[PATCH 4.19 166/267] crypto: stm32/crc32 - fix ext4 chksum BUG_ON()

Greg Kroah-Hartman
2020-06-19T16:22:31Z

From: Nicolas Toromanoff <nicolas.toromanoff@st.com>

[ Upstream commit 49c2c082e00e0bc4f5cbb7c21c7f0f873b35ab09 ]

Allow use of crc_update without prior call to crc_init.
And change (and fix) driver to use CRC device even on unaligned buffers.

Fixes: b51dbe90912a ("crypto: stm32 - Support for STM32 CRC32 crypto module")

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/stm32_crc32.c | 98 +++++++++++++++---------------
1 file changed, 48 insertions(+), 50 deletions(-)

diff --git a/drivers/crypto/stm32/stm32_crc32.c b/drivers/crypto/stm32/stm32_crc32.c
index 29d2095d9dfd..749b51762b18 100644
--- a/drivers/crypto/stm32/stm32_crc32.c
+++ b/drivers/crypto/stm32/stm32_crc32.c
@@ -28,8 +28,10 @@

/* Registers values */
#define CRC_CR_RESET BIT(0)
-#define CRC_CR_REVERSE (BIT(7) | BIT(6) | BIT(5))
#define CRC_INIT_DEFAULT 0xFFFFFFFF
+#define CRC_CR_REV_IN_WORD (BIT(6) | BIT(5))
+#define CRC_CR_REV_IN_BYTE BIT(5)
+#define CRC_CR_REV_OUT BIT(7)

#define CRC_AUTOSUSPEND_DELAY 50

@@ -38,8 +40,6 @@ struct stm32_crc {
struct device *dev;
void __iomem *regs;
struct clk *clk;
- u8 pending_data[sizeof(u32)];
- size_t nb_pending_bytes;
};

struct stm32_crc_list {
@@ -59,7 +59,6 @@ struct stm32_crc_ctx {

struct stm32_crc_desc_ctx {
u32 partial; /* crc32c: partial in first 4 bytes of that struct */
- struct stm32_crc *crc;
};

static int stm32_crc32_cra_init(struct crypto_tfm *tfm)
@@ -101,25 +100,22 @@ static int stm32_crc_init(struct shash_desc *desc)
struct stm32_crc *crc;

spin_lock_bh(&crc_list.lock);
- list_for_each_entry(crc, &crc_list.dev_list, list) {
- ctx->crc = crc;
- break;
- }
+ crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list);
spin_unlock_bh(&crc_list.lock);

- pm_runtime_get_sync(ctx->crc->dev);
+ pm_runtime_get_sync(crc->dev);

/* Reset, set key, poly and configure in bit reverse mode */
- writel_relaxed(bitrev32(mctx->key), ctx->crc->regs + CRC_INIT);
- writel_relaxed(bitrev32(mctx->poly), ctx->crc->regs + CRC_POL);
- writel_relaxed(CRC_CR_RESET | CRC_CR_REVERSE, ctx->crc->regs + CRC_CR);
+ writel_relaxed(bitrev32(mctx->key), crc->regs + CRC_INIT);
+ writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
+ writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+ crc->regs + CRC_CR);

/* Store partial result */
- ctx->partial = readl_relaxed(ctx->crc->regs + CRC_DR);
- ctx->crc->nb_pending_bytes = 0;
+ ctx->partial = readl_relaxed(crc->regs + CRC_DR);

- pm_runtime_mark_last_busy(ctx->crc->dev);
- pm_runtime_put_autosuspend(ctx->crc->dev);
+ pm_runtime_mark_last_busy(crc->dev);
+ pm_runtime_put_autosuspend(crc->dev);

return 0;
}
@@ -128,31 +124,49 @@ static int stm32_crc_update(struct shash_desc *desc, const u8 *d8,
unsigned int length)
{
struct stm32_crc_desc_ctx *ctx = shash_desc_ctx(desc);
- struct stm32_crc *crc = ctx->crc;
- u32 *d32;
- unsigned int i;
+ struct stm32_crc_ctx *mctx = crypto_shash_ctx(desc->tfm);
+ struct stm32_crc *crc;
+
+ spin_lock_bh(&crc_list.lock);
+ crc = list_first_entry(&crc_list.dev_list, struct stm32_crc, list);
+ spin_unlock_bh(&crc_list.lock);

pm_runtime_get_sync(crc->dev);

- if (unlikely(crc->nb_pending_bytes)) {
- while (crc->nb_pending_bytes != sizeof(u32) && length) {
- /* Fill in pending data */
- crc->pending_data[crc->nb_pending_bytes++] = *(d8++);
+ /*
+ * Restore previously calculated CRC for this context as init value
+ * Restore polynomial configuration
+ * Configure in register for word input data,
+ * Configure out register in reversed bit mode data.
+ */
+ writel_relaxed(bitrev32(ctx->partial), crc->regs + CRC_INIT);
+ writel_relaxed(bitrev32(mctx->poly), crc->regs + CRC_POL);
+ writel_relaxed(CRC_CR_RESET | CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+ crc->regs + CRC_CR);
+
+ if (d8 != PTR_ALIGN(d8, sizeof(u32))) {
+ /* Configure for byte data */
+ writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
+ crc->regs + CRC_CR);
+ while (d8 != PTR_ALIGN(d8, sizeof(u32)) && length) {
+ writeb_relaxed(*d8++, crc->regs + CRC_DR);
length--;
}
-
- if (crc->nb_pending_bytes == sizeof(u32)) {
- /* Process completed pending data */
- writel_relaxed(*(u32 *)crc->pending_data,
- crc->regs + CRC_DR);
- crc->nb_pending_bytes = 0;
- }
+ /* Configure for word data */
+ writel_relaxed(CRC_CR_REV_IN_WORD | CRC_CR_REV_OUT,
+ crc->regs + CRC_CR);
}

- d32 = (u32 *)d8;
- for (i = 0; i < length >> 2; i++)
- /* Process 32 bits data */
- writel_relaxed(*(d32++), crc->regs + CRC_DR);
+ for (; length >= sizeof(u32); d8 += sizeof(u32), length -= sizeof(u32))
+ writel_relaxed(*((u32 *)d8), crc->regs + CRC_DR);
+
+ if (length) {
+ /* Configure for byte data */
+ writel_relaxed(CRC_CR_REV_IN_BYTE | CRC_CR_REV_OUT,
+ crc->regs + CRC_CR);
+ while (length--)
+ writeb_relaxed(*d8++, crc->regs + CRC_DR);
+ }

/* Store partial result */
ctx->partial = readl_relaxed(crc->regs + CRC_DR);
@@ -160,22 +174,6 @@ static int stm32_crc_update(struct shash_desc *desc, const u8 *d8,
pm_runtime_mark_last_busy(crc->dev);
pm_runtime_put_autosuspend(crc->dev);

- /* Check for pending data (non 32 bits) */
- length &= 3;
- if (likely(!length))
- return 0;
-
- if ((crc->nb_pending_bytes + length) >= sizeof(u32)) {
- /* Shall not happen */
- dev_err(crc->dev, "Pending data overflow\n");
- return -EINVAL;
- }
-
- d8 = (const u8 *)d32;
- for (i = 0; i < length; i++)
- /* Store pending data */
- crc->pending_data[crc->nb_pending_bytes++] = *(d8++);
-
return 0;
}

--
2.25.1