linux.git/sound/core/memalloc.c, branch v5.19

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

2022-06-20T07:35:23+00:00

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:  # v5.18+
Link: https://lore.kernel.org/r/20220620073440.7514-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Add fallback SG-buffer allocations for x86

2022-04-13T05:48:53+00:00

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: 2c95b92ecd92 ("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: 
Link: https://lore.kernel.org/r/20220413054808.7547-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: invalidate SG pages before sync

2022-02-10T12:36:53+00:00

It seems that calling invalidate_kernel_vmap_range() is more correct
to be called before dma_sync_*(), judging from the other thread:
  https://lore.kernel.org/all/20220111085958.GA22795@lst.de/
Although this won't matter much in practice, let's fix the call order
for consistency.

Fixes: a25684a95646 ("ALSA: memalloc: Support for non-contiguous page allocation")
Reported-by: Ezequiel Garcia 
Cc: 
Link: https://lore.kernel.org/r/20220210123344.8756-3-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Fix dma_need_sync() checks

2022-02-10T12:36:39+00:00

dma_need_sync() checks each DMA address.  Fix the incorrect usages
for non-contiguous and non-coherent page allocations.
Fortunately, there are no actual call sites that need manual syncs
yet.

Fixes: a25684a95646 ("ALSA: memalloc: Support for non-contiguous page allocation")
Fixes: 73325f60e2ed ("ALSA: memalloc: Support for non-coherent page allocation")
Cc: 
Reported-by: Ezequiel Garcia 
Link: https://lore.kernel.org/r/20220210123344.8756-2-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Unify x86 SG-buffer handling (take#3)

2021-11-16T07:34:29+00:00

This is a second attempt to unify the x86-specific SG-buffer handling
code with the new standard non-contiguous page handler.

The first try (in commit 2d9ea39917a4) failed due to the wrong page
and address calculations, hence reverted.  (And the second try failed
due to a copy&paste error.)  Now it's corrected with the previous fix
for noncontig pages, and the proper sg page iteration by this patch.

After the migration, SNDRV_DMA_TYPE_DMA_SG becomes identical with
SNDRV_DMA_TYPE_NONCONTIG on x86, while others still fall back to
SNDRV_DMA_TYPE_DEV.

Tested-by: Alex Xu (Hello71) 
Tested-by: Harald Arnesen 
Link: https://lore.kernel.org/r/20211017074859.24112-4-tiwai@suse.de
Link: https://lore.kernel.org/r/20211109062235.22310-1-tiwai@suse.de
Link: https://lore.kernel.org/r/20211116073358.19741-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Remove a stale comment

2021-11-10T06:35:23+00:00

The comment about the reused vmalloc helpers is no longer valid after
the recent change for the noncontig allocator.  Drop the stale
comment.

Fixes: ad4f93ca4138 ("ALSA: memalloc: Use proper SG helpers for noncontig allocations")
Link: https://lore.kernel.org/r/20211110063100.21359-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Use proper SG helpers for noncontig allocations

2021-11-09T06:14:22+00:00

The recently introduced non-contiguous page allocation support helpers
are using the simplified code to calculate the page and DMA address
based on the vmalloc helpers, but this isn't quite right as the vmap
is valid only for the direct DMA.

This patch corrects those accessors to use the proper SG helpers
instead.

Fixes: a25684a95646 ("ALSA: memalloc: Support for non-contiguous page allocation")
Tested-by: Alex Xu (Hello71) 
Link: https://lore.kernel.org/r/20211108151059.31898-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: PCM: Fix NULL dereference at mmap checks

2021-11-07T16:55:05+00:00

The recent refactoring of mmap handling caused Oops on some devices
that don't use the standard memory allocations.  This patch addresses
it by allowing snd_dma_buffer_mmap() helper to receive the NULL
pointer dmab argument (and return an error appropriately).

Fixes: a202bd1ad86d ("ALSA: core: Move mmap handler into memalloc ops")
Cc: 
Link: https://lore.kernel.org/r/20211107163911.13534-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

ALSA: memalloc: Catch call with NULL snd_dma_buffer pointer

2021-11-05T10:27:10+00:00

Although we've covered all calls with NULL dma buffer pointer, so far,
there may be still some else in the wild.  For catching such a case
more easily, add a WARN_ON_ONCE() in snd_dma_get_ops().

Fixes: 37af81c5998f ("ALSA: core: Abstract memory alloc helpers")
Link: https://lore.kernel.org/r/20211105102103.28148-1-tiwai@suse.de
Signed-off-by: Takashi Iwai

Revert "ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type"

2021-11-04T21:10:03+00:00

This reverts commit 2d9ea39917a4e4293bc2caea902c7059a330b611.

We've got a regression report showing that the audio got broken the
device over AMD IOMMU.  The conversion assumed the wrong pointer /
page mapping for the indirect mapping case, and we need to correct
this urgently, so let's revert it for now.

Fixes: 2d9ea39917a4 ("ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type")
Reported-and-tested-by: Alex Xu (Hello71) 
Link: https://lore.kernel.org/r/20211104180846.16340-1-tiwai@suse.de
Signed-off-by: Takashi Iwai