On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote:

On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote:

...

On Fri, 09 Dec 2022 02:27:30 +0100, Marek Marczykowski-Górecki wrote:

...

Hi,

Under Xen PV dom0, with Linux >= 5.17, sound stops working after few hours. pavucontrol still shows meter bars moving, but the speakers remain silent. At least on some occasions I see the following message in dmesg:

[ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting

Hit the issue again, this message did not appear in the log (or at least not yet).

(...)

...

In anyway, please check the behavior with 6.1-rc8 + the commit cc26516374065a34e10c9a8bf3e940e42cd96e2a ALSA: memalloc: Allocate more contiguous pages for fallback case from for-next of my sound git tree (which will be in 6.2-rc1).

This did not helped.

Looking at the mentioned commits, there is one specific aspect of Xen PV that may be relevant. It configures PAT differently than native Linux. Theoretically Linux adapts automatically and using proper API (like set_memory_wc()) should just work, but at least for i915 driver it causes issues (not fully tracked down yet). Details about that bug report include some more background: https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/

Anyway, I have tested it on a Xen modified to setup PAT the same way as native Linux and the audio issue is still there.

...

If the problem persists, another thing to check is the hack below works.

Trying this one now.

...

-- 8< -- --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1808,9 +1808,16 @@ static int azx_create(struct snd_card *card, struct pci_dev *pci, if (err < 0) return err;

+#if 0 /* use the non-cached pages in non-snoop mode */ if (!azx_snoop(chip)) azx_bus(chip)->dma_type = SNDRV_DMA_TYPE_DEV_WC_SG; +#else

• if (!azx_snoop(chip))

• azx_bus(chip)->dma_type = SNDRV_DMA_TYPE_DEV_SG;
  

• else

• azx_bus(chip)->dma_type = SNDRV_DMA_TYPE_DEV;
  

+#endif

if (chip->driver_type == AZX_DRIVER_NVIDIA) { dev_dbg(chip->card->dev, "Enable delay in RIRB handling\n");

On Thu, Dec 22, 2022 at 09:09:15AM +0100, Takashi Iwai wrote:

On Sat, 10 Dec 2022 17:17:42 +0100, Marek Marczykowski-Górecki wrote:

...

On Sat, Dec 10, 2022 at 02:00:06AM +0100, Marek Marczykowski-Górecki wrote:

...

On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote:

...

On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote:

...

On Fri, 09 Dec 2022 02:27:30 +0100, Marek Marczykowski-Górecki wrote:

...

Hi,

Under Xen PV dom0, with Linux >= 5.17, sound stops working after few hours. pavucontrol still shows meter bars moving, but the speakers remain silent. At least on some occasions I see the following message in dmesg:

[ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting

Hit the issue again, this message did not appear in the log (or at least not yet).

(...)

...

...

In anyway, please check the behavior with 6.1-rc8 + the commit cc26516374065a34e10c9a8bf3e940e42cd96e2a ALSA: memalloc: Allocate more contiguous pages for fallback case from for-next of my sound git tree (which will be in 6.2-rc1).

This did not helped.

...

Looking at the mentioned commits, there is one specific aspect of Xen PV that may be relevant. It configures PAT differently than native Linux. Theoretically Linux adapts automatically and using proper API (like set_memory_wc()) should just work, but at least for i915 driver it causes issues (not fully tracked down yet). Details about that bug report include some more background: https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/

Anyway, I have tested it on a Xen modified to setup PAT the same way as native Linux and the audio issue is still there.

...

If the problem persists, another thing to check is the hack below works.

Trying this one now.

And this one didn't either :/

(Sorry for the late reply, as I've been off in the last weeks.)

I think the hack doesn't influence on the PCM buffer pages, but only about BDL pages. Could you check the patch below instead? It'll disable the SG-buffer handling on x86 completely.

This seems to "fix" the issue, thanks! I guess I'll run it this way for now, but a proper solution would be nice. Let me know if I can collect any more info that would help with that.

-- 8< -- --- a/sound/core/Kconfig +++ b/sound/core/Kconfig @@ -225,8 +225,8 @@ config SND_VMASTER bool

config SND_DMA_SGBUF

• def_bool y
• depends on X86

• def_bool n

+# depends on X86

config SND_CTL_LED tristate

On Mon, 16 Jan 2023 16:55:11 +0100, Takashi Iwai wrote:

On Tue, 27 Dec 2022 16:26:54 +0100, Marek Marczykowski-Górecki wrote:

...

On Thu, Dec 22, 2022 at 09:09:15AM +0100, Takashi Iwai wrote:

...

On Sat, 10 Dec 2022 17:17:42 +0100, Marek Marczykowski-Górecki wrote:

...

On Sat, Dec 10, 2022 at 02:00:06AM +0100, Marek Marczykowski-Górecki wrote:

...

On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote:

...

On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote: > On Fri, 09 Dec 2022 02:27:30 +0100, > Marek Marczykowski-Górecki wrote: > > > > Hi, > > > > Under Xen PV dom0, with Linux >= 5.17, sound stops working after few > > hours. pavucontrol still shows meter bars moving, but the speakers > > remain silent. At least on some occasions I see the following message in > > dmesg: > > > > [ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting

Hit the issue again, this message did not appear in the log (or at least not yet).

(...)

...

> In anyway, please check the behavior with 6.1-rc8 + the commit > cc26516374065a34e10c9a8bf3e940e42cd96e2a > ALSA: memalloc: Allocate more contiguous pages for fallback case > from for-next of my sound git tree (which will be in 6.2-rc1).

This did not helped.

...

Looking at the mentioned commits, there is one specific aspect of Xen PV that may be relevant. It configures PAT differently than native Linux. Theoretically Linux adapts automatically and using proper API (like set_memory_wc()) should just work, but at least for i915 driver it causes issues (not fully tracked down yet). Details about that bug report include some more background: https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/

Anyway, I have tested it on a Xen modified to setup PAT the same way as native Linux and the audio issue is still there.

> If the problem persists, another thing to check is the hack below > works.

Trying this one now.

And this one didn't either :/

(Sorry for the late reply, as I've been off in the last weeks.)

I think the hack doesn't influence on the PCM buffer pages, but only about BDL pages. Could you check the patch below instead? It'll disable the SG-buffer handling on x86 completely.

This seems to "fix" the issue, thanks! I guess I'll run it this way for now, but a proper solution would be nice. Let me know if I can collect any more info that would help with that.

Then we seem to go back again with the coherent memory allocation for the fallback sg cases. It was changed because the use of dma_alloc_coherent() caused a problem with IOMMU case for retrieving the page addresses, but since the commit 9736a325137b, we essentially avoid the fallback when IOMMU is used, so it should be fine again.

Let me know if the patch like below works for you instead of the previous hack to disable SG-buffer (note: totally untested!)

Gah, there was an obvious typo, scratch that.

Below is a proper patch. Please try this one instead.

thanks,

Takashi

-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: memalloc: Use coherent DMA allocation for fallback again

We switched the memory allocation for fallback cases in the noncontig type to use the standard alloc_pages*() at the commit a8d302a0b770 ("ALSA: memalloc: Revive x86-specific WC page allocations again"), while we used the dma_alloc_coherent() in the past. The reason was that the page address retrieved from the virtual pointer returned from dma_alloc_coherent() can't be used with IOMMU systems. Meanwhile, we explicitly disabled the fallback allocation for IOMMU systems at the commit 9736a325137b ("ALSA: memalloc: Don't fall back for SG-buffer with IOMMU") after the commit above; that is, the usage of dma_alloc_coherent() should be OK again.

Now, we've received reports that the current fallback page allocation caused a regression on Xen (and maybe other) systems; the sound disappear partially or completely. The further investigation showed that this can be worked around by the dma_alloc_coherent() pages. So, it's time to take it back.

This patch switches back to the dma_alloc_coherent() for the fallback allocations. Unlike the previous implementation, the allocation is implemented in a more optimized way to try larger chunks. The page count is stored in the lower bits of the addresses.

Fixes: a8d302a0b770 ("ALSA: memalloc: Revive x86-specific WC page allocations again") Fixes: 9736a325137b ("ALSA: memalloc: Don't fall back for SG-buffer with IOMMU") Link: https://lore.kernel.org/r/87tu256lqs.wl-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/memalloc.c | 44 +++++++++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 10 deletions(-)

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 81025f50a542..dff07cd6f209 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -719,17 +719,30 @@ static const struct snd_malloc_ops snd_dma_sg_wc_ops = { struct snd_dma_sg_fallback { size_t count; struct page **pages; + dma_addr_t *addrs; };

static void __snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab, struct snd_dma_sg_fallback *sgbuf) { - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; - size_t i; - - for (i = 0; i < sgbuf->count && sgbuf->pages[i]; i++) - do_free_pages(page_address(sgbuf->pages[i]), PAGE_SIZE, wc); + size_t i, size; + + if (sgbuf->pages && sgbuf->addrs) { + i = 0; + while (i < sgbuf->count) { + if (!sgbuf->pages[i] || !sgbuf->addrs[i]) + break; + size = sgbuf->addrs[i] & ~PAGE_MASK; + if (WARN_ON(!size)) + break; + dma_free_coherent(dmab->dev.dev, size, + page_address(sgbuf->pages[i]), + sgbuf->addrs[i] & PAGE_MASK); + i += size; + } + } kvfree(sgbuf->pages); + kvfree(sgbuf->addrs); kfree(sgbuf); }

@@ -738,9 +751,8 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) struct snd_dma_sg_fallback *sgbuf; struct page **pagep, *curp; size_t chunk, npages; - dma_addr_t addr; + dma_addr_t *addrp; void *p; - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;

sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); if (!sgbuf) @@ -748,14 +760,16 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size = PAGE_ALIGN(size); sgbuf->count = size >> PAGE_SHIFT; sgbuf->pages = kvcalloc(sgbuf->count, sizeof(*sgbuf->pages), GFP_KERNEL); - if (!sgbuf->pages) + sgbuf->addrs = kvcalloc(sgbuf->count, sizeof(*sgbuf->addrs), GFP_KERNEL); + if (!sgbuf->pages || !sgbuf->addrs) goto error;

pagep = sgbuf->pages; - chunk = size; + addrp = sgbuf->addrs; + chunk = (PAGE_SIZE - 1) << PAGE_SHIFT; /* to fit in low bits in addrs */ while (size > 0) { chunk = min(size, chunk); - p = do_alloc_pages(dmab->dev.dev, chunk, &addr, wc); + p = dma_alloc_coherent(dmab->dev.dev, chunk, addrp, DEFAULT_GFP); if (!p) { if (chunk <= PAGE_SIZE) goto error; @@ -767,6 +781,8 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size -= chunk; /* fill pages */ npages = chunk >> PAGE_SHIFT; + *addrp |= npages; /* store in lower bits */ + addrp += npages; curp = virt_to_page(p); while (npages--) *pagep++ = curp++; @@ -775,6 +791,10 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) p = vmap(sgbuf->pages, sgbuf->count, VM_MAP, PAGE_KERNEL); if (!p) goto error; + + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wc(sgbuf->pages, sgbuf->count); + dmab->private_data = sgbuf; /* store the first page address for convenience */ dmab->addr = snd_sgbuf_get_addr(dmab, 0); @@ -787,7 +807,11 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size)

static void snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab) { + struct snd_dma_sg_fallback *sgbuf = dmab->private_data; + vunmap(dmab->area); + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wb(sgbuf->pages, sgbuf->count); __snd_dma_sg_fallback_free(dmab, dmab->private_data); }

On Wed, Jan 18, 2023 at 01:39:56PM +0100, Takashi Iwai wrote:

On Wed, 18 Jan 2023 11:39:18 +0100, Marek Marczykowski-Górecki wrote:

...

On Wed, Jan 18, 2023 at 09:59:26AM +0100, Takashi Iwai wrote:

...

On Tue, 17 Jan 2023 21:34:11 +0100, Marek Marczykowski-Górecki wrote:

...

On Tue, Jan 17, 2023 at 05:52:25PM +0100, Takashi Iwai wrote:

...

On Tue, 17 Jan 2023 17:49:28 +0100, Marek Marczykowski-Górecki wrote:

...

On Tue, Jan 17, 2023 at 03:33:42PM +0100, Takashi Iwai wrote: > On Tue, 17 Jan 2023 15:21:23 +0100, > Marek Marczykowski-Górecki wrote: > > > > On Tue, Jan 17, 2023 at 12:36:28PM +0100, Marek Marczykowski-Górecki wrote: > > > On Tue, Jan 17, 2023 at 08:58:57AM +0100, Takashi Iwai wrote: > > > > On Mon, 16 Jan 2023 16:55:11 +0100, > > > > Takashi Iwai wrote: > > > > > > > > > > On Tue, 27 Dec 2022 16:26:54 +0100, > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > On Thu, Dec 22, 2022 at 09:09:15AM +0100, Takashi Iwai wrote: > > > > > > > On Sat, 10 Dec 2022 17:17:42 +0100, > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > On Sat, Dec 10, 2022 at 02:00:06AM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > > On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote: > > > > > > > > > > > On Fri, 09 Dec 2022 02:27:30 +0100, > > > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > > > > > Under Xen PV dom0, with Linux >= 5.17, sound stops working after few > > > > > > > > > > > > hours. pavucontrol still shows meter bars moving, but the speakers > > > > > > > > > > > > remain silent. At least on some occasions I see the following message in > > > > > > > > > > > > dmesg: > > > > > > > > > > > > > > > > > > > > > > > > [ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting > > > > > > > > > > > > > > > > > > Hit the issue again, this message did not appear in the log (or at least > > > > > > > > > not yet). > > > > > > > > > > > > > > > > > > (...) > > > > > > > > > > > > > > > > > > > > In anyway, please check the behavior with 6.1-rc8 + the commit > > > > > > > > > > > cc26516374065a34e10c9a8bf3e940e42cd96e2a > > > > > > > > > > > ALSA: memalloc: Allocate more contiguous pages for fallback case > > > > > > > > > > > from for-next of my sound git tree (which will be in 6.2-rc1). > > > > > > > > > > > > > > > > > > This did not helped. > > > > > > > > > > > > > > > > > > > Looking at the mentioned commits, there is one specific aspect of Xen PV > > > > > > > > > > that may be relevant. It configures PAT differently than native Linux. > > > > > > > > > > Theoretically Linux adapts automatically and using proper API (like > > > > > > > > > > set_memory_wc()) should just work, but at least for i915 driver it > > > > > > > > > > causes issues (not fully tracked down yet). Details about that bug > > > > > > > > > > report include some more background: > > > > > > > > > > https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/ > > > > > > > > > > > > > > > > > > > > Anyway, I have tested it on a Xen modified to setup PAT the same way as > > > > > > > > > > native Linux and the audio issue is still there. > > > > > > > > > > > > > > > > > > > > > If the problem persists, another thing to check is the hack below > > > > > > > > > > > works. > > > > > > > > > > > > > > > > > > Trying this one now. > > > > > > > > > > > > > > > > And this one didn't either :/ > > > > > > > > > > > > > > (Sorry for the late reply, as I've been off in the last weeks.) > > > > > > > > > > > > > > I think the hack doesn't influence on the PCM buffer pages, but only > > > > > > > about BDL pages. Could you check the patch below instead? > > > > > > > It'll disable the SG-buffer handling on x86 completely. > > > > > > > > > > > > This seems to "fix" the issue, thanks! > > > > > > I guess I'll run it this way for now, but a proper solution would be > > > > > > nice. Let me know if I can collect any more info that would help with > > > > > > that. > > > > > > > > > > Then we seem to go back again with the coherent memory allocation for > > > > > the fallback sg cases. It was changed because the use of > > > > > dma_alloc_coherent() caused a problem with IOMMU case for retrieving > > > > > the page addresses, but since the commit 9736a325137b, we essentially > > > > > avoid the fallback when IOMMU is used, so it should be fine again. > > > > > > > > > > Let me know if the patch like below works for you instead of the > > > > > previous hack to disable SG-buffer (note: totally untested!) > > > > > > > > Gah, there was an obvious typo, scratch that. > > > > > > > > Below is a proper patch. Please try this one instead. > > > > > > Thanks, I'll give it a try. > > > > Unfortunately, it doesn't help, it stopped working again, after about 3h > > uptime. > > Aha, then it might be rather other way round; > dma_alloc_noncontiguous() doesn't work on Xen properly. > > Could you try the one below instead of the previous?

Unfortunately, this one doesn't fix it either :/

Hmm. Then how about applying both of the last two patches? The last one to enforce the fallback allocation and the previous one to use dma_alloc_coherent(). It should be essentially reverting to the old way.

Oh, I noticed only now: the last patch made it fail to initialize.

The "last patch" means the patch to enforce the fallback allocation?

Yes, the one about dma_alloc_noncontiguous().

...

...

I don't see obvious errors in dmesg, but when trying aplay, I get:

ALSA lib pcm_direct.c:1284:(snd1_pcm_direct_initialize_slave) unable to install hw params
ALSA lib pcm_dmix.c:1087:(snd_pcm_dmix_open) unable to initialize slave
aplay: main:830: audio open error: Cannot allocate memory

It's -ENOMEM, so it must be from there. Does it appear always? If yes, your system is with IOMMU, and the patch made return always NULL intentionally.

While the system do have IOMMU, it isn't configured by Linux, but by Xen. And it maps all the memory that Linux see.

...

If that's the case, the problem is that IOMMU doesn't handle the coherent memory on Xen.

Please check more explicitly, whether get_dma_ops(dmab->dev.dev) call in snd_dma_noncontig_alloc() returns NULL or not.

Will do.

If get_dma_ops() is non-NULL,

Yes, it's non-NULL.

it means we need some Xen-specific workaround not to use dma_alloc_noncontiguous(). What's the best way to see whether the driver is running on Xen PV?

Usually it's this: cpu_feature_enabled(X86_FEATURE_XENPV)

Meanwhile, it's helpful if you can try the combo of my last two patches, too. It should work, and if it doesn't, it implies that we're looking at a wrong place.

It doesn't because the last of them causes "Cannot allocate memory". I'm trying now with this on top:

---8<--- diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 97d7b8106869..e927d18d1ebb 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -545,7 +545,7 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) // sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, // DEFAULT_GFP, 0); #ifdef CONFIG_SND_DMA_SGBUF - if (!sgt && !get_dma_ops(dmab->dev.dev)) { + if (!sgt) { // && !get_dma_ops(dmab->dev.dev)) { if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; else ---8<---

On Fri, 20 Jan 2023 03:24:30 +0100, Marek Marczykowski-Górecki wrote:

On Fri, Jan 20, 2023 at 02:10:37AM +0100, Marek Marczykowski-Górecki wrote:

...

On Wed, Jan 18, 2023 at 01:39:56PM +0100, Takashi Iwai wrote:

...

On Wed, 18 Jan 2023 11:39:18 +0100, Marek Marczykowski-Górecki wrote:

...

On Wed, Jan 18, 2023 at 09:59:26AM +0100, Takashi Iwai wrote:

...

On Tue, 17 Jan 2023 21:34:11 +0100, Marek Marczykowski-Górecki wrote:

...

On Tue, Jan 17, 2023 at 05:52:25PM +0100, Takashi Iwai wrote: > On Tue, 17 Jan 2023 17:49:28 +0100, > Marek Marczykowski-Górecki wrote: > > > > On Tue, Jan 17, 2023 at 03:33:42PM +0100, Takashi Iwai wrote: > > > On Tue, 17 Jan 2023 15:21:23 +0100, > > > Marek Marczykowski-Górecki wrote: > > > > > > > > On Tue, Jan 17, 2023 at 12:36:28PM +0100, Marek Marczykowski-Górecki wrote: > > > > > On Tue, Jan 17, 2023 at 08:58:57AM +0100, Takashi Iwai wrote: > > > > > > On Mon, 16 Jan 2023 16:55:11 +0100, > > > > > > Takashi Iwai wrote: > > > > > > > > > > > > > > On Tue, 27 Dec 2022 16:26:54 +0100, > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > On Thu, Dec 22, 2022 at 09:09:15AM +0100, Takashi Iwai wrote: > > > > > > > > > On Sat, 10 Dec 2022 17:17:42 +0100, > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > On Sat, Dec 10, 2022 at 02:00:06AM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > > > On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote: > > > > > > > > > > > > > On Fri, 09 Dec 2022 02:27:30 +0100, > > > > > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > > > > > > > > > Under Xen PV dom0, with Linux >= 5.17, sound stops working after few > > > > > > > > > > > > > > hours. pavucontrol still shows meter bars moving, but the speakers > > > > > > > > > > > > > > remain silent. At least on some occasions I see the following message in > > > > > > > > > > > > > > dmesg: > > > > > > > > > > > > > > > > > > > > > > > > > > > > [ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting > > > > > > > > > > > > > > > > > > > > > > Hit the issue again, this message did not appear in the log (or at least > > > > > > > > > > > not yet). > > > > > > > > > > > > > > > > > > > > > > (...) > > > > > > > > > > > > > > > > > > > > > > > > In anyway, please check the behavior with 6.1-rc8 + the commit > > > > > > > > > > > > > cc26516374065a34e10c9a8bf3e940e42cd96e2a > > > > > > > > > > > > > ALSA: memalloc: Allocate more contiguous pages for fallback case > > > > > > > > > > > > > from for-next of my sound git tree (which will be in 6.2-rc1). > > > > > > > > > > > > > > > > > > > > > > This did not helped. > > > > > > > > > > > > > > > > > > > > > > > Looking at the mentioned commits, there is one specific aspect of Xen PV > > > > > > > > > > > > that may be relevant. It configures PAT differently than native Linux. > > > > > > > > > > > > Theoretically Linux adapts automatically and using proper API (like > > > > > > > > > > > > set_memory_wc()) should just work, but at least for i915 driver it > > > > > > > > > > > > causes issues (not fully tracked down yet). Details about that bug > > > > > > > > > > > > report include some more background: > > > > > > > > > > > > https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/ > > > > > > > > > > > > > > > > > > > > > > > > Anyway, I have tested it on a Xen modified to setup PAT the same way as > > > > > > > > > > > > native Linux and the audio issue is still there. > > > > > > > > > > > > > > > > > > > > > > > > > If the problem persists, another thing to check is the hack below > > > > > > > > > > > > > works. > > > > > > > > > > > > > > > > > > > > > > Trying this one now. > > > > > > > > > > > > > > > > > > > > And this one didn't either :/ > > > > > > > > > > > > > > > > > > (Sorry for the late reply, as I've been off in the last weeks.) > > > > > > > > > > > > > > > > > > I think the hack doesn't influence on the PCM buffer pages, but only > > > > > > > > > about BDL pages. Could you check the patch below instead? > > > > > > > > > It'll disable the SG-buffer handling on x86 completely. > > > > > > > > > > > > > > > > This seems to "fix" the issue, thanks! > > > > > > > > I guess I'll run it this way for now, but a proper solution would be > > > > > > > > nice. Let me know if I can collect any more info that would help with > > > > > > > > that. > > > > > > > > > > > > > > Then we seem to go back again with the coherent memory allocation for > > > > > > > the fallback sg cases. It was changed because the use of > > > > > > > dma_alloc_coherent() caused a problem with IOMMU case for retrieving > > > > > > > the page addresses, but since the commit 9736a325137b, we essentially > > > > > > > avoid the fallback when IOMMU is used, so it should be fine again. > > > > > > > > > > > > > > Let me know if the patch like below works for you instead of the > > > > > > > previous hack to disable SG-buffer (note: totally untested!) > > > > > > > > > > > > Gah, there was an obvious typo, scratch that. > > > > > > > > > > > > Below is a proper patch. Please try this one instead. > > > > > > > > > > Thanks, I'll give it a try. > > > > > > > > Unfortunately, it doesn't help, it stopped working again, after about 3h > > > > uptime. > > > > > > Aha, then it might be rather other way round; > > > dma_alloc_noncontiguous() doesn't work on Xen properly. > > > > > > Could you try the one below instead of the previous? > > > > Unfortunately, this one doesn't fix it either :/ > > Hmm. Then how about applying both of the last two patches? The last > one to enforce the fallback allocation and the previous one to use > dma_alloc_coherent(). It should be essentially reverting to the old > way.

Oh, I noticed only now: the last patch made it fail to initialize.

The "last patch" means the patch to enforce the fallback allocation?

Yes, the one about dma_alloc_noncontiguous().

...

...

I don't see obvious errors in dmesg, but when trying aplay, I get:

ALSA lib pcm_direct.c:1284:(snd1_pcm_direct_initialize_slave) unable to install hw params
ALSA lib pcm_dmix.c:1087:(snd_pcm_dmix_open) unable to initialize slave
aplay: main:830: audio open error: Cannot allocate memory

It's -ENOMEM, so it must be from there. Does it appear always? If yes, your system is with IOMMU, and the patch made return always NULL intentionally.

While the system do have IOMMU, it isn't configured by Linux, but by Xen. And it maps all the memory that Linux see.

...

If that's the case, the problem is that IOMMU doesn't handle the coherent memory on Xen.

Please check more explicitly, whether get_dma_ops(dmab->dev.dev) call in snd_dma_noncontig_alloc() returns NULL or not.

Will do.

If get_dma_ops() is non-NULL,

Yes, it's non-NULL.

...

it means we need some Xen-specific workaround not to use dma_alloc_noncontiguous(). What's the best way to see whether the driver is running on Xen PV?

Usually it's this: cpu_feature_enabled(X86_FEATURE_XENPV)

...

Meanwhile, it's helpful if you can try the combo of my last two patches, too. It should work, and if it doesn't, it implies that we're looking at a wrong place.

It doesn't because the last of them causes "Cannot allocate memory". I'm trying now with this on top:

---8<--- diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 97d7b8106869..e927d18d1ebb 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -545,7 +545,7 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) // sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, // DEFAULT_GFP, 0); #ifdef CONFIG_SND_DMA_SGBUF

• if (!sgt && !get_dma_ops(dmab->dev.dev)) {

• if (!sgt) { // && !get_dma_ops(dmab->dev.dev)) { if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; else

---8<---

Unfortunately, the above doesn't help. I mean, I don't get an error anymore, but no sound output either (even though pavucontrol says I should hear it). So, it's like the original issue, but without any delay, just straight from the start.

Hmm, it's the result with the combination of both patches, right? What I meant as the combo is something like below.

Takashi

-- 8< -- --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -15,6 +15,7 @@ #include <linux/vmalloc.h> #ifdef CONFIG_X86 #include <asm/set_memory.h> +#include <xen/xen.h> #endif #include <sound/memalloc.h> #include "memalloc_local.h" @@ -541,10 +542,8 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) struct sg_table *sgt; void *p;

- sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, - DEFAULT_GFP, 0); #ifdef CONFIG_SND_DMA_SGBUF - if (!sgt && !get_dma_ops(dmab->dev.dev)) { + if (xen_domain() || !get_dma_ops(dmab->dev.dev)) { if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; else @@ -552,6 +551,8 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) return snd_dma_sg_fallback_alloc(dmab, size); } #endif + sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, + DEFAULT_GFP, 0); if (!sgt) return NULL;

@@ -719,17 +720,30 @@ static const struct snd_malloc_ops snd_dma_sg_wc_ops = { struct snd_dma_sg_fallback { size_t count; struct page **pages; + dma_addr_t *addrs; };

static void __snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab, struct snd_dma_sg_fallback *sgbuf) { - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; - size_t i; - - for (i = 0; i < sgbuf->count && sgbuf->pages[i]; i++) - do_free_pages(page_address(sgbuf->pages[i]), PAGE_SIZE, wc); + size_t i, size; + + if (sgbuf->pages && sgbuf->addrs) { + i = 0; + while (i < sgbuf->count) { + if (!sgbuf->pages[i] || !sgbuf->addrs[i]) + break; + size = sgbuf->addrs[i] & ~PAGE_MASK; + if (WARN_ON(!size)) + break; + dma_free_coherent(dmab->dev.dev, size, + page_address(sgbuf->pages[i]), + sgbuf->addrs[i] & PAGE_MASK); + i += size; + } + } kvfree(sgbuf->pages); + kvfree(sgbuf->addrs); kfree(sgbuf); }

@@ -738,9 +752,8 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) struct snd_dma_sg_fallback *sgbuf; struct page **pagep, *curp; size_t chunk, npages; - dma_addr_t addr; + dma_addr_t *addrp; void *p; - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;

sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); if (!sgbuf) @@ -748,14 +761,16 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size = PAGE_ALIGN(size); sgbuf->count = size >> PAGE_SHIFT; sgbuf->pages = kvcalloc(sgbuf->count, sizeof(*sgbuf->pages), GFP_KERNEL); - if (!sgbuf->pages) + sgbuf->addrs = kvcalloc(sgbuf->count, sizeof(*sgbuf->addrs), GFP_KERNEL); + if (!sgbuf->pages || !sgbuf->addrs) goto error;

pagep = sgbuf->pages; - chunk = size; + addrp = sgbuf->addrs; + chunk = (PAGE_SIZE - 1) << PAGE_SHIFT; /* to fit in low bits in addrs */ while (size > 0) { chunk = min(size, chunk); - p = do_alloc_pages(dmab->dev.dev, chunk, &addr, wc); + p = dma_alloc_coherent(dmab->dev.dev, chunk, addrp, DEFAULT_GFP); if (!p) { if (chunk <= PAGE_SIZE) goto error; @@ -767,6 +782,8 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size -= chunk; /* fill pages */ npages = chunk >> PAGE_SHIFT; + *addrp |= npages; /* store in lower bits */ + addrp += npages; curp = virt_to_page(p); while (npages--) *pagep++ = curp++; @@ -775,6 +792,10 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) p = vmap(sgbuf->pages, sgbuf->count, VM_MAP, PAGE_KERNEL); if (!p) goto error; + + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wc(sgbuf->pages, sgbuf->count); + dmab->private_data = sgbuf; /* store the first page address for convenience */ dmab->addr = snd_sgbuf_get_addr(dmab, 0); @@ -787,7 +808,11 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size)

static void snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab) { + struct snd_dma_sg_fallback *sgbuf = dmab->private_data; + vunmap(dmab->area); + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wb(sgbuf->pages, sgbuf->count); __snd_dma_sg_fallback_free(dmab, dmab->private_data); }

On Fri, 20 Jan 2023 13:11:34 +0100, Marek Marczykowski-Górecki wrote:

On Fri, Jan 20, 2023 at 08:26:09AM +0100, Takashi Iwai wrote:

...

On Fri, 20 Jan 2023 03:24:30 +0100, Marek Marczykowski-Górecki wrote:

...

On Fri, Jan 20, 2023 at 02:10:37AM +0100, Marek Marczykowski-Górecki wrote:

...

On Wed, Jan 18, 2023 at 01:39:56PM +0100, Takashi Iwai wrote:

...

On Wed, 18 Jan 2023 11:39:18 +0100, Marek Marczykowski-Górecki wrote:

...

On Wed, Jan 18, 2023 at 09:59:26AM +0100, Takashi Iwai wrote: > On Tue, 17 Jan 2023 21:34:11 +0100, > Marek Marczykowski-Górecki wrote: > > > > On Tue, Jan 17, 2023 at 05:52:25PM +0100, Takashi Iwai wrote: > > > On Tue, 17 Jan 2023 17:49:28 +0100, > > > Marek Marczykowski-Górecki wrote: > > > > > > > > On Tue, Jan 17, 2023 at 03:33:42PM +0100, Takashi Iwai wrote: > > > > > On Tue, 17 Jan 2023 15:21:23 +0100, > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > On Tue, Jan 17, 2023 at 12:36:28PM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > On Tue, Jan 17, 2023 at 08:58:57AM +0100, Takashi Iwai wrote: > > > > > > > > On Mon, 16 Jan 2023 16:55:11 +0100, > > > > > > > > Takashi Iwai wrote: > > > > > > > > > > > > > > > > > > On Tue, 27 Dec 2022 16:26:54 +0100, > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > On Thu, Dec 22, 2022 at 09:09:15AM +0100, Takashi Iwai wrote: > > > > > > > > > > > On Sat, 10 Dec 2022 17:17:42 +0100, > > > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > > > > > On Sat, Dec 10, 2022 at 02:00:06AM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > On Fri, Dec 09, 2022 at 01:40:15PM +0100, Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > On Fri, Dec 09, 2022 at 09:10:19AM +0100, Takashi Iwai wrote: > > > > > > > > > > > > > > > On Fri, 09 Dec 2022 02:27:30 +0100, > > > > > > > > > > > > > > > Marek Marczykowski-Górecki wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Under Xen PV dom0, with Linux >= 5.17, sound stops working after few > > > > > > > > > > > > > > > > hours. pavucontrol still shows meter bars moving, but the speakers > > > > > > > > > > > > > > > > remain silent. At least on some occasions I see the following message in > > > > > > > > > > > > > > > > dmesg: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [ 2142.484553] snd_hda_intel 0000:00:1f.3: Unstable LPIB (18144 >= 6396); disabling LPIB delay counting > > > > > > > > > > > > > > > > > > > > > > > > > > Hit the issue again, this message did not appear in the log (or at least > > > > > > > > > > > > > not yet). > > > > > > > > > > > > > > > > > > > > > > > > > > (...) > > > > > > > > > > > > > > > > > > > > > > > > > > > > In anyway, please check the behavior with 6.1-rc8 + the commit > > > > > > > > > > > > > > > cc26516374065a34e10c9a8bf3e940e42cd96e2a > > > > > > > > > > > > > > > ALSA: memalloc: Allocate more contiguous pages for fallback case > > > > > > > > > > > > > > > from for-next of my sound git tree (which will be in 6.2-rc1). > > > > > > > > > > > > > > > > > > > > > > > > > > This did not helped. > > > > > > > > > > > > > > > > > > > > > > > > > > > Looking at the mentioned commits, there is one specific aspect of Xen PV > > > > > > > > > > > > > > that may be relevant. It configures PAT differently than native Linux. > > > > > > > > > > > > > > Theoretically Linux adapts automatically and using proper API (like > > > > > > > > > > > > > > set_memory_wc()) should just work, but at least for i915 driver it > > > > > > > > > > > > > > causes issues (not fully tracked down yet). Details about that bug > > > > > > > > > > > > > > report include some more background: > > > > > > > > > > > > > > https://lore.kernel.org/intel-gfx/Y5Hst0bCxQDTN7lK@mail-itl/ > > > > > > > > > > > > > > > > > > > > > > > > > > > > Anyway, I have tested it on a Xen modified to setup PAT the same way as > > > > > > > > > > > > > > native Linux and the audio issue is still there. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > If the problem persists, another thing to check is the hack below > > > > > > > > > > > > > > > works. > > > > > > > > > > > > > > > > > > > > > > > > > > Trying this one now. > > > > > > > > > > > > > > > > > > > > > > > > And this one didn't either :/ > > > > > > > > > > > > > > > > > > > > > > (Sorry for the late reply, as I've been off in the last weeks.) > > > > > > > > > > > > > > > > > > > > > > I think the hack doesn't influence on the PCM buffer pages, but only > > > > > > > > > > > about BDL pages. Could you check the patch below instead? > > > > > > > > > > > It'll disable the SG-buffer handling on x86 completely. > > > > > > > > > > > > > > > > > > > > This seems to "fix" the issue, thanks! > > > > > > > > > > I guess I'll run it this way for now, but a proper solution would be > > > > > > > > > > nice. Let me know if I can collect any more info that would help with > > > > > > > > > > that. > > > > > > > > > > > > > > > > > > Then we seem to go back again with the coherent memory allocation for > > > > > > > > > the fallback sg cases. It was changed because the use of > > > > > > > > > dma_alloc_coherent() caused a problem with IOMMU case for retrieving > > > > > > > > > the page addresses, but since the commit 9736a325137b, we essentially > > > > > > > > > avoid the fallback when IOMMU is used, so it should be fine again. > > > > > > > > > > > > > > > > > > Let me know if the patch like below works for you instead of the > > > > > > > > > previous hack to disable SG-buffer (note: totally untested!) > > > > > > > > > > > > > > > > Gah, there was an obvious typo, scratch that. > > > > > > > > > > > > > > > > Below is a proper patch. Please try this one instead. > > > > > > > > > > > > > > Thanks, I'll give it a try. > > > > > > > > > > > > Unfortunately, it doesn't help, it stopped working again, after about 3h > > > > > > uptime. > > > > > > > > > > Aha, then it might be rather other way round; > > > > > dma_alloc_noncontiguous() doesn't work on Xen properly. > > > > > > > > > > Could you try the one below instead of the previous? > > > > > > > > Unfortunately, this one doesn't fix it either :/ > > > > > > Hmm. Then how about applying both of the last two patches? The last > > > one to enforce the fallback allocation and the previous one to use > > > dma_alloc_coherent(). It should be essentially reverting to the old > > > way. > > > > Oh, I noticed only now: the last patch made it fail to initialize. > > The "last patch" means the patch to enforce the fallback allocation?

Yes, the one about dma_alloc_noncontiguous().

> > I > > don't see obvious errors in dmesg, but when trying aplay, I get: > > > > ALSA lib pcm_direct.c:1284:(snd1_pcm_direct_initialize_slave) unable to install hw params > > ALSA lib pcm_dmix.c:1087:(snd_pcm_dmix_open) unable to initialize slave > > aplay: main:830: audio open error: Cannot allocate memory > > It's -ENOMEM, so it must be from there. Does it appear always? If > yes, your system is with IOMMU, and the patch made return always NULL > intentionally.

While the system do have IOMMU, it isn't configured by Linux, but by Xen. And it maps all the memory that Linux see.

> If that's the case, the problem is that IOMMU doesn't handle the > coherent memory on Xen. > > Please check more explicitly, whether get_dma_ops(dmab->dev.dev) call > in snd_dma_noncontig_alloc() returns NULL or not.

Will do.

If get_dma_ops() is non-NULL,

Yes, it's non-NULL.

...

it means we need some Xen-specific workaround not to use dma_alloc_noncontiguous(). What's the best way to see whether the driver is running on Xen PV?

Usually it's this: cpu_feature_enabled(X86_FEATURE_XENPV)

...

Meanwhile, it's helpful if you can try the combo of my last two patches, too. It should work, and if it doesn't, it implies that we're looking at a wrong place.

It doesn't because the last of them causes "Cannot allocate memory". I'm trying now with this on top:

---8<--- diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 97d7b8106869..e927d18d1ebb 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -545,7 +545,7 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) // sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, // DEFAULT_GFP, 0); #ifdef CONFIG_SND_DMA_SGBUF

• if (!sgt && !get_dma_ops(dmab->dev.dev)) {

• if (!sgt) { // && !get_dma_ops(dmab->dev.dev)) { if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; else

---8<---

Unfortunately, the above doesn't help. I mean, I don't get an error anymore, but no sound output either (even though pavucontrol says I should hear it). So, it's like the original issue, but without any delay, just straight from the start.

Hmm, it's the result with the combination of both patches, right?

Yes.

...

What I meant as the combo is something like below.

Something like this, yes.

It's puzzling, then. The patch changes the allocation with the dma_alloc_coherent(), and that's what does with the Kconfig hack you've tested. One possible significant difference is the use of the DMA address.

BTW, xen_domain() will also return true on PVH/HVM domain, which should not need any of this special treatment. It's PV that is weird.

OK, then it can be an overkill.

Below is another try: it changes the different use of the DMA buffer address. Let's cross fingers.

thanks,

Takashi

-- 8< -- --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -541,10 +541,9 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) struct sg_table *sgt; void *p;

- sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, - DEFAULT_GFP, 0); #ifdef CONFIG_SND_DMA_SGBUF - if (!sgt && !get_dma_ops(dmab->dev.dev)) { + if (cpu_feature_enabled(X86_FEATURE_XENPV) || + !get_dma_ops(dmab->dev.dev)) { if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; else @@ -552,6 +551,8 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) return snd_dma_sg_fallback_alloc(dmab, size); } #endif + sgt = dma_alloc_noncontiguous(dmab->dev.dev, size, dmab->dev.dir, + DEFAULT_GFP, 0); if (!sgt) return NULL;

@@ -719,17 +720,30 @@ static const struct snd_malloc_ops snd_dma_sg_wc_ops = { struct snd_dma_sg_fallback { size_t count; struct page **pages; + dma_addr_t *addrs; };

static void __snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab, struct snd_dma_sg_fallback *sgbuf) { - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; - size_t i; - - for (i = 0; i < sgbuf->count && sgbuf->pages[i]; i++) - do_free_pages(page_address(sgbuf->pages[i]), PAGE_SIZE, wc); + size_t i, size; + + if (sgbuf->pages && sgbuf->addrs) { + i = 0; + while (i < sgbuf->count) { + if (!sgbuf->pages[i] || !sgbuf->addrs[i]) + break; + size = sgbuf->addrs[i] & ~PAGE_MASK; + if (WARN_ON(!size)) + break; + dma_free_coherent(dmab->dev.dev, size, + page_address(sgbuf->pages[i]), + sgbuf->addrs[i] & PAGE_MASK); + i += size; + } + } kvfree(sgbuf->pages); + kvfree(sgbuf->addrs); kfree(sgbuf); }

@@ -738,9 +752,9 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) struct snd_dma_sg_fallback *sgbuf; struct page **pagep, *curp; size_t chunk, npages; + dma_addr_t *addrp; dma_addr_t addr; void *p; - bool wc = dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK;

sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); if (!sgbuf) @@ -748,14 +762,16 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size = PAGE_ALIGN(size); sgbuf->count = size >> PAGE_SHIFT; sgbuf->pages = kvcalloc(sgbuf->count, sizeof(*sgbuf->pages), GFP_KERNEL); - if (!sgbuf->pages) + sgbuf->addrs = kvcalloc(sgbuf->count, sizeof(*sgbuf->addrs), GFP_KERNEL); + if (!sgbuf->pages || !sgbuf->addrs) goto error;

pagep = sgbuf->pages; - chunk = size; + addrp = sgbuf->addrs; + chunk = (PAGE_SIZE - 1) << PAGE_SHIFT; /* to fit in low bits in addrs */ while (size > 0) { chunk = min(size, chunk); - p = do_alloc_pages(dmab->dev.dev, chunk, &addr, wc); + p = dma_alloc_coherent(dmab->dev.dev, chunk, &addr, DEFAULT_GFP); if (!p) { if (chunk <= PAGE_SIZE) goto error; @@ -767,17 +783,25 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size) size -= chunk; /* fill pages */ npages = chunk >> PAGE_SHIFT; + *addrp = npages; /* store in lower bits */ curp = virt_to_page(p); - while (npages--) + while (npages--) { *pagep++ = curp++; + *addrp++ |= addr; + addr += PAGE_SIZE; + } }

p = vmap(sgbuf->pages, sgbuf->count, VM_MAP, PAGE_KERNEL); if (!p) goto error; + + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wc(sgbuf->pages, sgbuf->count); + dmab->private_data = sgbuf; /* store the first page address for convenience */ - dmab->addr = snd_sgbuf_get_addr(dmab, 0); + dmab->addr = sgbuf->addrs[0] & PAGE_MASK; return p;

error: @@ -787,10 +811,23 @@ static void *snd_dma_sg_fallback_alloc(struct snd_dma_buffer *dmab, size_t size)

static void snd_dma_sg_fallback_free(struct snd_dma_buffer *dmab) { + struct snd_dma_sg_fallback *sgbuf = dmab->private_data; + vunmap(dmab->area); + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wb(sgbuf->pages, sgbuf->count); __snd_dma_sg_fallback_free(dmab, dmab->private_data); }

+static dma_addr_t snd_dma_sg_fallback_get_addr(struct snd_dma_buffer *dmab, + size_t offset) +{ + struct snd_dma_sg_fallback *sgbuf = dmab->private_data; + size_t index = offset >> PAGE_SHIFT; + + return (sgbuf->addrs[index] & PAGE_MASK) | (offset & ~PAGE_MASK); +} + static int snd_dma_sg_fallback_mmap(struct snd_dma_buffer *dmab, struct vm_area_struct *area) { @@ -805,8 +842,8 @@ static const struct snd_malloc_ops snd_dma_sg_fallback_ops = { .alloc = snd_dma_sg_fallback_alloc, .free = snd_dma_sg_fallback_free, .mmap = snd_dma_sg_fallback_mmap, + .get_addr = snd_dma_sg_fallback_get_addr, /* reuse vmalloc helpers */ - .get_addr = snd_dma_vmalloc_get_addr, .get_page = snd_dma_vmalloc_get_page, .get_chunk_size = snd_dma_vmalloc_get_chunk_size, };