Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752599AbcDVMPq (ORCPT ); Fri, 22 Apr 2016 08:15:46 -0400 Received: from mailout4.w1.samsung.com ([210.118.77.14]:9619 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752324AbcDVMPd (ORCPT ); Fri, 22 Apr 2016 08:15:33 -0400 X-AuditID: cbfec7f4-f796c6d000001486-ff-571a15e19342 From: Krzysztof Kozlowski To: Herbert Xu , "David S. Miller" , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Vladimir Zapolskiy , Krzysztof Kozlowski , stable@vger.kernel.org, Bartlomiej Zolnierkiewicz Subject: [PATCH 2/2] crypto: s5p-sss - Fix missed interrupts when working with 8 kB blocks Date: Fri, 22 Apr 2016 14:15:23 +0200 Message-id: <1461327323-23288-2-git-send-email-k.kozlowski@samsung.com> X-Mailer: git-send-email 1.9.1 In-reply-to: <1461327323-23288-1-git-send-email-k.kozlowski@samsung.com> References: <1461327323-23288-1-git-send-email-k.kozlowski@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprBLMWRmVeSWpSXmKPExsVy+t/xy7oPRaXCDbadl7HYOGM9q8Wc8y0s Ft2vZCxevzC0uH/vJ5PF5V1z2CwWbHzEaPH/VzOzA4fHlpU3mTy2HVD1+LdwCotH35ZVjB6f N8kFsEZx2aSk5mSWpRbp2yVwZUxtvMNccEO/4vvGj8wNjA3qXYycHBICJhLte1ewQNhiEhfu rWfrYuTiEBJYyijx8PtdVginkUmis+s0O0gVm4CxxOblS8CqRASmMkp8vn6CGcRhFljGKHF2 yjywWcICMRJ9xzqZQWwWAVWJbRe3g9m8Au4SK/6sY4TYJydx8thkVhCbU8BDomfpR7C4EFDN 2sP72Ccw8i5gZFjFKJpamlxQnJSea6hXnJhbXJqXrpecn7uJERJeX3YwLj5mdYhRgINRiYf3 Q4NkuBBrYllxZe4hRgkOZiUR3pWCUuFCvCmJlVWpRfnxRaU5qcWHGKU5WJTEeefueh8iJJCe WJKanZpakFoEk2Xi4JRqYGx+7l7yX/+rqP+3sPWHrjzZV2HDpqO1ZHWo5pM/hYeeljp8WuCm 9lF5Jp/XgW1VrzjNr3+Zrbm3cUPN/BVHTwSa/Hi8VnDKmhm7N/5zz+SZMWvJDh+rB7M/T/bu 1D/Vax7y/Gn3/HL+dBalaWsUE+R0QqWqSuZMeBKXOfnfncvs04UXB4kGOvxTYinOSDTUYi4q TgQAqLb5yisCAAA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5933 Lines: 169 The tcrypt testing module on Exynos5422-based Odroid XU3/4 board failed on testing 8 kB size blocks: $ sudo modprobe tcrypt sec=1 mode=500 testing speed of async ecb(aes) (ecb-aes-s5p) encryption test 0 (128 bit key, 16 byte blocks): 21971 operations in 1 seconds (351536 bytes) test 1 (128 bit key, 64 byte blocks): 21731 operations in 1 seconds (1390784 bytes) test 2 (128 bit key, 256 byte blocks): 21932 operations in 1 seconds (5614592 bytes) test 3 (128 bit key, 1024 byte blocks): 21685 operations in 1 seconds (22205440 bytes) test 4 (128 bit key, 8192 byte blocks): This was caused by a race issue of missed BRDMA_DONE ("Block cipher Receiving DMA") interrupt. Device starts processing the data in DMA mode immediately after setting length of DMA block: receiving (FCBRDMAL) or transmitting (FCBTDMAL). The driver sets these lengths from interrupt handler through s5p_set_dma_indata() function (or xxx_setdata()). However the interrupt handler was first dealing with receive buffer (dma-unmap old, dma-map new, set receive block length which starts the operation), then with transmit buffer and finally was clearing pending interrupts (FCINTPEND). Because of the time window between setting receive buffer length and clearing pending interrupts, the operation on receive buffer could end already and driver would miss new interrupt. User manual for Exynos5422 confirms in example code that setting DMA block lengths should be the last operation. The tcrypt hang could be also observed in following blocked-task dmesg: INFO: task modprobe:258 blocked for more than 120 seconds. Not tainted 4.6.0-rc4-next-20160419-00005-g9eac8b7b7753-dirty #42 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. modprobe D c06b09d8 0 258 256 0x00000000 [] (__schedule) from [] (schedule+0x40/0xac) [] (schedule) from [] (schedule_timeout+0x124/0x178) [] (schedule_timeout) from [] (wait_for_common+0xb8/0x144) [] (wait_for_common) from [] (test_acipher_speed+0x49c/0x740 [tcrypt]) [] (test_acipher_speed [tcrypt]) from [] (do_test+0x2240/0x30ec [tcrypt]) [] (do_test [tcrypt]) from [] (tcrypt_mod_init+0x48/0xa4 [tcrypt]) [] (tcrypt_mod_init [tcrypt]) from [] (do_one_initcall+0x3c/0x16c) [] (do_one_initcall) from [] (do_init_module+0x5c/0x1ac) [] (do_init_module) from [] (load_module+0x1a30/0x1d08) [] (load_module) from [] (SyS_finit_module+0x8c/0x98) [] (SyS_finit_module) from [] (ret_fast_syscall+0x0/0x3c) Fixes: a49e490c7a8a ("crypto: s5p-sss - add S5PV210 advanced crypto engine support") Cc: Signed-off-by: Krzysztof Kozlowski --- Issue was easily reproduced on newer (faster?) SoCs, like Odroid XU3/XU4 (Exynos5422). Still it was kind of time-related (adding printks or kernel debug options sometimes "was fixing" the issue). On older like Odroid U3 with Exynos4412 this works fine... I am marking this cc-stable because invalid operation comes from the first version of the driver. --- drivers/crypto/s5p-sss.c | 53 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 14 deletions(-) diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c index b96532078d0c..ac6d62b3be07 100644 --- a/drivers/crypto/s5p-sss.c +++ b/drivers/crypto/s5p-sss.c @@ -367,43 +367,55 @@ exit: return err; } -static void s5p_aes_tx(struct s5p_aes_dev *dev) +/* + * Returns true if new transmitting (output) data is ready and its + * address+length have to be written to device (by calling + * s5p_set_dma_outdata()). False otherwise. + */ +static bool s5p_aes_tx(struct s5p_aes_dev *dev) { int err = 0; + bool ret = false; s5p_unset_outdata(dev); if (!sg_is_last(dev->sg_dst)) { err = s5p_set_outdata(dev, sg_next(dev->sg_dst)); - if (err) { + if (err) s5p_aes_complete(dev, err); - return; - } - - s5p_set_dma_outdata(dev, dev->sg_dst); + else + ret = true; } else { s5p_aes_complete(dev, err); dev->busy = true; tasklet_schedule(&dev->tasklet); } + + return ret; } -static void s5p_aes_rx(struct s5p_aes_dev *dev) +/* + * Returns true if new receiving (input) data is ready and its + * address+length have to be written to device (by calling + * s5p_set_dma_indata()). False otherwise. + */ +static bool s5p_aes_rx(struct s5p_aes_dev *dev) { int err; + bool ret = false; s5p_unset_indata(dev); if (!sg_is_last(dev->sg_src)) { err = s5p_set_indata(dev, sg_next(dev->sg_src)); - if (err) { + if (err) s5p_aes_complete(dev, err); - return; - } - - s5p_set_dma_indata(dev, dev->sg_src); + else + ret = true; } + + return ret; } static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) @@ -412,17 +424,30 @@ static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id) struct s5p_aes_dev *dev = platform_get_drvdata(pdev); uint32_t status; unsigned long flags; + bool set_dma_tx = false; + bool set_dma_rx = false; spin_lock_irqsave(&dev->lock, flags); status = SSS_READ(dev, FCINTSTAT); if (status & SSS_FCINTSTAT_BRDMAINT) - s5p_aes_rx(dev); + set_dma_rx = s5p_aes_rx(dev); if (status & SSS_FCINTSTAT_BTDMAINT) - s5p_aes_tx(dev); + set_dma_tx = s5p_aes_tx(dev); SSS_WRITE(dev, FCINTPEND, status); + /* + * Writing length of DMA block (either receiving or transmitting) + * will start the operation immediately, so this should be done + * at the end (even after clearing pending interrupts to not miss the + * interrupt). + */ + if (set_dma_tx) + s5p_set_dma_outdata(dev, dev->sg_dst); + if (set_dma_rx) + s5p_set_dma_indata(dev, dev->sg_src); + spin_unlock_irqrestore(&dev->lock, flags); return IRQ_HANDLED; -- 1.9.1