This patch supports non-blocking mmc request function for the sdchi driver.
(commit: aa8b683a7d392271ed349c6ab9f36b8c313794b7)
pre_req() runs dma_map_sg(), post_req() runs dma_unmap_sg. If not calling
pre_req() before sdhci_request(), dma_map_sg will be issued before
starting the transfer. It is optional to use pre_req(). If issuing
pre_req(), post_req() must be called as well.
benchmark results:
ARM CA9 1GHz, UHS DDR50 mode
Before:
dd if=/dev/mmcblk0p15 of=/dev/null bs=64k count=1024
67108864 bytes (64.0MB) copied, 1.188846 seconds, 53.8MB/s
After:
dd if=/dev/mmcblk0p15 of=/dev/null bs=64k count=1024
67108864 bytes (64.0MB) copied, 0.993098 seconds, 64.4MB/s
Signed-off-by: Chanho Min <chanho.min@xxxxxxx>
---
drivers/mmc/host/sdhci.c | 96 +++++++++++++++++++++++++++++++++++++++------
include/linux/mmc/sdhci.h | 6 +++
2 files changed, 90 insertions(+), 12 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2ea429c..0465a9a 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -465,6 +465,42 @@ static void sdhci_set_adma_desc(u8 *desc, u32 addr, int len, unsigned cmd)
dataddr[0] = cpu_to_le32(addr);
}
+static int sdhci_pre_dma_transfer(struct sdhci_host *host,
+ struct mmc_data *data,
+ struct sdhci_next *next)
+{
+ int sg_count = 0;
+
+ if (!next && data->host_cookie &&
+ data->host_cookie != host->next_data.cookie) {
+ pr_warn("[%s] invalid cookie: data->host_cookie %d"
+ " host->next_data.cookie %d\n",
+ __func__, data->host_cookie, host->next_data.cookie);
+ data->host_cookie = 0;
+ }
+
+ /* Check if next job is already prepared */
+ if (next ||
+ (!next && data->host_cookie != host->next_data.cookie)) {
+ sg_count = dma_map_sg(mmc_dev(host->mmc), data->sg,
+ data->sg_len,
+ (data->flags & MMC_DATA_READ) ?
+ DMA_FROM_DEVICE :
+ DMA_TO_DEVICE);
+ } else {
+ sg_count = host->next_data.sg_count;
+ host->next_data.sg_count = 0;
+ }
+
+ if (next) {
+ next->sg_count = sg_count;
+ data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;
+ } else
+ host->sg_count = sg_count;
+
+ return sg_count;
+}
+
static int sdhci_adma_table_pre(struct sdhci_host *host,
struct mmc_data *data)
{
@@ -502,8 +538,8 @@ static int sdhci_adma_table_pre(struct sdhci_host *host,
goto fail;
BUG_ON(host->align_addr & 0x3);
- host->sg_count = dma_map_sg(mmc_dev(host->mmc),
- data->sg, data->sg_len, direction);
+ host->sg_count = sdhci_pre_dma_transfer(host, data, NULL);
+
if (host->sg_count == 0)
goto unmap_align;
@@ -643,9 +679,10 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
}
}
}
-
- dma_unmap_sg(mmc_dev(host->mmc), data->sg,
- data->sg_len, direction);
+ if (!data->host_cookie) {
+ dma_unmap_sg(mmc_dev(host->mmc), data->sg,
+ data->sg_len, direction);
+ }
}
static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd)
@@ -824,12 +861,8 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
}
} else {
int sg_cnt;
+ sg_cnt = sdhci_pre_dma_transfer(host, data, NULL);
- sg_cnt = dma_map_sg(mmc_dev(host->mmc),
- data->sg, data->sg_len,
- (data->flags & MMC_DATA_READ) ?
- DMA_FROM_DEVICE :
- DMA_TO_DEVICE);
if (sg_cnt == 0) {
/*
* This only happens when someone fed
@@ -928,9 +961,12 @@ static void sdhci_finish_data(struct sdhci_host *host)
if (host->flags & SDHCI_USE_ADMA)
sdhci_adma_table_post(host, data);
else {
- dma_unmap_sg(mmc_dev(host->mmc), data->sg,
- data->sg_len, (data->flags & MMC_DATA_READ) ?
+ if (!data->host_cookie) {
+ dma_unmap_sg(mmc_dev(host->mmc), data->sg,
+ data->sg_len,
+ (data->flags & MMC_DATA_READ) ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
+ }
}
}
@@ -2066,8 +2102,42 @@ static void sdhci_card_event(struct mmc_host *mmc)
spin_unlock_irqrestore(&host->lock, flags);
}
+static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
+ int err)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct mmc_data *data = mrq->data;
+
+ if (host->flags & SDHCI_REQ_USE_DMA) {
+ dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+ (data->flags & MMC_DATA_READ) ?
+ DMA_FROM_DEVICE :
+ DMA_TO_DEVICE);
+ data->host_cookie = 0;
+ }
+}
+
+static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
+ bool is_first_req)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct mmc_data *data = mrq->data;
+
+ if (mrq->data->host_cookie) {
+ mrq->data->host_cookie = 0;
+ return;
+ }
+
+ if (host->flags & SDHCI_REQ_USE_DMA) {
+ if (!sdhci_pre_dma_transfer(host, data, &host->next_data))
+ mrq->data->host_cookie = 0;
+ }
+}
+
static const struct mmc_host_ops sdhci_ops = {
.request = sdhci_request,
+ .post_req = sdhci_post_req,
+ .pre_req = sdhci_pre_req,
.set_ios = sdhci_set_ios,
.get_cd = sdhci_get_cd,
.get_ro = sdhci_get_ro,
@@ -3204,6 +3274,8 @@ int sdhci_add_host(struct sdhci_host *host)
}
#endif
+ host->next_data.cookie = 1;
+
mmiowb();
mmc_add_host(mmc);
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index b838ffc..220a515 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -17,6 +17,11 @@
#include <linux/io.h>
#include <linux/mmc/host.h>
+struct sdhci_next {
+ unsigned int sg_count;
+ s32 cookie;
+};
+
struct sdhci_host {
/* Data set by hardware interface driver */
const char *hw_name; /* Hardware bus name */
@@ -177,5 +182,6 @@ struct sdhci_host {
struct timer_list tuning_timer; /* Timer for tuning */
unsigned long private[0] ____cacheline_aligned;
+ struct sdhci_next next_data;
};
#endif /* LINUX_MMC_SDHCI_H */
--
1.7.9.5
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