mmc: msm_sdcc: Add correct DMA limitations and some cleanup
1) dma_map_sg() should be called before sg_dma_address()
is passed to dmov. This makes sure that buffer adresses
are bounced if present in HIGH_MEM region.
2) The maximum length of data transfer that DMA
can handle in box mode while operating with SDCC
would be 4095 (rows(64K-1)*fifo_size(64)) KiB.
It is likely that upper layers can send more
data than this as suggested by host->max_seg_size.
The data mover hangs if such requests are passed
to driver. Fix this by limiting box mode command
to handle only requests upto 4095KiB and iterate
over many such commands for larger requests.
3) Increase NR_SG to 128 for optimal performance.
4) Clean up hardcoded values to proper macros in .h file
Change-Id: I06d53396a639e2108f87022a2eef6822dda88305
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
diff --git a/drivers/mmc/host/msm_sdcc.h b/drivers/mmc/host/msm_sdcc.h
index 580da82..ca3eed8 100644
--- a/drivers/mmc/host/msm_sdcc.h
+++ b/drivers/mmc/host/msm_sdcc.h
@@ -207,7 +207,7 @@
#define MCI_FIFOHALFSIZE (MCI_FIFOSIZE / 2)
-#define NR_SG 32
+#define NR_SG 128
#define MSM_MMC_IDLE_TIMEOUT 5000 /* msecs */
@@ -217,10 +217,46 @@
*/
#define MSM_MMC_REQ_TIMEOUT 10000 /* msecs */
+/*
+ * Controller HW limitations
+ */
+#define MCI_DATALENGTH_BITS 25
+#define MMC_MAX_REQ_SIZE ((1 << MCI_DATALENGTH_BITS) - 1)
+/* MCI_DATA_CTL BLOCKSIZE up to 4096 */
+#define MMC_MAX_BLK_SIZE 4096
+#define MMC_MIN_BLK_SIZE 512
+#define MMC_MAX_BLK_CNT (MMC_MAX_REQ_SIZE / MMC_MIN_BLK_SIZE)
+
+/* 64KiB */
+#define MAX_SG_SIZE (64 * 1024)
+#define MAX_NR_SG_DMA_PIO (MMC_MAX_REQ_SIZE / MAX_SG_SIZE)
+
+/*
+ * BAM limitations
+ */
+/* upto 16 bits (64K - 1) */
+#define SPS_MAX_DESC_FIFO_SIZE 65535
+/* 16KiB */
+#define SPS_MAX_DESC_SIZE (16 * 1024)
+/* Each descriptor is of length 8 bytes */
+#define SPS_MAX_DESC_LENGTH 8
+#define SPS_MAX_DESCS (SPS_MAX_DESC_FIFO_SIZE / SPS_MAX_DESC_LENGTH)
+#define SPS_MAX_SG_DESCS (MAX_SG_SIZE / SPS_MAX_DESC_SIZE)
+#define MAX_NR_SG_SPS (SPS_MAX_DESCS / SPS_MAX_SG_DESCS)
+
+/*
+ * DMA limitations
+ */
+/* upto 16 bits (64K - 1) */
+#define MMC_MAX_DMA_ROWS (64 * 1024 - 1)
+#define MMC_MAX_DMA_BOX_LENGTH (MMC_MAX_DMA_ROWS * MCI_FIFOSIZE)
+#define MMC_MAX_DMA_CMDS (MAX_NR_SG_DMA_PIO * (MMC_MAX_REQ_SIZE / \
+ MMC_MAX_DMA_BOX_LENGTH))
+
struct clk;
struct msmsdcc_nc_dmadata {
- dmov_box cmd[NR_SG];
+ dmov_box cmd[MMC_MAX_DMA_CMDS];
uint32_t cmdptr;
};