From c74be58b7b3a8f5d3082ecc02af82bfc758cdd84 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 15 Apr 2021 16:37:57 -0700 Subject: [PATCH] dmaengine: idxd: fix cdev setup and free device lifetime issues The char device setup and cleanup has device lifetime issues regarding when parts are initialized and cleaned up. The initialization of struct device is done incorrectly. device_initialize() needs to be called on the 'struct device' and then additional changes can be added. The ->release() function needs to be setup via device_type before dev_set_name() to allow proper cleanup. The change re-parents the cdev under the wq->conf_dev to get natural reference inheritance. No known dependency on the old device path exists. Reported-by: Jason Gunthorpe Fixes: dfcb650c7779 ("dmaengine: idxd: add char driver to expose submission portal to userland") Signed-off-by: Dave Jiang Reviewed-by: Dan Williams Link: https://lore.kernel.org/r/161852987721.2203940.1478218825576630810.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul --- drivers/dma/idxd/cdev.c | 129 ++++++++++++++------------------------- drivers/dma/idxd/idxd.h | 7 ++- drivers/dma/idxd/init.c | 2 +- drivers/dma/idxd/irq.c | 4 +- drivers/dma/idxd/sysfs.c | 10 ++- 5 files changed, 63 insertions(+), 89 deletions(-) diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 0db9b82ed8cf5..1d8a3876b7452 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -39,15 +39,15 @@ struct idxd_user_context { struct iommu_sva *sva; }; -enum idxd_cdev_cleanup { - CDEV_NORMAL = 0, - CDEV_FAILED, -}; - static void idxd_cdev_dev_release(struct device *dev) { - dev_dbg(dev, "releasing cdev device\n"); - kfree(dev); + struct idxd_cdev *idxd_cdev = container_of(dev, struct idxd_cdev, dev); + struct idxd_cdev_context *cdev_ctx; + struct idxd_wq *wq = idxd_cdev->wq; + + cdev_ctx = &ictx[wq->idxd->type]; + ida_simple_remove(&cdev_ctx->minor_ida, idxd_cdev->minor); + kfree(idxd_cdev); } static struct device_type idxd_cdev_device_type = { @@ -62,14 +62,11 @@ static inline struct idxd_cdev *inode_idxd_cdev(struct inode *inode) return container_of(cdev, struct idxd_cdev, cdev); } -static inline struct idxd_wq *idxd_cdev_wq(struct idxd_cdev *idxd_cdev) -{ - return container_of(idxd_cdev, struct idxd_wq, idxd_cdev); -} - static inline struct idxd_wq *inode_wq(struct inode *inode) { - return idxd_cdev_wq(inode_idxd_cdev(inode)); + struct idxd_cdev *idxd_cdev = inode_idxd_cdev(inode); + + return idxd_cdev->wq; } static int idxd_cdev_open(struct inode *inode, struct file *filp) @@ -220,11 +217,10 @@ static __poll_t idxd_cdev_poll(struct file *filp, struct idxd_user_context *ctx = filp->private_data; struct idxd_wq *wq = ctx->wq; struct idxd_device *idxd = wq->idxd; - struct idxd_cdev *idxd_cdev = &wq->idxd_cdev; unsigned long flags; __poll_t out = 0; - poll_wait(filp, &idxd_cdev->err_queue, wait); + poll_wait(filp, &wq->err_queue, wait); spin_lock_irqsave(&idxd->dev_lock, flags); if (idxd->sw_err.valid) out = EPOLLIN | EPOLLRDNORM; @@ -246,98 +242,67 @@ int idxd_cdev_get_major(struct idxd_device *idxd) return MAJOR(ictx[idxd->type].devt); } -static int idxd_wq_cdev_dev_setup(struct idxd_wq *wq) +int idxd_wq_add_cdev(struct idxd_wq *wq) { struct idxd_device *idxd = wq->idxd; - struct idxd_cdev *idxd_cdev = &wq->idxd_cdev; - struct idxd_cdev_context *cdev_ctx; + struct idxd_cdev *idxd_cdev; + struct cdev *cdev; struct device *dev; - int minor, rc; + struct idxd_cdev_context *cdev_ctx; + int rc, minor; - idxd_cdev->dev = kzalloc(sizeof(*idxd_cdev->dev), GFP_KERNEL); - if (!idxd_cdev->dev) + idxd_cdev = kzalloc(sizeof(*idxd_cdev), GFP_KERNEL); + if (!idxd_cdev) return -ENOMEM; - dev = idxd_cdev->dev; - dev->parent = &idxd->pdev->dev; - dev_set_name(dev, "%s/wq%u.%u", idxd_get_dev_name(idxd), - idxd->id, wq->id); - dev->bus = idxd_get_bus_type(idxd); - + idxd_cdev->wq = wq; + cdev = &idxd_cdev->cdev; + dev = &idxd_cdev->dev; cdev_ctx = &ictx[wq->idxd->type]; minor = ida_simple_get(&cdev_ctx->minor_ida, 0, MINORMASK, GFP_KERNEL); if (minor < 0) { - rc = minor; - kfree(dev); - goto ida_err; - } - - dev->devt = MKDEV(MAJOR(cdev_ctx->devt), minor); - dev->type = &idxd_cdev_device_type; - rc = device_register(dev); - if (rc < 0) { - dev_err(&idxd->pdev->dev, "device register failed\n"); - goto dev_reg_err; + kfree(idxd_cdev); + return minor; } idxd_cdev->minor = minor; - return 0; - - dev_reg_err: - ida_simple_remove(&cdev_ctx->minor_ida, MINOR(dev->devt)); - put_device(dev); - ida_err: - idxd_cdev->dev = NULL; - return rc; -} - -static void idxd_wq_cdev_cleanup(struct idxd_wq *wq, - enum idxd_cdev_cleanup cdev_state) -{ - struct idxd_cdev *idxd_cdev = &wq->idxd_cdev; - struct idxd_cdev_context *cdev_ctx; - - cdev_ctx = &ictx[wq->idxd->type]; - if (cdev_state == CDEV_NORMAL) - cdev_del(&idxd_cdev->cdev); - device_unregister(idxd_cdev->dev); - /* - * The device_type->release() will be called on the device and free - * the allocated struct device. We can just forget it. - */ - ida_simple_remove(&cdev_ctx->minor_ida, idxd_cdev->minor); - idxd_cdev->dev = NULL; - idxd_cdev->minor = -1; -} - -int idxd_wq_add_cdev(struct idxd_wq *wq) -{ - struct idxd_cdev *idxd_cdev = &wq->idxd_cdev; - struct cdev *cdev = &idxd_cdev->cdev; - struct device *dev; - int rc; + device_initialize(dev); + dev->parent = &wq->conf_dev; + dev->bus = idxd_get_bus_type(idxd); + dev->type = &idxd_cdev_device_type; + dev->devt = MKDEV(MAJOR(cdev_ctx->devt), minor); - rc = idxd_wq_cdev_dev_setup(wq); + rc = dev_set_name(dev, "%s/wq%u.%u", idxd_get_dev_name(idxd), + idxd->id, wq->id); if (rc < 0) - return rc; + goto err; - dev = idxd_cdev->dev; + wq->idxd_cdev = idxd_cdev; cdev_init(cdev, &idxd_cdev_fops); - cdev_set_parent(cdev, &dev->kobj); - rc = cdev_add(cdev, dev->devt, 1); + rc = cdev_device_add(cdev, dev); if (rc) { dev_dbg(&wq->idxd->pdev->dev, "cdev_add failed: %d\n", rc); - idxd_wq_cdev_cleanup(wq, CDEV_FAILED); - return rc; + goto err; } - init_waitqueue_head(&idxd_cdev->err_queue); return 0; + + err: + put_device(dev); + wq->idxd_cdev = NULL; + return rc; } void idxd_wq_del_cdev(struct idxd_wq *wq) { - idxd_wq_cdev_cleanup(wq, CDEV_NORMAL); + struct idxd_cdev *idxd_cdev; + struct idxd_cdev_context *cdev_ctx; + + cdev_ctx = &ictx[wq->idxd->type]; + idxd_cdev = wq->idxd_cdev; + wq->idxd_cdev = NULL; + cdev_device_del(&idxd_cdev->cdev, &idxd_cdev->dev); + put_device(&idxd_cdev->dev); } int idxd_cdev_register(void) diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index 3c4ce7997c887..89daf746d1215 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -80,10 +80,10 @@ enum idxd_wq_type { }; struct idxd_cdev { + struct idxd_wq *wq; struct cdev cdev; - struct device *dev; + struct device dev; int minor; - struct wait_queue_head err_queue; }; #define IDXD_ALLOCATED_BATCH_SIZE 128U @@ -109,7 +109,8 @@ struct idxd_dma_chan { struct idxd_wq { void __iomem *portal; struct device conf_dev; - struct idxd_cdev idxd_cdev; + struct idxd_cdev *idxd_cdev; + struct wait_queue_head err_queue; struct idxd_device *idxd; int id; enum idxd_wq_type type; diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index c20ea6bf09bf8..07cf7977a0450 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -176,7 +176,7 @@ static int idxd_setup_wqs(struct idxd_device *idxd) } mutex_init(&wq->wq_lock); - wq->idxd_cdev.minor = -1; + init_waitqueue_head(&wq->err_queue); wq->max_xfer_bytes = idxd->max_xfer_bytes; wq->max_batch_size = idxd->max_batch_size; wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev)); diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c index 7b0181532f770..fc0781e3f36d4 100644 --- a/drivers/dma/idxd/irq.c +++ b/drivers/dma/idxd/irq.c @@ -133,7 +133,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause) struct idxd_wq *wq = idxd->wqs[id]; if (wq->type == IDXD_WQT_USER) - wake_up_interruptible(&wq->idxd_cdev.err_queue); + wake_up_interruptible(&wq->err_queue); } else { int i; @@ -141,7 +141,7 @@ static int process_misc_interrupts(struct idxd_device *idxd, u32 cause) struct idxd_wq *wq = idxd->wqs[i]; if (wq->type == IDXD_WQT_USER) - wake_up_interruptible(&wq->idxd_cdev.err_queue); + wake_up_interruptible(&wq->err_queue); } } diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c index f793688039c98..9586b55abce56 100644 --- a/drivers/dma/idxd/sysfs.c +++ b/drivers/dma/idxd/sysfs.c @@ -1169,8 +1169,16 @@ static ssize_t wq_cdev_minor_show(struct device *dev, struct device_attribute *attr, char *buf) { struct idxd_wq *wq = container_of(dev, struct idxd_wq, conf_dev); + int minor = -1; - return sprintf(buf, "%d\n", wq->idxd_cdev.minor); + mutex_lock(&wq->wq_lock); + if (wq->idxd_cdev) + minor = wq->idxd_cdev->minor; + mutex_unlock(&wq->wq_lock); + + if (minor == -1) + return -ENXIO; + return sysfs_emit(buf, "%d\n", minor); } static struct device_attribute dev_attr_wq_cdev_minor = -- 2.39.5