Subject: [PATCH v1] dmaengine: stm32_mdma: activate pack/unpack feature

From: [email-masked] (Vinod Koul)
Date: Tue, 31 Oct 2017 16:59:34 +0530

On Tue, Oct 17, 2017 at 04:26:50PM +0200, Benjamin Gaignard wrote:
> +Arnd since it should also fix 64 bits division issue

Arnd would be back from Prague, so would like to get an ack before I
apply...

> 
> 2017-10-17 15:43 GMT+02:00 Pierre-Yves MORDRET <[email-masked]>:
> > If source and destination bus width differs pack/unpack MDMA
> > feature has to be activated for alignment.
> > This pack/unpack feature implies to have both source/destination address
> > and buffer length aligned on bus width.
> >
> > Fixes: a4ffb13c8946 ("dmaengine: Add STM32 MDMA driver")
> > Signed-off-by: Pierre-Yves MORDRET <[email-masked]>
> > ---
> >  drivers/dma/stm32-mdma.c | 84 ++++++++++++++++++++++++++++--------------------
> >  1 file changed, 50 insertions(+), 34 deletions(-)
> >
> > diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
> > index d3be6bf..daa1602 100644
> > --- a/drivers/dma/stm32-mdma.c
> > +++ b/drivers/dma/stm32-mdma.c
> > @@ -387,14 +387,20 @@ static int stm32_mdma_get_width(struct stm32_mdma_chan *chan,
> >         }
> >  }
> >
> > -static enum dma_slave_buswidth stm32_mdma_get_max_width(u32 buf_len, u32 tlen)
> > +static enum dma_slave_buswidth stm32_mdma_get_max_width(dma_addr_t addr,
> > +                                                       u32 buf_len, u32 tlen)
> >  {
> >         enum dma_slave_buswidth max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
> >
> >         for (max_width = DMA_SLAVE_BUSWIDTH_8_BYTES;
> >              max_width > DMA_SLAVE_BUSWIDTH_1_BYTE;
> >              max_width >>= 1) {
> > -               if (((buf_len % max_width) == 0) && (tlen >= max_width))
> > +               /*
> > +                * Address and buffer length both have to be aligned on
> > +                * bus width
> > +                */
> > +               if ((((buf_len | addr) & (max_width - 1)) == 0) &&
> > +                   tlen >= max_width)
> >                         break;
> >         }
> >
> > @@ -486,7 +492,8 @@ static void stm32_mdma_set_bus(struct stm32_mdma_device *dmadev, u32 *ctbr,
> >  static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >                                      enum dma_transfer_direction direction,
> >                                      u32 *mdma_ccr, u32 *mdma_ctcr,
> > -                                    u32 *mdma_ctbr, u32 buf_len)
> > +                                    u32 *mdma_ctbr, dma_addr_t addr,
> > +                                    u32 buf_len)
> >  {
> >         struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
> >         struct stm32_mdma_chan_config *chan_config = &chan->chan_config;
> > @@ -520,6 +527,9 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >         ctcr &= ~STM32_MDMA_CTCR_LEN2_MSK;
> >         ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
> >
> > +       /* Disable Pack Enable */
> > +       ctcr &= ~STM32_MDMA_CTCR_PKE;
> > +
> >         /* Check burst size constraints */
> >         if (src_maxburst * src_addr_width > STM32_MDMA_MAX_BURST ||
> >             dst_maxburst * dst_addr_width > STM32_MDMA_MAX_BURST) {
> > @@ -551,6 +561,8 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >
> >         switch (direction) {
> >         case DMA_MEM_TO_DEV:
> > +               dst_addr = chan->dma_config.dst_addr;
> > +
> >                 /* Set device data size */
> >                 dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
> >                 if (dst_bus_width < 0)
> > @@ -567,7 +579,7 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >                 ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
> >
> >                 /* Set memory data size */
> > -               src_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
> > +               src_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
> >                 chan->mem_width = src_addr_width;
> >                 src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
> >                 if (src_bus_width < 0)
> > @@ -587,15 +599,19 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >                 ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
> >
> >                 /* Select bus */
> > -               dst_addr = chan->dma_config.dst_addr;
> >                 stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> >                                    dst_addr);
> >
> > +               if (dst_bus_width != src_bus_width)
> > +                       ctcr |= STM32_MDMA_CTCR_PKE;
> > +
> >                 /* Set destination address */
> >                 stm32_mdma_write(dmadev, STM32_MDMA_CDAR(chan->id), dst_addr);
> >                 break;
> >
> >         case DMA_DEV_TO_MEM:
> > +               src_addr = chan->dma_config.src_addr;
> > +
> >                 /* Set device data size */
> >                 src_bus_width = stm32_mdma_get_width(chan, src_addr_width);
> >                 if (src_bus_width < 0)
> > @@ -611,7 +627,7 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >                 ctcr |= STM32_MDMA_CTCR_SBURST((ilog2(src_best_burst)));
> >
> >                 /* Set memory data size */
> > -               dst_addr_width = stm32_mdma_get_max_width(buf_len, tlen);
> > +               dst_addr_width = stm32_mdma_get_max_width(addr, buf_len, tlen);
> >                 chan->mem_width = dst_addr_width;
> >                 dst_bus_width = stm32_mdma_get_width(chan, dst_addr_width);
> >                 if (dst_bus_width < 0)
> > @@ -630,10 +646,12 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> >                 ctcr |= STM32_MDMA_CTCR_DBURST((ilog2(dst_best_burst)));
> >
> >                 /* Select bus */
> > -               src_addr = chan->dma_config.src_addr;
> >                 stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> >                                    src_addr);
> >
> > +               if (dst_bus_width != src_bus_width)
> > +                       ctcr |= STM32_MDMA_CTCR_PKE;
> > +
> >                 /* Set source address */
> >                 stm32_mdma_write(dmadev, STM32_MDMA_CSAR(chan->id), src_addr);
> >                 break;
> > @@ -719,23 +737,27 @@ static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
> >                         return -EINVAL;
> >                 }
> >
> > -               ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> > -                                               &ctbr, sg_dma_len(sg));
> > -               if (ret < 0)
> > -                       return ret;
> > -
> >                 if (direction == DMA_MEM_TO_DEV) {
> >                         src_addr = sg_dma_address(sg);
> >                         dst_addr = dma_config->dst_addr;
> > +                       ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
> > +                                                       &ctcr, &ctbr, src_addr,
> > +                                                       sg_dma_len(sg));
> >                         stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> >                                            src_addr);
> >                 } else {
> >                         src_addr = dma_config->src_addr;
> >                         dst_addr = sg_dma_address(sg);
> > +                       ret = stm32_mdma_set_xfer_param(chan, direction, &ccr,
> > +                                                       &ctcr, &ctbr, dst_addr,
> > +                                                       sg_dma_len(sg));
> >                         stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> >                                            dst_addr);
> >                 }
> >
> > +               if (ret < 0)
> > +                       return ret;
> > +
> >                 stm32_mdma_setup_hwdesc(chan, desc, direction, i, src_addr,
> >                                         dst_addr, sg_dma_len(sg), ctcr, ctbr,
> >                                         i == sg_len - 1, i == 0, false);
> > @@ -830,27 +852,29 @@ stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
> >         if (!desc)
> >                 return NULL;
> >
> > -       ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr, &ctbr,
> > -                                       period_len);
> > -       if (ret < 0)
> > -               goto xfer_setup_err;
> > -
> > -       /* Enable interrupts */
> > -       ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
> > -       ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
> > -       desc->ccr = ccr;
> > -
> >         /* Select bus */
> >         if (direction == DMA_MEM_TO_DEV) {
> >                 src_addr = buf_addr;
> > +               ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> > +                                               &ctbr, src_addr, period_len);
> >                 stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_SBUS,
> >                                    src_addr);
> >         } else {
> >                 dst_addr = buf_addr;
> > +               ret = stm32_mdma_set_xfer_param(chan, direction, &ccr, &ctcr,
> > +                                               &ctbr, dst_addr, period_len);
> >                 stm32_mdma_set_bus(dmadev, &ctbr, STM32_MDMA_CTBR_DBUS,
> >                                    dst_addr);
> >         }
> >
> > +       if (ret < 0)
> > +               goto xfer_setup_err;
> > +
> > +       /* Enable interrupts */
> > +       ccr &= ~STM32_MDMA_CCR_IRQ_MASK;
> > +       ccr |= STM32_MDMA_CCR_TEIE | STM32_MDMA_CCR_CTCIE | STM32_MDMA_CCR_BTIE;
> > +       desc->ccr = ccr;
> > +
> >         /* Configure hwdesc list */
> >         for (i = 0; i < count; i++) {
> >                 if (direction == DMA_MEM_TO_DEV) {
> > @@ -956,9 +980,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> >                 ctcr |= STM32_MDMA_CTCR_TLEN((tlen - 1));
> >
> >                 /* Set source best burst size */
> > -               max_width = stm32_mdma_get_max_width(len, tlen);
> > -               if (src % max_width)
> > -                       max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > +               max_width = stm32_mdma_get_max_width(src, len, tlen);
> >                 src_bus_width = stm32_mdma_get_width(chan, max_width);
> >
> >                 max_burst = tlen / max_width;
> > @@ -971,9 +993,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> >                         STM32_MDMA_CTCR_SINCOS(src_bus_width);
> >
> >                 /* Set destination best burst size */
> > -               max_width = stm32_mdma_get_max_width(len, tlen);
> > -               if (dest % max_width)
> > -                       max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > +               max_width = stm32_mdma_get_max_width(dest, len, tlen);
> >                 dst_bus_width = stm32_mdma_get_width(chan, max_width);
> >
> >                 max_burst = tlen / max_width;
> > @@ -1014,9 +1034,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> >                                            STM32_MDMA_MAX_BLOCK_LEN);
> >
> >                         /* Set source best burst size */
> > -                       max_width = stm32_mdma_get_max_width(len, tlen);
> > -                       if (src % max_width)
> > -                               max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > +                       max_width = stm32_mdma_get_max_width(src, len, tlen);
> >                         src_bus_width = stm32_mdma_get_width(chan, max_width);
> >
> >                         max_burst = tlen / max_width;
> > @@ -1030,9 +1048,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> >                                 STM32_MDMA_CTCR_SINCOS(src_bus_width);
> >
> >                         /* Set destination best burst size */
> > -                       max_width = stm32_mdma_get_max_width(len, tlen);
> > -                       if (dest % max_width)
> > -                               max_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
> > +                       max_width = stm32_mdma_get_max_width(dest, len, tlen);
> >                         dst_bus_width = stm32_mdma_get_width(chan, max_width);
> >
> >                         max_burst = tlen / max_width;
> > --
> > 2.7.4
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 
> 
> 
> -- 
> Benjamin Gaignard
> 
> Graphic Study Group
> 
> Linaro.org ? Open source software for ARM SoCs
> 
> Follow Linaro: Facebook | Twitter | Blog
> --
> To unsubscribe from this list: send the line "unsubscribe dmaengine" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
~Vinod