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

From: Vinod Koul
Date: Tue Oct 31 2017 - 07:26:38 EST


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 <pierre-yves.mordret@xxxxxx>:
> > 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 <pierre-yves.mordret@xxxxxx>
> > ---
> > 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@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
> --
> Benjamin Gaignard
>
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--
~Vinod