mmc: tmio: simplify the DMA mode test
diff mbox series

Message ID 1539356588-18191-1-git-send-email-yamada.masahiro@socionext.com
State New
Headers show
Series
  • mmc: tmio: simplify the DMA mode test
Related show

Commit Message

Masahiro Yamada Oct. 12, 2018, 3:03 p.m. UTC
host->chan_{rx,tx} represents the DMA capability of the platform.
Even if DMA is supported, there are cases where we want to use PIO,
for example, data length is short enough as commit 5f52c3552946
("mmc: tmio: use PIO for short transfers") mentioned.

Regarding the hardware control flow, we are interested in whether DMA
is currently enabled or not, instead of whether the platform has the
DMA capability.

Hence, the several conditionals in tmio_mmc_core.c end up with
checking host->chan_{rx,tx} and !host->force_pio. This is not nice.

Let's flip the flag host->force_pio into host->dma_on.

host->dma_on represents whether the DMA is currently enabled or not.
This flag is set false in the beginning of each command, then should
be set true by tmio_mmc_start_dma() when the DMA is turned on.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/mmc/host/renesas_sdhi_internal_dmac.c |  3 ++-
 drivers/mmc/host/renesas_sdhi_sys_dmac.c      | 10 ++++------
 drivers/mmc/host/tmio_mmc.h                   |  2 +-
 drivers/mmc/host/tmio_mmc_core.c              | 14 +++++++-------
 drivers/mmc/host/uniphier-sd.c                |  6 ++++--
 5 files changed, 18 insertions(+), 17 deletions(-)

Comments

Wolfram Sang Oct. 14, 2018, 10:36 p.m. UTC | #1
On Sat, Oct 13, 2018 at 12:03:08AM +0900, Masahiro Yamada wrote:
> host->chan_{rx,tx} represents the DMA capability of the platform.
> Even if DMA is supported, there are cases where we want to use PIO,
> for example, data length is short enough as commit 5f52c3552946
> ("mmc: tmio: use PIO for short transfers") mentioned.
> 
> Regarding the hardware control flow, we are interested in whether DMA
> is currently enabled or not, instead of whether the platform has the
> DMA capability.
> 
> Hence, the several conditionals in tmio_mmc_core.c end up with
> checking host->chan_{rx,tx} and !host->force_pio. This is not nice.
> 
> Let's flip the flag host->force_pio into host->dma_on.
> 
> host->dma_on represents whether the DMA is currently enabled or not.
> This flag is set false in the beginning of each command, then should
> be set true by tmio_mmc_start_dma() when the DMA is turned on.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

I like it. Much easier to read!

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Also here, I'd like to test this on Monday on some more devices.
Wolfram Sang Oct. 15, 2018, 11:33 a.m. UTC | #2
On Mon, Oct 15, 2018 at 12:36:36AM +0200, Wolfram Sang wrote:
> On Sat, Oct 13, 2018 at 12:03:08AM +0900, Masahiro Yamada wrote:
> > host->chan_{rx,tx} represents the DMA capability of the platform.
> > Even if DMA is supported, there are cases where we want to use PIO,
> > for example, data length is short enough as commit 5f52c3552946
> > ("mmc: tmio: use PIO for short transfers") mentioned.
> > 
> > Regarding the hardware control flow, we are interested in whether DMA
> > is currently enabled or not, instead of whether the platform has the
> > DMA capability.
> > 
> > Hence, the several conditionals in tmio_mmc_core.c end up with
> > checking host->chan_{rx,tx} and !host->force_pio. This is not nice.
> > 
> > Let's flip the flag host->force_pio into host->dma_on.
> > 
> > host->dma_on represents whether the DMA is currently enabled or not.
> > This flag is set false in the beginning of each command, then should
> > be set true by tmio_mmc_start_dma() when the DMA is turned on.
> > 
> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> 
> I like it. Much easier to read!
> 
> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Tested on R-Car H3 ES1.0 and ES2.0, M3N, and H2. No regressions,
especially no performance regressions (since "when to enable DMA" code
was refactored).

Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Ulf Hansson Oct. 15, 2018, 1:15 p.m. UTC | #3
On 12 October 2018 at 17:03, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> host->chan_{rx,tx} represents the DMA capability of the platform.
> Even if DMA is supported, there are cases where we want to use PIO,
> for example, data length is short enough as commit 5f52c3552946
> ("mmc: tmio: use PIO for short transfers") mentioned.
>
> Regarding the hardware control flow, we are interested in whether DMA
> is currently enabled or not, instead of whether the platform has the
> DMA capability.
>
> Hence, the several conditionals in tmio_mmc_core.c end up with
> checking host->chan_{rx,tx} and !host->force_pio. This is not nice.
>
> Let's flip the flag host->force_pio into host->dma_on.
>
> host->dma_on represents whether the DMA is currently enabled or not.
> This flag is set false in the beginning of each command, then should
> be set true by tmio_mmc_start_dma() when the DMA is turned on.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Applied for next, thanks!

Kind regards
Uffe

> ---
>
>  drivers/mmc/host/renesas_sdhi_internal_dmac.c |  3 ++-
>  drivers/mmc/host/renesas_sdhi_sys_dmac.c      | 10 ++++------
>  drivers/mmc/host/tmio_mmc.h                   |  2 +-
>  drivers/mmc/host/tmio_mmc_core.c              | 14 +++++++-------
>  drivers/mmc/host/uniphier-sd.c                |  6 ++++--
>  5 files changed, 18 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> index ca0b439..885676b 100644
> --- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> +++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
> @@ -201,13 +201,14 @@ renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
>         renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
>                                             sg_dma_address(sg));
>
> +       host->dma_on = true;
> +
>         return;
>
>  force_pio_with_unmap:
>         dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));
>
>  force_pio:
> -       host->force_pio = true;
>         renesas_sdhi_internal_dmac_enable_dma(host, false);
>  }
>
> diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> index 5389c48..3c97831 100644
> --- a/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> +++ b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
> @@ -213,10 +213,8 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
>                 goto pio;
>         }
>
> -       if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
> -               host->force_pio = true;
> +       if (sg->length < TMIO_MMC_MIN_DMA_LEN)
>                 return;
> -       }
>
>         /* The only sg element can be unaligned, use our bounce buffer then */
>         if (!aligned) {
> @@ -240,6 +238,7 @@ static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
>                         desc = NULL;
>                         ret = cookie;
>                 }
> +               host->dma_on = true;
>         }
>  pio:
>         if (!desc) {
> @@ -286,10 +285,8 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
>                 goto pio;
>         }
>
> -       if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
> -               host->force_pio = true;
> +       if (sg->length < TMIO_MMC_MIN_DMA_LEN)
>                 return;
> -       }
>
>         /* The only sg element can be unaligned, use our bounce buffer then */
>         if (!aligned) {
> @@ -318,6 +315,7 @@ static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
>                         desc = NULL;
>                         ret = cookie;
>                 }
> +               host->dma_on = true;
>         }
>  pio:
>         if (!desc) {
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index 18b4308..1c3bdad 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -142,7 +142,7 @@ struct tmio_mmc_host {
>         struct tmio_mmc_data *pdata;
>
>         /* DMA support */
> -       bool                    force_pio;
> +       bool                    dma_on;
>         struct dma_chan         *chan_rx;
>         struct dma_chan         *chan_tx;
>         struct tasklet_struct   dma_issue;
> diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
> index a571106..38be3fc 100644
> --- a/drivers/mmc/host/tmio_mmc_core.c
> +++ b/drivers/mmc/host/tmio_mmc_core.c
> @@ -364,7 +364,7 @@ static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
>         unsigned int count;
>         unsigned long flags;
>
> -       if ((host->chan_tx || host->chan_rx) && !host->force_pio) {
> +       if (host->dma_on) {
>                 pr_err("PIO IRQ in DMA mode!\n");
>                 return;
>         } else if (!data) {
> @@ -436,7 +436,7 @@ void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
>          */
>
>         if (data->flags & MMC_DATA_READ) {
> -               if (host->chan_rx && !host->force_pio)
> +               if (host->dma_on)
>                         tmio_mmc_check_bounce_buffer(host);
>                 dev_dbg(&host->pdev->dev, "Complete Rx request %p\n",
>                         host->mrq);
> @@ -473,7 +473,7 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
>         if (stat & TMIO_STAT_CRCFAIL || stat & TMIO_STAT_STOPBIT_ERR ||
>             stat & TMIO_STAT_TXUNDERRUN)
>                 data->error = -EILSEQ;
> -       if (host->chan_tx && (data->flags & MMC_DATA_WRITE) && !host->force_pio) {
> +       if (host->dma_on && (data->flags & MMC_DATA_WRITE)) {
>                 u32 status = sd_ctrl_read16_and_16_as_32(host, CTL_STATUS);
>                 bool done = false;
>
> @@ -497,7 +497,7 @@ static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
>                         tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
>                         tmio_mmc_dataend_dma(host);
>                 }
> -       } else if (host->chan_rx && (data->flags & MMC_DATA_READ) && !host->force_pio) {
> +       } else if (host->dma_on && (data->flags & MMC_DATA_READ)) {
>                 tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
>                 tmio_mmc_dataend_dma(host);
>         } else {
> @@ -550,7 +550,7 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
>          */
>         if (host->data && (!cmd->error || cmd->error == -EILSEQ)) {
>                 if (host->data->flags & MMC_DATA_READ) {
> -                       if (host->force_pio || !host->chan_rx) {
> +                       if (!host->dma_on) {
>                                 tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_READOP);
>                         } else {
>                                 tmio_mmc_disable_mmc_irqs(host,
> @@ -558,7 +558,7 @@ static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
>                                 tasklet_schedule(&host->dma_issue);
>                         }
>                 } else {
> -                       if (host->force_pio || !host->chan_tx) {
> +                       if (!host->dma_on) {
>                                 tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_WRITEOP);
>                         } else {
>                                 tmio_mmc_disable_mmc_irqs(host,
> @@ -688,7 +688,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
>
>         tmio_mmc_init_sg(host, data);
>         host->data = data;
> -       host->force_pio = false;
> +       host->dma_on = false;
>
>         /* Set transfer length / blocksize */
>         sd_ctrl_write16(host, CTL_SD_XFER_LEN, data->blksz);
> diff --git a/drivers/mmc/host/uniphier-sd.c b/drivers/mmc/host/uniphier-sd.c
> index 1ee9fd0..91a2be4 100644
> --- a/drivers/mmc/host/uniphier-sd.c
> +++ b/drivers/mmc/host/uniphier-sd.c
> @@ -157,13 +157,14 @@ static void uniphier_sd_external_dma_start(struct tmio_mmc_host *host,
>         if (cookie < 0)
>                 goto unmap_sg;
>
> +       host->dma_on = true;
> +
>         return;
>
>  unmap_sg:
>         dma_unmap_sg(mmc_dev(host->mmc), host->sg_ptr, host->sg_len,
>                      priv->dma_dir);
>  force_pio:
> -       host->force_pio = true;
>         uniphier_sd_dma_endisable(host, 0);
>  }
>
> @@ -283,9 +284,10 @@ static void uniphier_sd_internal_dma_start(struct tmio_mmc_host *host,
>         writel(lower_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_L);
>         writel(upper_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_H);
>
> +       host->dma_on = true;
> +
>         return;
>  force_pio:
> -       host->force_pio = true;
>         uniphier_sd_dma_endisable(host, 0);
>  }
>
> --
> 2.7.4
>

Patch
diff mbox series

diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
index ca0b439..885676b 100644
--- a/drivers/mmc/host/renesas_sdhi_internal_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -201,13 +201,14 @@  renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
 	renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
 					    sg_dma_address(sg));
 
+	host->dma_on = true;
+
 	return;
 
 force_pio_with_unmap:
 	dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));
 
 force_pio:
-	host->force_pio = true;
 	renesas_sdhi_internal_dmac_enable_dma(host, false);
 }
 
diff --git a/drivers/mmc/host/renesas_sdhi_sys_dmac.c b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
index 5389c48..3c97831 100644
--- a/drivers/mmc/host/renesas_sdhi_sys_dmac.c
+++ b/drivers/mmc/host/renesas_sdhi_sys_dmac.c
@@ -213,10 +213,8 @@  static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
 		goto pio;
 	}
 
-	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
-		host->force_pio = true;
+	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
 		return;
-	}
 
 	/* The only sg element can be unaligned, use our bounce buffer then */
 	if (!aligned) {
@@ -240,6 +238,7 @@  static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
 			desc = NULL;
 			ret = cookie;
 		}
+		host->dma_on = true;
 	}
 pio:
 	if (!desc) {
@@ -286,10 +285,8 @@  static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
 		goto pio;
 	}
 
-	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
-		host->force_pio = true;
+	if (sg->length < TMIO_MMC_MIN_DMA_LEN)
 		return;
-	}
 
 	/* The only sg element can be unaligned, use our bounce buffer then */
 	if (!aligned) {
@@ -318,6 +315,7 @@  static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
 			desc = NULL;
 			ret = cookie;
 		}
+		host->dma_on = true;
 	}
 pio:
 	if (!desc) {
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 18b4308..1c3bdad 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -142,7 +142,7 @@  struct tmio_mmc_host {
 	struct tmio_mmc_data *pdata;
 
 	/* DMA support */
-	bool			force_pio;
+	bool			dma_on;
 	struct dma_chan		*chan_rx;
 	struct dma_chan		*chan_tx;
 	struct tasklet_struct	dma_issue;
diff --git a/drivers/mmc/host/tmio_mmc_core.c b/drivers/mmc/host/tmio_mmc_core.c
index a571106..38be3fc 100644
--- a/drivers/mmc/host/tmio_mmc_core.c
+++ b/drivers/mmc/host/tmio_mmc_core.c
@@ -364,7 +364,7 @@  static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
 	unsigned int count;
 	unsigned long flags;
 
-	if ((host->chan_tx || host->chan_rx) && !host->force_pio) {
+	if (host->dma_on) {
 		pr_err("PIO IRQ in DMA mode!\n");
 		return;
 	} else if (!data) {
@@ -436,7 +436,7 @@  void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
 	 */
 
 	if (data->flags & MMC_DATA_READ) {
-		if (host->chan_rx && !host->force_pio)
+		if (host->dma_on)
 			tmio_mmc_check_bounce_buffer(host);
 		dev_dbg(&host->pdev->dev, "Complete Rx request %p\n",
 			host->mrq);
@@ -473,7 +473,7 @@  static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
 	if (stat & TMIO_STAT_CRCFAIL || stat & TMIO_STAT_STOPBIT_ERR ||
 	    stat & TMIO_STAT_TXUNDERRUN)
 		data->error = -EILSEQ;
-	if (host->chan_tx && (data->flags & MMC_DATA_WRITE) && !host->force_pio) {
+	if (host->dma_on && (data->flags & MMC_DATA_WRITE)) {
 		u32 status = sd_ctrl_read16_and_16_as_32(host, CTL_STATUS);
 		bool done = false;
 
@@ -497,7 +497,7 @@  static void tmio_mmc_data_irq(struct tmio_mmc_host *host, unsigned int stat)
 			tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
 			tmio_mmc_dataend_dma(host);
 		}
-	} else if (host->chan_rx && (data->flags & MMC_DATA_READ) && !host->force_pio) {
+	} else if (host->dma_on && (data->flags & MMC_DATA_READ)) {
 		tmio_mmc_disable_mmc_irqs(host, TMIO_STAT_DATAEND);
 		tmio_mmc_dataend_dma(host);
 	} else {
@@ -550,7 +550,7 @@  static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
 	 */
 	if (host->data && (!cmd->error || cmd->error == -EILSEQ)) {
 		if (host->data->flags & MMC_DATA_READ) {
-			if (host->force_pio || !host->chan_rx) {
+			if (!host->dma_on) {
 				tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_READOP);
 			} else {
 				tmio_mmc_disable_mmc_irqs(host,
@@ -558,7 +558,7 @@  static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat)
 				tasklet_schedule(&host->dma_issue);
 			}
 		} else {
-			if (host->force_pio || !host->chan_tx) {
+			if (!host->dma_on) {
 				tmio_mmc_enable_mmc_irqs(host, TMIO_MASK_WRITEOP);
 			} else {
 				tmio_mmc_disable_mmc_irqs(host,
@@ -688,7 +688,7 @@  static int tmio_mmc_start_data(struct tmio_mmc_host *host,
 
 	tmio_mmc_init_sg(host, data);
 	host->data = data;
-	host->force_pio = false;
+	host->dma_on = false;
 
 	/* Set transfer length / blocksize */
 	sd_ctrl_write16(host, CTL_SD_XFER_LEN, data->blksz);
diff --git a/drivers/mmc/host/uniphier-sd.c b/drivers/mmc/host/uniphier-sd.c
index 1ee9fd0..91a2be4 100644
--- a/drivers/mmc/host/uniphier-sd.c
+++ b/drivers/mmc/host/uniphier-sd.c
@@ -157,13 +157,14 @@  static void uniphier_sd_external_dma_start(struct tmio_mmc_host *host,
 	if (cookie < 0)
 		goto unmap_sg;
 
+	host->dma_on = true;
+
 	return;
 
 unmap_sg:
 	dma_unmap_sg(mmc_dev(host->mmc), host->sg_ptr, host->sg_len,
 		     priv->dma_dir);
 force_pio:
-	host->force_pio = true;
 	uniphier_sd_dma_endisable(host, 0);
 }
 
@@ -283,9 +284,10 @@  static void uniphier_sd_internal_dma_start(struct tmio_mmc_host *host,
 	writel(lower_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_L);
 	writel(upper_32_bits(dma_addr), host->ctl + UNIPHIER_SD_DMA_ADDR_H);
 
+	host->dma_on = true;
+
 	return;
 force_pio:
-	host->force_pio = true;
 	uniphier_sd_dma_endisable(host, 0);
 }