mmc: rtsx: add support for pre_req and post_req

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 CPU(for some embedded
platform).

Users can get a great benefit from this patch. if CPU frequency is 800MHz,
SDR104 or DDR50 card read/write speed may increase more than 15%.

test results:
intel i3(800MHz - 2.3GHz), SD card clock 208MHz

performance mode(2.3GHz):
Before:
dd if=/dev/mmcblk0p1 of=/dev/null bs=64k count=1024
67108864 bytes (67 MB) copied, 1.18191 s, 56.8 MB/s
After:
 dd if=/dev/mmcblk0p1 of=/dev/null bs=64k count=1024
67108864 bytes (67 MB) copied, 1.09276 s, 61.4 MB/s

powersave mode(800MHz):
Before:
dd if=/dev/mmcblk0p1 of=/dev/null bs=64k count=1024
67108864 bytes (67 MB) copied, 1.29569 s, 51.8 MB/s
After:
dd if=/dev/mmcblk0p1 of=/dev/null bs=64k count=1024
67108864 bytes (67 MB) copied, 1.11218 s, 60.3 MB/s
Signed-off-by: Micky Ching <micky_ching@realsil.com.cn>
Signed-off-by: Chris Ball <chris@printf.net>

drivers/mfd/rtsx_pcr.c

@@ -338,58 +338,28 @@ int rtsx_pci_transfer_data(struct rtsx_pcr *pcr, struct scatterlist *sglist,
 		int num_sg, bool read, int timeout)
 {
 	struct completion trans_done;
-	u8 dir;
-	int err = 0, i, count;
+	int err = 0, count;
 	long timeleft;
 	unsigned long flags;
-	struct scatterlist *sg;
-	enum dma_data_direction dma_dir;
-	u32 val;
-	dma_addr_t addr;
-	unsigned int len;
-
-	dev_dbg(&(pcr->pci->dev), "--> %s: num_sg = %d\n", __func__, num_sg);
-
-	/* don't transfer data during abort processing */
-	if (pcr->remove_pci)
-		return -EINVAL;
-
-	if ((sglist == NULL) || (num_sg <= 0))
-		return -EINVAL;
 
-	if (read) {
-		dir = DEVICE_TO_HOST;
-		dma_dir = DMA_FROM_DEVICE;
-	} else {
-		dir = HOST_TO_DEVICE;
-		dma_dir = DMA_TO_DEVICE;
-	}
-
-	count = dma_map_sg(&(pcr->pci->dev), sglist, num_sg, dma_dir);
+	count = rtsx_pci_dma_map_sg(pcr, sglist, num_sg, read);
 	if (count < 1) {
 		dev_err(&(pcr->pci->dev), "scatterlist map failed\n");
 		return -EINVAL;
 	}
 	dev_dbg(&(pcr->pci->dev), "DMA mapping count: %d\n", count);
 
-	val = ((u32)(dir & 0x01) << 29) | TRIG_DMA | ADMA_MODE;
-	pcr->sgi = 0;
-	for_each_sg(sglist, sg, count, i) {
-		addr = sg_dma_address(sg);
-		len = sg_dma_len(sg);
-		rtsx_pci_add_sg_tbl(pcr, addr, len, i == count - 1);
-	}
 
 	spin_lock_irqsave(&pcr->lock, flags);
 
 	pcr->done = &trans_done;
 	pcr->trans_result = TRANS_NOT_READY;
 	init_completion(&trans_done);
-	rtsx_pci_writel(pcr, RTSX_HDBAR, pcr->host_sg_tbl_addr);
-	rtsx_pci_writel(pcr, RTSX_HDBCTLR, val);
 
 	spin_unlock_irqrestore(&pcr->lock, flags);
 
+	rtsx_pci_dma_transfer(pcr, sglist, count, read);
+
 	timeleft = wait_for_completion_interruptible_timeout(
 			&trans_done, msecs_to_jiffies(timeout));
 	if (timeleft <= 0) {
@@ -413,7 +383,7 @@ int rtsx_pci_transfer_data(struct rtsx_pcr *pcr, struct scatterlist *sglist,
 	pcr->done = NULL;
 	spin_unlock_irqrestore(&pcr->lock, flags);
 
-	dma_unmap_sg(&(pcr->pci->dev), sglist, num_sg, dma_dir);
+	rtsx_pci_dma_unmap_sg(pcr, sglist, num_sg, read);
 
 	if ((err < 0) && (err != -ENODEV))
 		rtsx_pci_stop_cmd(pcr);
@@ -425,6 +395,73 @@ int rtsx_pci_transfer_data(struct rtsx_pcr *pcr, struct scatterlist *sglist,
 }
 EXPORT_SYMBOL_GPL(rtsx_pci_transfer_data);
 
+int rtsx_pci_dma_map_sg(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int num_sg, bool read)
+{
+	enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	if (pcr->remove_pci)
+		return -EINVAL;
+
+	if ((sglist == NULL) || num_sg < 1)
+		return -EINVAL;
+
+	return dma_map_sg(&(pcr->pci->dev), sglist, num_sg, dir);
+}
+EXPORT_SYMBOL_GPL(rtsx_pci_dma_map_sg);
+
+int rtsx_pci_dma_unmap_sg(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int num_sg, bool read)
+{
+	enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	if (pcr->remove_pci)
+		return -EINVAL;
+
+	if (sglist == NULL || num_sg < 1)
+		return -EINVAL;
+
+	dma_unmap_sg(&(pcr->pci->dev), sglist, num_sg, dir);
+	return num_sg;
+}
+EXPORT_SYMBOL_GPL(rtsx_pci_dma_unmap_sg);
+
+int rtsx_pci_dma_transfer(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int sg_count, bool read)
+{
+	struct scatterlist *sg;
+	dma_addr_t addr;
+	unsigned int len;
+	int i;
+	u32 val;
+	u8 dir = read ? DEVICE_TO_HOST : HOST_TO_DEVICE;
+	unsigned long flags;
+
+	if (pcr->remove_pci)
+		return -EINVAL;
+
+	if ((sglist == NULL) || (sg_count < 1))
+		return -EINVAL;
+
+	val = ((u32)(dir & 0x01) << 29) | TRIG_DMA | ADMA_MODE;
+	pcr->sgi = 0;
+	for_each_sg(sglist, sg, sg_count, i) {
+		addr = sg_dma_address(sg);
+		len = sg_dma_len(sg);
+		rtsx_pci_add_sg_tbl(pcr, addr, len, i == sg_count - 1);
+	}
+
+	spin_lock_irqsave(&pcr->lock, flags);
+
+	rtsx_pci_writel(pcr, RTSX_HDBAR, pcr->host_sg_tbl_addr);
+	rtsx_pci_writel(pcr, RTSX_HDBCTLR, val);
+
+	spin_unlock_irqrestore(&pcr->lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rtsx_pci_dma_transfer);
+
 int rtsx_pci_read_ppbuf(struct rtsx_pcr *pcr, u8 *buf, int buf_len)
 {
 	int err;
@@ -836,6 +873,8 @@ static irqreturn_t rtsx_pci_isr(int irq, void *dev_id)
 	int_reg = rtsx_pci_readl(pcr, RTSX_BIPR);
 	/* Clear interrupt flag */
 	rtsx_pci_writel(pcr, RTSX_BIPR, int_reg);
+	dev_dbg(&pcr->pci->dev, "=========== BIPR 0x%8x ==========\n", int_reg);
+
 	if ((int_reg & pcr->bier) == 0) {
 		spin_unlock(&pcr->lock);
 		return IRQ_NONE;
@@ -866,16 +905,27 @@ static irqreturn_t rtsx_pci_isr(int irq, void *dev_id)
 	}
 
 	if (int_reg & (NEED_COMPLETE_INT | DELINK_INT)) {
-		if (int_reg & (TRANS_FAIL_INT | DELINK_INT)) {
+		if (int_reg & (TRANS_FAIL_INT | DELINK_INT))
 			pcr->trans_result = TRANS_RESULT_FAIL;
-			if (pcr->done)
-				complete(pcr->done);
-		} else if (int_reg & TRANS_OK_INT) {
+		else if (int_reg & TRANS_OK_INT)
 			pcr->trans_result = TRANS_RESULT_OK;
+
 		if (pcr->done)
 			complete(pcr->done);
+
+		if (int_reg & SD_EXIST) {
+			struct rtsx_slot *slot = &pcr->slots[RTSX_SD_CARD];
+			if (slot && slot->done_transfer)
+				slot->done_transfer(slot->p_dev);
 		}
+
+		if (int_reg & MS_EXIST) {
+			struct rtsx_slot *slot = &pcr->slots[RTSX_SD_CARD];
+			if (slot && slot->done_transfer)
+				slot->done_transfer(slot->p_dev);
 		}
+	}
+
 
 	if (pcr->card_inserted || pcr->card_removed)
 		schedule_delayed_work(&pcr->carddet_work,

include/linux/mfd/rtsx_common.h

@@ -45,6 +45,7 @@ struct platform_device;
 struct rtsx_slot {
 	struct platform_device	*p_dev;
 	void			(*card_event)(struct platform_device *p_dev);
+	void			(*done_transfer)(struct platform_device *p_dev);
 };
 
 #endif

include/linux/mfd/rtsx_pci.h

@@ -943,6 +943,12 @@ void rtsx_pci_send_cmd_no_wait(struct rtsx_pcr *pcr);
 int rtsx_pci_send_cmd(struct rtsx_pcr *pcr, int timeout);
 int rtsx_pci_transfer_data(struct rtsx_pcr *pcr, struct scatterlist *sglist,
 		int num_sg, bool read, int timeout);
+int rtsx_pci_dma_map_sg(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int num_sg, bool read);
+int rtsx_pci_dma_unmap_sg(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int num_sg, bool read);
+int rtsx_pci_dma_transfer(struct rtsx_pcr *pcr, struct scatterlist *sglist,
+		int sg_count, bool read);
 int rtsx_pci_read_ppbuf(struct rtsx_pcr *pcr, u8 *buf, int buf_len);
 int rtsx_pci_write_ppbuf(struct rtsx_pcr *pcr, u8 *buf, int buf_len);
 int rtsx_pci_card_pull_ctl_enable(struct rtsx_pcr *pcr, int card);