From: Nicolas Toromanoff <nicolas.toromanoff@st.com>
To: Herbert Xu <herbert@gondor.apana.org.au>,
"David S . Miller" <davem@davemloft.net>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@st.com>
Cc: Ard Biesheuvel <ardb@kernel.org>,
Nicolas Toromanoff <nicolas.toromanoff@st.com>,
<linux-crypto@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used
Date: Fri, 4 Sep 2020 13:25:27 +0200 [thread overview]
Message-ID: <20200904112527.15677-1-nicolas.toromanoff@st.com> (raw)
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>
---
drivers/crypto/stm32/Kconfig | 2 ++
drivers/crypto/stm32/stm32-crc32.c | 15 ++++++++++++---
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/stm32/Kconfig b/drivers/crypto/stm32/Kconfig
index 4ef3eb11361c..8d605b07571f 100644
--- a/drivers/crypto/stm32/Kconfig
+++ b/drivers/crypto/stm32/Kconfig
@@ -3,6 +3,8 @@ config CRYPTO_DEV_STM32_CRC
tristate "Support for STM32 crc accelerators"
depends on ARCH_STM32
select CRYPTO_HASH
+ select CRYPTO_CRC32
+ select CRYPTO_CRC32C
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 783a64f3f635..75867c0b0017 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/io.h>
#include <linux/kernel.h>
@@ -149,7 +150,6 @@ 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)
@@ -157,7 +157,15 @@ 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
@@ -197,8 +205,9 @@ 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);
--
2.17.1
next reply other threads:[~2020-09-04 11:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-04 11:25 Nicolas Toromanoff [this message]
2020-09-11 4:28 ` [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used Herbert Xu
2020-09-15 15:54 ` Nicolas TOROMANOFF
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