From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC4B2369D4A; Sat, 12 Sep 2026 14:44:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789224288; cv=none; b=ZZ8Ktp4ckScioWi4TUSJ3BY9W0FbmoFQ9YEEKG1HWCHgWOcC5bmooTlEZCX/iMyFvAd71uAQBDuFFazoWuY42m/CCGztJYj2UAEO20iRj15ElSY9u7ncUrBxrHJZdB0WPMtiXaoSdyk52TLSeMlQQ+oJLxthfEmnU95w+Pa92rQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789224288; c=relaxed/simple; bh=7ITDGj1c6UeKC0soXu5Cj6jqDEPgdK/5rKXPdC44VrE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JIm631oszbUSmdt6yjPSyHMfOqSaO2up51A0XbHYgL12p5UiEYpeFbc0kzP9Yh8ZZtVms22zS7x+/emEeY0yTMHOIcCSvtnsPY6CpXh8JN5MfAXoQb3sIfJ/nqwHtgUw59uceynEVW7qEl9z0XSpugNCZC+oQzrxVmBL/I08XbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sjmkjReC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sjmkjReC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 773791F000FF; Sat, 12 Sep 2026 14:44:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789224285; bh=Lwm7e+6innhk4bPI2eDA2GLOlWjrqgs9FGCrtjyDx8k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=sjmkjReC4F8sXpnywBpt/kHSRmbD0Hscesvnvww/9tfPAFIq5rEZfK03iTrByws2q L//FTAGTTIDyuB364PkprVzuL8ZrQYQmG4zNhmh4c4wvWrhW2QPJjwWufJqpg7Dw9Y Vd0QIiTs8OhTUzWnO2omM/HoKvWjT1j8bKK3Rf2g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jason Gunthorpe , Michael Kelley , Mostafa Saleh , Petr Tesarik , "Aneesh Kumar K.V (Arm)" , Marek Szyprowski , Sasha Levin Subject: [PATCH 6.6 0963/1424] swiotlb: Preserve allocation virtual address for dynamic pools Date: Sat, 12 Sep 2026 08:56:35 +0200 Message-ID: <20260912065628.878370942@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Aneesh Kumar K.V (Arm) [ Upstream commit 57d29044d0f29a76c6ec0c112c8c7371d5608dc7 ] swiotlb_alloc_tlb() can allocate from the DMA atomic pool when a decrypted pool is needed from atomic context. With CONFIG_DMA_DIRECT_REMAP, the atomic pool is backed by remapped virtual addresses, which are not the same as the direct-map addresses returned by phys_to_virt(). swiotlb_init_io_tlb_pool() currently reconstructs the pool virtual address from the physical start address. For atomic-pool backed allocations this stores the wrong address in pool->vaddr. Later, swiotlb_free_tlb() passes that address to dma_free_from_pool(), which will fail to recognize the chunk Pass the virtual address returned by the allocation path into swiotlb_init_io_tlb_pool(), and store that address in pool->vaddr. This keeps the pool free path using the same virtual address as the allocator. Fixes: 79636caad361 ("swiotlb: if swiotlb is full, fall back to a transient memory pool") Reviewed-by: Jason Gunthorpe Tested-by: Michael Kelley Tested-by: Mostafa Saleh Reviewed-by: Petr Tesarik Signed-off-by: Aneesh Kumar K.V (Arm) Reviewed-by: Mostafa Saleh Link: https://lore.kernel.org/r/20260717180442.110954-6-aneesh.kumar@kernel.org Signed-off-by: Marek Szyprowski Signed-off-by: Sasha Levin --- kernel/dma/swiotlb.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 2959309c4fb82..0968155a638e3 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -268,9 +268,9 @@ void __init swiotlb_update_mem_attributes(void) } static void swiotlb_init_io_tlb_pool(struct io_tlb_pool *mem, phys_addr_t start, - unsigned long nslabs, bool late_alloc, unsigned int nareas) + void *vaddr, unsigned long nslabs, bool late_alloc, + unsigned int nareas) { - void *vaddr = phys_to_virt(start); unsigned long bytes = nslabs << IO_TLB_SHIFT, i; mem->nslabs = nslabs; @@ -411,7 +411,7 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, return; } - swiotlb_init_io_tlb_pool(mem, __pa(tlb), nslabs, false, nareas); + swiotlb_init_io_tlb_pool(mem, __pa(tlb), tlb, nslabs, false, nareas); add_mem_pool(&io_tlb_default_mem, mem); if (flags & SWIOTLB_VERBOSE) @@ -509,7 +509,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, set_memory_decrypted((unsigned long)vstart, (nslabs << IO_TLB_SHIFT) >> PAGE_SHIFT); - swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), nslabs, true, + swiotlb_init_io_tlb_pool(mem, virt_to_phys(vstart), vstart, nslabs, true, nareas); add_mem_pool(&io_tlb_default_mem, mem); @@ -607,25 +607,26 @@ static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes, u64 phys_limit) * @bytes: Size of the buffer. * @phys_limit: Maximum allowed physical address of the buffer. * @gfp: GFP flags for the allocation. + * @vaddr: Receives the virtual address for the allocated buffer. * * Return: Allocated pages, or %NULL on allocation failure. */ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, - u64 phys_limit, gfp_t gfp) + u64 phys_limit, gfp_t gfp, void **vaddr) { struct page *page; + *vaddr = NULL; + /* * Allocate from the atomic pools if memory is encrypted and * the allocation is atomic, because decrypting may block. */ if (!gfpflags_allow_blocking(gfp) && dev && force_dma_unencrypted(dev)) { - void *vaddr; - if (!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)) return NULL; - return dma_alloc_from_pool(dev, bytes, &vaddr, gfp, + return dma_alloc_from_pool(dev, bytes, vaddr, gfp, dma_coherent_ok); } @@ -647,6 +648,8 @@ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, return NULL; } + if (page) + *vaddr = phys_to_virt(page_to_phys(page)); return page; } @@ -687,6 +690,7 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, { struct io_tlb_pool *pool; unsigned int slot_order; + void *tlb_vaddr; struct page *tlb; size_t pool_size; size_t tlb_size; @@ -703,7 +707,8 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, pool->areas = (void *)pool + sizeof(*pool); tlb_size = nslabs << IO_TLB_SHIFT; - while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, gfp))) { + while (!(tlb = swiotlb_alloc_tlb(dev, tlb_size, phys_limit, gfp, + &tlb_vaddr))) { if (nslabs <= minslabs) goto error_tlb; nslabs = ALIGN(nslabs >> 1, IO_TLB_SEGSIZE); @@ -717,11 +722,12 @@ static struct io_tlb_pool *swiotlb_alloc_pool(struct device *dev, if (!pool->slots) goto error_slots; - swiotlb_init_io_tlb_pool(pool, page_to_phys(tlb), nslabs, true, nareas); + swiotlb_init_io_tlb_pool(pool, page_to_phys(tlb), tlb_vaddr, nslabs, + true, nareas); return pool; error_slots: - swiotlb_free_tlb(page_address(tlb), tlb_size); + swiotlb_free_tlb(tlb_vaddr, tlb_size); error_tlb: kfree(pool); error: @@ -1746,7 +1752,8 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, set_memory_decrypted((unsigned long)phys_to_virt(rmem->base), rmem->size >> PAGE_SHIFT); - swiotlb_init_io_tlb_pool(pool, rmem->base, nslabs, + swiotlb_init_io_tlb_pool(pool, rmem->base, phys_to_virt(rmem->base), + nslabs, false, nareas); mem->force_bounce = true; mem->for_alloc = true; -- 2.53.0