From c0c3c89ae34764890c2294dc4ddf055940b64c36 Mon Sep 17 00:00:00 2001 From: Steffen Trumtrar Date: Mon, 1 Dec 2014 13:26:33 +0100 Subject: [PATCH] crypto: sahara - replace tasklets with kthread In preparation for SHA support, replace the tasklets with a kthread that manages one crypto_queue for the core. As the Sahara can only process one AES or SHA request at a time, we make sure that the queue serializes all requests from userspace. Instead of a watchdog timer we now use a completion mechanism in the queue manager thread. This makes the control flow more obvious and guarantees, that only one request is dequeued until the completion is completed. Signed-off-by: Steffen Trumtrar Signed-off-by: Herbert Xu --- drivers/crypto/sahara.c | 154 +++++++++++++++++----------------------- 1 file changed, 67 insertions(+), 87 deletions(-) diff --git a/drivers/crypto/sahara.c b/drivers/crypto/sahara.c index 55c0d2bea426..04d3b4309e4c 100644 --- a/drivers/crypto/sahara.c +++ b/drivers/crypto/sahara.c @@ -22,7 +22,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -38,7 +40,6 @@ #define FLAGS_ENCRYPT BIT(0) #define FLAGS_CBC BIT(1) #define FLAGS_NEW_KEY BIT(3) -#define FLAGS_BUSY 4 #define SAHARA_HDR_BASE 0x00800000 #define SAHARA_HDR_SKHA_ALG_AES 0 @@ -119,7 +120,6 @@ struct sahara_hw_link { }; struct sahara_ctx { - struct sahara_dev *dev; unsigned long flags; int keylen; u8 key[AES_KEYSIZE_128]; @@ -136,15 +136,15 @@ struct sahara_dev { void __iomem *regs_base; struct clk *clk_ipg; struct clk *clk_ahb; + struct mutex queue_mutex; + struct task_struct *kthread; + struct completion dma_completion; struct sahara_ctx *ctx; spinlock_t lock; struct crypto_queue queue; unsigned long flags; - struct tasklet_struct done_task; - struct tasklet_struct queue_task; - struct sahara_hw_desc *hw_desc[SAHARA_MAX_HW_DESC]; dma_addr_t hw_phys_desc[SAHARA_MAX_HW_DESC]; @@ -157,7 +157,6 @@ struct sahara_dev { struct sahara_hw_link *hw_link[SAHARA_MAX_HW_LINK]; dma_addr_t hw_phys_link[SAHARA_MAX_HW_LINK]; - struct ablkcipher_request *req; size_t total; struct scatterlist *in_sg; unsigned int nb_in_sg; @@ -165,7 +164,6 @@ struct sahara_dev { unsigned int nb_out_sg; u32 error; - struct timer_list watchdog; }; static struct sahara_dev *dev_ptr; @@ -404,34 +402,6 @@ static void sahara_dump_links(struct sahara_dev *dev) dev_dbg(dev->device, "\n"); } -static void sahara_aes_done_task(unsigned long data) -{ - struct sahara_dev *dev = (struct sahara_dev *)data; - - dma_unmap_sg(dev->device, dev->out_sg, dev->nb_out_sg, - DMA_TO_DEVICE); - dma_unmap_sg(dev->device, dev->in_sg, dev->nb_in_sg, - DMA_FROM_DEVICE); - - spin_lock(&dev->lock); - clear_bit(FLAGS_BUSY, &dev->flags); - spin_unlock(&dev->lock); - - dev->req->base.complete(&dev->req->base, dev->error); -} - -static void sahara_watchdog(unsigned long data) -{ - struct sahara_dev *dev = (struct sahara_dev *)data; - unsigned int err = sahara_read(dev, SAHARA_REG_ERRSTATUS); - unsigned int stat = sahara_read(dev, SAHARA_REG_STATUS); - - sahara_decode_status(dev, stat); - sahara_decode_error(dev, err); - dev->error = -ETIMEDOUT; - sahara_aes_done_task(data); -} - static int sahara_hw_descriptor_create(struct sahara_dev *dev) { struct sahara_ctx *ctx = dev->ctx; @@ -515,9 +485,6 @@ static int sahara_hw_descriptor_create(struct sahara_dev *dev) sahara_dump_descriptors(dev); sahara_dump_links(dev); - /* Start processing descriptor chain. */ - mod_timer(&dev->watchdog, - jiffies + msecs_to_jiffies(SAHARA_TIMEOUT_MS)); sahara_write(dev, dev->hw_phys_desc[0], SAHARA_REG_DAR); return 0; @@ -532,37 +499,19 @@ static int sahara_hw_descriptor_create(struct sahara_dev *dev) return -EINVAL; } -static void sahara_aes_queue_task(unsigned long data) +static int sahara_aes_process(struct ablkcipher_request *req) { - struct sahara_dev *dev = (struct sahara_dev *)data; - struct crypto_async_request *async_req, *backlog; + struct sahara_dev *dev = dev_ptr; struct sahara_ctx *ctx; struct sahara_aes_reqctx *rctx; - struct ablkcipher_request *req; int ret; - spin_lock(&dev->lock); - backlog = crypto_get_backlog(&dev->queue); - async_req = crypto_dequeue_request(&dev->queue); - if (!async_req) - clear_bit(FLAGS_BUSY, &dev->flags); - spin_unlock(&dev->lock); - - if (!async_req) - return; - - if (backlog) - backlog->complete(backlog, -EINPROGRESS); - - req = ablkcipher_request_cast(async_req); - /* Request is ready to be dispatched by the device */ dev_dbg(dev->device, "dispatch request (nbytes=%d, src=%p, dst=%p)\n", req->nbytes, req->src, req->dst); /* assign new request to device */ - dev->req = req; dev->total = req->nbytes; dev->in_sg = req->src; dev->out_sg = req->dst; @@ -576,16 +525,25 @@ static void sahara_aes_queue_task(unsigned long data) memcpy(dev->iv_base, req->info, AES_KEYSIZE_128); /* assign new context to device */ - ctx->dev = dev; dev->ctx = ctx; + reinit_completion(&dev->dma_completion); + ret = sahara_hw_descriptor_create(dev); - if (ret < 0) { - spin_lock(&dev->lock); - clear_bit(FLAGS_BUSY, &dev->flags); - spin_unlock(&dev->lock); - dev->req->base.complete(&dev->req->base, ret); + + ret = wait_for_completion_timeout(&dev->dma_completion, + msecs_to_jiffies(SAHARA_TIMEOUT_MS)); + if (!ret) { + dev_err(dev->device, "AES timeout\n"); + return -ETIMEDOUT; } + + dma_unmap_sg(dev->device, dev->out_sg, dev->nb_out_sg, + DMA_TO_DEVICE); + dma_unmap_sg(dev->device, dev->in_sg, dev->nb_in_sg, + DMA_FROM_DEVICE); + + return 0; } static int sahara_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key, @@ -627,12 +585,9 @@ static int sahara_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key, static int sahara_aes_crypt(struct ablkcipher_request *req, unsigned long mode) { - struct sahara_ctx *ctx = crypto_ablkcipher_ctx( - crypto_ablkcipher_reqtfm(req)); struct sahara_aes_reqctx *rctx = ablkcipher_request_ctx(req); struct sahara_dev *dev = dev_ptr; int err = 0; - int busy; dev_dbg(dev->device, "nbytes: %d, enc: %d, cbc: %d\n", req->nbytes, !!(mode & FLAGS_ENCRYPT), !!(mode & FLAGS_CBC)); @@ -643,16 +598,13 @@ static int sahara_aes_crypt(struct ablkcipher_request *req, unsigned long mode) return -EINVAL; } - ctx->dev = dev; - rctx->mode = mode; - spin_lock_bh(&dev->lock); - err = ablkcipher_enqueue_request(&dev->queue, req); - busy = test_and_set_bit(FLAGS_BUSY, &dev->flags); - spin_unlock_bh(&dev->lock); - if (!busy) - tasklet_schedule(&dev->queue_task); + mutex_lock(&dev->queue_mutex); + err = ablkcipher_enqueue_request(&dev->queue, req); + mutex_unlock(&dev->queue_mutex); + + wake_up_process(dev->kthread); return err; } @@ -755,6 +707,36 @@ static void sahara_aes_cra_exit(struct crypto_tfm *tfm) ctx->fallback = NULL; } +static int sahara_queue_manage(void *data) +{ + struct sahara_dev *dev = (struct sahara_dev *)data; + struct crypto_async_request *async_req; + int ret = 0; + + do { + __set_current_state(TASK_INTERRUPTIBLE); + + mutex_lock(&dev->queue_mutex); + async_req = crypto_dequeue_request(&dev->queue); + mutex_unlock(&dev->queue_mutex); + + if (async_req) { + struct ablkcipher_request *req = + ablkcipher_request_cast(async_req); + + ret = sahara_aes_process(req); + + async_req->complete(async_req, ret); + + continue; + } + + schedule(); + } while (!kthread_should_stop()); + + return 0; +} + static struct crypto_alg aes_algs[] = { { .cra_name = "ecb(aes)", @@ -806,8 +788,6 @@ static irqreturn_t sahara_irq_handler(int irq, void *data) unsigned int stat = sahara_read(dev, SAHARA_REG_STATUS); unsigned int err = sahara_read(dev, SAHARA_REG_ERRSTATUS); - del_timer(&dev->watchdog); - sahara_write(dev, SAHARA_CMD_CLEAR_INT | SAHARA_CMD_CLEAR_ERR, SAHARA_REG_CMD); @@ -822,7 +802,7 @@ static irqreturn_t sahara_irq_handler(int irq, void *data) dev->error = -EINVAL; } - tasklet_schedule(&dev->done_task); + complete(&dev->dma_completion); return IRQ_HANDLED; } @@ -961,17 +941,17 @@ static int sahara_probe(struct platform_device *pdev) crypto_init_queue(&dev->queue, SAHARA_QUEUE_LENGTH); spin_lock_init(&dev->lock); + mutex_init(&dev->queue_mutex); dev_ptr = dev; - tasklet_init(&dev->queue_task, sahara_aes_queue_task, - (unsigned long)dev); - tasklet_init(&dev->done_task, sahara_aes_done_task, - (unsigned long)dev); + dev->kthread = kthread_run(sahara_queue_manage, dev, "sahara_crypto"); + if (IS_ERR(dev->kthread)) { + err = PTR_ERR(dev->kthread); + goto err_link; + } - init_timer(&dev->watchdog); - dev->watchdog.function = &sahara_watchdog; - dev->watchdog.data = (unsigned long)dev; + init_completion(&dev->dma_completion); clk_prepare_enable(dev->clk_ipg); clk_prepare_enable(dev->clk_ahb); @@ -1016,6 +996,7 @@ static int sahara_probe(struct platform_device *pdev) dev->hw_link[0], dev->hw_phys_link[0]); clk_disable_unprepare(dev->clk_ipg); clk_disable_unprepare(dev->clk_ahb); + kthread_stop(dev->kthread); dev_ptr = NULL; err_link: dma_free_coherent(&pdev->dev, @@ -1043,8 +1024,7 @@ static int sahara_remove(struct platform_device *pdev) SAHARA_MAX_HW_DESC * sizeof(struct sahara_hw_desc), dev->hw_desc[0], dev->hw_phys_desc[0]); - tasklet_kill(&dev->done_task); - tasklet_kill(&dev->queue_task); + kthread_stop(dev->kthread); sahara_unregister_algs(dev);