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925ca893b4
The recent change for memory allocator replaced the SG-buffer handling
helper for x86 with the standard non-contiguous page handler. This
works for most cases, but there is a corner case I obviously
overlooked, namely, the fallback of non-contiguous handler without
IOMMU. When the system runs without IOMMU, the core handler tries to
use the continuous pages with a single SGL entry. It works nicely for
most cases, but when the system memory gets fragmented, the large
allocation may fail frequently.
Ideally the non-contig handler could deal with the proper SG pages,
it's cumbersome to extend for now. As a workaround, here we add new
types for (minimalistic) SG allocations, instead, so that the
allocator falls back to those types automatically when the allocation
with the standard API failed.
BTW, one better (but pretty minor) improvement from the previous
SG-buffer code is that this provides the proper mmap support without
the PCM's page fault handling.
Fixes: 2c95b92ecd ("ALSA: memalloc: Unify x86 SG-buffer handling (take#3)")
BugLink: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/2272
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1198248
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220413054808.7547-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
129 lines
3.9 KiB
C
129 lines
3.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* Copyright (c) by Jaroslav Kysela <perex@perex.cz>
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* Takashi Iwai <tiwai@suse.de>
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*
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* Generic memory allocators
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*/
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#ifndef __SOUND_MEMALLOC_H
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#define __SOUND_MEMALLOC_H
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#include <linux/dma-direction.h>
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#include <asm/page.h>
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struct device;
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struct vm_area_struct;
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struct sg_table;
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/*
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* buffer device info
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*/
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struct snd_dma_device {
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int type; /* SNDRV_DMA_TYPE_XXX */
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enum dma_data_direction dir; /* DMA direction */
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bool need_sync; /* explicit sync needed? */
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struct device *dev; /* generic device */
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};
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#define snd_dma_continuous_data(x) ((struct device *)(__force unsigned long)(x))
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/*
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* buffer types
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*/
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#define SNDRV_DMA_TYPE_UNKNOWN 0 /* not defined */
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#define SNDRV_DMA_TYPE_CONTINUOUS 1 /* continuous no-DMA memory */
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#define SNDRV_DMA_TYPE_DEV 2 /* generic device continuous */
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#define SNDRV_DMA_TYPE_DEV_WC 5 /* continuous write-combined */
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#ifdef CONFIG_GENERIC_ALLOCATOR
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#define SNDRV_DMA_TYPE_DEV_IRAM 4 /* generic device iram-buffer */
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#else
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#define SNDRV_DMA_TYPE_DEV_IRAM SNDRV_DMA_TYPE_DEV
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#endif
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#define SNDRV_DMA_TYPE_VMALLOC 7 /* vmalloc'ed buffer */
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#define SNDRV_DMA_TYPE_NONCONTIG 8 /* non-coherent SG buffer */
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#define SNDRV_DMA_TYPE_NONCOHERENT 9 /* non-coherent buffer */
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#ifdef CONFIG_SND_DMA_SGBUF
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#define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_NONCONTIG
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#define SNDRV_DMA_TYPE_DEV_WC_SG 6 /* SG write-combined */
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#else
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#define SNDRV_DMA_TYPE_DEV_SG SNDRV_DMA_TYPE_DEV /* no SG-buf support */
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#define SNDRV_DMA_TYPE_DEV_WC_SG SNDRV_DMA_TYPE_DEV_WC
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#endif
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/* fallback types, don't use those directly */
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#ifdef CONFIG_SND_DMA_SGBUF
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#define SNDRV_DMA_TYPE_DEV_SG_FALLBACK 10
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#define SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK 11
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#endif
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/*
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* info for buffer allocation
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*/
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struct snd_dma_buffer {
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struct snd_dma_device dev; /* device type */
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unsigned char *area; /* virtual pointer */
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dma_addr_t addr; /* physical address */
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size_t bytes; /* buffer size in bytes */
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void *private_data; /* private for allocator; don't touch */
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};
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/*
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* return the pages matching with the given byte size
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*/
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static inline unsigned int snd_sgbuf_aligned_pages(size_t size)
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{
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return (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
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}
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/* allocate/release a buffer */
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int snd_dma_alloc_dir_pages(int type, struct device *dev,
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enum dma_data_direction dir, size_t size,
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struct snd_dma_buffer *dmab);
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static inline int snd_dma_alloc_pages(int type, struct device *dev,
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size_t size, struct snd_dma_buffer *dmab)
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{
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return snd_dma_alloc_dir_pages(type, dev, DMA_BIDIRECTIONAL, size, dmab);
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}
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int snd_dma_alloc_pages_fallback(int type, struct device *dev, size_t size,
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struct snd_dma_buffer *dmab);
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void snd_dma_free_pages(struct snd_dma_buffer *dmab);
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int snd_dma_buffer_mmap(struct snd_dma_buffer *dmab,
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struct vm_area_struct *area);
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enum snd_dma_sync_mode { SNDRV_DMA_SYNC_CPU, SNDRV_DMA_SYNC_DEVICE };
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#ifdef CONFIG_HAS_DMA
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void snd_dma_buffer_sync(struct snd_dma_buffer *dmab,
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enum snd_dma_sync_mode mode);
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#else
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static inline void snd_dma_buffer_sync(struct snd_dma_buffer *dmab,
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enum snd_dma_sync_mode mode) {}
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#endif
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dma_addr_t snd_sgbuf_get_addr(struct snd_dma_buffer *dmab, size_t offset);
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struct page *snd_sgbuf_get_page(struct snd_dma_buffer *dmab, size_t offset);
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unsigned int snd_sgbuf_get_chunk_size(struct snd_dma_buffer *dmab,
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unsigned int ofs, unsigned int size);
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/* device-managed memory allocator */
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struct snd_dma_buffer *snd_devm_alloc_dir_pages(struct device *dev, int type,
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enum dma_data_direction dir,
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size_t size);
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static inline struct snd_dma_buffer *
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snd_devm_alloc_pages(struct device *dev, int type, size_t size)
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{
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return snd_devm_alloc_dir_pages(dev, type, DMA_BIDIRECTIONAL, size);
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}
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static inline struct sg_table *
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snd_dma_noncontig_sg_table(struct snd_dma_buffer *dmab)
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{
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return dmab->private_data;
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}
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#endif /* __SOUND_MEMALLOC_H */
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