From: Nicolas Toromanoff nicolas.toromanoff@st.com
[ Upstream commit bbf2cb1ea1e1428589d7f4d652bed15b265ce92d ]
If STM32 CRC device is already in use, calculate CRC by software.
This will release CPU constraint for a concurrent access to the hardware, and avoid masking irqs during the whole block processing.
Fixes: 7795c0baf5ac ("crypto: stm32/crc32 - protect from concurrent accesses")
Signed-off-by: Nicolas Toromanoff nicolas.toromanoff@st.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/crypto/stm32/Kconfig | 1 + drivers/crypto/stm32/stm32-crc32.c | 15 ++++++++++++--- 2 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/stm32/Kconfig b/drivers/crypto/stm32/Kconfig index 4ef3eb11361c2..4a4c3284ae1f3 100644 --- a/drivers/crypto/stm32/Kconfig +++ b/drivers/crypto/stm32/Kconfig @@ -3,6 +3,7 @@ config CRYPTO_DEV_STM32_CRC tristate "Support for STM32 crc accelerators" depends on ARCH_STM32 select CRYPTO_HASH + select CRC32 help This enables support for the CRC32 hw accelerator which can be found on STMicroelectronics STM32 SOC. diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c index 3ba41148c2a46..2c13f5214d2cf 100644 --- a/drivers/crypto/stm32/stm32-crc32.c +++ b/drivers/crypto/stm32/stm32-crc32.c @@ -6,6 +6,7 @@
#include <linux/bitrev.h> #include <linux/clk.h> +#include <linux/crc32.h> #include <linux/crc32poly.h> #include <linux/module.h> #include <linux/mod_devicetable.h> @@ -147,7 +148,6 @@ static int burst_update(struct shash_desc *desc, const u8 *d8, struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc); struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm); struct stm32_crc *crc; - unsigned long flags;
crc = stm32_crc_get_next_crc(); if (!crc) @@ -155,7 +155,15 @@ static int burst_update(struct shash_desc *desc, const u8 *d8,
pm_runtime_get_sync(crc->dev);
- spin_lock_irqsave(&crc->lock, flags); + if (!spin_trylock(&crc->lock)) { + /* Hardware is busy, calculate crc32 by software */ + if (mctx->poly == CRC32_POLY_LE) + ctx->partial = crc32_le(ctx->partial, d8, length); + else + ctx->partial = __crc32c_le(ctx->partial, d8, length); + + goto pm_out; + }
/* * Restore previously calculated CRC for this context as init value @@ -195,8 +203,9 @@ static int burst_update(struct shash_desc *desc, const u8 *d8, /* Store partial result */ ctx->partial = readl_relaxed(crc->regs + CRC_DR);
- spin_unlock_irqrestore(&crc->lock, flags); + spin_unlock(&crc->lock);
+pm_out: pm_runtime_mark_last_busy(crc->dev); pm_runtime_put_autosuspend(crc->dev);