2013-08-20 15:02:33

by Lokesh Vutla

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Subject: [PATCH 0/2] crypto: omap-sham: Misc updates for driver

This patch series updates the following for the driver:
-> Enable polling mode if DMA fails.
-> Correct the DMA burst size.

Lokesh Vutla (2):
crypto: omap-sham: Enable Polling mode if DMA fails
crypto: omap-sham: correct dma burst size

drivers/crypto/omap-sham.c | 72 ++++++++++++++++++++++++++++----------------
1 file changed, 46 insertions(+), 26 deletions(-)

--
1.7.9.5



2013-08-20 15:02:34

by Lokesh Vutla

[permalink] [raw]
Subject: [PATCH 1/2] crypto: omap-sham: Enable Polling mode if DMA fails

For writing input buffer into DATA_IN register current driver
has the following state machine:
-> if input buffer < 9 : use fallback driver
-> else if input buffer < block size : Copy input buffer into data_in regs
-> else use dma transfer.

In cases where requesting for DMA channels fails for some reason,
or channel numbers are not provided in DT or platform data, probe
also fails. Instead of returning from driver use cpu polling mode.
In this mode processor polls on INPUT_READY bit and writes data into
data_in regs when it equals 1. This operation is repeated until the
length of message.

Now the state machine looks like:
-> if input buffer < 9 : use fallback driver
-> else if input buffer < block size : Copy input buffer into data_in regs
-> else if dma enabled: use dma transfer
else use cpu polling mode.

Signed-off-by: Lokesh Vutla <[email protected]>
---
drivers/crypto/omap-sham.c | 61 ++++++++++++++++++++++++++++++--------------
1 file changed, 42 insertions(+), 19 deletions(-)

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index ae1ca8b2..0a2bd16 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -225,6 +225,7 @@ struct omap_sham_dev {
unsigned int dma;
struct dma_chan *dma_lch;
struct tasklet_struct done_task;
+ u8 polling_mode;

unsigned long flags;
struct crypto_queue queue;
@@ -510,7 +511,7 @@ static int omap_sham_xmit_cpu(struct omap_sham_dev *dd, const u8 *buf,
size_t length, int final)
{
struct omap_sham_reqctx *ctx = ahash_request_ctx(dd->req);
- int count, len32;
+ int count, len32, bs32, offset = 0;
const u32 *buffer = (const u32 *)buf;

dev_dbg(dd->dev, "xmit_cpu: digcnt: %d, length: %d, final: %d\n",
@@ -522,18 +523,23 @@ static int omap_sham_xmit_cpu(struct omap_sham_dev *dd, const u8 *buf,
/* should be non-zero before next lines to disable clocks later */
ctx->digcnt += length;

- if (dd->pdata->poll_irq(dd))
- return -ETIMEDOUT;
-
if (final)
set_bit(FLAGS_FINAL, &dd->flags); /* catch last interrupt */

set_bit(FLAGS_CPU, &dd->flags);

len32 = DIV_ROUND_UP(length, sizeof(u32));
+ bs32 = get_block_size(ctx) / sizeof(u32);
+
+ while (len32) {
+ if (dd->pdata->poll_irq(dd))
+ return -ETIMEDOUT;

- for (count = 0; count < len32; count++)
- omap_sham_write(dd, SHA_REG_DIN(dd, count), buffer[count]);
+ for (count = 0; count < min(len32, bs32); count++, offset++)
+ omap_sham_write(dd, SHA_REG_DIN(dd, count),
+ buffer[offset]);
+ len32 -= min(len32, bs32);
+ }

return -EINPROGRESS;
}
@@ -774,13 +780,22 @@ static int omap_sham_update_dma_start(struct omap_sham_dev *dd)
static int omap_sham_update_cpu(struct omap_sham_dev *dd)
{
struct omap_sham_reqctx *ctx = ahash_request_ctx(dd->req);
- int bufcnt;
+ int bufcnt, final;
+
+ if (!ctx->total)
+ return 0;

omap_sham_append_sg(ctx);
+
+ final = (ctx->flags & BIT(FLAGS_FINUP)) && !ctx->total;
+
+ dev_dbg(dd->dev, "cpu: bufcnt: %u, digcnt: %d, final: %d\n",
+ ctx->bufcnt, ctx->digcnt, final);
+
bufcnt = ctx->bufcnt;
ctx->bufcnt = 0;

- return omap_sham_xmit_cpu(dd, ctx->buffer, bufcnt, 1);
+ return omap_sham_xmit_cpu(dd, ctx->buffer, bufcnt, final);
}

static int omap_sham_update_dma_stop(struct omap_sham_dev *dd)
@@ -903,8 +918,11 @@ static int omap_sham_final_req(struct omap_sham_dev *dd)
struct omap_sham_reqctx *ctx = ahash_request_ctx(req);
int err = 0, use_dma = 1;

- if (ctx->bufcnt <= DMA_MIN)
- /* faster to handle last block with cpu */
+ if ((ctx->bufcnt <= get_block_size(ctx)) || dd->polling_mode)
+ /*
+ * faster to handle last block with cpu or
+ * use cpu when dma is not present.
+ */
use_dma = 0;

if (use_dma)
@@ -1056,6 +1074,7 @@ static int omap_sham_enqueue(struct ahash_request *req, unsigned int op)
static int omap_sham_update(struct ahash_request *req)
{
struct omap_sham_reqctx *ctx = ahash_request_ctx(req);
+ struct omap_sham_dev *dd = ctx->dd;
int bs = get_block_size(ctx);

if (!req->nbytes)
@@ -1074,10 +1093,12 @@ static int omap_sham_update(struct ahash_request *req)
*/
omap_sham_append_sg(ctx);
return 0;
- } else if (ctx->bufcnt + ctx->total <= bs) {
+ } else if ((ctx->bufcnt + ctx->total <= bs) ||
+ dd->polling_mode) {
/*
- * faster to use CPU for short transfers
- */
+ * faster to use CPU for short transfers or
+ * use cpu when dma is not present.
+ */
ctx->flags |= BIT(FLAGS_CPU);
}
} else if (ctx->bufcnt + ctx->total < ctx->buflen) {
@@ -1589,8 +1610,12 @@ static void omap_sham_done_task(unsigned long data)
}

if (test_bit(FLAGS_CPU, &dd->flags)) {
- if (test_and_clear_bit(FLAGS_OUTPUT_READY, &dd->flags))
- goto finish;
+ if (test_and_clear_bit(FLAGS_OUTPUT_READY, &dd->flags)) {
+ /* hash or semi-hash ready */
+ err = omap_sham_update_cpu(dd);
+ if (err != -EINPROGRESS)
+ 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);
@@ -1910,10 +1935,8 @@ static int omap_sham_probe(struct platform_device *pdev)
dd->dma_lch = dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
&dd->dma, dev, "rx");
if (!dd->dma_lch) {
- dev_err(dev, "unable to obtain RX DMA engine channel %u\n",
- dd->dma);
- err = -ENXIO;
- goto data_err;
+ dd->polling_mode = 1;
+ dev_dbg(dev, "using polling mode instead of dma\n");
}

dd->flags |= dd->pdata->flags;
--
1.7.9.5


2013-08-20 15:02:47

by Lokesh Vutla

[permalink] [raw]
Subject: [PATCH 2/2] crypto: omap-sham: correct dma burst size

Each cycle of SHA512 operates on 32 data words where as
SHA256 operates on 16 data words. This needs to be updated
while configuring DMA channels. Doing the same.

Signed-off-by: Lokesh Vutla <[email protected]>
---
drivers/crypto/omap-sham.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 0a2bd16..8bdde57 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -46,9 +46,6 @@

#define MD5_DIGEST_SIZE 16

-#define DST_MAXBURST 16
-#define DMA_MIN (DST_MAXBURST * sizeof(u32))
-
#define SHA_REG_IDIGEST(dd, x) ((dd)->pdata->idigest_ofs + ((x)*0x04))
#define SHA_REG_DIN(dd, x) ((dd)->pdata->din_ofs + ((x) * 0x04))
#define SHA_REG_DIGCNT(dd) ((dd)->pdata->digcnt_ofs)
@@ -558,7 +555,7 @@ static int omap_sham_xmit_dma(struct omap_sham_dev *dd, dma_addr_t dma_addr,
struct omap_sham_reqctx *ctx = ahash_request_ctx(dd->req);
struct dma_async_tx_descriptor *tx;
struct dma_slave_config cfg;
- int len32, ret;
+ int len32, ret, dma_min = get_block_size(ctx);

dev_dbg(dd->dev, "xmit_dma: digcnt: %d, length: %d, final: %d\n",
ctx->digcnt, length, final);
@@ -567,7 +564,7 @@ static int omap_sham_xmit_dma(struct omap_sham_dev *dd, dma_addr_t dma_addr,

cfg.dst_addr = dd->phys_base + SHA_REG_DIN(dd, 0);
cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
- cfg.dst_maxburst = DST_MAXBURST;
+ cfg.dst_maxburst = dma_min / DMA_SLAVE_BUSWIDTH_4_BYTES;

ret = dmaengine_slave_config(dd->dma_lch, &cfg);
if (ret) {
@@ -575,7 +572,7 @@ static int omap_sham_xmit_dma(struct omap_sham_dev *dd, dma_addr_t dma_addr,
return ret;
}

- len32 = DIV_ROUND_UP(length, DMA_MIN) * DMA_MIN;
+ len32 = DIV_ROUND_UP(length, dma_min) * dma_min;

if (is_sg) {
/*
@@ -729,7 +726,7 @@ static int omap_sham_update_dma_start(struct omap_sham_dev *dd)
* the dmaengine infrastructure will calculate that it needs
* to transfer 0 frames which ultimately fails.
*/
- if (ctx->total < (DST_MAXBURST * sizeof(u32)))
+ if (ctx->total < get_block_size(ctx))
return omap_sham_update_dma_slow(dd);

dev_dbg(dd->dev, "fast: digcnt: %d, bufcnt: %u, total: %u\n",
--
1.7.9.5

2013-08-21 11:51:32

by Herbert Xu

[permalink] [raw]
Subject: Re: [PATCH 0/2] crypto: omap-sham: Misc updates for driver

On Tue, Aug 20, 2013 at 08:32:33PM +0530, Lokesh Vutla wrote:
> This patch series updates the following for the driver:
> -> Enable polling mode if DMA fails.
> -> Correct the DMA burst size.
>
> Lokesh Vutla (2):
> crypto: omap-sham: Enable Polling mode if DMA fails
> crypto: omap-sham: correct dma burst size

Both patches applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt