kernel/linux.git/sound/core/memalloc.c, branch v6.0

ALSA: hda: Once again fix regression of page allocations with IOMMU

2022-09-06T09:03:48+00:00

The last fix for trying to recover the regression on AMD platforms, unfortunately, leaded to yet another regression: it turned out that IOMMUs don't like the usage of raw page allocations. This is yet another attempt for addressing the log saga; at this time, we re-use the existing buffer allocation mechanism with SG-pages although we require only single pages. The SG buffer allocation itself was confirmed to work for stream buffers, so it's relatively easy to adapt for other places. The only problem is: although the HD-audio code is accessing the address directly via dmab->address field, SG-pages don't set up it. For the ease of adaption, we now set up the dmab->addr field from the address of the first page as default, so that it can run with the HD-audio driver code as-is without the excessive call of snd_sgbuf_get_addr() multiple times; that's the only change in the memalloc helper side. The rest is nothing but a flip of the dma_type field in the HD-audio side. Fixes: a8d302a0b770 ("ALSA: memalloc: Revive x86-specific WC page allocations again") Reported-by: Mikhail Gavrilov Tested-by: Mikhail Gavrilov Cc: Link: https://lore.kernel.org/r/CABXGCsO+kB2t5QyHY-rUe76npr1m0-5JOtt8g8SiHUo34ur7Ww@mail.gmail.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=216112 Link: https://bugzilla.kernel.org/show_bug.cgi?id=216363 Link: https://lore.kernel.org/r/20220906090319.23358-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: memalloc: Revive x86-specific WC page allocations again

2022-08-22T11:01:27+00:00

We dropped the x86-specific hack for WC-page allocations with a hope that the standard dma_alloc_wc() works nowadays. Alas, it doesn't, and we need to take back some workaround again, but in a different form, as the previous one was broken for some platforms. This patch re-introduces the x86-specific WC-page allocations, but it uses rather the manual page allocations instead of dma_alloc_coherent(). The use of dma_alloc_coherent() was also a potential problem in the recent addition of the fallback allocation for noncontig pages, and this patch eliminates both at once. Fixes: 9882d63bea14 ("ALSA: memalloc: Drop x86-specific hack for WC allocations") Cc: BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216363 Link: https://lore.kernel.org/r/20220821155911.10715-1-tiwai@suse.de Signed-off-by: Takashi Iwai

ALSA: memalloc: Fix missing return value comments for kernel docs

2022-07-13T11:42:37+00:00

Each kernel doc comment expects the definition of the return value in a proper format. This patch adds or fixes the missing entries for memory allocation helpers. Link: https://lore.kernel.org/r/20220713104759.4365-7-tiwai@suse.de Signed-off-by: Takashi Iwai

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