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authorDmitry Kasatkin <dmitry.kasatkin@nokia.com>2011-06-02 22:10:10 +0400
committerHerbert Xu <herbert@gondor.apana.org.au>2011-06-30 03:44:04 +0400
commit6c63db821d4663c92cd326f6adb8f3d627971a53 (patch)
tree733b36b077b4cca37f2f9d7846745564ed8fc2f2 /drivers
parent6cb3ffe100ef4c6d5be0bfe4f8ac6d4227bb91bd (diff)
downloadlinux-6c63db821d4663c92cd326f6adb8f3d627971a53.tar.xz
crypto: omap-sham - irq and dma handling changes
It could be a situation, that tasklet is executed twice because of certain delay between dma callback and irq handler execution. In that case, second tasklet execution could actually corrupt the data of the new started dma transactions. This patch improves tasklet logic and prevents above described cases. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/crypto/omap-sham.c40
1 files changed, 27 insertions, 13 deletions
diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 24de4ace9783..a8de7b890d45 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -79,6 +79,7 @@
#define FLAGS_OUTPUT_READY 3
#define FLAGS_INIT 4
#define FLAGS_CPU 5
+#define FLAGS_DMA_READY 6
/* context flags */
#define FLAGS_FINUP 16
#define FLAGS_SG 17
@@ -304,6 +305,8 @@ static int omap_sham_xmit_cpu(struct omap_sham_dev *dd, const u8 *buf,
if (final)
set_bit(FLAGS_FINAL, &dd->flags); /* catch last interrupt */
+ set_bit(FLAGS_CPU, &dd->flags);
+
len32 = DIV_ROUND_UP(length, sizeof(u32));
for (count = 0; count < len32; count++)
@@ -1033,29 +1036,39 @@ static struct ahash_alg algs[] = {
static void omap_sham_done_task(unsigned long data)
{
struct omap_sham_dev *dd = (struct omap_sham_dev *)data;
- int ready = 0, err = 0;
+ int err = 0;
if (!test_bit(FLAGS_BUSY, &dd->flags)) {
omap_sham_handle_queue(dd, NULL);
return;
}
- if (test_and_clear_bit(FLAGS_OUTPUT_READY, &dd->flags))
- ready = 1;
-
- if (test_and_clear_bit(FLAGS_DMA_ACTIVE, &dd->flags)) {
- omap_sham_update_dma_stop(dd);
- if (!dd->err)
+ if (test_bit(FLAGS_CPU, &dd->flags)) {
+ if (test_and_clear_bit(FLAGS_OUTPUT_READY, &dd->flags))
+ goto finish;
+ } else if (test_bit(FLAGS_DMA_READY, &dd->flags)) {
+ if (test_and_clear_bit(FLAGS_DMA_ACTIVE, &dd->flags)) {
+ omap_sham_update_dma_stop(dd);
+ if (dd->err) {
+ err = dd->err;
+ goto finish;
+ }
+ }
+ if (test_and_clear_bit(FLAGS_OUTPUT_READY, &dd->flags)) {
+ /* hash or semi-hash ready */
+ clear_bit(FLAGS_DMA_READY, &dd->flags);
err = omap_sham_update_dma_start(dd);
+ if (err != -EINPROGRESS)
+ goto finish;
+ }
}
- err = dd->err ? : err;
+ return;
- if (err != -EINPROGRESS && (ready || err)) {
- dev_dbg(dd->dev, "update done: err: %d\n", err);
- /* finish curent request */
- omap_sham_finish_req(dd->req, err);
- }
+finish:
+ dev_dbg(dd->dev, "update done: err: %d\n", err);
+ /* finish curent request */
+ omap_sham_finish_req(dd->req, err);
}
static irqreturn_t omap_sham_irq(int irq, void *dev_id)
@@ -1087,6 +1100,7 @@ static void omap_sham_dma_callback(int lch, u16 ch_status, void *data)
clear_bit(FLAGS_INIT, &dd->flags);/* request to re-initialize */
}
+ set_bit(FLAGS_DMA_READY, &dd->flags);
tasklet_schedule(&dd->done_task);
}