (ret && OBJECT_COUNTS_NUM_OO(user_args.counts))
			goto out;
	}
start_waiting_for_requests:
	/*
	 * Once response has been delivered, thread will wait for another
	 * callback req to process.
	 */
	do {
		ret = wait_event_interruptible(server_info->req_wait_q,
				!hash_empty(server_info->reqs_table));
		if (ret) {
			trace_process_accept_req_ret(current->pid, current->tgid, ret);
			/*
			 * Ideally, we should destroy server if accept threads
			 * are returning due to client being killed or device
			 * going down (Shutdown/Reboot) but that would make
			 * server_info invalid. Other accept/invoke threads are
			 * using server_info and would crash. So dont do that.
			 */
			mutex_lock(&g_smcinvoke_lock);

			if(freezing(current)) {
				pr_err_ratelimited("Server id :%d interrupted probaby due to suspend, pid:%d\n",
					server_info->server_id, current->pid);
				/*
				 * Each accept thread is identified by bits ranging from
				 * 0 to DEFAULT_CBOBJ_THREAD_CNT-1. When an accept thread is
				 * interrupted by a signal other than SIGUSR1,SIGKILL,SIGTERM,
				 * set the corresponding bit of accept thread, indicating that
				 * current accept thread's state to be "suspended"/ or something
				 * that needs infinite timeout for invoke thread.
				 */
				server_info->is_server_suspended =
						SET_BIT(server_info->is_server_suspended,
							(current->pid)%DEFAULT_CB_OBJ_THREAD_CNT);
			} else {
				pr_err_ratelimited("Setting pid:%d, server id : %d state to defunct\n",
						current->pid, server_info->server_id);
						server_info->state = SMCINVOKE_SERVER_STATE_DEFUNCT;
			}
			mutex_unlock(&g_smcinvoke_lock);
			wake_up_interruptible(&server_info->rsp_wait_q);
			goto out;
		}
		mutex_lock(&g_smcinvoke_lock);
		cb_txn = find_cbtxn_locked(server_info,
				SMCINVOKE_NEXT_AVAILABLE_TXN,
				SMCINVOKE_REQ_PLACED);
		mutex_unlock(&g_smcinvoke_lock);
		if (cb_txn) {
			cb_txn->state = SMCINVOKE_REQ_PROCESSING;
			ret = marshal_in_tzcb_req(cb_txn, &user_args,
					server_obj->server_id);
			if (ret) {
				pr_err("failed to marshal in the callback request\n");
				cb_txn->cb_req->result = OBJECT_ERROR_UNAVAIL;
				cb_txn->state = SMCINVOKE_REQ_PROCESSED;
				mutex_lock(&g_smcinvoke_lock);
				kref_put(&cb_txn->ref_cnt, delete_cb_txn_locked);
				mutex_unlock(&g_smcinvoke_lock);
				wake_up_interruptible(&server_info->rsp_wait_q);
				continue;
			}
			mutex_lock(&g_smcinvoke_lock);
			hash_add(server_info->responses_table, &cb_txn->hash,
					cb_txn->txn_id);
			kref_put(&cb_txn->ref_cnt, delete_cb_txn_locked);
			mutex_unlock(&g_smcinvoke_lock);

			trace_process_accept_req_placed(current->pid, current->tgid);

			ret = copy_to_user((void __user *)arg, &user_args,
					sizeof(struct smcinvoke_accept));
		}
	} while (!cb_txn);
out:
	if (server_info)
		kref_put(&server_info->ref_cnt, destroy_cb_server);

	if (ret && ret != -ERESTARTSYS)
		pr_err("accept thread returning with ret: %d\n", ret);

	return ret;
}

static long process_invoke_req(struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	int    ret = -1, nr_args = 0;
	struct smcinvoke_cmd_req req = {0};
	void   *in_msg = NULL, *out_msg = NULL;
	size_t inmsg_size = 0, outmsg_size = SMCINVOKE_TZ_MIN_BUF_SIZE;
	union  smcinvoke_arg *args_buf = NULL;
	struct smcinvoke_file_data *tzobj = filp->private_data;
	struct qtee_shm in_shm = {0}, out_shm = {0};
	LIST_HEAD(l_mem_objs_pending_async);    /* Holds new memory objects, to be later sent to TZ */

	/*
	 * Hold reference to remote object until invoke op is not
	 * completed. Release once invoke is done.
	 */
	struct file *filp_to_release[OBJECT_COUNTS_MAX_OO] = {NULL};
	/*
	 * If anything goes wrong, release alloted tzhandles for
	 * local objs which could be either CBObj or MemObj.
	 */
	int32_t tzhandles_to_release[OBJECT_COUNTS_MAX_OO] = {0};
	bool tz_acked = false;
	uint32_t context_type = tzobj->context_type;

	if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ &&
			_IOC_SIZE(cmd) != sizeof(req)) {
		pr_err("command size for invoke req is invalid\n");
		return -EINVAL;
	}

	if (context_type != SMCINVOKE_OBJ_TYPE_TZ_OBJ &&
			context_type != SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL) {
		pr_err("invalid context_type %d\n", context_type);
		return -EPERM;
	}
	if (context_type != SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL) {
		ret = copy_from_user(&req, (void __user *)arg, sizeof(req));
		if (ret) {
			pr_err("copying invoke req failed\n");
			return -EFAULT;
		}
	} else {
		req = *(struct smcinvoke_cmd_req *)arg;
	}
	if (req.argsize != sizeof(union smcinvoke_arg)) {
		pr_err("arguments size for invoke req is invalid\n");
		return -EINVAL;
	}

	if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ &&
			tzobj->tzhandle == SMCINVOKE_TZ_ROOT_OBJ &&
			(req.op == IClientEnv_OP_notifyDomainChange ||
			req.op == IClientEnv_OP_registerWithCredentials ||
			req.op == IClientEnv_OP_adciAccept ||
			req.op == IClientEnv_OP_adciShutdown)) {
		pr_err("invalid rootenv op\n");
		return -EINVAL;
	}

	nr_args = OBJECT_COUNTS_NUM_buffers(req.counts) +
			OBJECT_COUNTS_NUM_objects(req.counts);

	if (nr_args) {
		args_buf = kcalloc(nr_args, req.argsize, GFP_KERNEL);
		if (!args_buf)
			return -ENOMEM;
		if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ) {
			ret = copy_from_user(args_buf,
					u64_to_user_ptr(req.args),
					nr_args * req.argsize);
			if (ret) {
				ret = -EFAULT;
				goto out;
			}
		} else {
			memcpy(args_buf, (void *)(req.args),
					nr_args * req.argsize);
		}
	}

	inmsg_size = compute_in_msg_size(&req, args_buf);
	ret = qtee_shmbridge_allocate_shm(inmsg_size, &in_shm);
	if (ret) {
		ret = -ENOMEM;
		pr_err("shmbridge alloc failed for in msg in invoke req\n");
		goto out;
	}
	in_msg = in_shm.vaddr;

	mutex_lock(&g_smcinvoke_lock);
	outmsg_size = PAGE_ALIGN(g_max_cb_buf_size);
	mutex_unlock(&g_smcinvoke_lock);
	ret = qtee_shmbridge_allocate_shm(outmsg_size, &out_shm);
	if (ret) {
		ret = -ENOMEM;
		pr_err("shmbridge alloc failed for out msg in invoke req\n");
		goto out;
	}
	out_msg = out_shm.vaddr;

	trace_process_invoke_req_tzhandle(tzobj->tzhandle, req.op, req.counts);

	ret = marshal_in_invoke_req(&req, args_buf, tzobj->tzhandle, in_msg,
			inmsg_size, filp_to_release, tzhandles_to_release,
			context_type, &l_mem_objs_pending_async);
	if (ret) {
		pr_err("failed to marshal in invoke req, ret :%d\n", ret);
		goto out;
	}

	if (mem_obj_async_support) {
		mutex_lock(&g_smcinvoke_lock);
		add_mem_obj_info_to_async_side_channel_locked(out_msg, outmsg_size, &l_mem_objs_pending_async);
		mutex_unlock(&g_smcinvoke_lock);
	}

	ret = prepare_send_scm_msg(in_msg, in_shm.paddr, inmsg_size,
			out_msg, out_shm.paddr, outmsg_size,
			&req, args_buf, &tz_acked, context_type,
			&in_shm, &out_shm, true);

	/*
	 * If scm_call is success, TZ owns responsibility to release
	 * refs for local objs.
	 */
	if (!tz_acked) {
		trace_status(__func__, "scm call successful");
		goto out;
	}
	memset(tzhandles_to_release, 0, sizeof(tzhandles_to_release));

	/*
	 * if invoke op results in an err, no need to marshal_out and
	 * copy args buf to user space
	 */
	if (!req.result) {
		/*
		 * Dont check ret of marshal_out because there might be a
		 * FD for OO which userspace must release even if an error
		 * occurs. Releasing FD from user space is much simpler than
		 * doing here. ORing of ret is reqd not to miss past error
		 */
		if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ)
			ret |= copy_to_user(u64_to_user_ptr(req.args),
					args_buf, nr_args * req.argsize);
		else
			memcpy((void *)(req.args), args_buf,
					nr_args * req.argsize);

	}
	/* copy result of invoke op */
	if (context_type == SMCINVOKE_OBJ_TYPE_TZ_OBJ) {
		ret |= copy_to_user((void __user *)arg, &req, sizeof(req));
		if (ret)
			goto out;
	} else {
		memcpy((void *)arg, (void *)&req, sizeof(req));
	}

	/* Outbuf could be carrying local objs to be released. */
	process_piggyback_data(out_msg, outmsg_size);
out:
	trace_process_invoke_req_result(ret, req.result, tzobj->tzhandle,
			req.op, req.counts);

	release_filp(filp_to_release, OBJECT_COUNTS_MAX_OO);
	if (ret) {
		release_map_obj_pending_async_list_locked(&l_mem_objs_pending_async);
		release_tzhandles(tzhandles_to_release, OBJECT_COUNTS_MAX_OO);
	}
	delete_pending_async_list_locked(&l_mem_objs_pending_async);
	qtee_shmbridge_free_shm(&in_shm);
	qtee_shmbridge_free_shm(&out_shm);
	kfree(args_buf);

	if (ret)
		pr_err("invoke thread returning with ret = %d\n", ret);

	return ret;
}

static long process_log_info(struct file *filp, unsigned int cmd,
					unsigned long arg)
{
	int ret = 0;
	char buf[SMCINVOKE_LOG_BUF_SIZE];
	struct smcinvoke_file_data *tzobj = filp->private_data;

	ret = copy_from_user(buf, (void __user *)arg, SMCINVOKE_LOG_BUF_SIZE);
	if (ret) {
		pr_err("logging HLOS info copy failed\n");
		return -EFAULT;
	}
	buf[SMCINVOKE_LOG_BUF_SIZE - 1] = '\0';

	trace_process_log_info(buf, tzobj->context_type, tzobj->tzhandle);

	return ret;
}

static long smcinvoke_ioctl(struct file *filp, unsigned int cmd,
						unsigned long arg)
{
	long ret = 0;

	switch (cmd) {
	case SMCINVOKE_IOCTL_INVOKE_REQ:
		ret = process_invoke_req(filp, cmd, arg);
		break;
	case SMCINVOKE_IOCTL_ACCEPT_REQ:
		ret = process_accept_req(filp, cmd, arg);
		break;
	case SMCINVOKE_IOCTL_SERVER_REQ:
		ret = process_server_req(filp, cmd, arg);
		break;
	case SMCINVOKE_IOCTL_ACK_LOCAL_OBJ:
		ret = process_ack_local_obj(filp, cmd, arg);
		break;
	case SMCINVOKE_IOCTL_LOG:
		ret = process_log_info(filp, cmd, arg);
		break;
	default:
		ret = -ENOIOCTLCMD;
		break;
	}
	trace_smcinvoke_ioctl(cmd, ret);
	return ret;
}

int get_root_fd(int *root_fd)
{
	if (!root_fd)
		return -EINVAL;
	else
		return get_fd_for_obj(SMCINVOKE_OBJ_TYPE_TZ_OBJ_FOR_KERNEL,
				SMCINVOKE_TZ_ROOT_OBJ, root_fd);
}

int process_invoke_request_from_kernel_client(int fd,
			struct smcinvoke_cmd_req *req)
{
	struct file *filp = NULL;
	int ret = 0;

	if (!req) {
		pr_err("NULL req\n");
		return -EINVAL;
	}

	filp = fget(fd);
	if (!filp) {
		pr_err("Invalid fd %d\n", fd);
		return -EINVAL;
	}
	ret = process_invoke_req(filp, 0, (uintptr_t)req);
	fput(filp);
	trace_process_invoke_request_from_kernel_client(fd, filp, file_count(filp));
	return ret;
}

static int smcinvoke_open(struct inode *nodp, struct file *filp)
{
	struct smcinvoke_file_data *tzcxt = NULL;

	tzcxt = kzalloc(sizeof(*tzcxt), GFP_KERNEL);
	if (!tzcxt)
		return -ENOMEM;

	tzcxt->tzhandle = SMCINVOKE_TZ_ROOT_OBJ;
	tzcxt->context_type = SMCINVOKE_OBJ_TYPE_TZ_OBJ;
	filp->private_data = tzcxt;

	return 0;
}

static int release_cb_server(uint16_t server_id)
{
	struct smcinvoke_server_info *server = NULL;

	mutex_lock(&g_smcinvoke_lock);
	server = find_cb_server_locked(server_id);
	if (server)
		kref_put(&server->ref_cnt, destroy_cb_server);
	mutex_unlock(&g_smcinvoke_lock);
	return 0;
}

int smcinvoke_release_filp(struct file *filp)
{
	int ret = 0;
	struct smcinvoke_file_data *file_data = filp->private_data;
	uint32_t tzhandle = 0;
	struct smcinvoke_object_release_pending_list *entry = NULL;
	struct qtee_shm in_shm = {0}, out_shm = {0};

	trace_smcinvoke_release_filp(current->files, filp,
			file_count(filp), file_data->context_type);

	if (file_data->context_type == SMCINVOKE_OBJ_TYPE_SERVER) {
		ret = release_cb_server(file_data->server_id);
		goto out;
	}

	tzhandle = file_data->tzhandle;
	/* Root object is special in sense it is indestructible */
	if (!tzhandle || tzhandle == SMCINVOKE_TZ_ROOT_OBJ) {
		if (!tzhandle)
			pr_err("tzhandle not valid in object release\n");
		goto out;
	}

	ret = qtee_shmbridge_allocate_shm(SMCINVOKE_TZ_MIN_BUF_SIZE, &in_shm);
	if (ret) {
		pr_err("shmbridge alloc failed for in msg in object release"
				"with ret %d\n", ret);
		goto out;
	}

	ret = qtee_shmbridge_allocate_shm(SMCINVOKE_TZ_MIN_BUF_SIZE, &out_shm);
	if (ret) {
		pr_err("shmbridge alloc failed for out msg in object release"
				"with ret:%d\n", ret);
		goto out;
	}

	ret = smcinvoke_release_tz_object(&in_shm, &out_shm,
		tzhandle, file_data->context_type);

	if (-EBUSY == ret) {
		pr_debug("failed to release handle in sync adding to list\n");
		entry = kzalloc(sizeof(*entry), GFP_KERNEL);
		if (!entry) {
			ret = -ENOMEM;
			goto out;
		}
		ret = 0;
		entry->data.tzhandle = tzhandle;
		entry->data.context_type = file_data->context_type;
		mutex_lock(&object_postprocess_lock);
		list_add_tail(&entry->list, &g_object_postprocess);
		mutex_unlock(&object_postprocess_lock);
		pr_debug("Object release list: added a handle:0x%lx\n", tzhandle);
		__wakeup_postprocess_kthread(&smcinvoke[OBJECT_WORKER_THREAD]);
	}

out:
	qtee_shmbridge_free_shm(&in_shm);
	qtee_shmbridge_free_shm(&out_shm);
	kfree(filp->private_data);
	filp->private_data = NULL;

	if (ret != 0)
		pr_err ("Object release failed with ret %d\n", ret);
	return ret;
}

int smcinvoke_release_from_kernel_client(int fd)
{
	struct file *filp = NULL;

	/* use fget() to get filp, but this will increase file ref_cnt to 1,
	 * then decrease file ref_cnt to 0 with fput().
	 */
	filp = fget(fd);
	if (!filp) {
		pr_err("invalid fd %d to release\n", fd);
		return -EINVAL;
	}
	trace_smcinvoke_release_from_kernel_client(current->files, filp,
			file_count(filp));
	/* free filp, notify TZ to release object */
	smcinvoke_release_filp(filp);
	fput(filp);
	return 0;
}

static int smcinvoke_release(struct inode *nodp, struct file *filp)
{
	trace_smcinvoke_release(current->files, filp, file_count(filp),
			filp->private_data);

	if (filp->private_data)
		return smcinvoke_release_filp(filp);
	else
		return 0;
}

static int smcinvoke_probe(struct platform_device *pdev)
{
	unsigned int baseminor = 0;
	unsigned int count = 1;
	int rc = 0;

	rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
	if (rc) {
		pr_err("dma_set_mask_and_coherent failed %d\n", rc);
		return rc;
	}
	legacy_smc_call = of_property_read_bool((&pdev->dev)->of_node,
			"qcom,support-legacy_smc");
	invoke_cmd = legacy_smc_call ? SMCINVOKE_INVOKE_CMD_LEGACY : SMCINVOKE_INVOKE_CMD;

	rc = smcinvoke_create_kthreads();
	if (rc) {
		pr_err("smcinvoke_create_kthreads failed %d\n", rc);
		return rc;
	}

	rc = alloc_chrdev_region(&smcinvoke_device_no, baseminor, count,
							SMCINVOKE_DEV);
	if (rc < 0) {
		pr_err("chrdev_region failed %d for %s\n", rc, SMCINVOKE_DEV);
		goto exit_destroy_wkthread;
	}
	driver_class = class_create(THIS_MODULE, SMCINVOKE_DEV);
	if (IS_ERR(driver_class)) {
		rc = -ENOMEM;
		pr_err("class_create failed %d\n", rc);
		goto exit_unreg_chrdev_region;
	}
	class_dev = device_create(driver_class, NULL, smcinvoke_device_no,
						NULL, SMCINVOKE_DEV);
	if (!class_dev) {
		pr_err("class_device_create failed %d\n", rc);
		rc = -ENOMEM;
		goto exit_destroy_class;
	}

	cdev_init(&smcinvoke_cdev, &g_smcinvoke_fops);
	smcinvoke_cdev.owner = THIS_MODULE;

	rc = cdev_add(&smcinvoke_cdev, MKDEV(MAJOR(smcinvoke_device_no), 0),
								count);
	if (rc < 0) {
		pr_err("cdev_add failed %d for %s\n", rc, SMCINVOKE_DEV);
		goto exit_destroy_device;
	}
	smcinvoke_pdev = pdev;

#if IS_ENABLED(CONFIG_QSEECOM_COMPAT) && IS_ENABLED(CONFIG_QSEECOM_PROXY)
	/*If the api fails to get the func ops, print the error and continue
	* Do not treat it as fatal*/
	rc = get_qseecom_kernel_fun_ops();
	if (rc) {
		pr_err("failed to get qseecom kernel func ops %d", rc);
	}
#endif
	__wakeup_postprocess_kthread(&smcinvoke[ADCI_WORKER_THREAD]);
	return 0;

exit_destroy_device:
	device_destroy(driver_class, smcinvoke_device_no);
exit_destroy_class:
	class_destroy(driver_class);
exit_unreg_chrdev_region:
	unregister_chrdev_region(smcinvoke_device_no, count);
exit_destroy_wkthread:
	smcinvoke_destroy_kthreads();
	return rc;
}

static int smcinvoke_remove(struct platform_device *pdev)
{
	int count = 1;

	smcinvoke_destroy_kthreads();
	cdev_del(&smcinvoke_cdev);
	device_destroy(driver_class, smcinvoke_device_no);
	class_destroy(driver_class);
	unregister_chrdev_region(smcinvoke_device_no, count);
	return 0;
}

static int __maybe_unused smcinvoke_suspend(struct platform_device *pdev,
					pm_message_t state)
{
	int ret = 0;

	mutex_lock(&g_smcinvoke_lock);
	if (cb_reqs_inflight) {
		pr_err("Failed to suspend smcinvoke driver\n");
		ret = -EIO;
	}
	mutex_unlock(&g_smcinvoke_lock);
	return ret;
}

static int __maybe_unused smcinvoke_resume(struct platform_device *pdev)
{
	return 0;
}

static const struct of_device_id smcinvoke_match[] = {
	{
		.compatible = "qcom,smcinvoke",
	},
	{},
};

static struct platform_driver smcinvoke_plat_driver = {
	.probe = smcinvoke_probe,
	.remove = smcinvoke_remove,
	.suspend = smcinvoke_suspend,
	.resume = smcinvoke_resume,
	.driver = {
		.name = "smcinvoke",
		.of_match_table = smcinvoke_match,
	},
};

static int smcinvoke_init(void)
{
	return platform_driver_register(&smcinvoke_plat_driver);
}

static void smcinvoke_exit(void)
{
	platform_driver_unregister(&smcinvoke_plat_driver);
}

module_init(smcinvoke_init);
module_exit(smcinvoke_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SMC Invoke driver");
MODULE_IMPORT_NS(VFS_internal_I_am_really_a_filesystem_and_am_NOT_a_driver);
MODULE_IMPORT_NS(DMA_BUF);