123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541 |
- // 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/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 struct mutex minors_idr_lock;
- static struct idr minors_idr;
- static struct ocxl_afu *find_and_get_afu(dev_t devno)
- {
- struct ocxl_afu *afu;
- int afu_minor;
- afu_minor = MINOR(devno);
- /*
- * We don't declare an RCU critical section here, as our AFU
- * is protected by a reference counter on the device. By the time the
- * minor number of a device is removed from the idr, the ref count of
- * the device is already at 0, so no user API will access that AFU and
- * this function can't return it.
- */
- afu = idr_find(&minors_idr, afu_minor);
- if (afu)
- ocxl_afu_get(afu);
- return afu;
- }
- static int allocate_afu_minor(struct ocxl_afu *afu)
- {
- int minor;
- mutex_lock(&minors_idr_lock);
- minor = idr_alloc(&minors_idr, afu, 0, OCXL_NUM_MINORS, GFP_KERNEL);
- mutex_unlock(&minors_idr_lock);
- return minor;
- }
- static void free_afu_minor(struct ocxl_afu *afu)
- {
- mutex_lock(&minors_idr_lock);
- idr_remove(&minors_idr, MINOR(afu->dev.devt));
- mutex_unlock(&minors_idr_lock);
- }
- static int afu_open(struct inode *inode, struct file *file)
- {
- struct ocxl_afu *afu;
- struct ocxl_context *ctx;
- int rc;
- pr_debug("%s for device %x\n", __func__, inode->i_rdev);
- afu = find_and_get_afu(inode->i_rdev);
- if (!afu)
- return -ENODEV;
- ctx = ocxl_context_alloc();
- if (!ctx) {
- rc = -ENOMEM;
- goto put_afu;
- }
- rc = ocxl_context_init(ctx, afu, inode->i_mapping);
- if (rc)
- goto put_afu;
- file->private_data = ctx;
- ocxl_afu_put(afu);
- return 0;
- put_afu:
- ocxl_afu_put(afu);
- return rc;
- }
- static long afu_ioctl_attach(struct ocxl_context *ctx,
- struct ocxl_ioctl_attach __user *uarg)
- {
- struct ocxl_ioctl_attach arg;
- u64 amr = 0;
- int rc;
- 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);
- rc = ocxl_context_attach(ctx, amr);
- return rc;
- }
- 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;
- struct link *link = ctx->afu->fn->link;
- rc = ocxl_link_update_pe(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 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;
- u64 irq_offset;
- long rc;
- pr_debug("%s for context %d, command %s\n", __func__, ctx->pasid,
- CMD_STR(cmd));
- if (ctx->status == 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_offset);
- if (!rc) {
- rc = copy_to_user((u64 __user *) args, &irq_offset,
- sizeof(irq_offset));
- if (rc) {
- ocxl_afu_irq_free(ctx, irq_offset);
- return -EFAULT;
- }
- }
- break;
- case OCXL_IOCTL_IRQ_FREE:
- rc = copy_from_user(&irq_offset, (u64 __user *) args,
- sizeof(irq_offset));
- if (rc)
- return -EFAULT;
- rc = ocxl_afu_irq_free(ctx, irq_offset);
- 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;
- rc = ocxl_afu_irq_set_fd(ctx, irq_fd.irq_offset,
- irq_fd.eventfd);
- 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,
- };
- int ocxl_create_cdev(struct ocxl_afu *afu)
- {
- int rc;
- cdev_init(&afu->cdev, &ocxl_afu_fops);
- rc = cdev_add(&afu->cdev, afu->dev.devt, 1);
- if (rc) {
- dev_err(&afu->dev, "Unable to add afu char device: %d\n", rc);
- return rc;
- }
- return 0;
- }
- void ocxl_destroy_cdev(struct ocxl_afu *afu)
- {
- cdev_del(&afu->cdev);
- }
- int ocxl_register_afu(struct ocxl_afu *afu)
- {
- int minor;
- minor = allocate_afu_minor(afu);
- if (minor < 0)
- return minor;
- afu->dev.devt = MKDEV(MAJOR(ocxl_dev), minor);
- afu->dev.class = ocxl_class;
- return device_register(&afu->dev);
- }
- void ocxl_unregister_afu(struct ocxl_afu *afu)
- {
- free_afu_minor(afu);
- }
- static char *ocxl_devnode(struct device *dev, umode_t *mode)
- {
- return kasprintf(GFP_KERNEL, "ocxl/%s", dev_name(dev));
- }
- int ocxl_file_init(void)
- {
- int rc;
- mutex_init(&minors_idr_lock);
- 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);
- }
|