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crypto: omap-sham - replace flags operation with atomic bit operations 

Some flags are changed in interrupt handlers and verified in the tasklet.
There might be a race condition when tasklet is interrupted or another
cpu/core will run IRQ handler and tasklet in parallel.
Atomic bitops functions are now used instead of bitmask operations.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Dmitry Kasatkin 2011-06-02 21:10:06 +03:00 committed by Herbert Xu
parent ea1fd2246f
commit a929cbeef7
1 changed files with 13 additions and 16 deletions
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29
drivers/crypto/omap-sham.c
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@ -240,7 +240,7 @@ static int omap_sham_hw_init(struct omap_sham_dev *dd)
{
clk_enable(dd->iclk);
if (!(dd->flags & BIT(FLAGS_INIT))) {
if (!test_bit(FLAGS_INIT, &dd->flags)) {
omap_sham_write_mask(dd, SHA_REG_MASK,
SHA_REG_MASK_SOFTRESET, SHA_REG_MASK_SOFTRESET);
@ -248,7 +248,7 @@ static int omap_sham_hw_init(struct omap_sham_dev *dd)
SHA_REG_SYSSTATUS_RESETDONE))
return -ETIMEDOUT;
dd->flags |= BIT(FLAGS_INIT);
set_bit(FLAGS_INIT, &dd->flags);
dd->err = 0;
}
@ -303,7 +303,7 @@ static int omap_sham_xmit_cpu(struct omap_sham_dev *dd, const u8 *buf,
return -ETIMEDOUT;
if (final)
ctx->flags |= BIT(FLAGS_FINAL); /* catch last interrupt */
set_bit(FLAGS_FINAL, &ctx->flags); /* catch last interrupt */
len32 = DIV_ROUND_UP(length, sizeof(u32));
@ -336,9 +336,9 @@ static int omap_sham_xmit_dma(struct omap_sham_dev *dd, dma_addr_t dma_addr,
ctx->digcnt += length;
if (final)
ctx->flags |= BIT(FLAGS_FINAL); /* catch last interrupt */
set_bit(FLAGS_FINAL, &ctx->flags); /* catch last interrupt */
dd->flags |= BIT(FLAGS_DMA_ACTIVE);
set_bit(FLAGS_DMA_ACTIVE, &dd->flags);
omap_start_dma(dd->dma_lch);
@ -642,7 +642,7 @@ static void omap_sham_finish_req(struct ahash_request *req, int err)
if (!err) {
omap_sham_copy_hash(req, 1);
if (ctx->flags & BIT(FLAGS_FINAL))
if (test_bit(FLAGS_FINAL, &ctx->flags))
err = omap_sham_finish(req);
} else {
ctx->flags |= BIT(FLAGS_ERROR);
@ -666,14 +666,14 @@ static int omap_sham_handle_queue(struct omap_sham_dev *dd,
spin_lock_irqsave(&dd->lock, flags);
if (req)
ret = ahash_enqueue_request(&dd->queue, req);
if (dd->flags & BIT(FLAGS_BUSY)) {
if (test_bit(FLAGS_BUSY, &dd->flags)) {
spin_unlock_irqrestore(&dd->lock, flags);
return ret;
}
backlog = crypto_get_backlog(&dd->queue);
async_req = crypto_dequeue_request(&dd->queue);
if (async_req)
dd->flags |= BIT(FLAGS_BUSY);
set_bit(FLAGS_BUSY, &dd->flags);
spin_unlock_irqrestore(&dd->lock, flags);
if (!async_req)
@ -1037,13 +1037,10 @@ static void omap_sham_done_task(unsigned long data)
struct omap_sham_reqctx *ctx = ahash_request_ctx(req);
int ready = 0, err = 0;
if (ctx->flags & BIT(FLAGS_OUTPUT_READY)) {
ctx->flags &= ~BIT(FLAGS_OUTPUT_READY);
if (test_and_clear_bit(FLAGS_OUTPUT_READY, &ctx->flags))
ready = 1;
}
if (dd->flags & BIT(FLAGS_DMA_ACTIVE)) {
dd->flags &= ~BIT(FLAGS_DMA_ACTIVE);
if (test_and_clear_bit(FLAGS_DMA_ACTIVE, &dd->flags)) {
omap_sham_update_dma_stop(dd);
if (!dd->err)
err = omap_sham_update_dma_start(dd);
@ -1077,7 +1074,7 @@ static irqreturn_t omap_sham_irq(int irq, void *dev_id)
return IRQ_HANDLED;
}
if (unlikely(ctx->flags & BIT(FLAGS_FINAL)))
if (unlikely(test_bit(FLAGS_FINAL, &ctx->flags)))
/* final -> allow device to go to power-saving mode */
omap_sham_write_mask(dd, SHA_REG_CTRL, 0, SHA_REG_CTRL_LENGTH);
@ -1085,7 +1082,7 @@ static irqreturn_t omap_sham_irq(int irq, void *dev_id)
SHA_REG_CTRL_OUTPUT_READY);
omap_sham_read(dd, SHA_REG_CTRL);
ctx->flags |= BIT(FLAGS_OUTPUT_READY);
set_bit(FLAGS_OUTPUT_READY, &ctx->flags);
dd->err = 0;
tasklet_schedule(&dd->done_task);
@ -1099,7 +1096,7 @@ static void omap_sham_dma_callback(int lch, u16 ch_status, void *data)
if (ch_status != OMAP_DMA_BLOCK_IRQ) {
pr_err("omap-sham DMA error status: 0x%hx\n", ch_status);
dd->err = -EIO;
dd->flags &= ~BIT(FLAGS_INIT); /* request to re-initialize */
clear_bit(FLAGS_INIT, &dd->flags);/* request to re-initialize */
}
tasklet_schedule(&dd->done_task);