| Message ID | 1464602968-7526-1-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
On Mon, May 30, 2016 at 12:09:28PM +0200, Krzysztof Kozlowski wrote: > commit 79152e8d085fd64484afd473ef6830b45518acba upstream. > > 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 > [<c06b09d8>] (__schedule) from [<c06b0f24>] (schedule+0x40/0xac) > [<c06b0f24>] (schedule) from [<c06b49f8>] (schedule_timeout+0x124/0x178) > [<c06b49f8>] (schedule_timeout) from [<c06b17fc>] (wait_for_common+0xb8/0x144) > [<c06b17fc>] (wait_for_common) from [<bf0013b8>] (test_acipher_speed+0x49c/0x740 [tcrypt]) > [<bf0013b8>] (test_acipher_speed [tcrypt]) from [<bf003e8c>] (do_test+0x2240/0x30ec [tcrypt]) > [<bf003e8c>] (do_test [tcrypt]) from [<bf008048>] (tcrypt_mod_init+0x48/0xa4 [tcrypt]) > [<bf008048>] (tcrypt_mod_init [tcrypt]) from [<c010177c>] (do_one_initcall+0x3c/0x16c) > [<c010177c>] (do_one_initcall) from [<c0191ff0>] (do_init_module+0x5c/0x1ac) > [<c0191ff0>] (do_init_module) from [<c0185610>] (load_module+0x1a30/0x1d08) > [<c0185610>] (load_module) from [<c0185ab0>] (SyS_finit_module+0x8c/0x98) > [<c0185ab0>] (SyS_finit_module) from [<c01078c0>] (ret_fast_syscall+0x0/0x3c) > > Fixes: a49e490c7a8a ("crypto: s5p-sss - add S5PV210 advanced crypto engine support") > Cc: <stable@vger.kernel.org> # 3.16+ > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> > Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > [k.kozlowski: Backport to v3.16] Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/s5p-sss.c b/drivers/crypto/s5p-sss.c index 4197ad9a711b..8a46de76b834 100644 --- a/drivers/crypto/s5p-sss.c +++ b/drivers/crypto/s5p-sss.c @@ -313,43 +313,55 @@ static int s5p_set_indata(struct s5p_aes_dev *dev, struct scatterlist *sg) 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) @@ -358,19 +370,32 @@ 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); if (irq == dev->irq_fc) { 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;
commit 79152e8d085fd64484afd473ef6830b45518acba upstream. 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 [<c06b09d8>] (__schedule) from [<c06b0f24>] (schedule+0x40/0xac) [<c06b0f24>] (schedule) from [<c06b49f8>] (schedule_timeout+0x124/0x178) [<c06b49f8>] (schedule_timeout) from [<c06b17fc>] (wait_for_common+0xb8/0x144) [<c06b17fc>] (wait_for_common) from [<bf0013b8>] (test_acipher_speed+0x49c/0x740 [tcrypt]) [<bf0013b8>] (test_acipher_speed [tcrypt]) from [<bf003e8c>] (do_test+0x2240/0x30ec [tcrypt]) [<bf003e8c>] (do_test [tcrypt]) from [<bf008048>] (tcrypt_mod_init+0x48/0xa4 [tcrypt]) [<bf008048>] (tcrypt_mod_init [tcrypt]) from [<c010177c>] (do_one_initcall+0x3c/0x16c) [<c010177c>] (do_one_initcall) from [<c0191ff0>] (do_init_module+0x5c/0x1ac) [<c0191ff0>] (do_init_module) from [<c0185610>] (load_module+0x1a30/0x1d08) [<c0185610>] (load_module) from [<c0185ab0>] (SyS_finit_module+0x8c/0x98) [<c0185ab0>] (SyS_finit_module) from [<c01078c0>] (ret_fast_syscall+0x0/0x3c) Fixes: a49e490c7a8a ("crypto: s5p-sss - add S5PV210 advanced crypto engine support") Cc: <stable@vger.kernel.org> # 3.16+ Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> [k.kozlowski: Backport to v3.16] --- Backporting to earlier kernels does not make much sense as the driver differs and the testing won't be possible probably. --- drivers/crypto/s5p-sss.c | 53 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 39 insertions(+), 14 deletions(-)