Re: [alsa-devel] [PATCH V2 1/2] ALSA: Support writecombine DMA buffer memory page alloc/free
At Mon, 2 Jul 2012 14:24:32 +0530, Laxman Dewangan wrote:
Some of architecture like ARM support the writecombine DMA buffer which is used for pcm substream DMA buffer.
Supporting writecombine DMA buffer allocation/free/mmap through the sound library memory management.
Signed-off-by: Laxman Dewangan ldewangan@nvidia.com
Changes from V1: Integrate the changes from Takashi's sample code for supporting writecombine.
Could you give a short comment in each file that ifdef CONFIG_ARM is a workaround?
thanks,
Takashi
include/sound/memalloc.h | 1 + sound/core/memalloc.c | 74 +++++++++++++++++++++++++++++++++++++++++----- sound/core/pcm_native.c | 10 ++++++ 3 files changed, 77 insertions(+), 8 deletions(-)
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h index c425062..0328e37 100644 --- a/include/sound/memalloc.h +++ b/include/sound/memalloc.h @@ -52,6 +52,7 @@ struct snd_dma_device { #else #define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */ #endif +#define SNDRV_DMA_TYPE_DEV_WC 4 /* writecombine page */
/*
- info for buffer allocation
diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 6915692..7468251 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -124,8 +124,10 @@ void snd_free_pages(void *ptr, size_t size) */
#ifdef CONFIG_HAS_DMA -/* allocate the coherent DMA pages */ -static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *dma) +static void *_snd_malloc_dev_pages(struct device *dev, size_t size,
dma_addr_t *dma,void *(*alloc_func)(struct device *dev, size_t size,dma_addr_t *dma, gfp_t gfp_flags)){ int pg; void *res; @@ -138,16 +140,18 @@ static void *snd_malloc_dev_pages(struct device *dev, size_t size, dma_addr_t *d | __GFP_COMP /* compound page lets parts be mapped */ | __GFP_NORETRY /* don't trigger OOM-killer */ | __GFP_NOWARN; /* no stack trace print - this call is non-critical */
- res = dma_alloc_coherent(dev, PAGE_SIZE << pg, dma, gfp_flags);
res = alloc_func(dev, PAGE_SIZE << pg, dma, gfp_flags); if (res != NULL) inc_snd_pages(pg);
return res;
}
-/* free the coherent DMA pages */ -static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma)+static void _snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma,void (*free_func)(struct device *dev,size_t size, void *vaddr,dma_addr_t dma_handle)){ int pg;
@@ -155,8 +159,51 @@ static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr, return; pg = get_order(size); dec_snd_pages(pg);
- dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma);
- free_func(dev, PAGE_SIZE << pg, ptr, dma);
+}
+static void *_dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)+{
- return dma_alloc_coherent(dev, size, dma_handle, flag);
+}
+static void _dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)+{
- dma_free_coherent(dev, size, vaddr, dma_handle);
+}
+/* allocate the coherent DMA pages */ +static void *snd_malloc_dev_pages(struct device *dev, size_t size,
dma_addr_t *dma)+{
- return _snd_malloc_dev_pages(dev, size, dma, _dma_alloc_coherent);
+}
+/* free the coherent DMA pages */ +static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma)+{
- _snd_free_dev_pages(dev, size, ptr, dma, _dma_free_coherent);
}
+#ifdef CONFIG_ARM +/* allocate the writecombine DMA pages */ +static void *snd_malloc_dev_wc_pages(struct device *dev, size_t size,
dma_addr_t *dma)+{
- return _snd_malloc_dev_pages(dev, size, dma, dma_alloc_writecombine);
+}
+/* free the writecombine DMA pages */ +static void snd_free_dev_wc_pages(struct device *dev, size_t size, void *ptr,
dma_addr_t dma)+{
- _snd_free_dev_pages(dev, size, ptr, dma, dma_free_writecombine);
+} +#endif #endif /* CONFIG_HAS_DMA */
/* @@ -200,6 +247,11 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size, case SNDRV_DMA_TYPE_DEV: dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr); break; +#ifdef CONFIG_ARM
- case SNDRV_DMA_TYPE_DEV_WC:
dmab->area = snd_malloc_dev_wc_pages(device, size, &dmab->addr);break;+#endif #endif #ifdef CONFIG_SND_DMA_SGBUF case SNDRV_DMA_TYPE_DEV_SG: @@ -272,6 +324,12 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab) case SNDRV_DMA_TYPE_DEV: snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr); break; +#ifdef CONFIG_ARM
- case SNDRV_DMA_TYPE_DEV_WC:
snd_free_dev_wc_pages(dmab->dev.dev, dmab->bytes, dmab->area,dmab->addr);break;+#endif #endif #ifdef CONFIG_SND_DMA_SGBUF case SNDRV_DMA_TYPE_DEV_SG: @@ -378,7 +436,7 @@ static int snd_mem_proc_read(struct seq_file *seq, void *offset) long pages = snd_allocated_pages >> (PAGE_SHIFT-12); struct snd_mem_list *mem; int devno;
- static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG" };
static char *types[] = { "UNKNOWN", "CONT", "DEV", "DEV-SG" , "WC"};
mutex_lock(&list_mutex); seq_printf(seq, "pages : %li bytes (%li pages per %likB)\n",
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 53b5ada..28d949c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3170,6 +3170,16 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *area) { area->vm_flags |= VM_RESERVED;
+#ifdef CONFIG_ARM
- if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_WC)
return dma_mmap_writecombine(substream->dma_buffer.dev.dev,area,substream->runtime->dma_area,substream->runtime->dma_addr,area->vm_end - area->vm_start);+#endif
#ifdef ARCH_HAS_DMA_MMAP_COHERENT if (!substream->ops->page && substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) -- 1.7.1.1
participants (1)
-
Takashi Iwai