crypto: omap-aes - error handling implementation improved

Previous version had not error handling.
Request could remain uncompleted.

Also in the case of DMA error, FLAGS_INIT is unset
and accelerator will be initialized again.

Buffer size allignment is checked.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 93 insertions, 41 deletions

diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c
index 2d8f72eaf896..704cc701ab42 100644
--- a/drivers/crypto/omap-aes.c
+++ b/drivers/crypto/omap-aes.c
@@ -103,14 +103,16 @@ struct omap_aes_dev {
         struct omap_aes_ctx     *ctx;
         struct device           *dev;
         unsigned long           flags;
+        int                     err;
 
         u32                     *iv;
         u32                     ctrl;
 
-        spinlock_t                      lock;
-        struct crypto_queue             queue;
+        spinlock_t              lock;
+        struct crypto_queue     queue;
 
-        struct tasklet_struct           task;
+        struct tasklet_struct   done_task;
+        struct tasklet_struct   queue_task;
 
         struct ablkcipher_request       *req;
         size_t                          total;
@@ -198,24 +200,30 @@ static int omap_aes_hw_init(struct omap_aes_dev *dd)
                         return -ETIMEDOUT;
                 }
                 dd->flags |= FLAGS_INIT;
+                dd->err = 0;
         }
 
         return 0;
 }
 
-static void omap_aes_write_ctrl(struct omap_aes_dev *dd)
+static int omap_aes_write_ctrl(struct omap_aes_dev *dd)
 {
         unsigned int key32;
-        int i;
+        int i, err, init = dd->flags & FLAGS_INIT;
         u32 val, mask;
 
+        err = omap_aes_hw_init(dd);
+        if (err)
+                return err;
+
         val = FLD_VAL(((dd->ctx->keylen >> 3) - 1), 4, 3);
         if (dd->flags & FLAGS_CBC)
                 val |= AES_REG_CTRL_CBC;
         if (dd->flags & FLAGS_ENCRYPT)
                 val |= AES_REG_CTRL_DIRECTION;
 
-        if (dd->ctrl == val && !(dd->flags & FLAGS_NEW_IV) &&
+        /* check if hw state & mode have not changed */
+        if (init && dd->ctrl == val && !(dd->flags & FLAGS_NEW_IV) &&
                    !(dd->ctx->flags & FLAGS_NEW_KEY))
                 goto out;
 
@@ -257,6 +265,8 @@ out:
         /* start DMA or disable idle mode */
         omap_aes_write_mask(dd, AES_REG_MASK, AES_REG_MASK_START,
                             AES_REG_MASK_START);
+
+        return 0;
 }
 
 static struct omap_aes_dev *omap_aes_find_dev(struct omap_aes_ctx *ctx)
@@ -284,8 +294,16 @@ static void omap_aes_dma_callback(int lch, u16 ch_status, void *data)
 {
         struct omap_aes_dev *dd = data;
 
-        if (lch == dd->dma_lch_out)
-                tasklet_schedule(&dd->task);
+        if (ch_status != OMAP_DMA_BLOCK_IRQ) {
+                pr_err("omap-aes DMA error status: 0x%hx\n", ch_status);
+                dd->err = -EIO;
+                dd->flags &= ~FLAGS_INIT; /* request to re-initialize */
+        } else if (lch == dd->dma_lch_in) {
+                return;
+        }
+
+        /* dma_lch_out - completed */
+        tasklet_schedule(&dd->done_task);
 }
 
 static int omap_aes_dma_init(struct omap_aes_dev *dd)
@@ -390,6 +408,11 @@ static int sg_copy(struct scatterlist **sg, size_t *offset, void *buf,
                 if (!count)
                         return off;
 
+                /*
+                 * buflen and total are AES_BLOCK_SIZE size aligned,
+                 * so count should be also aligned
+                 */
+
                 sg_copy_buf(buf + off, *sg, *offset, count, out);
 
                 off += count;
@@ -415,6 +438,7 @@ static int omap_aes_crypt_dma(struct crypto_tfm *tfm, dma_addr_t dma_addr_in,
         struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
         struct omap_aes_dev *dd = ctx->dd;
         int len32;
+        int err;
 
         pr_debug("len: %d\n", length);
 
@@ -454,11 +478,13 @@ static int omap_aes_crypt_dma(struct crypto_tfm *tfm, dma_addr_t dma_addr_in,
         omap_set_dma_dest_params(dd->dma_lch_out, 0, OMAP_DMA_AMODE_POST_INC,
                                  dma_addr_out, 0, 0);
 
+        err = omap_aes_write_ctrl(dd);
+        if (err)
+                return err;
+
         omap_start_dma(dd->dma_lch_in);
         omap_start_dma(dd->dma_lch_out);
 
-        omap_aes_write_ctrl(dd);
-
         return 0;
 }
 
@@ -484,8 +510,10 @@ static int omap_aes_crypt_dma_start(struct omap_aes_dev *dd)
                 count = min(dd->total, sg_dma_len(dd->in_sg));
                 count = min(count, sg_dma_len(dd->out_sg));
 
-                if (count != dd->total)
+                if (count != dd->total) {
+                        pr_err("request length != buffer length\n");
                         return -EINVAL;
+                }
 
                 pr_debug("fast\n");
 
@@ -521,25 +549,28 @@ static int omap_aes_crypt_dma_start(struct omap_aes_dev *dd)
 
         dd->total -= count;
 
-        err = omap_aes_hw_init(dd);
-
         err = omap_aes_crypt_dma(tfm, addr_in, addr_out, count);
+        if (err) {
+                dma_unmap_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
+                dma_unmap_sg(dd->dev, dd->out_sg, 1, DMA_TO_DEVICE);
+        }
 
         return err;
 }
 
 static void omap_aes_finish_req(struct omap_aes_dev *dd, int err)
 {
+        struct ablkcipher_request *req = dd->req;
         struct omap_aes_ctx *ctx;
 
         pr_debug("err: %d\n", err);
 
         dd->flags &= ~FLAGS_BUSY;
 
-        ctx = crypto_ablkcipher_ctx(crypto_ablkcipher_reqtfm(dd->req));
+        ctx = crypto_ablkcipher_ctx(crypto_ablkcipher_reqtfm(req));
 
-        if (!dd->total)
-                dd->req->base.complete(&dd->req->base, err);
+        if (req->base.complete)
+                req->base.complete(&req->base, err);
 }
 
 static int omap_aes_crypt_dma_stop(struct omap_aes_dev *dd)
@@ -551,11 +582,11 @@ static int omap_aes_crypt_dma_stop(struct omap_aes_dev *dd)
 
         omap_aes_write_mask(dd, AES_REG_MASK, 0, AES_REG_MASK_START);
 
-        clk_disable(dd->iclk);
-
         omap_stop_dma(dd->dma_lch_in);
         omap_stop_dma(dd->dma_lch_out);
 
+        clk_disable(dd->iclk);
+
         if (dd->flags & FLAGS_FAST) {
                 dma_unmap_sg(dd->dev, dd->out_sg, 1, DMA_FROM_DEVICE);
                 dma_unmap_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
@@ -572,27 +603,24 @@ static int omap_aes_crypt_dma_stop(struct omap_aes_dev *dd)
                 }
         }
 
-        if (err || !dd->total)
-                omap_aes_finish_req(dd, err);
-
         return err;
 }
 
-static int omap_aes_handle_req(struct omap_aes_dev *dd,
+static int omap_aes_handle_queue(struct omap_aes_dev *dd,
                                struct ablkcipher_request *req)
 {
         struct crypto_async_request *async_req, *backlog;
         struct omap_aes_ctx *ctx;
         struct omap_aes_reqctx *rctx;
         unsigned long flags;
-        int err = 0;
+        int err, ret = 0;
 
         spin_lock_irqsave(&dd->lock, flags);
         if (req)
-                err = ablkcipher_enqueue_request(&dd->queue, req);
+                ret = ablkcipher_enqueue_request(&dd->queue, req);
         if (dd->flags & FLAGS_BUSY) {
                 spin_unlock_irqrestore(&dd->lock, flags);
-                return err;
+                return ret;
         }
         backlog = crypto_get_backlog(&dd->queue);
         async_req = crypto_dequeue_request(&dd->queue);
@@ -601,7 +629,7 @@ static int omap_aes_handle_req(struct omap_aes_dev *dd,
         spin_unlock_irqrestore(&dd->lock, flags);
 
         if (!async_req)
-                return 0;
+                return ret;
 
         if (backlog)
                 backlog->complete(backlog, -EINPROGRESS);
@@ -636,30 +664,46 @@ static int omap_aes_handle_req(struct omap_aes_dev *dd,
                 ctx->flags |= FLAGS_NEW_KEY;
         }
 
-        if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE))
-                pr_err("request size is not exact amount of AES blocks\n");
-
-        omap_aes_crypt_dma_start(dd);
+        err = omap_aes_crypt_dma_start(dd);
+        if (err) {
+                /* aes_task will not finish it, so do it here */
+                omap_aes_finish_req(dd, err);
+                tasklet_schedule(&dd->queue_task);
+        }
 
-        return err;
+        return ret; /* return ret, which is enqueue return value */
 }
 
-static void omap_aes_task(unsigned long data)
+static void omap_aes_done_task(unsigned long data)
 {
         struct omap_aes_dev *dd = (struct omap_aes_dev *)data;
+        int err;
 
         pr_debug("enter\n");
 
-        omap_aes_crypt_dma_stop(dd);
+        err = omap_aes_crypt_dma_stop(dd);
 
-        if (dd->total)
-                omap_aes_crypt_dma_start(dd);
-        else
-                omap_aes_handle_req(dd, NULL);
+        err = dd->err ? : err;
+
+        if (dd->total && !err) {
+                err = omap_aes_crypt_dma_start(dd);
+                if (!err)
+                        return; /* DMA started. Not fininishing. */
+        }
+
+        omap_aes_finish_req(dd, err);
+        omap_aes_handle_queue(dd, NULL);
 
         pr_debug("exit\n");
 }
 
+static void omap_aes_queue_task(unsigned long data)
+{
+        struct omap_aes_dev *dd = (struct omap_aes_dev *)data;
+
+        omap_aes_handle_queue(dd, NULL);
+}
+
 static int omap_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
 {
         struct omap_aes_ctx *ctx = crypto_ablkcipher_ctx(
@@ -671,13 +715,18 @@ static int omap_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
                   !!(mode & FLAGS_ENCRYPT),
                   !!(mode & FLAGS_CBC));
 
+        if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE)) {
+                pr_err("request size is not exact amount of AES blocks\n");
+                return -EINVAL;
+        }
+
         dd = omap_aes_find_dev(ctx);
         if (!dd)
                 return -ENODEV;
 
         rctx->mode = mode;
 
-        return omap_aes_handle_req(dd, req);
+        return omap_aes_handle_queue(dd, req);
 }
 
 /* ********************** ALG API ************************************ */
@@ -843,7 +892,8 @@ static int omap_aes_probe(struct platform_device *pdev)
                  (reg & AES_REG_REV_MAJOR) >> 4, reg & AES_REG_REV_MINOR);
         clk_disable(dd->iclk);
 
-        tasklet_init(&dd->task, omap_aes_task, (unsigned long)dd);
+        tasklet_init(&dd->done_task, omap_aes_done_task, (unsigned long)dd);
+        tasklet_init(&dd->queue_task, omap_aes_queue_task, (unsigned long)dd);
 
         err = omap_aes_dma_init(dd);
         if (err)
@@ -870,7 +920,8 @@ err_algs:
                 crypto_unregister_alg(&algs[j]);
         omap_aes_dma_cleanup(dd);
 err_dma:
-        tasklet_kill(&dd->task);
+        tasklet_kill(&dd->done_task);
+        tasklet_kill(&dd->queue_task);
         iounmap(dd->io_base);
 err_io:
         clk_put(dd->iclk);
@@ -897,7 +948,8 @@ static int omap_aes_remove(struct platform_device *pdev)
         for (i = 0; i < ARRAY_SIZE(algs); i++)
                 crypto_unregister_alg(&algs[i]);
 
-        tasklet_kill(&dd->task);
+        tasklet_kill(&dd->done_task);
+        tasklet_kill(&dd->queue_task);
         omap_aes_dma_cleanup(dd);
         iounmap(dd->io_base);
         clk_put(dd->iclk);