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crypto: omap-aes - Don't idle/start AES device between Encrypt operations

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Calling runtime PM API for every block causes serious perf hit to
crypto operations that are done on a long buffer.
As crypto is performed on a page boundary, encrypting large buffers can
cause a series of crypto operations divided by page. The runtime PM API
is also called those many times.

We call runtime_pm_get_sync only at beginning on the session (cra_init)
and runtime_pm_put at the end. This result in upto a 50% speedup as below.
This doesn't make the driver to keep the system awake as runtime get/put
is only called during a crypto session which completes usually quickly.

Before:
root@beagleboard:~# time -v openssl speed -evp aes-128-cbc
Doing aes-128-cbc for 3s on 16 size blocks: 13310 aes-128-cbc's in 0.01s
Doing aes-128-cbc for 3s on 64 size blocks: 13040 aes-128-cbc's in 0.04s
Doing aes-128-cbc for 3s on 256 size blocks: 9134 aes-128-cbc's in 0.03s
Doing aes-128-cbc for 3s on 1024 size blocks: 8939 aes-128-cbc's in 0.01s
Doing aes-128-cbc for 3s on 8192 size blocks: 4299 aes-128-cbc's in 0.00s

After:
root@beagleboard:~# time -v openssl speed -evp aes-128-cbc
Doing aes-128-cbc for 3s on 16 size blocks: 18911 aes-128-cbc's in 0.02s
Doing aes-128-cbc for 3s on 64 size blocks: 18878 aes-128-cbc's in 0.02s
Doing aes-128-cbc for 3s on 256 size blocks: 11878 aes-128-cbc's in 0.10s
Doing aes-128-cbc for 3s on 1024 size blocks: 11538 aes-128-cbc's in 0.05s
Doing aes-128-cbc for 3s on 8192 size blocks: 4857 aes-128-cbc's in 0.03s

While at it, also drop enter and exit pr_debugs, in related code. tracers
can be used for that.

Tested on a Beaglebone (AM335x SoC) board.

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Joel A Fernandes 2013-05-28 19:02:55 -05:00 committed by Herbert Xu
parent 67822649d7
commit a3485e685f
1 changed files with 19 additions and 10 deletions
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29
drivers/crypto/omap-aes.c
View file

@ -203,13 +203,6 @@ static void omap_aes_write_n(struct omap_aes_dev *dd, u32 offset,
static int omap_aes_hw_init(struct omap_aes_dev *dd)
{
/*
* clocks are enabled when request starts and disabled when finished.
* It may be long delays between requests.
* Device might go to off mode to save power.
*/
pm_runtime_get_sync(dd->dev);
if (!(dd->flags & FLAGS_INIT)) {
dd->flags |= FLAGS_INIT;
dd->err = 0;
@ -636,7 +629,6 @@ static void omap_aes_finish_req(struct omap_aes_dev *dd, int err)
pr_debug("err: %d\n", err);
pm_runtime_put(dd->dev);
dd->flags &= ~FLAGS_BUSY;
req->base.complete(&req->base, err);
@ -837,8 +829,16 @@ static int omap_aes_ctr_decrypt(struct ablkcipher_request *req)
static int omap_aes_cra_init(struct crypto_tfm *tfm)
{
pr_debug("enter\n");
struct omap_aes_dev *dd = NULL;
/* Find AES device, currently picks the first device */
spin_lock_bh(&list_lock);
list_for_each_entry(dd, &dev_list, list) {
break;
}
spin_unlock_bh(&list_lock);
pm_runtime_get_sync(dd->dev);
tfm->crt_ablkcipher.reqsize = sizeof(struct omap_aes_reqctx);
return 0;
@ -846,7 +846,16 @@ static int omap_aes_cra_init(struct crypto_tfm *tfm)
static void omap_aes_cra_exit(struct crypto_tfm *tfm)
{
pr_debug("enter\n");
struct omap_aes_dev *dd = NULL;
/* Find AES device, currently picks the first device */
spin_lock_bh(&list_lock);
list_for_each_entry(dd, &dev_list, list) {
break;
}
spin_unlock_bh(&list_lock);
pm_runtime_put_sync(dd->dev);
}
/* ********************** ALGS ************************************ */