Merge tag 'tee-drv-dynamic-shm-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee into next/drivers

Pull "tee dynamic shm for v4.16" from Jens Wiklander:

This pull request enables dynamic shared memory support in the TEE
subsystem as a whole and in OP-TEE in particular.

Global Platform TEE specification [1] allows client applications
to register part of own memory as a shared buffer between
application and TEE. This allows fast zero-copy communication between
TEE and REE. But current implementation of TEE in Linux does not support
this feature.

Also, current implementation of OP-TEE transport uses fixed size
pre-shared buffer for all communications with OP-TEE OS. This is okay
in the most use cases. But this prevents use of OP-TEE in virtualized
environments, because:
 a) We can't share the same buffer between different virtual machines
 b) Physically contiguous memory as seen by VM can be non-contiguous
    in reality (and as seen by OP-TEE OS) due to second stage of
    MMU translation.
 c) Size of this pre-shared buffer is limited.

So, first part of this pull request adds generic register/unregister
interface to tee subsystem. The second part adds necessary features into
OP-TEE driver, so it can use not only static pre-shared buffer, but
whole RAM to communicate with OP-TEE OS.

This change is backwards compatible allowing older secure world or
user space to work with newer kernels and vice versa.

[1] https://www.globalplatform.org/specificationsdevice.asp

* tag 'tee-drv-dynamic-shm-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: shm: inline tee_shm_get_id()
  tee: use reference counting for tee_context
  tee: optee: enable dynamic SHM support
  tee: optee: add optee-specific shared pool implementation
  tee: optee: store OP-TEE capabilities in private data
  tee: optee: add registered buffers handling into RPC calls
  tee: optee: add registered shared parameters handling
  tee: optee: add shared buffer registration functions
  tee: optee: add page list manipulation functions
  tee: optee: Update protocol definitions
  tee: shm: add page accessor functions
  tee: shm: add accessors for buffer size and page offset
  tee: add register user memory
  tee: flexible shared memory pool creation

drivers/tee/optee/Makefile

@@ -4,3 +4,4 @@ optee-objs += core.o
 optee-objs += call.o
 optee-objs += rpc.o
 optee-objs += supp.o
+optee-objs += shm_pool.o

drivers/tee/optee/call.c

@@ -11,6 +11,7 @@
  * GNU General Public License for more details.
  *
  */
+#include <asm/pgtable.h>
 #include <linux/arm-smccc.h>
 #include <linux/device.h>
 #include <linux/err.h>
@@ -135,6 +136,7 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
 	struct optee *optee = tee_get_drvdata(ctx->teedev);
 	struct optee_call_waiter w;
 	struct optee_rpc_param param = { };
+	struct optee_call_ctx call_ctx = { };
 	u32 ret;
 
 	param.a0 = OPTEE_SMC_CALL_WITH_ARG;
@@ -159,13 +161,14 @@ u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
 			param.a1 = res.a1;
 			param.a2 = res.a2;
 			param.a3 = res.a3;
-			optee_handle_rpc(ctx, &param);
+			optee_handle_rpc(ctx, &param, &call_ctx);
 		} else {
 			ret = res.a0;
 			break;
 		}
 	}
 
+	optee_rpc_finalize_call(&call_ctx);
 	/*
 	 * We're done with our thread in secure world, if there's any
 	 * thread waiters wake up one.
@@ -442,3 +445,177 @@ void optee_disable_shm_cache(struct optee *optee)
 	}
 	optee_cq_wait_final(&optee->call_queue, &w);
 }
+
+#define PAGELIST_ENTRIES_PER_PAGE				\
+	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
+
+/**
+ * optee_fill_pages_list() - write list of user pages to given shared
+ * buffer.
+ *
+ * @dst: page-aligned buffer where list of pages will be stored
+ * @pages: array of pages that represents shared buffer
+ * @num_pages: number of entries in @pages
+ * @page_offset: offset of user buffer from page start
+ *
+ * @dst should be big enough to hold list of user page addresses and
+ *	links to the next pages of buffer
+ */
+void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
+			   size_t page_offset)
+{
+	int n = 0;
+	phys_addr_t optee_page;
+	/*
+	 * Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h
+	 * for details.
+	 */
+	struct {
+		u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
+		u64 next_page_data;
+	} *pages_data;
+
+	/*
+	 * Currently OP-TEE uses 4k page size and it does not looks
+	 * like this will change in the future.  On other hand, there are
+	 * no know ARM architectures with page size < 4k.
+	 * Thus the next built assert looks redundant. But the following
+	 * code heavily relies on this assumption, so it is better be
+	 * safe than sorry.
+	 */
+	BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);
+
+	pages_data = (void *)dst;
+	/*
+	 * If linux page is bigger than 4k, and user buffer offset is
+	 * larger than 4k/8k/12k/etc this will skip first 4k pages,
+	 * because they bear no value data for OP-TEE.
+	 */
+	optee_page = page_to_phys(*pages) +
+		round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);
+
+	while (true) {
+		pages_data->pages_list[n++] = optee_page;
+
+		if (n == PAGELIST_ENTRIES_PER_PAGE) {
+			pages_data->next_page_data =
+				virt_to_phys(pages_data + 1);
+			pages_data++;
+			n = 0;
+		}
+
+		optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;
+		if (!(optee_page & ~PAGE_MASK)) {
+			if (!--num_pages)
+				break;
+			pages++;
+			optee_page = page_to_phys(*pages);
+		}
+	}
+}
+
+/*
+ * The final entry in each pagelist page is a pointer to the next
+ * pagelist page.
+ */
+static size_t get_pages_list_size(size_t num_entries)
+{
+	int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);
+
+	return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;
+}
+
+u64 *optee_allocate_pages_list(size_t num_entries)
+{
+	return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
+}
+
+void optee_free_pages_list(void *list, size_t num_entries)
+{
+	free_pages_exact(list, get_pages_list_size(num_entries));
+}
+
+int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
+		       struct page **pages, size_t num_pages)
+{
+	struct tee_shm *shm_arg = NULL;
+	struct optee_msg_arg *msg_arg;
+	u64 *pages_list;
+	phys_addr_t msg_parg;
+	int rc = 0;
+
+	if (!num_pages)
+		return -EINVAL;
+
+	pages_list = optee_allocate_pages_list(num_pages);
+	if (!pages_list)
+		return -ENOMEM;
+
+	shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
+	if (IS_ERR(shm_arg)) {
+		rc = PTR_ERR(shm_arg);
+		goto out;
+	}
+
+	optee_fill_pages_list(pages_list, pages, num_pages,
+			      tee_shm_get_page_offset(shm));
+
+	msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
+	msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
+				OPTEE_MSG_ATTR_NONCONTIG;
+	msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
+	msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
+	/*
+	 * In the least bits of msg_arg->params->u.tmem.buf_ptr we
+	 * store buffer offset from 4k page, as described in OP-TEE ABI.
+	 */
+	msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
+	  (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
+
+	if (optee_do_call_with_arg(ctx, msg_parg) ||
+	    msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+
+	tee_shm_free(shm_arg);
+out:
+	optee_free_pages_list(pages_list, num_pages);
+	return rc;
+}
+
+int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
+{
+	struct tee_shm *shm_arg;
+	struct optee_msg_arg *msg_arg;
+	phys_addr_t msg_parg;
+	int rc = 0;
+
+	shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
+	if (IS_ERR(shm_arg))
+		return PTR_ERR(shm_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;
+
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+	msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;
+
+	if (optee_do_call_with_arg(ctx, msg_parg) ||
+	    msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+	tee_shm_free(shm_arg);
+	return rc;
+}
+
+int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
+			    struct page **pages, size_t num_pages)
+{
+	/*
+	 * We don't want to register supplicant memory in OP-TEE.
+	 * Instead information about it will be passed in RPC code.
+	 */
+	return 0;
+}
+
+int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm)
+{
+	return 0;
+}

drivers/tee/optee/core.c

@@ -28,6 +28,7 @@
 #include <linux/uaccess.h>
 #include "optee_private.h"
 #include "optee_smc.h"
+#include "shm_pool.h"
 
 #define DRIVER_NAME "optee"
 
@@ -97,6 +98,25 @@ int optee_from_msg_param(struct tee_param *params, size_t num_params,
 					return rc;
 			}
 			break;
+		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
+			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
+				  attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+			p->u.memref.size = mp->u.rmem.size;
+			shm = (struct tee_shm *)(unsigned long)
+				mp->u.rmem.shm_ref;
+
+			if (!shm) {
+				p->u.memref.shm_offs = 0;
+				p->u.memref.shm = NULL;
+				break;
+			}
+			p->u.memref.shm_offs = mp->u.rmem.offs;
+			p->u.memref.shm = shm;
+
+			break;
+
 		default:
 			return -EINVAL;
 		}
@@ -104,6 +124,46 @@ int optee_from_msg_param(struct tee_param *params, size_t num_params,
 	return 0;
 }
 
+static int to_msg_param_tmp_mem(struct optee_msg_param *mp,
+				const struct tee_param *p)
+{
+	int rc;
+	phys_addr_t pa;
+
+	mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT + p->attr -
+		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+
+	mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
+	mp->u.tmem.size = p->u.memref.size;
+
+	if (!p->u.memref.shm) {
+		mp->u.tmem.buf_ptr = 0;
+		return 0;
+	}
+
+	rc = tee_shm_get_pa(p->u.memref.shm, p->u.memref.shm_offs, &pa);
+	if (rc)
+		return rc;
+
+	mp->u.tmem.buf_ptr = pa;
+	mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
+		    OPTEE_MSG_ATTR_CACHE_SHIFT;
+
+	return 0;
+}
+
+static int to_msg_param_reg_mem(struct optee_msg_param *mp,
+				const struct tee_param *p)
+{
+	mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
+		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+
+	mp->u.rmem.shm_ref = (unsigned long)p->u.memref.shm;
+	mp->u.rmem.size = p->u.memref.size;
+	mp->u.rmem.offs = p->u.memref.shm_offs;
+	return 0;
+}
+
 /**
  * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
  * @msg_params:	OPTEE_MSG parameters
@@ -116,7 +176,6 @@ int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
 {
 	int rc;
 	size_t n;
-	phys_addr_t pa;
 
 	for (n = 0; n < num_params; n++) {
 		const struct tee_param *p = params + n;
@@ -139,22 +198,12 @@ int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
-			mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT +
-				   p->attr -
-				   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
-			mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
-			mp->u.tmem.size = p->u.memref.size;
-			if (!p->u.memref.shm) {
-				mp->u.tmem.buf_ptr = 0;
-				break;
-			}
-			rc = tee_shm_get_pa(p->u.memref.shm,
-					    p->u.memref.shm_offs, &pa);
+			if (tee_shm_is_registered(p->u.memref.shm))
+				rc = to_msg_param_reg_mem(mp, p);
+			else
+				rc = to_msg_param_tmp_mem(mp, p);
 			if (rc)
 				return rc;
-			mp->u.tmem.buf_ptr = pa;
-			mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
-					OPTEE_MSG_ATTR_CACHE_SHIFT;
 			break;
 		default:
 			return -EINVAL;
@@ -171,6 +220,10 @@ static void optee_get_version(struct tee_device *teedev,
 		.impl_caps = TEE_OPTEE_CAP_TZ,
 		.gen_caps = TEE_GEN_CAP_GP,
 	};
+	struct optee *optee = tee_get_drvdata(teedev);
+
+	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
+		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
 	*vers = v;
 }
 
@@ -264,6 +317,8 @@ static const struct tee_driver_ops optee_ops = {
 	.close_session = optee_close_session,
 	.invoke_func = optee_invoke_func,
 	.cancel_req = optee_cancel_req,
+	.shm_register = optee_shm_register,
+	.shm_unregister = optee_shm_unregister,
 };
 
 static const struct tee_desc optee_desc = {
@@ -278,6 +333,8 @@ static const struct tee_driver_ops optee_supp_ops = {
 	.release = optee_release,
 	.supp_recv = optee_supp_recv,
 	.supp_send = optee_supp_send,
+	.shm_register = optee_shm_register_supp,
+	.shm_unregister = optee_shm_unregister_supp,
 };
 
 static const struct tee_desc optee_supp_desc = {
@@ -342,21 +399,22 @@ static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
 }
 
 static struct tee_shm_pool *
-optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
+optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm,
+			  u32 sec_caps)
 {
 	union {
 		struct arm_smccc_res smccc;
 		struct optee_smc_get_shm_config_result result;
 	} res;
-	struct tee_shm_pool *pool;
 	unsigned long vaddr;
 	phys_addr_t paddr;
 	size_t size;
 	phys_addr_t begin;
 	phys_addr_t end;
 	void *va;
-	struct tee_shm_pool_mem_info priv_info;
-	struct tee_shm_pool_mem_info dmabuf_info;
+	struct tee_shm_pool_mgr *priv_mgr;
+	struct tee_shm_pool_mgr *dmabuf_mgr;
+	void *rc;
 
 	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
 	if (res.result.status != OPTEE_SMC_RETURN_OK) {
@@ -386,22 +444,49 @@ optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
 	}
 	vaddr = (unsigned long)va;
 
-	priv_info.vaddr = vaddr;
-	priv_info.paddr = paddr;
-	priv_info.size = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
-	dmabuf_info.vaddr = vaddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
-	dmabuf_info.paddr = paddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
-	dmabuf_info.size = size - OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
+	/*
+	 * If OP-TEE can work with unregistered SHM, we will use own pool
+	 * for private shm
+	 */
+	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) {
+		rc = optee_shm_pool_alloc_pages();
+		if (IS_ERR(rc))
+			goto err_memunmap;
+		priv_mgr = rc;
+	} else {
+		const size_t sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
 
-	pool = tee_shm_pool_alloc_res_mem(&priv_info, &dmabuf_info);
-	if (IS_ERR(pool)) {
-		memunmap(va);
-		goto out;
+		rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
+						    3 /* 8 bytes aligned */);
+		if (IS_ERR(rc))
+			goto err_memunmap;
+		priv_mgr = rc;
+
+		vaddr += sz;
+		paddr += sz;
+		size -= sz;
 	}
 
+	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
+	if (IS_ERR(rc))
+		goto err_free_priv_mgr;
+	dmabuf_mgr = rc;
+
+	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
+	if (IS_ERR(rc))
+		goto err_free_dmabuf_mgr;
+
 	*memremaped_shm = va;
-out:
-	return pool;
+
+	return rc;
+
+err_free_dmabuf_mgr:
+	tee_shm_pool_mgr_destroy(dmabuf_mgr);
+err_free_priv_mgr:
+	tee_shm_pool_mgr_destroy(priv_mgr);
+err_memunmap:
+	memunmap(va);
+	return rc;
 }
 
 /* Simple wrapper functions to be able to use a function pointer */
@@ -479,7 +564,7 @@ static struct optee *optee_probe(struct device_node *np)
 	if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
 		return ERR_PTR(-EINVAL);
 
-	pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
+	pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm, sec_caps);
 	if (IS_ERR(pool))
 		return (void *)pool;
 
@@ -490,6 +575,7 @@ static struct optee *optee_probe(struct device_node *np)
 	}
 
 	optee->invoke_fn = invoke_fn;
+	optee->sec_caps = sec_caps;
 
 	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
 	if (IS_ERR(teedev)) {

drivers/tee/optee/optee_msg.h

@@ -67,11 +67,32 @@
 #define OPTEE_MSG_ATTR_META			BIT(8)
 
 /*
- * The temporary shared memory object is not physically contigous and this
- * temp memref is followed by another fragment until the last temp memref
- * that doesn't have this bit set.
+ * Pointer to a list of pages used to register user-defined SHM buffer.
+ * Used with OPTEE_MSG_ATTR_TYPE_TMEM_*.
+ * buf_ptr should point to the beginning of the buffer. Buffer will contain
+ * list of page addresses. OP-TEE core can reconstruct contiguous buffer from
+ * that page addresses list. Page addresses are stored as 64 bit values.
+ * Last entry on a page should point to the next page of buffer.
+ * Every entry in buffer should point to a 4k page beginning (12 least
+ * significant bits must be equal to zero).
+ *
+ * 12 least significant bints of optee_msg_param.u.tmem.buf_ptr should hold page
+ * offset of the user buffer.
+ *
+ * So, entries should be placed like members of this structure:
+ *
+ * struct page_data {
+ *   uint64_t pages_array[OPTEE_MSG_NONCONTIG_PAGE_SIZE/sizeof(uint64_t) - 1];
+ *   uint64_t next_page_data;
+ * };
+ *
+ * Structure is designed to exactly fit into the page size
+ * OPTEE_MSG_NONCONTIG_PAGE_SIZE which is a standard 4KB page.
+ *
+ * The size of 4KB is chosen because this is the smallest page size for ARM
+ * architectures. If REE uses larger pages, it should divide them to 4KB ones.
  */
-#define OPTEE_MSG_ATTR_FRAGMENT			BIT(9)
+#define OPTEE_MSG_ATTR_NONCONTIG		BIT(9)
 
 /*
  * Memory attributes for caching passed with temp memrefs. The actual value
@@ -94,6 +115,11 @@
 #define OPTEE_MSG_LOGIN_APPLICATION_USER	0x00000005
 #define OPTEE_MSG_LOGIN_APPLICATION_GROUP	0x00000006
 
+/*
+ * Page size used in non-contiguous buffer entries
+ */
+#define OPTEE_MSG_NONCONTIG_PAGE_SIZE		4096
+
 /**
  * struct optee_msg_param_tmem - temporary memory reference parameter
  * @buf_ptr:	Address of the buffer
@@ -145,8 +171,8 @@ struct optee_msg_param_value {
  *
  * @attr & OPTEE_MSG_ATTR_TYPE_MASK indicates if tmem, rmem or value is used in
  * the union. OPTEE_MSG_ATTR_TYPE_VALUE_* indicates value,
- * OPTEE_MSG_ATTR_TYPE_TMEM_* indicates tmem and
- * OPTEE_MSG_ATTR_TYPE_RMEM_* indicates rmem.
+ * OPTEE_MSG_ATTR_TYPE_TMEM_* indicates @tmem and
+ * OPTEE_MSG_ATTR_TYPE_RMEM_* indicates @rmem,
  * OPTEE_MSG_ATTR_TYPE_NONE indicates that none of the members are used.
  */
 struct optee_msg_param {

drivers/tee/optee/optee_private.h

@@ -84,6 +84,8 @@ struct optee_supp {
  * @supp:		supplicant synchronization struct for RPC to supplicant
  * @pool:		shared memory pool
  * @memremaped_shm	virtual address of memory in shared memory pool
+ * @sec_caps:		secure world capabilities defined by
+ *			OPTEE_SMC_SEC_CAP_* in optee_smc.h
  */
 struct optee {
 	struct tee_device *supp_teedev;
@@ -94,6 +96,7 @@ struct optee {
 	struct optee_supp supp;
 	struct tee_shm_pool *pool;
 	void *memremaped_shm;
+	u32 sec_caps;
 };
 
 struct optee_session {
@@ -118,7 +121,16 @@ struct optee_rpc_param {
 	u32	a7;
 };
 
-void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param);
+/* Holds context that is preserved during one STD call */
+struct optee_call_ctx {
+	/* information about pages list used in last allocation */
+	void *pages_list;
+	size_t num_entries;
+};
+
+void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
+		      struct optee_call_ctx *call_ctx);
+void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx);
 
 void optee_wait_queue_init(struct optee_wait_queue *wq);
 void optee_wait_queue_exit(struct optee_wait_queue *wq);
@@ -149,11 +161,24 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
 void optee_enable_shm_cache(struct optee *optee);
 void optee_disable_shm_cache(struct optee *optee);
 
+int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
+		       struct page **pages, size_t num_pages);
+int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm);
+
+int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
+			    struct page **pages, size_t num_pages);
+int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm);
+
 int optee_from_msg_param(struct tee_param *params, size_t num_params,
 			 const struct optee_msg_param *msg_params);
 int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
 		       const struct tee_param *params);
 
+u64 *optee_allocate_pages_list(size_t num_entries);
+void optee_free_pages_list(void *array, size_t num_entries);
+void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
+			   size_t page_offset);
+
 /*
  * Small helpers
  */

drivers/tee/optee/optee_smc.h

@@ -222,6 +222,13 @@ struct optee_smc_get_shm_config_result {
 #define OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM	BIT(0)
 /* Secure world can communicate via previously unregistered shared memory */
 #define OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM	BIT(1)
+
+/*
+ * Secure world supports commands "register/unregister shared memory",
+ * secure world accepts command buffers located in any parts of non-secure RAM
+ */
+#define OPTEE_SMC_SEC_CAP_DYNAMIC_SHM		BIT(2)
+
 #define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES	9
 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \
 	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES)

drivers/tee/optee/rpc.c

@@ -200,7 +200,8 @@ static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
 }
 
 static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
-					  struct optee_msg_arg *arg)
+					  struct optee_msg_arg *arg,
+					  struct optee_call_ctx *call_ctx)
 {
 	phys_addr_t pa;
 	struct tee_shm *shm;
@@ -245,10 +246,49 @@ static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
 		goto bad;
 	}
 
-	arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
-	arg->params[0].u.tmem.buf_ptr = pa;
-	arg->params[0].u.tmem.size = sz;
-	arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
+	sz = tee_shm_get_size(shm);
+
+	if (tee_shm_is_registered(shm)) {
+		struct page **pages;
+		u64 *pages_list;
+		size_t page_num;
+
+		pages = tee_shm_get_pages(shm, &page_num);
+		if (!pages || !page_num) {
+			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
+			goto bad;
+		}
+
+		pages_list = optee_allocate_pages_list(page_num);
+		if (!pages_list) {
+			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
+			goto bad;
+		}
+
+		call_ctx->pages_list = pages_list;
+		call_ctx->num_entries = page_num;
+
+		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
+				      OPTEE_MSG_ATTR_NONCONTIG;
+		/*
+		 * In the least bits of u.tmem.buf_ptr we store buffer offset
+		 * from 4k page, as described in OP-TEE ABI.
+		 */
+		arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
+			(tee_shm_get_page_offset(shm) &
+			 (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
+		arg->params[0].u.tmem.size = tee_shm_get_size(shm);
+		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
+
+		optee_fill_pages_list(pages_list, pages, page_num,
+				      tee_shm_get_page_offset(shm));
+	} else {
+		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
+		arg->params[0].u.tmem.buf_ptr = pa;
+		arg->params[0].u.tmem.size = sz;
+		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
+	}
+
 	arg->ret = TEEC_SUCCESS;
 	return;
 bad:
@@ -307,8 +347,24 @@ static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
 	arg->ret = TEEC_SUCCESS;
 }
 
+static void free_pages_list(struct optee_call_ctx *call_ctx)
+{
+	if (call_ctx->pages_list) {
+		optee_free_pages_list(call_ctx->pages_list,
+				      call_ctx->num_entries);
+		call_ctx->pages_list = NULL;
+		call_ctx->num_entries = 0;
+	}
+}
+
+void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx)
+{
+	free_pages_list(call_ctx);
+}
+
 static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
-				struct tee_shm *shm)
+				struct tee_shm *shm,
+				struct optee_call_ctx *call_ctx)
 {
 	struct optee_msg_arg *arg;
 
@@ -329,7 +385,8 @@ static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
 		handle_rpc_func_cmd_wait(arg);
 		break;
 	case OPTEE_MSG_RPC_CMD_SHM_ALLOC:
-		handle_rpc_func_cmd_shm_alloc(ctx, arg);
+		free_pages_list(call_ctx);
+		handle_rpc_func_cmd_shm_alloc(ctx, arg, call_ctx);
 		break;
 	case OPTEE_MSG_RPC_CMD_SHM_FREE:
 		handle_rpc_func_cmd_shm_free(ctx, arg);
@@ -343,10 +400,12 @@ static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
  * optee_handle_rpc() - handle RPC from secure world
  * @ctx:	context doing the RPC
  * @param:	value of registers for the RPC
+ * @call_ctx:	call context. Preserved during one OP-TEE invocation
  *
  * Result of RPC is written back into @param.
  */
-void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param)
+void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
+		      struct optee_call_ctx *call_ctx)
 {
 	struct tee_device *teedev = ctx->teedev;
 	struct optee *optee = tee_get_drvdata(teedev);
@@ -381,7 +440,7 @@ void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param)
 		break;
 	case OPTEE_SMC_RPC_FUNC_CMD:
 		shm = reg_pair_to_ptr(param->a1, param->a2);
-		handle_rpc_func_cmd(ctx, optee, shm);
+		handle_rpc_func_cmd(ctx, optee, shm, call_ctx);
 		break;
 	default:
 		pr_warn("Unknown RPC func 0x%x\n",

drivers/tee/optee/shm_pool.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ * Copyright (c) 2017, EPAM Systems
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/genalloc.h>
+#include <linux/slab.h>
+#include <linux/tee_drv.h>
+#include "optee_private.h"
+#include "optee_smc.h"
+#include "shm_pool.h"
+
+static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
+			 struct tee_shm *shm, size_t size)
+{
+	unsigned int order = get_order(size);
+	struct page *page;
+
+	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+	if (!page)
+		return -ENOMEM;
+
+	shm->kaddr = page_address(page);
+	shm->paddr = page_to_phys(page);
+	shm->size = PAGE_SIZE << order;
+
+	return 0;
+}
+
+static void pool_op_free(struct tee_shm_pool_mgr *poolm,
+			 struct tee_shm *shm)
+{
+	free_pages((unsigned long)shm->kaddr, get_order(shm->size));
+	shm->kaddr = NULL;
+}
+
+static void pool_op_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
+{
+	kfree(poolm);
+}
+
+static const struct tee_shm_pool_mgr_ops pool_ops = {
+	.alloc = pool_op_alloc,
+	.free = pool_op_free,
+	.destroy_poolmgr = pool_op_destroy_poolmgr,
+};
+
+/**
+ * optee_shm_pool_alloc_pages() - create page-based allocator pool
+ *
+ * This pool is used when OP-TEE supports dymanic SHM. In this case
+ * command buffers and such are allocated from kernel's own memory.
+ */
+struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void)
+{
+	struct tee_shm_pool_mgr *mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
+
+	if (!mgr)
+		return ERR_PTR(-ENOMEM);
+
+	mgr->ops = &pool_ops;
+
+	return mgr;
+}

drivers/tee/optee/shm_pool.h

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ * Copyright (c) 2016, EPAM Systems
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef SHM_POOL_H
+#define SHM_POOL_H
+
+#include <linux/tee_drv.h>
+
+struct tee_shm_pool_mgr *optee_shm_pool_alloc_pages(void);
+
+#endif