crypto: stm32/crc32 - fix ext4 chksum BUG_ON()

[ 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>

diff --git a/drivers/crypto/stm32/stm32-crc32.c b/drivers/crypto/stm32/stm32-crc32.c
index 9e11c34..17b371e 100644 (file)
--- 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;
 }