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| author | Nicolas Toromanoff <nicolas.toromanoff@st.com> | 2020-09-16 08:33:44 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2020-09-25 17:48:14 +1000 |
| commit | bbf2cb1ea1e1428589d7f4d652bed15b265ce92d (patch) | |
| tree | cec14bb4328b0a7f435453ad1a9cfdb515a0af98 /drivers/crypto/stm32/stm32-crc32.c | |
| parent | c4c75fcbd8b9cc9c9fcddcb8ee68ab680d486c01 (diff) | |
| download | lwn-bbf2cb1ea1e1428589d7f4d652bed15b265ce92d.tar.gz lwn-bbf2cb1ea1e1428589d7f4d652bed15b265ce92d.zip | |
crypto: stm32/crc32 - Avoid lock if hardware is already used
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>
Diffstat (limited to 'drivers/crypto/stm32/stm32-crc32.c')
| -rw-r--r-- | drivers/crypto/stm32/stm32-crc32.c | 15 |
1 files changed, 12 insertions, 3 deletions
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); |