Commit 9882d63b authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: memalloc: Drop x86-specific hack for WC allocations 

The recent report for a crash on Haswell machines implied that the
x86-specific (rather hackish) implementation for write-cache memory
buffer allocation in ALSA core is buggy with the recent kernel in some
corner cases.  This patch drops the x86-specific implementation and
uses the standard dma_alloc_wc() & co generically for avoiding the bug
and also for simplification.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216112
Cc: <stable@vger.kernel.org> # v5.18+
Link: https://lore.kernel.org/r/20220620073440.7514-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent d4995121

sound/core/memalloc.c

+1 −22
Original line number Diff line number Diff line
@@ -431,33 +431,17 @@ static const struct snd_malloc_ops snd_dma_iram_ops = { 
 */

static void *snd_dma_dev_alloc(struct snd_dma_buffer *dmab, size_t size)

{

	void *p;



	p = dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);

#ifdef CONFIG_X86

	if (p && dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)

		set_memory_wc((unsigned long)p, PAGE_ALIGN(size) >> PAGE_SHIFT);

#endif

	return p;

	return dma_alloc_coherent(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);

}



static void snd_dma_dev_free(struct snd_dma_buffer *dmab)

{

#ifdef CONFIG_X86

	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)

		set_memory_wb((unsigned long)dmab->area,

			      PAGE_ALIGN(dmab->bytes) >> PAGE_SHIFT);

#endif

	dma_free_coherent(dmab->dev.dev, dmab->bytes, dmab->area, dmab->addr);

}



static int snd_dma_dev_mmap(struct snd_dma_buffer *dmab,

			    struct vm_area_struct *area)

{

#ifdef CONFIG_X86

	if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC)

		area->vm_page_prot = pgprot_writecombine(area->vm_page_prot);

#endif

	return dma_mmap_coherent(dmab->dev.dev, area,

				 dmab->area, dmab->addr, dmab->bytes);

}
@@ -471,10 +455,6 @@ static const struct snd_malloc_ops snd_dma_dev_ops = { 
/*

 * Write-combined pages

 */

#ifdef CONFIG_X86

/* On x86, share the same ops as the standard dev ops */

#define snd_dma_wc_ops	snd_dma_dev_ops

#else /* CONFIG_X86 */

static void *snd_dma_wc_alloc(struct snd_dma_buffer *dmab, size_t size)

{

	return dma_alloc_wc(dmab->dev.dev, size, &dmab->addr, DEFAULT_GFP);
@@ -497,7 +477,6 @@ static const struct snd_malloc_ops snd_dma_wc_ops = { 
	.free = snd_dma_wc_free,

	.mmap = snd_dma_wc_mmap,

};

#endif /* CONFIG_X86 */



#ifdef CONFIG_SND_DMA_SGBUF

static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size);