[alsa-devel] [PATCH v2 1/2] ALSA: Add SoC on-chip internal memory support for DMA buffer allocation
Now it's quite common that an SoC contains its on-chip internal memory. By using this memory space for DMA buffer during audio playback/record, we can shutdown the voltage for external memory to save power.
Thus add new DEV type with iram malloc()/free() and accordingly modify current default mmap() for the iram circumstance.
Signed-off-by: Nicolin Chen b42378@freescale.com --- Changelog v1->v2: * Added of_node check * Dropped noops and unused physical addr in snd_free_dev_iram()
--- include/sound/memalloc.h | 5 ++++ sound/core/memalloc.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++ sound/core/pcm_native.c | 8 +++++- 3 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h index cf15b82..b53443e 100644 --- a/include/sound/memalloc.h +++ b/include/sound/memalloc.h @@ -52,6 +52,11 @@ struct snd_dma_device { #else #define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */ #endif +#ifdef CONFIG_OF +#define SNDRV_DMA_TYPE_DEV_IRAM 4 /* generic device iram-buffer */ +#else +#define SNDRV_DMA_TYPE_DEV_IRAM SNDRV_DMA_TYPE_DEV +#endif
/* * info for buffer allocation diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index bdf826f..2957938 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -30,6 +30,7 @@ #include <linux/seq_file.h> #include <asm/uaccess.h> #include <linux/dma-mapping.h> +#include <linux/genalloc.h> #include <linux/moduleparam.h> #include <linux/mutex.h> #include <sound/memalloc.h> @@ -157,6 +158,61 @@ static void snd_free_dev_pages(struct device *dev, size_t size, void *ptr, dec_snd_pages(pg); dma_free_coherent(dev, PAGE_SIZE << pg, ptr, dma); } + +#ifdef CONFIG_OF +/** + * snd_malloc_dev_iram - allocate memory from on-chip internal memory + * @dev: DMA device pointer + * @size: number of bytes to allocate from the iram + * @dma: dma-view physical address + * + * Return cpu-view address or NULL indicating allocating failure + * + * This function requires iram phandle provided via of_node + */ +void *snd_malloc_dev_iram(struct device *dev, size_t size, dma_addr_t *dma) +{ + struct gen_pool *pool; + unsigned long vaddr; + + if (!dev->of_node) + return NULL; + + pool = of_get_named_gen_pool(dev->of_node, "iram", 0); + if (!pool) + return NULL; + + vaddr = gen_pool_alloc(pool, size); + if (!vaddr) + return NULL; + + *dma = gen_pool_virt_to_phys(pool, vaddr); + + return (void *)vaddr; +} + +/** + * snd_free_dev_iram - free allocated specific memory from on-chip internal memory + * @dev: DMA device pointer + * @size: size in bytes of memory to free + * @ptr: cpu-view address returned from snd_malloc_dev_iram + * + * This function requires iram phandle provided via of_node + */ +void snd_free_dev_iram(struct device *dev, size_t size, void *ptr) +{ + struct gen_pool *pool; + + if (!dev->of_node) + return; + + pool = of_get_named_gen_pool(dev->of_node, "iram", 0); + if (!pool) + return; + + gen_pool_free(pool, (unsigned long)ptr, size); +} +#endif /* CONFIG_OF */ #endif /* CONFIG_HAS_DMA */
/* @@ -197,6 +253,17 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size, dmab->addr = 0; break; #ifdef CONFIG_HAS_DMA + case SNDRV_DMA_TYPE_DEV_IRAM: +#ifdef CONFIG_OF + dmab->area = snd_malloc_dev_iram(device, size, &dmab->addr); + if (dmab->area) + break; +#endif + /* + * Internal memory might have limited size and no enough space, + * so if we fail to malloc, try to fetch memory traditionally. + */ + dmab->dev.type = SNDRV_DMA_TYPE_DEV; case SNDRV_DMA_TYPE_DEV: dmab->area = snd_malloc_dev_pages(device, size, &dmab->addr); break; @@ -269,6 +336,11 @@ void snd_dma_free_pages(struct snd_dma_buffer *dmab) snd_free_pages(dmab->area, dmab->bytes); break; #ifdef CONFIG_HAS_DMA + case SNDRV_DMA_TYPE_DEV_IRAM: +#ifdef CONFIG_OF + snd_free_dev_iram(dmab->dev.dev, dmab->bytes, dmab->area); + break; +#endif case SNDRV_DMA_TYPE_DEV: snd_free_dev_pages(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr); break; diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index a68d4c6..5578bd0 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3201,12 +3201,18 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; #ifdef ARCH_HAS_DMA_MMAP_COHERENT if (!substream->ops->page && - substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) + substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) { return dma_mmap_coherent(substream->dma_buffer.dev.dev, area, substream->runtime->dma_area, substream->runtime->dma_addr, area->vm_end - area->vm_start); + } else if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_IRAM) { + area->vm_page_prot = pgprot_writecombine(area->vm_page_prot); + return remap_pfn_range(area, area->vm_start, + substream->dma_buffer.addr >> PAGE_SHIFT, + area->vm_end - area->vm_start, area->vm_page_prot); + } #elif defined(CONFIG_MIPS) && defined(CONFIG_DMA_NONCOHERENT) if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV && !plat_device_is_coherent(substream->dma_buffer.dev.dev))
When allocating memory space for DMA buffer, use on-chip internal memory as default to save power.
Signed-off-by: Nicolin Chen b42378@freescale.com --- Changelog v1->v2: * Use iram memory space as default
--- sound/soc/soc-generic-dmaengine-pcm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c index e29ec3c..e5b61e3 100644 --- a/sound/soc/soc-generic-dmaengine-pcm.c +++ b/sound/soc/soc-generic-dmaengine-pcm.c @@ -163,7 +163,7 @@ static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) }
ret = snd_pcm_lib_preallocate_pages(substream, - SNDRV_DMA_TYPE_DEV, + SNDRV_DMA_TYPE_DEV_IRAM, dmaengine_dma_dev(pcm, substream), config->prealloc_buffer_size, config->pcm_hardware->buffer_bytes_max);
At Wed, 16 Oct 2013 17:34:45 +0800, Nicolin Chen wrote:
--- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3201,12 +3201,18 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; #ifdef ARCH_HAS_DMA_MMAP_COHERENT if (!substream->ops->page &&
substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)
return dma_mmap_coherent(substream->dma_buffer.dev.dev, area, substream->runtime->dma_area, substream->runtime->dma_addr, area->vm_end - area->vm_start);substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) {
- } else if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_IRAM) {
area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
return remap_pfn_range(area, area->vm_start,
substream->dma_buffer.addr >> PAGE_SHIFT,
area->vm_end - area->vm_start, area->vm_page_prot);
- }
Here is a wrong place to put. The handling of SNDRV_DMA_TYPE_IRAM must be irrelevant with the existence of dma_mmap_coherent(), thus it should be outside the ifdef block.
In addition, you need the check whether SNDRV_DMA_TYPE_DEV_IRAM != SNDRV_DMA_TYPE_DEV.
thanks,
Takashi
On Wed, Oct 16, 2013 at 11:54:38AM +0200, Takashi Iwai wrote:
At Wed, 16 Oct 2013 17:34:45 +0800, Nicolin Chen wrote:
--- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3201,12 +3201,18 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; #ifdef ARCH_HAS_DMA_MMAP_COHERENT if (!substream->ops->page &&
substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)
return dma_mmap_coherent(substream->dma_buffer.dev.dev, area, substream->runtime->dma_area, substream->runtime->dma_addr, area->vm_end - area->vm_start);substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV) {
- } else if (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_IRAM) {
area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);
return remap_pfn_range(area, area->vm_start,
substream->dma_buffer.addr >> PAGE_SHIFT,
area->vm_end - area->vm_start, area->vm_page_prot);
- }
Here is a wrong place to put. The handling of SNDRV_DMA_TYPE_IRAM must be irrelevant with the existence of dma_mmap_coherent(), thus it should be outside the ifdef block.
In addition, you need the check whether SNDRV_DMA_TYPE_DEV_IRAM != SNDRV_DMA_TYPE_DEV.
Thank you, Iwai-san. I'll fix it in v3.
thanks,
Takashi
participants (2)
-
Nicolin Chen
-
Takashi Iwai