[PATCH 1/2] mmc: dw_mmc: split out preparation of desc for IDMAC32 and IDMAC64

From: Shawn Lin
Date: Fri Aug 19 2016 - 05:56:11 EST


We intend to add more check for descriptors when
preparing desc. Let's spilt out the separate body
to make the dw_mci_translate_sglist not so lengthy.

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
---

drivers/mmc/host/dw_mmc.c | 148 +++++++++++++++++++++++++---------------------
1 file changed, 81 insertions(+), 67 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 32380d5..0a5a49f 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -467,103 +467,117 @@ static void dw_mci_dmac_complete_dma(void *arg)
}
}

-static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
- unsigned int sg_len)
+static inline void dw_mci_prepare_desc64(struct dw_mci *host,
+ struct mmc_data *data,
+ unsigned int sg_len)
{
unsigned int desc_len;
+ struct idmac_desc_64addr *desc_first, *desc_last, *desc;
int i;

- if (host->dma_64bit_address == 1) {
- struct idmac_desc_64addr *desc_first, *desc_last, *desc;
-
- desc_first = desc_last = desc = host->sg_cpu;
+ desc_first = desc_last = desc = host->sg_cpu;

- for (i = 0; i < sg_len; i++) {
- unsigned int length = sg_dma_len(&data->sg[i]);
+ for (i = 0; i < sg_len; i++) {
+ unsigned int length = sg_dma_len(&data->sg[i]);

- u64 mem_addr = sg_dma_address(&data->sg[i]);
+ u64 mem_addr = sg_dma_address(&data->sg[i]);

- for ( ; length ; desc++) {
- desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
- length : DW_MCI_DESC_DATA_LENGTH;
+ for ( ; length ; desc++) {
+ desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
+ length : DW_MCI_DESC_DATA_LENGTH;

- length -= desc_len;
+ length -= desc_len;

- /*
- * Set the OWN bit and disable interrupts
- * for this descriptor
- */
- desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
- IDMAC_DES0_CH;
+ /*
+ * Set the OWN bit and disable interrupts
+ * for this descriptor
+ */
+ desc->des0 = IDMAC_DES0_OWN | IDMAC_DES0_DIC |
+ IDMAC_DES0_CH;

- /* Buffer length */
- IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, desc_len);
+ /* Buffer length */
+ IDMAC_64ADDR_SET_BUFFER1_SIZE(desc, desc_len);

- /* Physical address to DMA to/from */
- desc->des4 = mem_addr & 0xffffffff;
- desc->des5 = mem_addr >> 32;
+ /* Physical address to DMA to/from */
+ desc->des4 = mem_addr & 0xffffffff;
+ desc->des5 = mem_addr >> 32;

- /* Update physical address for the next desc */
- mem_addr += desc_len;
+ /* Update physical address for the next desc */
+ mem_addr += desc_len;

- /* Save pointer to the last descriptor */
- desc_last = desc;
- }
+ /* Save pointer to the last descriptor */
+ desc_last = desc;
}
+ }

- /* Set first descriptor */
- desc_first->des0 |= IDMAC_DES0_FD;
+ /* Set first descriptor */
+ desc_first->des0 |= IDMAC_DES0_FD;

- /* Set last descriptor */
- desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
- desc_last->des0 |= IDMAC_DES0_LD;
+ /* Set last descriptor */
+ desc_last->des0 &= ~(IDMAC_DES0_CH | IDMAC_DES0_DIC);
+ desc_last->des0 |= IDMAC_DES0_LD;
+}

- } else {
- struct idmac_desc *desc_first, *desc_last, *desc;

- desc_first = desc_last = desc = host->sg_cpu;
+static inline void dw_mci_prepare_desc32(struct dw_mci *host,
+ struct mmc_data *data,
+ unsigned int sg_len)
+{
+ unsigned int desc_len;
+ struct idmac_desc *desc_first, *desc_last, *desc;
+ int i;

- for (i = 0; i < sg_len; i++) {
- unsigned int length = sg_dma_len(&data->sg[i]);
+ desc_first = desc_last = desc = host->sg_cpu;

- u32 mem_addr = sg_dma_address(&data->sg[i]);
+ for (i = 0; i < sg_len; i++) {
+ unsigned int length = sg_dma_len(&data->sg[i]);

- for ( ; length ; desc++) {
- desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
- length : DW_MCI_DESC_DATA_LENGTH;
+ u32 mem_addr = sg_dma_address(&data->sg[i]);

- length -= desc_len;
+ for ( ; length ; desc++) {
+ desc_len = (length <= DW_MCI_DESC_DATA_LENGTH) ?
+ length : DW_MCI_DESC_DATA_LENGTH;

- /*
- * Set the OWN bit and disable interrupts
- * for this descriptor
- */
- desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
- IDMAC_DES0_DIC |
- IDMAC_DES0_CH);
+ length -= desc_len;

- /* Buffer length */
- IDMAC_SET_BUFFER1_SIZE(desc, desc_len);
+ /*
+ * Set the OWN bit and disable interrupts
+ * for this descriptor
+ */
+ desc->des0 = cpu_to_le32(IDMAC_DES0_OWN |
+ IDMAC_DES0_DIC |
+ IDMAC_DES0_CH);

- /* Physical address to DMA to/from */
- desc->des2 = cpu_to_le32(mem_addr);
+ /* Buffer length */
+ IDMAC_SET_BUFFER1_SIZE(desc, desc_len);

- /* Update physical address for the next desc */
- mem_addr += desc_len;
+ /* Physical address to DMA to/from */
+ desc->des2 = cpu_to_le32(mem_addr);

- /* Save pointer to the last descriptor */
- desc_last = desc;
- }
+ /* Update physical address for the next desc */
+ mem_addr += desc_len;
+
+ /* Save pointer to the last descriptor */
+ desc_last = desc;
}
+ }

- /* Set first descriptor */
- desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);
+ /* Set first descriptor */
+ desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);

- /* Set last descriptor */
- desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
- IDMAC_DES0_DIC));
- desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
- }
+ /* Set last descriptor */
+ desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
+ IDMAC_DES0_DIC));
+ desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
+}
+
+static void dw_mci_translate_sglist(struct dw_mci *host, struct mmc_data *data,
+ unsigned int sg_len)
+{
+ if (host->dma_64bit_address == 1)
+ dw_mci_prepare_desc64(host, data, sg_len);
+ else
+ dw_mci_prepare_desc32(host, data, sg_len);

wmb(); /* drain writebuffer */
}
--
2.3.7