[PATCH 2/2] mmc: rtsx: add support for async request

From: micky_ching
Date: Fri Jun 06 2014 - 03:01:59 EST


From: Micky Ching <micky_ching@xxxxxxxxxxxxxx>

Add support for non-blocking request, pre_req() runs dma_map_sg() and
post_req() runs dma_unmap_sg(). This patch can increase card read/write
speed, especially for high speed card and slow speed CPU.

Test on intel i3(800MHz - 2.3GHz) performance mode(2.3GHz), SD card
clock 208MHz

run dd if=/dev/mmcblk0 of=/dev/null bs=64k count=1024
before:
67108864 bytes (67 MB) copied, 0.85427 s, 78.6 MB/s
after:
67108864 bytes (67 MB) copied, 0.74799 s, 89.7 MB/s

Signed-off-by: Micky Ching <micky_ching@xxxxxxxxxxxxxx>
---
drivers/mmc/host/rtsx_pci_sdmmc.c | 133 +++++++++++++++++++++++++++++++++++--
1 file changed, 127 insertions(+), 6 deletions(-)

diff --git a/drivers/mmc/host/rtsx_pci_sdmmc.c b/drivers/mmc/host/rtsx_pci_sdmmc.c
index 1c68e0d..a2c0858 100644
--- a/drivers/mmc/host/rtsx_pci_sdmmc.c
+++ b/drivers/mmc/host/rtsx_pci_sdmmc.c
@@ -24,6 +24,7 @@
#include <linux/highmem.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
+#include <linux/workqueue.h>
#include <linux/mmc/host.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
@@ -36,7 +37,10 @@ struct realtek_pci_sdmmc {
struct rtsx_pcr *pcr;
struct mmc_host *mmc;
struct mmc_request *mrq;
+ struct workqueue_struct *workq;
+#define SDMMC_WORKQ_NAME "rtsx_pci_sdmmc_workq"

+ struct work_struct work;
struct mutex host_mutex;

u8 ssc_depth;
@@ -48,6 +52,11 @@ struct realtek_pci_sdmmc {
int power_state;
#define SDMMC_POWER_ON 1
#define SDMMC_POWER_OFF 0
+
+ unsigned int sg_count;
+ s32 cookie;
+ unsigned int cookie_sg_count;
+ bool using_cookie;
};

static inline struct device *sdmmc_dev(struct realtek_pci_sdmmc *host)
@@ -86,6 +95,77 @@ static void sd_print_debug_regs(struct realtek_pci_sdmmc *host)
#define sd_print_debug_regs(host)
#endif /* DEBUG */

+/*
+ * sd_pre_dma_transfer - do dma_map_sg() or using cookie
+ *
+ * @pre: if called in pre_req()
+ * return:
+ * 0 - do dma_map_sg()
+ * 1 - using cookie
+ */
+static int sd_pre_dma_transfer(struct realtek_pci_sdmmc *host,
+ struct mmc_data *data, bool pre)
+{
+ struct rtsx_pcr *pcr = host->pcr;
+ int read = data->flags & MMC_DATA_READ;
+ int count = 0;
+ int using_cookie = 0;
+
+ if (!pre && data->host_cookie && data->host_cookie != host->cookie) {
+ dev_err(sdmmc_dev(host),
+ "error: data->host_cookie = %d, host->cookie = %d\n",
+ data->host_cookie, host->cookie);
+ data->host_cookie = 0;
+ }
+
+ if (pre || data->host_cookie != host->cookie) {
+ count = rtsx_pci_dma_map_sg(pcr, data->sg, data->sg_len, read);
+ } else {
+ count = host->cookie_sg_count;
+ using_cookie = 1;
+ }
+
+ if (pre) {
+ host->cookie_sg_count = count;
+ if (++host->cookie < 0)
+ host->cookie = 1;
+ data->host_cookie = host->cookie;
+ } else {
+ host->sg_count = count;
+ }
+
+ return using_cookie;
+}
+
+static void sdmmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
+ bool is_first_req)
+{
+ struct realtek_pci_sdmmc *host = mmc_priv(mmc);
+ struct mmc_data *data = mrq->data;
+
+ if (data->host_cookie) {
+ dev_err(sdmmc_dev(host),
+ "error: reset data->host_cookie = %d\n",
+ data->host_cookie);
+ data->host_cookie = 0;
+ }
+
+ sd_pre_dma_transfer(host, data, true);
+ dev_dbg(sdmmc_dev(host), "pre dma sg: %d\n", host->cookie_sg_count);
+}
+
+static void sdmmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
+ int err)
+{
+ struct realtek_pci_sdmmc *host = mmc_priv(mmc);
+ struct rtsx_pcr *pcr = host->pcr;
+ struct mmc_data *data = mrq->data;
+ int read = data->flags & MMC_DATA_READ;
+
+ rtsx_pci_dma_unmap_sg(pcr, data->sg, data->sg_len, read);
+ data->host_cookie = 0;
+}
+
static int sd_read_data(struct realtek_pci_sdmmc *host, u8 *cmd, u16 byte_cnt,
u8 *buf, int buf_len, int timeout)
{
@@ -415,7 +495,7 @@ static int sd_rw_multi(struct realtek_pci_sdmmc *host, struct mmc_request *mrq)

rtsx_pci_send_cmd_no_wait(pcr);

- err = rtsx_pci_transfer_data(pcr, data->sg, data->sg_len, read, 10000);
+ err = rtsx_pci_dma_transfer(pcr, data->sg, host->sg_count, read, 10000);
if (err < 0) {
sd_clear_error(host);
return err;
@@ -640,12 +720,24 @@ static int sd_tuning_rx(struct realtek_pci_sdmmc *host, u8 opcode)
return 0;
}

-static void sdmmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+static inline int sd_rw_cmd(struct mmc_command *cmd)
{
- struct realtek_pci_sdmmc *host = mmc_priv(mmc);
+ return mmc_op_multi(cmd->opcode) ||
+ (cmd->opcode == MMC_READ_SINGLE_BLOCK) ||
+ (cmd->opcode == MMC_WRITE_BLOCK);
+}
+
+static void sd_request(struct work_struct *work)
+{
+ struct realtek_pci_sdmmc *host = container_of(work,
+ struct realtek_pci_sdmmc, work);
struct rtsx_pcr *pcr = host->pcr;
+
+ struct mmc_host *mmc = host->mmc;
+ struct mmc_request *mrq = host->mrq;
struct mmc_command *cmd = mrq->cmd;
struct mmc_data *data = mrq->data;
+
unsigned int data_size = 0;
int err;

@@ -677,13 +769,13 @@ static void sdmmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
if (mrq->data)
data_size = data->blocks * data->blksz;

- if (!data_size || mmc_op_multi(cmd->opcode) ||
- (cmd->opcode == MMC_READ_SINGLE_BLOCK) ||
- (cmd->opcode == MMC_WRITE_BLOCK)) {
+ if (!data_size || sd_rw_cmd(cmd)) {
sd_send_cmd_get_rsp(host, cmd);

if (!cmd->error && data_size) {
sd_rw_multi(host, mrq);
+ if (!host->using_cookie)
+ sdmmc_post_req(host->mmc, host->mrq, 0);

if (mmc_op_multi(cmd->opcode) && mrq->stop)
sd_send_cmd_get_rsp(host, mrq->stop);
@@ -712,6 +804,21 @@ finish:
mmc_request_done(mmc, mrq);
}

+static void sdmmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+ struct realtek_pci_sdmmc *host = mmc_priv(mmc);
+ struct mmc_data *data = mrq->data;
+
+ mutex_lock(&host->host_mutex);
+ host->mrq = mrq;
+ mutex_unlock(&host->host_mutex);
+
+ if (sd_rw_cmd(mrq->cmd))
+ host->using_cookie = sd_pre_dma_transfer(host, data, false);
+
+ queue_work(host->workq, &host->work);
+}
+
static int sd_set_bus_width(struct realtek_pci_sdmmc *host,
unsigned char bus_width)
{
@@ -1144,6 +1251,8 @@ out:
}

static const struct mmc_host_ops realtek_pci_sdmmc_ops = {
+ .pre_req = sdmmc_pre_req,
+ .post_req = sdmmc_post_req,
.request = sdmmc_request,
.set_ios = sdmmc_set_ios,
.get_ro = sdmmc_get_ro,
@@ -1222,10 +1331,16 @@ static int rtsx_pci_sdmmc_drv_probe(struct platform_device *pdev)
return -ENOMEM;

host = mmc_priv(mmc);
+ host->workq = create_singlethread_workqueue(SDMMC_WORKQ_NAME);
+ if (!host->workq) {
+ mmc_free_host(mmc);
+ return -ENOMEM;
+ }
host->pcr = pcr;
host->mmc = mmc;
host->pdev = pdev;
host->power_state = SDMMC_POWER_OFF;
+ INIT_WORK(&host->work, sd_request);
platform_set_drvdata(pdev, host);
pcr->slots[RTSX_SD_CARD].p_dev = pdev;
pcr->slots[RTSX_SD_CARD].card_event = rtsx_pci_sdmmc_card_event;
@@ -1253,6 +1368,8 @@ static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
pcr->slots[RTSX_SD_CARD].card_event = NULL;
mmc = host->mmc;

+ cancel_work_sync(&host->work);
+
mutex_lock(&host->host_mutex);
if (host->mrq) {
dev_dbg(&(pdev->dev),
@@ -1271,6 +1388,10 @@ static int rtsx_pci_sdmmc_drv_remove(struct platform_device *pdev)
mmc_remove_host(mmc);
host->eject = true;

+ flush_workqueue(host->workq);
+ destroy_workqueue(host->workq);
+ host->workq = NULL;
+
mmc_free_host(mmc);

dev_dbg(&(pdev->dev),
--
1.7.9.5

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