diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/misc/ocxl/file.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/misc/ocxl/file.c')
| -rw-r--r-- | drivers/misc/ocxl/file.c | 623 |
1 files changed, 623 insertions, 0 deletions
diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c new file mode 100644 index 000000000..1abbde33e --- /dev/null +++ b/drivers/misc/ocxl/file.c @@ -0,0 +1,623 @@ +// 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 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); + 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); +} + +static char *ocxl_devnode(const struct device *dev, umode_t *mode) +{ + return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev)); +} + +static const struct class ocxl_class = { + .name = "ocxl", + .devnode = ocxl_devnode, +}; + +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_obj(*info); + 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); +} + +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; + } + + rc = class_register(&ocxl_class); + if (rc) { + pr_err("Unable to create ocxl class\n"); + unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); + return rc; + } + + return 0; +} + +void ocxl_file_exit(void) +{ + class_unregister(&ocxl_class); + unregister_chrdev_region(ocxl_dev, OCXL_NUM_MINORS); + idr_destroy(&minors_idr); +} |
