From d955dab33af4ebff0f6c486da216ebbf590eb7e4 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 15 Jun 2020 18:00:42 +0200 Subject: [PATCH 1/4] ALSA: pcm: Use dma_mmap_coherent() on x86, too We avoided the explicit use of dma_mmap_coherent() on x86 because of a spurious warning in x86 APT code in the past. However, this blindly assumes that the pages allocated via dma_alloc_coherent() on x86 are the ones convertible via virt_to_page() (that is used in the default mmap handler), and it's no longer true; with the indirect DMA ops, this can be handled differently. The only certain way for doing mmap such pages is the dma_mmap_coherent(), and the warning seems already gone in the recent code, so let's use it consistently. Link: https://lore.kernel.org/r/20200615160045.2703-2-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/core/pcm_native.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 9630d25239480..1e51c849d3d4c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -3713,7 +3713,6 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, area->vm_end - area->vm_start, area->vm_page_prot); } #endif /* CONFIG_GENERIC_ALLOCATOR */ -#ifndef CONFIG_X86 /* for avoiding warnings arch/x86/mm/pat.c */ if (IS_ENABLED(CONFIG_HAS_DMA) && !substream->ops->page && (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV || substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_UC)) @@ -3722,7 +3721,6 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream, substream->runtime->dma_area, substream->runtime->dma_addr, substream->runtime->dma_bytes); -#endif /* CONFIG_X86 */ /* mmap with fault handler */ area->vm_ops = &snd_pcm_vm_ops_data_fault; return 0; From 28e60dbb83f76b18acade913dfdb029cd908c9b0 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 15 Jun 2020 18:00:43 +0200 Subject: [PATCH 2/4] ALSA: memalloc: Initialize all fields of snd_dma_buffer properly Some fields in snd_dma_buffer aren't touched in snd_dma_alloc_pages() and might be left uninitialized. Let's clear all fields properly, so that we can use a NULL check (e.g. dmab->private_data) as conditional in a later patch. Link: https://lore.kernel.org/r/20200615160045.2703-3-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/core/memalloc.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index bea46ed157a6d..d8f28d0309854 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -135,16 +135,17 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size, dmab->dev.type = type; dmab->dev.dev = device; dmab->bytes = 0; + dmab->area = NULL; + dmab->addr = 0; + dmab->private_data = NULL; switch (type) { case SNDRV_DMA_TYPE_CONTINUOUS: gfp = snd_mem_get_gfp_flags(device, GFP_KERNEL); dmab->area = alloc_pages_exact(size, gfp); - dmab->addr = 0; break; case SNDRV_DMA_TYPE_VMALLOC: gfp = snd_mem_get_gfp_flags(device, GFP_KERNEL | __GFP_HIGHMEM); dmab->area = __vmalloc(size, gfp); - dmab->addr = 0; break; #ifdef CONFIG_HAS_DMA #ifdef CONFIG_GENERIC_ALLOCATOR @@ -171,8 +172,6 @@ int snd_dma_alloc_pages(int type, struct device *device, size_t size, #endif default: pr_err("snd-malloc: invalid device type %d\n", type); - dmab->area = NULL; - dmab->addr = 0; return -ENXIO; } if (! dmab->area) From 2a1f3368bff609504cdc984cdb7cef467bb0b2b0 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 15 Jun 2020 18:00:44 +0200 Subject: [PATCH 3/4] ALSA: memalloc: Make SG-buffer helper usable for continuous buffer, too We have a few helper functions for making the access to the buffer address easier on SG-buffer. Those are specific to the buffer that is allocated with SG-buffer type, and it makes hard to use both SG and non-SG buffers in the same code. This patch adds a few simple checks and lets the helpers to deal with both SG- and continuous buffers gracefully. It's a preliminary step for the upcoming patch that mimics the buffer type on the fly. Link: https://lore.kernel.org/r/20200615160045.2703-4-tiwai@suse.de Signed-off-by: Takashi Iwai --- include/sound/memalloc.h | 9 ++++++++- sound/core/sgbuf.c | 3 +++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/sound/memalloc.h b/include/sound/memalloc.h index 3b47832b1c1f7..5daa937684a46 100644 --- a/include/sound/memalloc.h +++ b/include/sound/memalloc.h @@ -94,7 +94,11 @@ static inline dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset) { struct snd_sg_buf *sgbuf = dmab->private_data; - dma_addr_t addr = sgbuf->table[offset >> PAGE_SHIFT].addr; + dma_addr_t addr; + + if (!sgbuf) + return dmab->addr + offset; + addr = sgbuf->table[offset >> PAGE_SHIFT].addr; addr &= ~((dma_addr_t)PAGE_SIZE - 1); return addr + offset % PAGE_SIZE; } @@ -106,6 +110,9 @@ static inline void *snd_sgbuf_get_ptr(struct snd_dma_buffer *dmab, size_t offset) { struct snd_sg_buf *sgbuf = dmab->private_data; + + if (!sgbuf) + return dmab->area + offset; return sgbuf->table[offset >> PAGE_SHIFT].buf + offset % PAGE_SIZE; } diff --git a/sound/core/sgbuf.c b/sound/core/sgbuf.c index c42217e2dd195..29ddb76187e57 100644 --- a/sound/core/sgbuf.c +++ b/sound/core/sgbuf.c @@ -142,6 +142,9 @@ unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab, struct snd_sg_buf *sg = dmab->private_data; unsigned int start, end, pg; + if (!sg) + return size; + start = ofs >> PAGE_SHIFT; end = (ofs + size - 1) >> PAGE_SHIFT; /* check page continuity */ From 3ad796cbc36a7bc8bfd4de191d791b9490bc112b Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 15 Jun 2020 18:00:45 +0200 Subject: [PATCH 4/4] ALSA: pcm: Use SG-buffer only when direct DMA is available The DMA-coherent SG-buffer is tricky to use, as it does need the mapping. It used to work stably on x86 over years (and that's why we had enabled SG-buffer on solely x86) with the default mmap handler and vmap(), but our luck seems no forever success. The chance of breakage is high when the special DMA handling is introduced in the arch side. In this patch, we change the buffer allocation to use the SG-buffer only when the device in question is with the direct DMA. It's a bit hackish, but it's currently the only condition that may work (more or less) reliably with the default mmap and vmap() for mapping the pages that are deduced via virt_to_page(). In theory, we can apply the similar hack in the sound/core memory allocation helper, too; but it's used by SOF for allocating SG pages without re-mapping via vmap() or mmap, and it's fine to use it in that way, so let's keep it and adds the workaround in PCM side. Link: https://lore.kernel.org/r/20200615160045.2703-5-tiwai@suse.de Signed-off-by: Takashi Iwai --- sound/core/pcm_memory.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/sound/core/pcm_memory.c b/sound/core/pcm_memory.c index 860935e3aea49..8326d16d35964 100644 --- a/sound/core/pcm_memory.c +++ b/sound/core/pcm_memory.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -39,6 +40,18 @@ static int do_alloc_pages(struct snd_card *card, int type, struct device *dev, if (max_alloc_per_card && card->total_pcm_alloc_bytes + size > max_alloc_per_card) return -ENOMEM; + + if (IS_ENABLED(CONFIG_SND_DMA_SGBUF) && + (type == SNDRV_DMA_TYPE_DEV_SG || type == SNDRV_DMA_TYPE_DEV_UC_SG) && + !dma_is_direct(get_dma_ops(dev))) { + /* mutate to continuous page allocation */ + dev_dbg(dev, "Use continuous page allocator\n"); + if (type == SNDRV_DMA_TYPE_DEV_SG) + type = SNDRV_DMA_TYPE_DEV; + else + type = SNDRV_DMA_TYPE_DEV_UC; + } + err = snd_dma_alloc_pages(type, dev, size, dmab); if (!err) { mutex_lock(&card->memory_mutex);