[PATCH v2 2/2] dmaengine: stm32-mdma: Fix incomplete Hw descriptors allocator
Robin Murphy
robin.murphy at arm.com
Fri Apr 13 04:48:53 PDT 2018
On 11/04/18 15:44, Pierre-Yves MORDRET wrote:
> Only 1 Hw Descriptor is allocated. Loop over required Hw descriptor for
> proper allocation.
>
> Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret at st.com>
> ---
> Version history:
> v1:
> * Initial
> v2:
> * Fix kbuild warning format: /0x%08x/%pad/
> ---
> ---
> drivers/dma/stm32-mdma.c | 90 ++++++++++++++++++++++++++++++------------------
> 1 file changed, 56 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
> index fbcffa2..3a477bc 100644
> --- a/drivers/dma/stm32-mdma.c
> +++ b/drivers/dma/stm32-mdma.c
> @@ -252,13 +252,17 @@ struct stm32_mdma_hwdesc {
> u32 cmdr;
> } __aligned(64);
>
> +struct stm32_mdma_desc_node {
> + struct stm32_mdma_hwdesc *hwdesc;
> + dma_addr_t hwdesc_phys;
> +};
> +
> struct stm32_mdma_desc {
> struct virt_dma_desc vdesc;
> u32 ccr;
> - struct stm32_mdma_hwdesc *hwdesc;
> - dma_addr_t hwdesc_phys;
> bool cyclic;
> u32 count;
> + struct stm32_mdma_desc_node node[];
> };
>
> struct stm32_mdma_chan {
> @@ -344,30 +348,43 @@ static struct stm32_mdma_desc *stm32_mdma_alloc_desc(
> struct stm32_mdma_chan *chan, u32 count)
> {
> struct stm32_mdma_desc *desc;
> + int i;
>
> - desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
> + desc = kzalloc(sizeof(*desc) +
> + sizeof(struct stm32_mdma_desc_node) * count, GFP_NOWAIT);
You could use "offsetof(typeof(*desc), node[count])" instead of the
explicit calculation here.
Robin.
> if (!desc)
> return NULL;
>
> - desc->hwdesc = dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
> - &desc->hwdesc_phys);
> - if (!desc->hwdesc) {
> - dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
> - kfree(desc);
> - return NULL;
> + for (i = 0; i < count; i++) {
> + desc->node[i].hwdesc =
> + dma_pool_alloc(chan->desc_pool, GFP_NOWAIT,
> + &desc->node[i].hwdesc_phys);
> + if (!desc->node[i].hwdesc)
> + goto err;
> }
>
> desc->count = count;
>
> return desc;
> +
> +err:
> + dev_err(chan2dev(chan), "Failed to allocate descriptor\n");
> + while (--i >= 0)
> + dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
> + desc->node[i].hwdesc_phys);
> + kfree(desc);
> + return NULL;
> }
>
> static void stm32_mdma_desc_free(struct virt_dma_desc *vdesc)
> {
> struct stm32_mdma_desc *desc = to_stm32_mdma_desc(vdesc);
> struct stm32_mdma_chan *chan = to_stm32_mdma_chan(vdesc->tx.chan);
> + int i;
>
> - dma_pool_free(chan->desc_pool, desc->hwdesc, desc->hwdesc_phys);
> + for (i = 0; i < desc->count; i++)
> + dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
> + desc->node[i].hwdesc_phys);
> kfree(desc);
> }
>
> @@ -669,18 +686,18 @@ static int stm32_mdma_set_xfer_param(struct stm32_mdma_chan *chan,
> }
>
> static void stm32_mdma_dump_hwdesc(struct stm32_mdma_chan *chan,
> - struct stm32_mdma_hwdesc *hwdesc)
> + struct stm32_mdma_desc_node *node)
> {
> - dev_dbg(chan2dev(chan), "hwdesc: 0x%p\n", hwdesc);
> - dev_dbg(chan2dev(chan), "CTCR: 0x%08x\n", hwdesc->ctcr);
> - dev_dbg(chan2dev(chan), "CBNDTR: 0x%08x\n", hwdesc->cbndtr);
> - dev_dbg(chan2dev(chan), "CSAR: 0x%08x\n", hwdesc->csar);
> - dev_dbg(chan2dev(chan), "CDAR: 0x%08x\n", hwdesc->cdar);
> - dev_dbg(chan2dev(chan), "CBRUR: 0x%08x\n", hwdesc->cbrur);
> - dev_dbg(chan2dev(chan), "CLAR: 0x%08x\n", hwdesc->clar);
> - dev_dbg(chan2dev(chan), "CTBR: 0x%08x\n", hwdesc->ctbr);
> - dev_dbg(chan2dev(chan), "CMAR: 0x%08x\n", hwdesc->cmar);
> - dev_dbg(chan2dev(chan), "CMDR: 0x%08x\n\n", hwdesc->cmdr);
> + dev_dbg(chan2dev(chan), "hwdesc: %pad\n", &node->hwdesc_phys);
> + dev_dbg(chan2dev(chan), "CTCR: 0x%08x\n", node->hwdesc->ctcr);
> + dev_dbg(chan2dev(chan), "CBNDTR: 0x%08x\n", node->hwdesc->cbndtr);
> + dev_dbg(chan2dev(chan), "CSAR: 0x%08x\n", node->hwdesc->csar);
> + dev_dbg(chan2dev(chan), "CDAR: 0x%08x\n", node->hwdesc->cdar);
> + dev_dbg(chan2dev(chan), "CBRUR: 0x%08x\n", node->hwdesc->cbrur);
> + dev_dbg(chan2dev(chan), "CLAR: 0x%08x\n", node->hwdesc->clar);
> + dev_dbg(chan2dev(chan), "CTBR: 0x%08x\n", node->hwdesc->ctbr);
> + dev_dbg(chan2dev(chan), "CMAR: 0x%08x\n", node->hwdesc->cmar);
> + dev_dbg(chan2dev(chan), "CMDR: 0x%08x\n\n", node->hwdesc->cmdr);
> }
>
> static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
> @@ -694,7 +711,7 @@ static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
> struct stm32_mdma_hwdesc *hwdesc;
> u32 next = count + 1;
>
> - hwdesc = &desc->hwdesc[count];
> + hwdesc = desc->node[count].hwdesc;
> hwdesc->ctcr = ctcr;
> hwdesc->cbndtr &= ~(STM32_MDMA_CBNDTR_BRC_MK |
> STM32_MDMA_CBNDTR_BRDUM |
> @@ -704,19 +721,20 @@ static void stm32_mdma_setup_hwdesc(struct stm32_mdma_chan *chan,
> hwdesc->csar = src_addr;
> hwdesc->cdar = dst_addr;
> hwdesc->cbrur = 0;
> - hwdesc->clar = desc->hwdesc_phys + next * sizeof(*hwdesc);
> hwdesc->ctbr = ctbr;
> hwdesc->cmar = config->mask_addr;
> hwdesc->cmdr = config->mask_data;
>
> if (is_last) {
> if (is_cyclic)
> - hwdesc->clar = desc->hwdesc_phys;
> + hwdesc->clar = desc->node[0].hwdesc_phys;
> else
> hwdesc->clar = 0;
> + } else {
> + hwdesc->clar = desc->node[next].hwdesc_phys;
> }
>
> - stm32_mdma_dump_hwdesc(chan, hwdesc);
> + stm32_mdma_dump_hwdesc(chan, &desc->node[count]);
> }
>
> static int stm32_mdma_setup_xfer(struct stm32_mdma_chan *chan,
> @@ -780,7 +798,7 @@ stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
> {
> struct stm32_mdma_chan *chan = to_stm32_mdma_chan(c);
> struct stm32_mdma_desc *desc;
> - int ret;
> + int i, ret;
>
> /*
> * Once DMA is in setup cyclic mode the channel we cannot assign this
> @@ -806,7 +824,9 @@ stm32_mdma_prep_slave_sg(struct dma_chan *c, struct scatterlist *sgl,
> return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
>
> xfer_setup_err:
> - dma_pool_free(chan->desc_pool, &desc->hwdesc, desc->hwdesc_phys);
> + for (i = 0; i < desc->count; i++)
> + dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
> + desc->node[i].hwdesc_phys);
> kfree(desc);
> return NULL;
> }
> @@ -895,7 +915,9 @@ stm32_mdma_prep_dma_cyclic(struct dma_chan *c, dma_addr_t buf_addr,
> return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
>
> xfer_setup_err:
> - dma_pool_free(chan->desc_pool, &desc->hwdesc, desc->hwdesc_phys);
> + for (i = 0; i < desc->count; i++)
> + dma_pool_free(chan->desc_pool, desc->node[i].hwdesc,
> + desc->node[i].hwdesc_phys);
> kfree(desc);
> return NULL;
> }
> @@ -1009,7 +1031,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> ctcr |= STM32_MDMA_CTCR_PKE;
>
> /* Prepare hardware descriptor */
> - hwdesc = desc->hwdesc;
> + hwdesc = desc->node[0].hwdesc;
> hwdesc->ctcr = ctcr;
> hwdesc->cbndtr = cbndtr;
> hwdesc->csar = src;
> @@ -1020,7 +1042,7 @@ stm32_mdma_prep_dma_memcpy(struct dma_chan *c, dma_addr_t dest, dma_addr_t src,
> hwdesc->cmar = 0;
> hwdesc->cmdr = 0;
>
> - stm32_mdma_dump_hwdesc(chan, hwdesc);
> + stm32_mdma_dump_hwdesc(chan, &desc->node[0]);
> } else {
> /* Setup a LLI transfer */
> ctcr |= STM32_MDMA_CTCR_TRGM(STM32_MDMA_LINKED_LIST) |
> @@ -1120,7 +1142,7 @@ static void stm32_mdma_start_transfer(struct stm32_mdma_chan *chan)
> }
>
> chan->desc = to_stm32_mdma_desc(vdesc);
> - hwdesc = chan->desc->hwdesc;
> + hwdesc = chan->desc->node[0].hwdesc;
> chan->curr_hwdesc = 0;
>
> stm32_mdma_write(dmadev, STM32_MDMA_CCR(id), chan->desc->ccr);
> @@ -1198,7 +1220,7 @@ static int stm32_mdma_resume(struct dma_chan *c)
> unsigned long flags;
> u32 status, reg;
>
> - hwdesc = &chan->desc->hwdesc[chan->curr_hwdesc];
> + hwdesc = chan->desc->node[chan->curr_hwdesc].hwdesc;
>
> spin_lock_irqsave(&chan->vchan.lock, flags);
>
> @@ -1268,13 +1290,13 @@ static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
> u32 curr_hwdesc)
> {
> struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
> + struct stm32_mdma_hwdesc *hwdesc = desc->node[0].hwdesc;
> u32 cbndtr, residue, modulo, burst_size;
> int i;
>
> residue = 0;
> for (i = curr_hwdesc + 1; i < desc->count; i++) {
> - struct stm32_mdma_hwdesc *hwdesc = &desc->hwdesc[i];
> -
> + hwdesc = desc->node[i].hwdesc;
> residue += STM32_MDMA_CBNDTR_BNDT(hwdesc->cbndtr);
> }
> cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
>
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