* [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used
@ 2020-09-04 11:25 Nicolas Toromanoff
2020-09-11 4:28 ` Herbert Xu
0 siblings, 1 reply; 3+ messages in thread
From: Nicolas Toromanoff @ 2020-09-04 11:25 UTC (permalink / raw)
To: Herbert Xu, David S . Miller, Maxime Coquelin, Alexandre Torgue
Cc: Ard Biesheuvel, Nicolas Toromanoff, linux-crypto, linux-stm32,
linux-arm-kernel, linux-kernel
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used
2020-09-04 11:25 [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used Nicolas Toromanoff
@ 2020-09-11 4:28 ` Herbert Xu
2020-09-15 15:54 ` Nicolas TOROMANOFF
0 siblings, 1 reply; 3+ messages in thread
From: Herbert Xu @ 2020-09-11 4:28 UTC (permalink / raw)
To: Nicolas Toromanoff
Cc: David S . Miller, Maxime Coquelin, Alexandre Torgue,
Ard Biesheuvel, linux-crypto, linux-stm32, linux-arm-kernel,
linux-kernel
On Fri, Sep 04, 2020 at 01:25:27PM +0200, Nicolas Toromanoff wrote:
> 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
Shouldn't this be "select CRC32"?
Thanks,
--
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used
2020-09-11 4:28 ` Herbert Xu
@ 2020-09-15 15:54 ` Nicolas TOROMANOFF
0 siblings, 0 replies; 3+ messages in thread
From: Nicolas TOROMANOFF @ 2020-09-15 15:54 UTC (permalink / raw)
To: Herbert Xu
Cc: David S . Miller, Maxime Coquelin, Alexandre TORGUE,
Ard Biesheuvel, linux-crypto, linux-stm32, linux-arm-kernel,
linux-kernel
Hello Herbert,
On 9/11/20 6:28 AM, Herbert Xu wrote:
> On Fri, Sep 04, 2020 at 01:25:27PM +0200, Nicolas Toromanoff wrote:
>> 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
>
> Shouldn't this be "select CRC32"?
Correct "select CRC32" is enough.
I'll send a version 2 with only "select CRC32".
Nicolas.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-09-04 11:25 [PATCH] crypto: stm32/crc32 - Avoid lock if hardware is already used Nicolas Toromanoff
2020-09-11 4:28 ` Herbert Xu
2020-09-15 15:54 ` Nicolas TOROMANOFF
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