[PATCH 03/15] dmaengine: dw-axi-dmac: move dma_pool_create() to alloc_chan_resources()

[Sia Jee Heng]

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.

Reviewed-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
Signed-off-by: Sia Jee Heng <jee.heng....@intel.com>
---
 .../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 8cfd645479e1..46e2ba978e20 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 41e775e6e593..f886b2bb75de 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;
-- 
2.18.0