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 v4->v5: * Minimized the OF dependency. v3->v4: * Appropriately placed '#ifdef CONFIG_OF' * Tested by adding '#undef CONFIG_OF' to modified files, and passed compiling. v2->v3: * Moved iram specific mmap procedure out of ifdef ARCH_HAS_DMA_MMAP_COHERENT v1->v2: * Added of_node check * Dropped noops and unused physical addr in snd_free_dev_iram()
--- include/sound/memalloc.h | 1 + sound/core/memalloc.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++ sound/core/pcm_native.c | 6 +++++ 3 files changed, 76 insertions(+)
diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h index cf15b82..510aec4 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_IRAM 4 /* generic device iram-buffer */
/* * info for buffer allocation diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index bdf826f..c1dd704 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 +158,63 @@ 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); } + +/** + * 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 = NULL; + unsigned long vaddr; + +#ifdef CONFIG_OF + if (!dev->of_node) + return NULL; + + pool = of_get_named_gen_pool(dev->of_node, "iram", 0); +#endif + 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 = NULL; + +#ifdef CONFIG_OF + if (!dev->of_node) + return; + + pool = of_get_named_gen_pool(dev->of_node, "iram", 0); +#endif + if (!pool) + return; + + gen_pool_free(pool, (unsigned long)ptr, size); +} #endif /* CONFIG_HAS_DMA */
/* @@ -197,6 +255,14 @@ 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: + dmab->area = snd_malloc_dev_iram(device, size, &dmab->addr); + if (dmab->area) + break; + /* 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 +335,9 @@ 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: + snd_free_dev_iram(dmab->dev.dev, dmab->bytes, dmab->area); + break; 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..513f095 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3199,6 +3199,12 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, struct vm_area_struct *area) { area->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + 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); + } #ifdef ARCH_HAS_DMA_MMAP_COHERENT if (!substream->ops->page && substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV)