Re: [PATCH v2 2/2] dmaengine: stm32-mdma: Fix incomplete Hw descriptors allocator
From: Robin Murphy
Date: Fri Apr 13 2018 - 07:49:01 EST
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@xxxxxx>
---
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));