Re: [PATCH v2 1/4] mmc: dw_mmc: split out preparation of desc for IDMAC32 and IDMAC64

From: Jaehoon Chung
Date: Thu Sep 22 2016 - 00:26:12 EST


On 09/02/2016 01:14 PM, Shawn Lin wrote:
> 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.
> After spliting out these two functions, we could
> remove dw_mci_translate_sglist and call both of them
> when staring idmac.

Applied on my tree. Thanks!

Best Regards,
Jaehoon Chung

>
> Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>
> ---
>
> Changes in v2:
> - remove dw_mci_translate_sglist
>
> drivers/mmc/host/dw_mmc.c | 149 ++++++++++++++++++++++++----------------------
> 1 file changed, 79 insertions(+), 70 deletions(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 22dacae..782b303 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -467,112 +467,121 @@ 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;
> - }
> - }
> -
> - /* Set first descriptor */
> - desc_first->des0 |= cpu_to_le32(IDMAC_DES0_FD);
> + /* Update physical address for the next desc */
> + mem_addr += desc_len;
>
> - /* Set last descriptor */
> - desc_last->des0 &= cpu_to_le32(~(IDMAC_DES0_CH |
> - IDMAC_DES0_DIC));
> - desc_last->des0 |= cpu_to_le32(IDMAC_DES0_LD);
> + /* Save pointer to the last descriptor */
> + desc_last = desc;
> + }
> }
>
> - wmb(); /* drain writebuffer */
> + /* 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);
> }
>
> static int dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
> {
> u32 temp;
>
> - dw_mci_translate_sglist(host, host->data, sg_len);
> + if (host->dma_64bit_address == 1)
> + dw_mci_prepare_desc64(host, host->data, sg_len);
> + else
> + dw_mci_prepare_desc32(host, host->data, sg_len);
> +
> + /* drain writebuffer */
> + wmb();
>
> /* Make sure to reset DMA in case we did PIO before this */
> dw_mci_ctrl_reset(host, SDMMC_CTRL_DMA_RESET);
>