Messages in this thread Patch in this message | | | From | Laxman Dewangan <> | Subject | [PATCH V2 1/2] ALSA: Support writecombine DMA buffer memory page alloc/free | Date | Mon, 2 Jul 2012 14:24:32 +0530 |
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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.
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
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