// SPDX-License-Identifier: GPL-2.0+ // Copyright 2017 IBM Corp. #include <linux/fs.h> #include <linux/poll.h> #include <linux/sched/signal.h> #include <linux/eventfd.h> #include <linux/uaccess.h> #include <uapi/misc/ocxl.h> #include <asm/reg.h> #include <asm/switch_to.h> #include "ocxl_internal.h" #define OCXL_NUM_MINORS 256 /* Total to reserve */ static dev_t ocxl_dev; static struct class *ocxl_class; static DEFINE_MUTEX(minors_idr_lock); static struct idr minors_idr; static struct ocxl_file_info *find_and_get_file_info(dev_t devno) { struct ocxl_file_info *info; mutex_lock(&minors_idr_lock); info = idr_find(&minors_idr, MINOR(devno)); if (info) get_device(&info->dev); mutex_unlock(&minors_idr_lock); return info; } static int allocate_minor(struct ocxl_file_info *info) { int minor; mutex_lock(&minors_idr_lock); minor = idr_alloc(&minors_idr, info, 0, OCXL_NUM_MINORS, GFP_KERNEL); mutex_unlock(&minors_idr_lock); return minor; } static void free_minor(struct ocxl_file_info *info) { mutex_lock(&minors_idr_lock); idr_remove(&minors_idr, MINOR(info->dev.devt)); mutex_unlock(&minors_idr_lock); } static int afu_open(struct inode *inode, struct file *file) { struct ocxl_file_info *info; struct ocxl_context *ctx; int rc; pr_debug("%s for device %x\n", __func__, inode->i_rdev); info = find_and_get_file_info(inode->i_rdev); if (!info) return -ENODEV; rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping); if (rc) { put_device(&info->dev); return rc; } put_device(&info->dev); file->private_data = ctx; return 0; } static long afu_ioctl_attach(struct ocxl_context *ctx, struct ocxl_ioctl_attach __user *uarg) { struct ocxl_ioctl_attach arg; u64 amr = 0; pr_debug("%s for context %d\n", __func__, ctx->pasid); if (copy_from_user(&arg, uarg, sizeof(arg))) return -EFAULT; /* Make sure reserved fields are not set for forward compatibility */ if (arg.reserved1 || arg.reserved2 || arg.reserved3) return -EINVAL; amr = arg.amr & mfspr(SPRN_UAMOR); return ocxl_context_attach(ctx, amr, current->mm); } static long afu_ioctl_get_metadata(struct ocxl_context *ctx, struct ocxl_ioctl_metadata __user *uarg) { struct ocxl_ioctl_metadata arg; memset(&arg, 0, sizeof(arg)); arg.version = 0; arg.afu_version_major = ctx->afu->config.version_major; arg.afu_version_minor = ctx->afu->config.version_minor; arg.pasid = ctx->pasid; arg.pp_mmio_size = ctx->afu->config.pp_mmio_stride; arg.global_mmio_size = ctx->afu->config.global_mmio_size; if (copy_to_user(uarg, &arg, sizeof(arg))) return -EFAULT; return 0; } #ifdef CONFIG_PPC64 static long afu_ioctl_enable_p9_wait(struct ocxl_context *ctx, struct ocxl_ioctl_p9_wait __user *uarg) { struct ocxl_ioctl_p9_wait arg; memset(&arg, 0, sizeof(arg)); if (cpu_has_feature(CPU_FTR_P9_TIDR)) { enum ocxl_context_status status; // Locks both status & tidr mutex_lock(&ctx->status_mutex); if (!ctx->tidr) { if (set_thread_tidr(current)) { mutex_unlock(&ctx->status_mutex); return -ENOENT; } ctx->tidr = current->thread.tidr; } status = ctx->status; mutex_unlock(&ctx->status_mutex); if (status == ATTACHED) { int rc = ocxl_link_update_pe(ctx->afu->fn->link, ctx->pasid, ctx->tidr); if (rc) return rc; } arg.thread_id = ctx->tidr; } else return -ENOENT; if (copy_to_user(uarg, &arg, sizeof(arg))) return -EFAULT; return 0; } #endif static long afu_ioctl_get_features(struct ocxl_context *ctx, struct ocxl_ioctl_features __user *uarg) { struct ocxl_ioctl_features arg; memset(&arg, 0, sizeof(arg)); #ifdef CONFIG_PPC64 if (cpu_has_feature(CPU_FTR_P9_TIDR)) arg.flags[0] |= OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT; #endif if (copy_to_user(uarg, &arg, sizeof(arg))) return -EFAULT; return 0; } #define CMD_STR(x) (x == OCXL_IOCTL_ATTACH ? "ATTACH" : \ x == OCXL_IOCTL_IRQ_ALLOC ? "IRQ_ALLOC" : \ x == OCXL_IOCTL_IRQ_FREE ? "IRQ_FREE" : \ x == OCXL_IOCTL_IRQ_SET_FD ? "IRQ_SET_FD" : \ x == OCXL_IOCTL_GET_METADATA ? "GET_METADATA" : \ x == OCXL_IOCTL_ENABLE_P9_WAIT ? "ENABLE_P9_WAIT" : \ x == OCXL_IOCTL_GET_FEATURES ? "GET_FEATURES" : \ "UNKNOWN") static irqreturn_t irq_handler(void *private) { struct eventfd_ctx *ev_ctx = private; eventfd_signal(ev_ctx, 1); return IRQ_HANDLED; } static void irq_free(void *private) { struct eventfd_ctx *ev_ctx = private; eventfd_ctx_put(ev_ctx); } static long afu_ioctl(struct file *file, unsigned int cmd, unsigned long args) { struct ocxl_context *ctx = file->private_data; struct ocxl_ioctl_irq_fd irq_fd; struct eventfd_ctx *ev_ctx; int irq_id; u64 irq_offset; long rc; bool closed; pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid, CMD_STR(cmd)); mutex_lock(&ctx->status_mutex); closed = (ctx->status == CLOSED); mutex_unlock(&ctx->status_mutex); if (closed) return -EIO; switch (cmd) { case OCXL_IOCTL_ATTACH: rc = afu_ioctl_attach(ctx, (struct ocxl_ioctl_attach __user *) args); break; case OCXL_IOCTL_IRQ_ALLOC: rc = ocxl_afu_irq_alloc(ctx, &irq_id); if (!rc) { irq_offset = ocxl_irq_id_to_offset(ctx, irq_id); rc = copy_to_user((u64 __user *) args, &irq_offset, sizeof(irq_offset)); if (rc) { ocxl_afu_irq_free(ctx, irq_id); return -EFAULT; } } break; case OCXL_IOCTL_IRQ_FREE: rc = copy_from_user(&irq_offset, (u64 __user *) args, sizeof(irq_offset)); if (rc) return -EFAULT; irq_id = ocxl_irq_offset_to_id(ctx, irq_offset); rc = ocxl_afu_irq_free(ctx, irq_id); break; case OCXL_IOCTL_IRQ_SET_FD: rc = copy_from_user(&irq_fd, (u64 __user *) args, sizeof(irq_fd)); if (rc) return -EFAULT; if (irq_fd.reserved) return -EINVAL; irq_id = ocxl_irq_offset_to_id(ctx, irq_fd.irq_offset); ev_ctx = eventfd_ctx_fdget(irq_fd.eventfd); if (IS_ERR(ev_ctx)) return PTR_ERR(ev_ctx); rc = ocxl_irq_set_handler(ctx, irq_id, irq_handler, irq_free, ev_ctx); if (rc) eventfd_ctx_put(ev_ctx); break; case OCXL_IOCTL_GET_METADATA: rc = afu_ioctl_get_metadata(ctx, (struct ocxl_ioctl_metadata __user *) args); break; #ifdef CONFIG_PPC64 case OCXL_IOCTL_ENABLE_P9_WAIT: rc = afu_ioctl_enable_p9_wait(ctx, (struct ocxl_ioctl_p9_wait __user *) args); break; #endif case OCXL_IOCTL_GET_FEATURES: rc = afu_ioctl_get_features(ctx, (struct ocxl_ioctl_features __user *) args); break; default: rc = -EINVAL; } return rc; } static long afu_compat_ioctl(struct file *file, unsigned int cmd, unsigned long args) { return afu_ioctl(file, cmd, args); } static int afu_mmap(struct file *file, struct vm_area_struct *vma) { struct ocxl_context *ctx = file->private_data; pr_debug("%s for context %d\n", __func__, ctx->pasid); return ocxl_context_mmap(ctx, vma); } static bool has_xsl_error(struct ocxl_context *ctx) { bool ret; mutex_lock(&ctx->xsl_error_lock); ret = !!ctx->xsl_error.addr; mutex_unlock(&ctx->xsl_error_lock); return ret; } /* * Are there any events pending on the AFU * ctx: The AFU context * Returns: true if there are events pending */ static bool afu_events_pending(struct ocxl_context *ctx) { if (has_xsl_error(ctx)) return true; return false; } static unsigned int afu_poll(struct file *file, struct poll_table_struct *wait) { struct ocxl_context *ctx = file->private_data; unsigned int mask = 0; bool closed; pr_debug("%s for context %d\n", __func__, ctx->pasid); poll_wait(file, &ctx->events_wq, wait); mutex_lock(&ctx->status_mutex); closed = (ctx->status == CLOSED); mutex_unlock(&ctx->status_mutex); if (afu_events_pending(ctx)) mask = EPOLLIN | EPOLLRDNORM; else if (closed) mask = EPOLLERR; return mask; } /* * Populate the supplied buffer with a single XSL error * ctx: The AFU context to report the error from * header: the event header to populate * buf: The buffer to write the body into (should be at least * AFU_EVENT_BODY_XSL_ERROR_SIZE) * Return: the amount of buffer that was populated */ static ssize_t append_xsl_error(struct ocxl_context *ctx, struct ocxl_kernel_event_header *header, char __user *buf) { struct ocxl_kernel_event_xsl_fault_error body; memset(&body, 0, sizeof(body)); mutex_lock(&ctx->xsl_error_lock); if (!ctx->xsl_error.addr) { mutex_unlock(&ctx->xsl_error_lock); return 0; } body.addr = ctx->xsl_error.addr; body.dsisr = ctx->xsl_error.dsisr; body.count = ctx->xsl_error.count; ctx->xsl_error.addr = 0; ctx->xsl_error.dsisr = 0; ctx->xsl_error.count = 0; mutex_unlock(&ctx->xsl_error_lock); header->type = OCXL_AFU_EVENT_XSL_FAULT_ERROR; if (copy_to_user(buf, &body, sizeof(body))) return -EFAULT; return sizeof(body); } #define AFU_EVENT_BODY_MAX_SIZE sizeof(struct ocxl_kernel_event_xsl_fault_error) /* * Reports events on the AFU * Format: * Header (struct ocxl_kernel_event_header) * Body (struct ocxl_kernel_event_*) * Header... */ static ssize_t afu_read(struct file *file, char __user *buf, size_t count, loff_t *off) { struct ocxl_context *ctx = file->private_data; struct ocxl_kernel_event_header header; ssize_t rc; ssize_t used = 0; DEFINE_WAIT(event_wait); memset(&header, 0, sizeof(header)); /* Require offset to be 0 */ if (*off != 0) return -EINVAL; if (count < (sizeof(struct ocxl_kernel_event_header) + AFU_EVENT_BODY_MAX_SIZE)) return -EINVAL; for (;;) { prepare_to_wait(&ctx->events_wq, &event_wait, TASK_INTERRUPTIBLE); if (afu_events_pending(ctx)) break; if (ctx->status == CLOSED) break; if (file->f_flags & O_NONBLOCK) { finish_wait(&ctx->events_wq, &event_wait); return -EAGAIN; } if (signal_pending(current)) { finish_wait(&ctx->events_wq, &event_wait); return -ERESTARTSYS; } schedule(); } finish_wait(&ctx->events_wq, &event_wait); if (has_xsl_error(ctx)) { used = append_xsl_error(ctx, &header, buf + sizeof(header)); if (used < 0) return used; } if (!afu_events_pending(ctx)) header.flags |= OCXL_KERNEL_EVENT_FLAG_LAST; if (copy_to_user(buf, &header, sizeof(header))) return -EFAULT; used += sizeof(header); rc = used; return rc; } static int afu_release(struct inode *inode, struct file *file) { struct ocxl_context *ctx = file->private_data; int rc; pr_debug("%s for device %x\n", __func__, inode->i_rdev); rc = ocxl_context_detach(ctx); mutex_lock(&ctx->mapping_lock); ctx->mapping = NULL; mutex_unlock(&ctx->mapping_lock); wake_up_all(&ctx->events_wq); if (rc != -EBUSY) ocxl_context_free(ctx); return 0; } static const struct file_operations ocxl_afu_fops = { .owner = THIS_MODULE, .open = afu_open, .unlocked_ioctl = afu_ioctl, .compat_ioctl = afu_compat_ioctl, .mmap = afu_mmap, .poll = afu_poll, .read = afu_read, .release = afu_release, }; // Free the info struct static void info_release(struct device *dev) { struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev); ocxl_afu_put(info->afu); kfree(info); } static int ocxl_file_make_visible(struct ocxl_file_info *info) { int rc; cdev_init(&info->cdev, &ocxl_afu_fops); rc = cdev_add(&info->cdev, info->dev.devt, 1); if (rc) { dev_err(&info->dev, "Unable to add afu char device: %d\n", rc); return rc; } return 0; } static void ocxl_file_make_invisible(struct ocxl_file_info *info) { cdev_del(&info->cdev); } int ocxl_file_register_afu(struct ocxl_afu *afu) { int minor; int rc; struct ocxl_file_info *info; struct ocxl_fn *fn = afu->fn; struct pci_dev *pci_dev = to_pci_dev(fn->dev.parent); info = kzalloc(sizeof(*info), GFP_KERNEL); if (info == NULL) return -ENOMEM; minor = allocate_minor(info); if (minor < 0) { kfree(info); return minor; } info->dev.parent = &fn->dev; info->dev.devt = MKDEV(MAJOR(ocxl_dev), minor); info->dev.class = ocxl_class; info->dev.release = info_release; info->afu = afu; ocxl_afu_get(afu); rc = dev_set_name(&info->dev, "%s.%s.%hhu", afu->config.name, dev_name(&pci_dev->dev), afu->config.idx); if (rc) goto err_put; rc = device_register(&info->dev); if (rc) { free_minor(info); put_device(&info->dev); return rc; } rc = ocxl_sysfs_register_afu(info); if (rc) goto err_unregister; rc = ocxl_file_make_visible(info); if (rc) goto err_unregister; ocxl_afu_set_private(afu, info); return 0; err_unregister: ocxl_sysfs_unregister_afu(info); // safe to call even if register failed free_minor(info); device_unregister(&info->dev); return rc; err_put: ocxl_afu_put(afu); free_minor(info); kfree(info); return rc; } void ocxl_file_unregister_afu(struct ocxl_afu *afu) { struct ocxl_file_info *info = ocxl_afu_get_private(afu); if (!info) return; ocxl_file_make_invisible(info); ocxl_sysfs_unregister_afu(info); free_minor(info); device_unregister(&info->dev); } static char *ocxl_devnode(const struct device *dev, umode_t *mode) { return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev)); } int ocxl_file_init(void) { int rc; idr_init(&minors_idr); rc = alloc_chrdev_region(&ocxl_dev, 0, OCXL_NUM_MINORS, "ocxl"); if (rc) { pr_err("Unable to allocate ocxl major number: %d\n", rc); return rc; } ocxl_class = class_create(THIS_MODULE, "ocxl"); if (IS_ERR(ocxl_class)) { pr_err("Unable to create ocxl class\n"); unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); return PTR_ERR(ocxl_class); } ocxl_class->devnode = ocxl_devnode; return 0; } void ocxl_file_exit(void) { class_destroy(ocxl_class); unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); idr_destroy(&minors_idr); }