Optimize performance for single irq
Changes since v2.
* Clarify comment in process_sdio_pending_irqs
* Simplify sdio_single_irq if-condition
Stefan Nilsson XK (1):
sdio: optimized SDIO IRQ handling for single irq
drivers/mmc/core/sdio_irq.c | 33 ++++++++++++++++++++++++++++++++-
include/linux/mmc/card.h | 1 +
2 files changed, 33 insertions(+), 1 deletions(-)
--
1.7.4.1
From: Stefan Nilsson XK <[email protected]>
If there is only 1 function interrupt registered it is possible to
improve performance by directly calling the irq handler
and avoiding the overhead of reading the CCCR registers.
Signed-off-by: Per Forlin <[email protected]>
Acked-by: Ulf Hansson <[email protected]>
Reviewed-by: Nicolas Pitre <[email protected]>
---
drivers/mmc/core/sdio_irq.c | 33 ++++++++++++++++++++++++++++++++-
include/linux/mmc/card.h | 1 +
2 files changed, 33 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index b300161..03ead02 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -31,6 +31,17 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
{
int i, ret, count;
unsigned char pending;
+ struct sdio_func *func;
+
+ /*
+ * Optimization, if there is only 1 function interrupt registered
+ * call irq handler directly
+ */
+ func = card->sdio_single_irq;
+ if (func) {
+ func->irq_handler(func);
+ return 1;
+ }
ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
if (ret) {
@@ -42,7 +53,7 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
count = 0;
for (i = 1; i <= 7; i++) {
if (pending & (1 << i)) {
- struct sdio_func *func = card->sdio_func[i - 1];
+ func = card->sdio_func[i - 1];
if (!func) {
printk(KERN_WARNING "%s: pending IRQ for "
"non-existent function\n",
@@ -186,6 +197,24 @@ static int sdio_card_irq_put(struct mmc_card *card)
return 0;
}
+/* If there is only 1 function registered set sdio_single_irq */
+static void sdio_single_irq_set(struct mmc_card *card)
+{
+ struct sdio_func *func;
+ int i;
+
+ card->sdio_single_irq = NULL;
+ if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
+ card->host->sdio_irqs == 1)
+ for (i = 0; i < card->sdio_funcs; i++) {
+ func = card->sdio_func[i];
+ if (func && func->irq_handler) {
+ card->sdio_single_irq = func;
+ break;
+ }
+ }
+}
+
/**
* sdio_claim_irq - claim the IRQ for a SDIO function
* @func: SDIO function
@@ -227,6 +256,7 @@ int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
ret = sdio_card_irq_get(func->card);
if (ret)
func->irq_handler = NULL;
+ sdio_single_irq_set(func->card);
return ret;
}
@@ -251,6 +281,7 @@ int sdio_release_irq(struct sdio_func *func)
if (func->irq_handler) {
func->irq_handler = NULL;
sdio_card_irq_put(func->card);
+ sdio_single_irq_set(func->card);
}
ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index adb4888..0d64211 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -145,6 +145,7 @@ struct mmc_card {
struct sdio_cccr cccr; /* common card info */
struct sdio_cis cis; /* common tuple info */
struct sdio_func *sdio_func[SDIO_MAX_FUNCS]; /* SDIO functions (devices) */
+ struct sdio_func *sdio_single_irq; /* SDIO function when only one IRQ active */
unsigned num_info; /* number of info strings */
const char **info; /* info strings */
struct sdio_func_tuple *tuples; /* unknown common tuples */
--
1.7.4.1
Hi Per,
On Thu, May 05 2011, Per Forlin wrote:
> From: Stefan Nilsson XK <[email protected]>
>
> If there is only 1 function interrupt registered it is possible to
> improve performance by directly calling the irq handler
> and avoiding the overhead of reading the CCCR registers.
>
> Signed-off-by: Per Forlin <[email protected]>
> Acked-by: Ulf Hansson <[email protected]>
> Reviewed-by: Nicolas Pitre <[email protected]>
> ---
> drivers/mmc/core/sdio_irq.c | 33 ++++++++++++++++++++++++++++++++-
> include/linux/mmc/card.h | 1 +
> 2 files changed, 33 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
> index b300161..03ead02 100644
> --- a/drivers/mmc/core/sdio_irq.c
> +++ b/drivers/mmc/core/sdio_irq.c
> @@ -31,6 +31,17 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
> {
> int i, ret, count;
> unsigned char pending;
> + struct sdio_func *func;
> +
> + /*
> + * Optimization, if there is only 1 function interrupt registered
> + * call irq handler directly
> + */
> + func = card->sdio_single_irq;
> + if (func) {
> + func->irq_handler(func);
> + return 1;
> + }
>
> ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
> if (ret) {
> @@ -42,7 +53,7 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
> count = 0;
> for (i = 1; i <= 7; i++) {
> if (pending & (1 << i)) {
> - struct sdio_func *func = card->sdio_func[i - 1];
> + func = card->sdio_func[i - 1];
> if (!func) {
> printk(KERN_WARNING "%s: pending IRQ for "
> "non-existent function\n",
> @@ -186,6 +197,24 @@ static int sdio_card_irq_put(struct mmc_card *card)
> return 0;
> }
>
> +/* If there is only 1 function registered set sdio_single_irq */
> +static void sdio_single_irq_set(struct mmc_card *card)
> +{
> + struct sdio_func *func;
> + int i;
> +
> + card->sdio_single_irq = NULL;
> + if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
> + card->host->sdio_irqs == 1)
> + for (i = 0; i < card->sdio_funcs; i++) {
> + func = card->sdio_func[i];
> + if (func && func->irq_handler) {
> + card->sdio_single_irq = func;
> + break;
> + }
> + }
> +}
> +
> /**
> * sdio_claim_irq - claim the IRQ for a SDIO function
> * @func: SDIO function
> @@ -227,6 +256,7 @@ int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
> ret = sdio_card_irq_get(func->card);
> if (ret)
> func->irq_handler = NULL;
> + sdio_single_irq_set(func->card);
>
> return ret;
> }
> @@ -251,6 +281,7 @@ int sdio_release_irq(struct sdio_func *func)
> if (func->irq_handler) {
> func->irq_handler = NULL;
> sdio_card_irq_put(func->card);
> + sdio_single_irq_set(func->card);
> }
>
> ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, ®);
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index adb4888..0d64211 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -145,6 +145,7 @@ struct mmc_card {
> struct sdio_cccr cccr; /* common card info */
> struct sdio_cis cis; /* common tuple info */
> struct sdio_func *sdio_func[SDIO_MAX_FUNCS]; /* SDIO functions (devices) */
> + struct sdio_func *sdio_single_irq; /* SDIO function when only one IRQ active */
> unsigned num_info; /* number of info strings */
> const char **info; /* info strings */
> struct sdio_func_tuple *tuples; /* unknown common tuples */
This patch doesn't apply cleanly -- please re-send against mmc-next.
Thanks,
- Chris.
--
Chris Ball <[email protected]> <http://printf.net/>
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