diff options
| -rw-r--r-- | drivers/dma/idxd/cdev.c | 107 | ||||
| -rw-r--r-- | drivers/dma/idxd/idxd.h | 6 | ||||
| -rw-r--r-- | drivers/dma/idxd/init.c | 2 | ||||
| -rw-r--r-- | drivers/dma/idxd/sysfs.c | 1 |
4 files changed, 111 insertions, 5 deletions
diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index cbe29e1a6a44..8b8a0a0fb054 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -11,7 +11,9 @@ #include <linux/fs.h> #include <linux/poll.h> #include <linux/iommu.h> +#include <linux/highmem.h> #include <uapi/linux/idxd.h> +#include <linux/xarray.h> #include "registers.h" #include "idxd.h" @@ -34,6 +36,7 @@ struct idxd_user_context { struct idxd_wq *wq; struct task_struct *task; unsigned int pasid; + struct mm_struct *mm; unsigned int flags; struct iommu_sva *sva; }; @@ -68,6 +71,19 @@ static inline struct idxd_wq *inode_wq(struct inode *inode) return idxd_cdev->wq; } +static void idxd_xa_pasid_remove(struct idxd_user_context *ctx) +{ + struct idxd_wq *wq = ctx->wq; + void *ptr; + + mutex_lock(&wq->uc_lock); + ptr = xa_cmpxchg(&wq->upasid_xa, ctx->pasid, ctx, NULL, GFP_KERNEL); + if (ptr != (void *)ctx) + dev_warn(&wq->idxd->pdev->dev, "xarray cmpxchg failed for pasid %u\n", + ctx->pasid); + mutex_unlock(&wq->uc_lock); +} + static int idxd_cdev_open(struct inode *inode, struct file *filp) { struct idxd_user_context *ctx; @@ -108,20 +124,26 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) pasid = iommu_sva_get_pasid(sva); if (pasid == IOMMU_PASID_INVALID) { - iommu_sva_unbind_device(sva); rc = -EINVAL; - goto failed; + goto failed_get_pasid; } ctx->sva = sva; ctx->pasid = pasid; + ctx->mm = current->mm; + + mutex_lock(&wq->uc_lock); + rc = xa_insert(&wq->upasid_xa, pasid, ctx, GFP_KERNEL); + mutex_unlock(&wq->uc_lock); + if (rc < 0) + dev_warn(dev, "PASID entry already exist in xarray.\n"); if (wq_dedicated(wq)) { rc = idxd_wq_set_pasid(wq, pasid); if (rc < 0) { iommu_sva_unbind_device(sva); dev_err(dev, "wq set pasid failed: %d\n", rc); - goto failed; + goto failed_set_pasid; } } } @@ -130,7 +152,13 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) mutex_unlock(&wq->wq_lock); return 0; - failed: +failed_set_pasid: + if (device_user_pasid_enabled(idxd)) + idxd_xa_pasid_remove(ctx); +failed_get_pasid: + if (device_user_pasid_enabled(idxd)) + iommu_sva_unbind_device(sva); +failed: mutex_unlock(&wq->wq_lock); kfree(ctx); return rc; @@ -161,8 +189,10 @@ static int idxd_cdev_release(struct inode *node, struct file *filep) } } - if (ctx->sva) + if (ctx->sva) { iommu_sva_unbind_device(ctx->sva); + idxd_xa_pasid_remove(ctx); + } kfree(ctx); mutex_lock(&wq->wq_lock); idxd_wq_put(wq); @@ -418,3 +448,70 @@ void idxd_cdev_remove(void) ida_destroy(&ictx[i].minor_ida); } } + +/** + * idxd_copy_cr - copy completion record to user address space found by wq and + * PASID + * @wq: work queue + * @pasid: PASID + * @addr: user fault address to write + * @cr: completion record + * @len: number of bytes to copy + * + * This is called by a work that handles completion record fault. + * + * Return: number of bytes copied. + */ +int idxd_copy_cr(struct idxd_wq *wq, ioasid_t pasid, unsigned long addr, + void *cr, int len) +{ + struct device *dev = &wq->idxd->pdev->dev; + int left = len, status_size = 1; + struct idxd_user_context *ctx; + struct mm_struct *mm; + + mutex_lock(&wq->uc_lock); + + ctx = xa_load(&wq->upasid_xa, pasid); + if (!ctx) { + dev_warn(dev, "No user context\n"); + goto out; + } + + mm = ctx->mm; + /* + * The completion record fault handling work is running in kernel + * thread context. It temporarily switches to the mm to copy cr + * to addr in the mm. + */ + kthread_use_mm(mm); + left = copy_to_user((void __user *)addr + status_size, cr + status_size, + len - status_size); + /* + * Copy status only after the rest of completion record is copied + * successfully so that the user gets the complete completion record + * when a non-zero status is polled. + */ + if (!left) { + u8 status; + + /* + * Ensure that the completion record's status field is written + * after the rest of the completion record has been written. + * This ensures that the user receives the correct completion + * record information once polling for a non-zero status. + */ + wmb(); + status = *(u8 *)cr; + if (put_user(status, (u8 __user *)addr)) + left += status_size; + } else { + left += status_size; + } + kthread_unuse_mm(mm); + +out: + mutex_unlock(&wq->uc_lock); + + return len - left; +} diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index c5d99c179902..b3f9a12adce2 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -215,6 +215,10 @@ struct idxd_wq { char name[WQ_NAME_SIZE + 1]; u64 max_xfer_bytes; u32 max_batch_size; + + /* Lock to protect upasid_xa access. */ + struct mutex uc_lock; + struct xarray upasid_xa; }; struct idxd_engine { @@ -702,6 +706,8 @@ void idxd_cdev_remove(void); int idxd_cdev_get_major(struct idxd_device *idxd); int idxd_wq_add_cdev(struct idxd_wq *wq); void idxd_wq_del_cdev(struct idxd_wq *wq); +int idxd_copy_cr(struct idxd_wq *wq, ioasid_t pasid, unsigned long addr, + void *buf, int len); /* perfmon */ #if IS_ENABLED(CONFIG_INTEL_IDXD_PERFMON) diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 7828ac2d31aa..e6faff58733d 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -199,6 +199,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd) } bitmap_copy(wq->opcap_bmap, idxd->opcap_bmap, IDXD_MAX_OPCAP_BITS); } + mutex_init(&wq->uc_lock); + xa_init(&wq->upasid_xa); idxd->wqs[i] = wq; } diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index 8b9dfa0d2b99..465d2e7627e4 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1292,6 +1292,7 @@ static void idxd_conf_wq_release(struct device *dev) bitmap_free(wq->opcap_bmap); kfree(wq->wqcfg); + xa_destroy(&wq->upasid_xa); kfree(wq); } |