From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37EC0C636D6 for ; Tue, 7 Feb 2023 12:59:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230519AbjBGM7s (ORCPT ); Tue, 7 Feb 2023 07:59:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231951AbjBGM7b (ORCPT ); Tue, 7 Feb 2023 07:59:31 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 834277DB1 for ; Tue, 7 Feb 2023 04:59:30 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 12D96613F8 for ; Tue, 7 Feb 2023 12:59:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2600AC433D2; Tue, 7 Feb 2023 12:59:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675774769; bh=Xt/ek+ApdoMht0lN8y1NS92ksDZrNPeDsXf05bhnX/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kgwc+LxnKXrSVF7H/mijpIxsmcPYdYi1HcddtIb0oHGj7p8hLN6SndbzD58YPZo/4 25ENLHVvKn5EWvzDafUSU5s9NEUIFlgEKGTZczG4D7idOHXcjbmiLE/oTB6FkuCQbS u/uc7eAi0L9fV/9rotdNJWyztzWLLrNNxKJK4q+I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?= , Takashi Iwai , Sasha Levin Subject: [PATCH 6.1 028/208] ALSA: memalloc: Workaround for Xen PV Date: Tue, 7 Feb 2023 13:54:42 +0100 Message-Id: <20230207125635.580228103@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230207125634.292109991@linuxfoundation.org> References: <20230207125634.292109991@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai [ Upstream commit 53466ebdec614f915c691809b0861acecb941e30 ] We change recently the memalloc helper to use dma_alloc_noncontiguous() and the fallback to get_pages(). Although lots of issues with IOMMU (or non-IOMMU) have been addressed, but there seems still a regression on Xen PV. Interestingly, the only proper way to work is use dma_alloc_coherent(). The use of dma_alloc_coherent() for SG buffer was dropped as it's problematic on IOMMU systems. OTOH, Xen PV has a different way, and it's fine to use the dma_alloc_coherent(). This patch is a workaround for Xen PV. It consists of the following changes: - For Xen PV, use only the fallback allocation without dma_alloc_noncontiguous() - In the fallback allocation, use dma_alloc_coherent(); the DMA address from dma_alloc_coherent() is returned in get_addr ops - The DMA addresses are stored in an array; the first entry stores the number of allocated pages in lower bits, which are referred at releasing pages again Reported-by: Marek Marczykowski-Górecki Tested-by: Marek Marczykowski-Górecki 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 Link: https://lore.kernel.org/r/20230125153104.5527-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/memalloc.c | 87 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 69 insertions(+), 18 deletions(-) diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c index 7268304009ad..11ff1ee51345 100644 --- a/sound/core/memalloc.c +++ b/sound/core/memalloc.c @@ -542,16 +542,15 @@ static void *snd_dma_noncontig_alloc(struct snd_dma_buffer *dmab, size_t size) struct sg_table *sgt; void *p; +#ifdef CONFIG_SND_DMA_SGBUF + if (cpu_feature_enabled(X86_FEATURE_XENPV)) + return snd_dma_sg_fallback_alloc(dmab, size); +#endif 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 (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) - dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; - else - dmab->dev.type = SNDRV_DMA_TYPE_DEV_SG_FALLBACK; + if (!sgt && !get_dma_ops(dmab->dev.dev)) return snd_dma_sg_fallback_alloc(dmab, size); - } #endif if (!sgt) return NULL; @@ -718,19 +717,38 @@ static const struct snd_malloc_ops snd_dma_sg_wc_ops = { /* Fallback SG-buffer allocations for x86 */ struct snd_dma_sg_fallback { + bool use_dma_alloc_coherent; size_t count; struct page **pages; + /* DMA address array; the first page contains #pages in ~PAGE_MASK */ + 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; + if (sgbuf->use_dma_alloc_coherent) + dma_free_coherent(dmab->dev.dev, size << PAGE_SHIFT, + page_address(sgbuf->pages[i]), + sgbuf->addrs[i] & PAGE_MASK); + else + do_free_pages(page_address(sgbuf->pages[i]), + size << PAGE_SHIFT, false); + i += size; + } + } kvfree(sgbuf->pages); + kvfree(sgbuf->addrs); kfree(sgbuf); } @@ -739,24 +757,36 @@ 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; + + /* correct the type */ + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_SG) + dmab->dev.type = SNDRV_DMA_TYPE_DEV_SG_FALLBACK; + else if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG) + dmab->dev.type = SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK; sgbuf = kzalloc(sizeof(*sgbuf), GFP_KERNEL); if (!sgbuf) return NULL; + sgbuf->use_dma_alloc_coherent = cpu_feature_enabled(X86_FEATURE_XENPV); 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); + if (sgbuf->use_dma_alloc_coherent) + p = dma_alloc_coherent(dmab->dev.dev, chunk, &addr, DEFAULT_GFP); + else + p = do_alloc_pages(dmab->dev.dev, chunk, &addr, false); if (!p) { if (chunk <= PAGE_SIZE) goto error; @@ -768,17 +798,25 @@ 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: @@ -788,10 +826,23 @@ 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; + + if (dmab->dev.type == SNDRV_DMA_TYPE_DEV_WC_SG_FALLBACK) + set_pages_array_wb(sgbuf->pages, sgbuf->count); vunmap(dmab->area); __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) { @@ -806,8 +857,8 @@ 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, }; -- 2.39.0