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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Copyright 2014 IBM Corp.
- */
- #include <linux/pci.h>
- #include <linux/slab.h>
- #include <linux/file.h>
- #include <misc/cxl.h>
- #include <linux/module.h>
- #include <linux/mount.h>
- #include <linux/pseudo_fs.h>
- #include <linux/sched/mm.h>
- #include <linux/mmu_context.h>
- #include <linux/irqdomain.h>
- #include "cxl.h"
- /*
- * Since we want to track memory mappings to be able to force-unmap
- * when the AFU is no longer reachable, we need an inode. For devices
- * opened through the cxl user API, this is not a problem, but a
- * userland process can also get a cxl fd through the cxl_get_fd()
- * API, which is used by the cxlflash driver.
- *
- * Therefore we implement our own simple pseudo-filesystem and inode
- * allocator. We don't use the anonymous inode, as we need the
- * meta-data associated with it (address_space) and it is shared by
- * other drivers/processes, so it could lead to cxl unmapping VMAs
- * from random processes.
- */
- #define CXL_PSEUDO_FS_MAGIC 0x1697697f
- static int cxl_fs_cnt;
- static struct vfsmount *cxl_vfs_mount;
- static int cxl_fs_init_fs_context(struct fs_context *fc)
- {
- return init_pseudo(fc, CXL_PSEUDO_FS_MAGIC) ? 0 : -ENOMEM;
- }
- static struct file_system_type cxl_fs_type = {
- .name = "cxl",
- .owner = THIS_MODULE,
- .init_fs_context = cxl_fs_init_fs_context,
- .kill_sb = kill_anon_super,
- };
- void cxl_release_mapping(struct cxl_context *ctx)
- {
- if (ctx->kernelapi && ctx->mapping)
- simple_release_fs(&cxl_vfs_mount, &cxl_fs_cnt);
- }
- static struct file *cxl_getfile(const char *name,
- const struct file_operations *fops,
- void *priv, int flags)
- {
- struct file *file;
- struct inode *inode;
- int rc;
- /* strongly inspired by anon_inode_getfile() */
- if (fops->owner && !try_module_get(fops->owner))
- return ERR_PTR(-ENOENT);
- rc = simple_pin_fs(&cxl_fs_type, &cxl_vfs_mount, &cxl_fs_cnt);
- if (rc < 0) {
- pr_err("Cannot mount cxl pseudo filesystem: %d\n", rc);
- file = ERR_PTR(rc);
- goto err_module;
- }
- inode = alloc_anon_inode(cxl_vfs_mount->mnt_sb);
- if (IS_ERR(inode)) {
- file = ERR_CAST(inode);
- goto err_fs;
- }
- file = alloc_file_pseudo(inode, cxl_vfs_mount, name,
- flags & (O_ACCMODE | O_NONBLOCK), fops);
- if (IS_ERR(file))
- goto err_inode;
- file->private_data = priv;
- return file;
- err_inode:
- iput(inode);
- err_fs:
- simple_release_fs(&cxl_vfs_mount, &cxl_fs_cnt);
- err_module:
- module_put(fops->owner);
- return file;
- }
- struct cxl_context *cxl_dev_context_init(struct pci_dev *dev)
- {
- struct cxl_afu *afu;
- struct cxl_context *ctx;
- int rc;
- afu = cxl_pci_to_afu(dev);
- if (IS_ERR(afu))
- return ERR_CAST(afu);
- ctx = cxl_context_alloc();
- if (!ctx)
- return ERR_PTR(-ENOMEM);
- ctx->kernelapi = true;
- /* Make it a slave context. We can promote it later? */
- rc = cxl_context_init(ctx, afu, false);
- if (rc)
- goto err_ctx;
- return ctx;
- err_ctx:
- kfree(ctx);
- return ERR_PTR(rc);
- }
- EXPORT_SYMBOL_GPL(cxl_dev_context_init);
- struct cxl_context *cxl_get_context(struct pci_dev *dev)
- {
- return dev->dev.archdata.cxl_ctx;
- }
- EXPORT_SYMBOL_GPL(cxl_get_context);
- int cxl_release_context(struct cxl_context *ctx)
- {
- if (ctx->status >= STARTED)
- return -EBUSY;
- cxl_context_free(ctx);
- return 0;
- }
- EXPORT_SYMBOL_GPL(cxl_release_context);
- static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)
- {
- __u16 range;
- int r;
- for (r = 0; r < CXL_IRQ_RANGES; r++) {
- range = ctx->irqs.range[r];
- if (num < range) {
- return ctx->irqs.offset[r] + num;
- }
- num -= range;
- }
- return 0;
- }
- int cxl_set_priv(struct cxl_context *ctx, void *priv)
- {
- if (!ctx)
- return -EINVAL;
- ctx->priv = priv;
- return 0;
- }
- EXPORT_SYMBOL_GPL(cxl_set_priv);
- void *cxl_get_priv(struct cxl_context *ctx)
- {
- if (!ctx)
- return ERR_PTR(-EINVAL);
- return ctx->priv;
- }
- EXPORT_SYMBOL_GPL(cxl_get_priv);
- int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)
- {
- int res;
- irq_hw_number_t hwirq;
- if (num == 0)
- num = ctx->afu->pp_irqs;
- res = afu_allocate_irqs(ctx, num);
- if (res)
- return res;
- if (!cpu_has_feature(CPU_FTR_HVMODE)) {
- /* In a guest, the PSL interrupt is not multiplexed. It was
- * allocated above, and we need to set its handler
- */
- hwirq = cxl_find_afu_irq(ctx, 0);
- if (hwirq)
- cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");
- }
- if (ctx->status == STARTED) {
- if (cxl_ops->update_ivtes)
- cxl_ops->update_ivtes(ctx);
- else WARN(1, "BUG: cxl_allocate_afu_irqs must be called prior to starting the context on this platform\n");
- }
- return res;
- }
- EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);
- void cxl_free_afu_irqs(struct cxl_context *ctx)
- {
- irq_hw_number_t hwirq;
- unsigned int virq;
- if (!cpu_has_feature(CPU_FTR_HVMODE)) {
- hwirq = cxl_find_afu_irq(ctx, 0);
- if (hwirq) {
- virq = irq_find_mapping(NULL, hwirq);
- if (virq)
- cxl_unmap_irq(virq, ctx);
- }
- }
- afu_irq_name_free(ctx);
- cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);
- }
- EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);
- int cxl_map_afu_irq(struct cxl_context *ctx, int num,
- irq_handler_t handler, void *cookie, char *name)
- {
- irq_hw_number_t hwirq;
- /*
- * Find interrupt we are to register.
- */
- hwirq = cxl_find_afu_irq(ctx, num);
- if (!hwirq)
- return -ENOENT;
- return cxl_map_irq(ctx->afu->adapter, hwirq, handler, cookie, name);
- }
- EXPORT_SYMBOL_GPL(cxl_map_afu_irq);
- void cxl_unmap_afu_irq(struct cxl_context *ctx, int num, void *cookie)
- {
- irq_hw_number_t hwirq;
- unsigned int virq;
- hwirq = cxl_find_afu_irq(ctx, num);
- if (!hwirq)
- return;
- virq = irq_find_mapping(NULL, hwirq);
- if (virq)
- cxl_unmap_irq(virq, cookie);
- }
- EXPORT_SYMBOL_GPL(cxl_unmap_afu_irq);
- /*
- * Start a context
- * Code here similar to afu_ioctl_start_work().
- */
- int cxl_start_context(struct cxl_context *ctx, u64 wed,
- struct task_struct *task)
- {
- int rc = 0;
- bool kernel = true;
- pr_devel("%s: pe: %i\n", __func__, ctx->pe);
- mutex_lock(&ctx->status_mutex);
- if (ctx->status == STARTED)
- goto out; /* already started */
- /*
- * Increment the mapped context count for adapter. This also checks
- * if adapter_context_lock is taken.
- */
- rc = cxl_adapter_context_get(ctx->afu->adapter);
- if (rc)
- goto out;
- if (task) {
- ctx->pid = get_task_pid(task, PIDTYPE_PID);
- kernel = false;
- /* acquire a reference to the task's mm */
- ctx->mm = get_task_mm(current);
- /* ensure this mm_struct can't be freed */
- cxl_context_mm_count_get(ctx);
- if (ctx->mm) {
- /* decrement the use count from above */
- mmput(ctx->mm);
- /* make TLBIs for this context global */
- mm_context_add_copro(ctx->mm);
- }
- }
- /*
- * Increment driver use count. Enables global TLBIs for hash
- * and callbacks to handle the segment table
- */
- cxl_ctx_get();
- /* See the comment in afu_ioctl_start_work() */
- smp_mb();
- if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) {
- put_pid(ctx->pid);
- ctx->pid = NULL;
- cxl_adapter_context_put(ctx->afu->adapter);
- cxl_ctx_put();
- if (task) {
- cxl_context_mm_count_put(ctx);
- if (ctx->mm)
- mm_context_remove_copro(ctx->mm);
- }
- goto out;
- }
- ctx->status = STARTED;
- out:
- mutex_unlock(&ctx->status_mutex);
- return rc;
- }
- EXPORT_SYMBOL_GPL(cxl_start_context);
- int cxl_process_element(struct cxl_context *ctx)
- {
- return ctx->external_pe;
- }
- EXPORT_SYMBOL_GPL(cxl_process_element);
- /* Stop a context. Returns 0 on success, otherwise -Errno */
- int cxl_stop_context(struct cxl_context *ctx)
- {
- return __detach_context(ctx);
- }
- EXPORT_SYMBOL_GPL(cxl_stop_context);
- void cxl_set_master(struct cxl_context *ctx)
- {
- ctx->master = true;
- }
- EXPORT_SYMBOL_GPL(cxl_set_master);
- /* wrappers around afu_* file ops which are EXPORTED */
- int cxl_fd_open(struct inode *inode, struct file *file)
- {
- return afu_open(inode, file);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_open);
- int cxl_fd_release(struct inode *inode, struct file *file)
- {
- return afu_release(inode, file);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_release);
- long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
- {
- return afu_ioctl(file, cmd, arg);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_ioctl);
- int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm)
- {
- return afu_mmap(file, vm);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_mmap);
- __poll_t cxl_fd_poll(struct file *file, struct poll_table_struct *poll)
- {
- return afu_poll(file, poll);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_poll);
- ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
- loff_t *off)
- {
- return afu_read(file, buf, count, off);
- }
- EXPORT_SYMBOL_GPL(cxl_fd_read);
- #define PATCH_FOPS(NAME) if (!fops->NAME) fops->NAME = afu_fops.NAME
- /* Get a struct file and fd for a context and attach the ops */
- struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
- int *fd)
- {
- struct file *file;
- int rc, flags, fdtmp;
- char *name = NULL;
- /* only allow one per context */
- if (ctx->mapping)
- return ERR_PTR(-EEXIST);
- flags = O_RDWR | O_CLOEXEC;
- /* This code is similar to anon_inode_getfd() */
- rc = get_unused_fd_flags(flags);
- if (rc < 0)
- return ERR_PTR(rc);
- fdtmp = rc;
- /*
- * Patch the file ops. Needs to be careful that this is rentrant safe.
- */
- if (fops) {
- PATCH_FOPS(open);
- PATCH_FOPS(poll);
- PATCH_FOPS(read);
- PATCH_FOPS(release);
- PATCH_FOPS(unlocked_ioctl);
- PATCH_FOPS(compat_ioctl);
- PATCH_FOPS(mmap);
- } else /* use default ops */
- fops = (struct file_operations *)&afu_fops;
- name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe);
- file = cxl_getfile(name, fops, ctx, flags);
- kfree(name);
- if (IS_ERR(file))
- goto err_fd;
- cxl_context_set_mapping(ctx, file->f_mapping);
- *fd = fdtmp;
- return file;
- err_fd:
- put_unused_fd(fdtmp);
- return NULL;
- }
- EXPORT_SYMBOL_GPL(cxl_get_fd);
- struct cxl_context *cxl_fops_get_context(struct file *file)
- {
- return file->private_data;
- }
- EXPORT_SYMBOL_GPL(cxl_fops_get_context);
- void cxl_set_driver_ops(struct cxl_context *ctx,
- struct cxl_afu_driver_ops *ops)
- {
- WARN_ON(!ops->fetch_event || !ops->event_delivered);
- atomic_set(&ctx->afu_driver_events, 0);
- ctx->afu_driver_ops = ops;
- }
- EXPORT_SYMBOL_GPL(cxl_set_driver_ops);
- void cxl_context_events_pending(struct cxl_context *ctx,
- unsigned int new_events)
- {
- atomic_add(new_events, &ctx->afu_driver_events);
- wake_up_all(&ctx->wq);
- }
- EXPORT_SYMBOL_GPL(cxl_context_events_pending);
- int cxl_start_work(struct cxl_context *ctx,
- struct cxl_ioctl_start_work *work)
- {
- int rc;
- /* code taken from afu_ioctl_start_work */
- if (!(work->flags & CXL_START_WORK_NUM_IRQS))
- work->num_interrupts = ctx->afu->pp_irqs;
- else if ((work->num_interrupts < ctx->afu->pp_irqs) ||
- (work->num_interrupts > ctx->afu->irqs_max)) {
- return -EINVAL;
- }
- rc = afu_register_irqs(ctx, work->num_interrupts);
- if (rc)
- return rc;
- rc = cxl_start_context(ctx, work->work_element_descriptor, current);
- if (rc < 0) {
- afu_release_irqs(ctx, ctx);
- return rc;
- }
- return 0;
- }
- EXPORT_SYMBOL_GPL(cxl_start_work);
- void __iomem *cxl_psa_map(struct cxl_context *ctx)
- {
- if (ctx->status != STARTED)
- return NULL;
- pr_devel("%s: psn_phys%llx size:%llx\n",
- __func__, ctx->psn_phys, ctx->psn_size);
- return ioremap(ctx->psn_phys, ctx->psn_size);
- }
- EXPORT_SYMBOL_GPL(cxl_psa_map);
- void cxl_psa_unmap(void __iomem *addr)
- {
- iounmap(addr);
- }
- EXPORT_SYMBOL_GPL(cxl_psa_unmap);
- int cxl_afu_reset(struct cxl_context *ctx)
- {
- struct cxl_afu *afu = ctx->afu;
- int rc;
- rc = cxl_ops->afu_reset(afu);
- if (rc)
- return rc;
- return cxl_ops->afu_check_and_enable(afu);
- }
- EXPORT_SYMBOL_GPL(cxl_afu_reset);
- void cxl_perst_reloads_same_image(struct cxl_afu *afu,
- bool perst_reloads_same_image)
- {
- afu->adapter->perst_same_image = perst_reloads_same_image;
- }
- EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);
- ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)
- {
- struct cxl_afu *afu = cxl_pci_to_afu(dev);
- if (IS_ERR(afu))
- return -ENODEV;
- return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);
- }
- EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);
|