[PATCH 3/4] dmaengine: dw-axi-dmac: move dma_pool_create() to alloc_chan_resources()

Sia Jee Heng
2020-09-04T10:07:28Z

The DMA memory block is created at driver load time and exist for
device lifetime. Move the dma_pool_create() to the ->chan_resource()
callback function allowing the DMA memory blocks to be created as needed
and destroyed when the channel is freed.

Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Reviewed-by: Shevchenko, Andriy <andriy.shevchenko@intel.com>
---
drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 24 +++++++++++++-----------
drivers/dma/dw-axi-dmac/dw-axi-dmac.h | 2 +-
2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index 8cfd645..46e2ba9 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -216,11 +216,10 @@ static struct axi_dma_desc *axi_desc_alloc(u32 num)
static struct axi_dma_lli *axi_desc_get(struct axi_dma_chan *chan,
dma_addr_t *addr)
{
- struct dw_axi_dma *dw = chan->chip->dw;
struct axi_dma_lli *lli;
dma_addr_t phys;

- lli = dma_pool_zalloc(dw->desc_pool, GFP_NOWAIT, &phys);
+ lli = dma_pool_zalloc(chan->desc_pool, GFP_NOWAIT, &phys);
if (unlikely(!lli)) {
dev_err(chan2dev(chan), "%s: not enough descriptors available\n",
axi_chan_name(chan));
@@ -236,14 +235,13 @@ static struct axi_dma_lli *axi_desc_get(struct axi_dma_chan *chan,
static void axi_desc_put(struct axi_dma_desc *desc)
{
struct axi_dma_chan *chan = desc->chan;
- struct dw_axi_dma *dw = chan->chip->dw;
int count = atomic_read(&chan->descs_allocated);
struct axi_dma_hw_desc *hw_desc;
int descs_put;

for (descs_put = 0; descs_put < count; descs_put++) {
hw_desc = &desc->hw_desc[descs_put];
- dma_pool_free(dw->desc_pool, hw_desc->lli, hw_desc->llp);
+ dma_pool_free(chan->desc_pool, hw_desc->lli, hw_desc->llp);
}

kfree(desc->hw_desc);
@@ -360,6 +358,15 @@ static int dma_chan_alloc_chan_resources(struct dma_chan *dchan)
return -EBUSY;
}

+ /* LLI address must be aligned to a 64-byte boundary */
+ chan->desc_pool = dma_pool_create(dev_name(chan2dev(chan)),
+ chan->chip->dev,
+ sizeof(struct axi_dma_lli),
+ 64, 0);
+ if (!chan->desc_pool) {
+ dev_err(chan2dev(chan), "No memory for descriptors\n");
+ return -ENOMEM;
+ }
dev_vdbg(dchan2dev(dchan), "%s: allocating\n", axi_chan_name(chan));

pm_runtime_get(chan->chip->dev);
@@ -381,6 +388,8 @@ static void dma_chan_free_chan_resources(struct dma_chan *dchan)

vchan_free_chan_resources(&chan->vc);

+ dma_pool_destroy(chan->desc_pool);
+ chan->desc_pool = NULL;
dev_vdbg(dchan2dev(dchan),
"%s: free resources, descriptor still allocated: %u\n",
axi_chan_name(chan), atomic_read(&chan->descs_allocated));
@@ -896,13 +905,6 @@ static int dw_probe(struct platform_device *pdev)
if (ret)
return ret;

- /* Lli address must be aligned to a 64-byte boundary */
- dw->desc_pool = dmam_pool_create(KBUILD_MODNAME, chip->dev,
- sizeof(struct axi_dma_lli), 64, 0);
- if (!dw->desc_pool) {
- dev_err(chip->dev, "No memory for descriptors dma pool\n");
- return -ENOMEM;
- }

INIT_LIST_HEAD(&dw->dma.channels);
for (i = 0; i < hdata->nr_channels; i++) {
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index 41e775e..f886b2b 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -39,6 +39,7 @@ struct axi_dma_chan {
u8 id;
atomic_t descs_allocated;

+ struct dma_pool *desc_pool;
struct virt_dma_chan vc;

struct axi_dma_desc *desc;
@@ -49,7 +50,6 @@ struct axi_dma_chan {
struct dw_axi_dma {
struct dma_device dma;
struct dw_axi_dma_hcfg *hdata;
- struct dma_pool *desc_pool;

/* channels */
struct axi_dma_chan *chan;
--
1.9.1