From patchwork Mon Aug 26 13:25:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114605 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CC0041395 for ; Mon, 26 Aug 2019 13:26:08 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AA9152053B for ; Mon, 26 Aug 2019 13:26:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="P03AYJit" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AA9152053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=A5nh5eiMPOY4eG0i7+K5HzDF9bQNykK4mfUfc7K5NcQ=; b=P03AYJitzSCuqJ vtcX/ySKfqGS6JKnI0cZfo3hF8ISPLKbIrQgZC7k48eEReBRTIlHzbNusuCeAqZWbceTamB2nGuTo XKb2eWsfs/4B8eehSj/21nEZtcgQsx3MrkbkVEYU6b4Pd/s6b+ntktNnXFDzO9j8fJMmrnlpzKwBN 2bsBA06MBWpVw/DX97Bsx+ZdyJJeVpemULcjvnxsmoGo38CHMa3qqoMwY7JOp2vnQBRtQTFsZGwdB DL9UTbuMhgbp3gCiO/aBoKkOPx3TN5iY2N91hfRBmaC+z94ANWkDvDkmZC+i2HFEUJtC6KrpCfB7A tiTuBrG8p9H52P+e8uBA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0Z-0007v1-0A; Mon, 26 Aug 2019 13:26:07 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0R-0007uO-IH; Mon, 26 Aug 2019 13:26:00 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 1/6] unicore32: remove the unused pgprot_dmacoherent define Date: Mon, 26 Aug 2019 15:25:48 +0200 Message-Id: <20190826132553.4116-2-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Signed-off-by: Christoph Hellwig --- arch/unicore32/include/asm/pgtable.h | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/unicore32/include/asm/pgtable.h b/arch/unicore32/include/asm/pgtable.h index 9492aa304f03..126e961a8cb0 100644 --- a/arch/unicore32/include/asm/pgtable.h +++ b/arch/unicore32/include/asm/pgtable.h @@ -198,8 +198,6 @@ static inline pte_t pte_mkspecial(pte_t pte) { return pte; } __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) #define pgprot_writecombine(prot) \ __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) -#define pgprot_dmacoherent(prot) \ - __pgprot(pgprot_val(prot) & ~PTE_CACHEABLE) #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd) & PMD_PRESENT) From patchwork Mon Aug 26 13:25:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114619 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0018C1395 for ; Mon, 26 Aug 2019 13:26:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D2CE32186A for ; Mon, 26 Aug 2019 13:26:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="eB/eqvc9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2CE32186A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0tkwhm80a3/neSBQ2GJ+/lwswxnCDouiMzs8YQxL4HA=; b=eB/eqvc9w1qfd3 WBNriOVlFtFS8ASdzalDNbWCyTGvhpWv5NiKrBK0FQU8tSUguD/ywvd/pQFHLKmLG7Gp7Y3hkHzSA vXvdk1Iu0IO1oF4q6zzUHG4W3X8HEqgMMVLsZ0rbbVSzoFq+gHOXv6Tc6oCj3MvFbZq2SJz5sh0Ql 1fUuSDdS2bOCrY8CH6ampgULNegA2Shkl/XXXU8+QXaOsQjrDxZpB8TXbhspfStBYqqlUAqOjlQyr 9BmNaqiuyQYqDx1Q1TkMSf3rz1P91ivTWMlR8CAHwaTJWITUz8uaeNg5oVLUrAF0DYhAc+sLDymZ7 zkW+A2istbLiS5Xi4ZsQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F1F-0008NX-UX; Mon, 26 Aug 2019 13:26:50 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0U-0007uY-Cm; Mon, 26 Aug 2019 13:26:02 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 2/6] arm-nommu: remove the unused pgprot_dmacoherent define Date: Mon, 26 Aug 2019 15:25:49 +0200 Message-Id: <20190826132553.4116-3-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Signed-off-by: Christoph Hellwig --- arch/arm/include/asm/pgtable-nommu.h | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm/include/asm/pgtable-nommu.h b/arch/arm/include/asm/pgtable-nommu.h index 0b1f6799a32e..d0de24f06724 100644 --- a/arch/arm/include/asm/pgtable-nommu.h +++ b/arch/arm/include/asm/pgtable-nommu.h @@ -62,7 +62,6 @@ typedef pte_t *pte_addr_t; */ #define pgprot_noncached(prot) (prot) #define pgprot_writecombine(prot) (prot) -#define pgprot_dmacoherent(prot) (prot) #define pgprot_device(prot) (prot) From patchwork Mon Aug 26 13:25:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114621 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0008E1399 for ; Mon, 26 Aug 2019 13:27:10 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D269A2053B for ; Mon, 26 Aug 2019 13:27:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="KFu2gk5L" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D269A2053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rE8Go0tAYuLorLPbq66O3iEcCLJmMcjq7l78/L0lXPA=; b=KFu2gk5LrVCJrS SquBEHnNUps6MS/aAtAomRV7rxKQxNfk8ojgifxwRVVoyzhm8pjCfCVEbtkN5SL9vbB6Yz0l38CET uk8r+laNP6aT44IadJgKsS0NMw6xfzxKuFwvjg+7O0QmrgLNv5xNwx23BM4UO7d87us8BgKAz3FM2 BpwEw6cHK9XSAfB6SCWC9EDoEnD3MrJeyhJAWVi8jfez5AoicQp8sJGnhinju1MAnbMuCrNaxtSRX Nyoi3PNjTMUqAO3UUyP+ODxIMX7qFCsoJfybDyHVsTvQZr0Gt2GVmUWTWt4/v3wa3QOTwoujhbCmJ AcnsdJf3fYxeW4CHrG/Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F1U-00009K-DG; Mon, 26 Aug 2019 13:27:04 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0X-0007v0-9r; Mon, 26 Aug 2019 13:26:06 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 3/6] dma-mapping: remove arch_dma_mmap_pgprot Date: Mon, 26 Aug 2019 15:25:50 +0200 Message-Id: <20190826132553.4116-4-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org arch_dma_mmap_pgprot is used for two things: 1) to override the "normal" uncached page attributes for mapping memory coherent to devices that can't snoop the CPU caches 2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older arm systems and some mips platforms Replace one with the pgprot_dmacoherent macro that is already provided by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE handling to common code with an explicit arch opt-in. Signed-off-by: Christoph Hellwig Acked-by: Geert Uytterhoeven --- arch/arm/Kconfig | 2 +- arch/arm/mm/dma-mapping.c | 6 ------ arch/arm64/Kconfig | 1 - arch/arm64/include/asm/pgtable.h | 4 ++++ arch/arm64/mm/dma-mapping.c | 6 ------ arch/m68k/Kconfig | 1 - arch/m68k/include/asm/pgtable_mm.h | 3 +++ arch/m68k/kernel/dma.c | 3 +-- arch/mips/Kconfig | 2 +- arch/mips/mm/dma-noncoherent.c | 8 -------- include/linux/dma-noncoherent.h | 13 +++++++++++-- kernel/dma/Kconfig | 12 +++++++++--- kernel/dma/mapping.c | 8 +++++--- 13 files changed, 35 insertions(+), 34 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 24360211534a..217083caeabd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -8,7 +8,7 @@ config ARM select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB - select ARCH_HAS_DMA_MMAP_PGPROT if SWIOTLB + select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_KEEPINITRD diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index d42557ee69c2..d27b12f61737 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -2402,12 +2402,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, return dma_to_pfn(dev, dma_addr); } -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs) -{ - return __get_dma_pgprot(attrs, prot); -} - void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..dab9dda34206 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -13,7 +13,6 @@ config ARM64 select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_COHERENT_TO_PFN - select ARCH_HAS_DMA_MMAP_PGPROT select ARCH_HAS_DMA_PREP_COHERENT select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI select ARCH_HAS_ELF_RANDOMIZE diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index e09760ece844..6700371227d1 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -435,6 +435,10 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) #define pgprot_device(prot) \ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN) +#define pgprot_dmacoherent(prot) \ + __pgprot_modify(prot, PTE_ATTRINDX_MASK, \ + PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) + #define __HAVE_PHYS_MEM_ACCESS_PROT struct file; extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index bd2b039f43a6..676efcda51e6 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -11,12 +11,6 @@ #include -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs) -{ - return pgprot_writecombine(prot); -} - void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, size_t size, enum dma_data_direction dir) { diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index c518d695c376..a9e564306d3e 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -4,7 +4,6 @@ config M68K default y select ARCH_32BIT_OFF_T select ARCH_HAS_BINFMT_FLAT - select ARCH_HAS_DMA_MMAP_PGPROT if MMU && !COLDFIRE select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA select ARCH_MIGHT_HAVE_PC_PARPORT if ISA diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h index fe3ddd73a0cc..fde4534b974f 100644 --- a/arch/m68k/include/asm/pgtable_mm.h +++ b/arch/m68k/include/asm/pgtable_mm.h @@ -169,6 +169,9 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, ? (__pgprot((pgprot_val(prot) & _CACHEMASK040) | _PAGE_NOCACHE_S)) \ : (prot))) +pgprot_t pgprot_dmacoherent(pgprot_t prot); +#define pgprot_dmacoherent(prot) pgprot_dmacoherent(prot) + #endif /* CONFIG_COLDFIRE */ #include #endif /* !__ASSEMBLY__ */ diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c index 30cd59caf037..35064150e348 100644 --- a/arch/m68k/kernel/dma.c +++ b/arch/m68k/kernel/dma.c @@ -23,8 +23,7 @@ void arch_dma_prep_coherent(struct page *page, size_t size) cache_push(page_to_phys(page), size); } -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs) +pgprot_t pgprot_dmacoherent(pgprot_t prot) { if (CPU_IS_040_OR_060) { pgprot_val(prot) &= ~_PAGE_CACHE040; diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index d50fafd7bf3a..fc88f68ea1ee 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1119,7 +1119,7 @@ config DMA_PERDEV_COHERENT config DMA_NONCOHERENT bool - select ARCH_HAS_DMA_MMAP_PGPROT + select ARCH_HAS_DMA_WRITE_COMBINE select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_HAS_UNCACHED_SEGMENT select NEED_DMA_MAP_STATE diff --git a/arch/mips/mm/dma-noncoherent.c b/arch/mips/mm/dma-noncoherent.c index ed56c6fa7be2..1d4d57dd9acf 100644 --- a/arch/mips/mm/dma-noncoherent.c +++ b/arch/mips/mm/dma-noncoherent.c @@ -65,14 +65,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, return page_to_pfn(virt_to_page(cached_kernel_address(cpu_addr))); } -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs) -{ - if (attrs & DMA_ATTR_WRITE_COMBINE) - return pgprot_writecombine(prot); - return pgprot_noncached(prot); -} - static inline void dma_sync_virt(void *addr, size_t size, enum dma_data_direction dir) { diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h index 0bff3d7fac92..dd3de6d88fc0 100644 --- a/include/linux/dma-noncoherent.h +++ b/include/linux/dma-noncoherent.h @@ -3,6 +3,7 @@ #define _LINUX_DMA_NONCOHERENT_H 1 #include +#include #ifdef CONFIG_ARCH_HAS_DMA_COHERENCE_H #include @@ -42,10 +43,18 @@ void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs); long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, dma_addr_t dma_addr); -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs); #ifdef CONFIG_MMU +/* + * Page protection so that devices that can't snoop CPU caches can use the + * memory coherently. We default to pgprot_noncached which is usually used + * for ioremap as a safe bet, but architectures can override this with less + * strict semantics if possible. + */ +#ifndef pgprot_dmacoherent +#define pgprot_dmacoherent(prot) pgprot_noncached(prot) +#endif + pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs); #else static inline pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 9decbba255fc..73c5c2b8e824 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -20,6 +20,15 @@ config ARCH_HAS_DMA_COHERENCE_H config ARCH_HAS_DMA_SET_MASK bool +# +# Select this option if the architecture needs special handling for +# DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what +# people thing of when saying write combine, so very few platforms should +# need to enable this. +# +config ARCH_HAS_DMA_WRITE_COMBINE + bool + config DMA_DECLARE_COHERENT bool @@ -45,9 +54,6 @@ config ARCH_HAS_DMA_PREP_COHERENT config ARCH_HAS_DMA_COHERENT_TO_PFN bool -config ARCH_HAS_DMA_MMAP_PGPROT - bool - config ARCH_HAS_FORCE_DMA_UNENCRYPTED bool diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b0038ca3aa92..1b96616c9f20 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -161,9 +161,11 @@ pgprot_t dma_pgprot(struct device *dev, pgprot_t prot, unsigned long attrs) (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) && (attrs & DMA_ATTR_NON_CONSISTENT))) return prot; - if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_MMAP_PGPROT)) - return arch_dma_mmap_pgprot(dev, prot, attrs); - return pgprot_noncached(prot); +#ifdef CONFIG_ARCH_HAS_DMA_WRITE_COMBINE + if (attrs & DMA_ATTR_WRITE_COMBINE) + return pgprot_writecombine(prot); +#endif + return pgprot_dmacoherent(prot); } #endif /* CONFIG_MMU */ From patchwork Mon Aug 26 13:25:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114623 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ECFE81399 for ; Mon, 26 Aug 2019 13:27:35 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CB8A62053B for ; Mon, 26 Aug 2019 13:27:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="m3Amkv4X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB8A62053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ZbH1FKmolUUAGAYkAbHsj1R+UoEjFRcUckeY5JlYkik=; b=m3Amkv4XV22M9D n+M3DWzBYqrSLCLbfHhvrAXC3jrMRojt3oJpqHCqLY1iPB+LaMsSXOe4FjLr8301wdR/ASmI1O2aY dd1CoA+jwrBmtNUYRlorj3Z9UJNzbIAVcIlyzPhYwbqVCrfRJScXRcWUrw7u1tIIBPU3pyeI00IW9 Mpf36HC6lSW+9Qy1sOmtLMMVMWgcMXWIKTTJgxRx6FE+o9Wino6bNwL0tcTDB+pKm4AhUQLPI6c5J Yvk1CWa4TbPN/tgIS7ZE6WT/yW7eC3SsGO/4HctYb8kz8C23RiYjieK09y7saowIRZ06lvr3QKuWO skXdhDuQXNQvFTiCJl0Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F1y-0000P4-MO; Mon, 26 Aug 2019 13:27:34 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0a-0007wK-Gk; Mon, 26 Aug 2019 13:26:09 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 4/6] dma-mapping: make dma_atomic_pool_init self-contained Date: Mon, 26 Aug 2019 15:25:51 +0200 Message-Id: <20190826132553.4116-5-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org The memory allocated for the atomic pool needs to have the same mapping attributes that we use for remapping, so use pgprot_dmacoherent instead of open coding it. Also deduct a suitable zone to allocate the memory from based on the presence of the DMA zones. Signed-off-by: Christoph Hellwig --- arch/arc/mm/dma.c | 6 ------ arch/arm64/mm/dma-mapping.c | 6 ------ arch/csky/mm/dma-mapping.c | 6 ------ arch/nds32/kernel/dma.c | 6 ------ include/linux/dma-mapping.h | 1 - kernel/dma/remap.c | 17 ++++++++++++++--- 6 files changed, 14 insertions(+), 28 deletions(-) diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c index 62c210e7ee4c..ff4a5752f8cc 100644 --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -104,9 +104,3 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, dev_info(dev, "use %sncoherent DMA ops\n", dev->dma_coherent ? "" : "non"); } - -static int __init atomic_pool_init(void) -{ - return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL)); -} -postcore_initcall(atomic_pool_init); diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 676efcda51e6..a1d05f669f67 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -28,12 +28,6 @@ void arch_dma_prep_coherent(struct page *page, size_t size) __dma_flush_area(page_address(page), size); } -static int __init arm64_dma_init(void) -{ - return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC)); -} -arch_initcall(arm64_dma_init); - #ifdef CONFIG_IOMMU_DMA void arch_teardown_dma_ops(struct device *dev) { diff --git a/arch/csky/mm/dma-mapping.c b/arch/csky/mm/dma-mapping.c index 80783bb71c5c..602a60d47a94 100644 --- a/arch/csky/mm/dma-mapping.c +++ b/arch/csky/mm/dma-mapping.c @@ -14,12 +14,6 @@ #include #include -static int __init atomic_pool_init(void) -{ - return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL)); -} -postcore_initcall(atomic_pool_init); - void arch_dma_prep_coherent(struct page *page, size_t size) { if (PageHighMem(page)) { diff --git a/arch/nds32/kernel/dma.c b/arch/nds32/kernel/dma.c index 490e3720d694..4206d4b6c8ce 100644 --- a/arch/nds32/kernel/dma.c +++ b/arch/nds32/kernel/dma.c @@ -80,9 +80,3 @@ void arch_dma_prep_coherent(struct page *page, size_t size) { cache_op(page_to_phys(page), size, cpu_dma_wbinval_range); } - -static int __init atomic_pool_init(void) -{ - return dma_atomic_pool_init(GFP_KERNEL, pgprot_noncached(PAGE_KERNEL)); -} -postcore_initcall(atomic_pool_init); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index f7d1eea32c78..48ebe8295987 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -624,7 +624,6 @@ void *dma_common_pages_remap(struct page **pages, size_t size, const void *caller); void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags); -int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot); bool dma_in_atomic_pool(void *start, size_t size); void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags); bool dma_free_from_pool(void *start, size_t size); diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index ffe78f0b2fe4..838123f79639 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -105,7 +105,16 @@ static int __init early_coherent_pool(char *p) } early_param("coherent_pool", early_coherent_pool); -int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) +static gfp_t dma_atomic_pool_gfp(void) +{ + if (IS_ENABLED(CONFIG_ZONE_DMA)) + return GFP_DMA; + if (IS_ENABLED(CONFIG_ZONE_DMA32)) + return GFP_DMA32; + return GFP_KERNEL; +} + +static int __init dma_atomic_pool_init(void) { unsigned int pool_size_order = get_order(atomic_pool_size); unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; @@ -117,7 +126,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) page = dma_alloc_from_contiguous(NULL, nr_pages, pool_size_order, false); else - page = alloc_pages(gfp, pool_size_order); + page = alloc_pages(dma_atomic_pool_gfp(), pool_size_order); if (!page) goto out; @@ -128,7 +137,8 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) goto free_page; addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP, - prot, __builtin_return_address(0)); + pgprot_dmacoherent(PAGE_KERNEL), + __builtin_return_address(0)); if (!addr) goto destroy_genpool; @@ -155,6 +165,7 @@ int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) atomic_pool_size / 1024); return -ENOMEM; } +postcore_initcall(dma_atomic_pool_init); bool dma_in_atomic_pool(void *start, size_t size) { From patchwork Mon Aug 26 13:25:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114625 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 81C6914F7 for ; Mon, 26 Aug 2019 13:28:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5F82E2053B for ; Mon, 26 Aug 2019 13:28:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="U7xTr2dQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F82E2053B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=TEUOsiov/p/HgW0xwt9iDfawUuhJfVM8BsZrMcpjHZs=; b=U7xTr2dQff2+cQ 2A/X460XqOkveJNFuyGL55nPg4ow/I2k4mxQH+S3QQANzZnB8FO6wQ6knUp298AXVMgPxvb7ge8Oz +SBcRz6SVOJ8HPp/TpBfHFbeCMkgHy9iDii+/3EpfsNLMspwGuAmNtiFn3Y2q0U8wYTgzGwu7c6SB mro+2iUES+XGDj2+nbnd+qyQ7JeQmhPDKuyi/zVCWRe2vOdepk2Bm97HxjV/zZ93F763Ci2mSoXcx aXLo0fhaMS7UnKiIZvJl2lLDkJYEAKxKboCsDNZauAxjcvA+P883q60oMnqTqhbMjGDJKOxpXMAQH wcMzvllpnKJ4pFrY9exQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F2K-0000fN-W8; Mon, 26 Aug 2019 13:27:57 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0e-0007xw-57; Mon, 26 Aug 2019 13:26:12 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 5/6] arm64: document the choice of page attributes for pgprot_dmacoherent Date: Mon, 26 Aug 2019 15:25:52 +0200 Message-Id: <20190826132553.4116-6-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Based on an email from Will Deacon. Signed-off-by: Christoph Hellwig Acked-by: Will Deacon Acked-by: Mark Rutland --- arch/arm64/include/asm/pgtable.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 6700371227d1..fd40fb05eb51 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -435,6 +435,14 @@ static inline pmd_t pmd_mkdevmap(pmd_t pmd) __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) #define pgprot_device(prot) \ __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN) +/* + * DMA allocations for non-coherent devices use what the Arm architecture calls + * "Normal non-cacheable" memory, which permits speculation, unaligned accesses + * and merging of writes. This is different from "Device-nGnR[nE]" memory which + * is intended for MMIO and thus forbids speculation, preserves access size, + * requires strict alignment and can also force write responses to come from the + * endpoint. + */ #define pgprot_dmacoherent(prot) \ __pgprot_modify(prot, PTE_ATTRINDX_MASK, \ PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) From patchwork Mon Aug 26 13:25:53 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11114627 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4522C1399 for ; Mon, 26 Aug 2019 13:28:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 232B2206BB for ; Mon, 26 Aug 2019 13:28:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XtMZaK2n" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 232B2206BB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=zjwq3T+WA5GFlPjtEDEl3Iq8UiTO/9MSk80p/vB43zY=; b=XtMZaK2n9XEJ1Q xXrFnTi5T0ypvfjIt5OaJPI82xPFXrRd4otQGjr/z4QV2bwBm3TRuc+DMVimDEkzuK6pQddjZ+Tgu B2O/ALTVT+5WVQRlMhdr59rulB7S0AfnFKMTf38EUS+faM5WxOh4WU4bddYjpUUflsrJEKiapHFdj sPADxVvPHR5FdcYWYiB5fSEn3EG26C2SHHIINbd8U2N5ppLGx3sAgLTzULv9TDqCj/k2wl04UaU2e PR4DDDlRvKn19MxqgvwaLFsk05gL1+Nng5eNM4GwKWCnlalUe2kQQ83uQjVY18YWO5NVu8OlK7krA h3Ul35HJuk81Vm6+Wktg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i2F2c-0000t8-Vh; Mon, 26 Aug 2019 13:28:15 +0000 Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1i2F0h-0007zP-RH; Mon, 26 Aug 2019 13:26:16 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org Subject: [PATCH 6/6] MIPS: document mixing "slightly different CCAs" Date: Mon, 26 Aug 2019 15:25:53 +0200 Message-Id: <20190826132553.4116-7-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190826132553.4116-1-hch@lst.de> References: <20190826132553.4116-1-hch@lst.de> MIME-Version: 1.0 X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Shawn Anastasio , Will Deacon , linux-m68k@lists.linux-m68k.org, Guan Xuetao , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Russell King , linux-mips@vger.kernel.org, Paul Burton , Geert Uytterhoeven , Catalin Marinas , James Hogan , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Based on an email from Paul Burton, quoting section 4.8 "Cacheability and Coherency Attributes and Access Types" of "MIPS Architecture Volume 1: Introduction to the MIPS32 Architecture" (MD00080, revision 6.01). Signed-off-by: Christoph Hellwig Acked-by: Paul Burton --- arch/mips/Kconfig | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index fc88f68ea1ee..aff1cadeea43 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1119,6 +1119,13 @@ config DMA_PERDEV_COHERENT config DMA_NONCOHERENT bool + # + # MIPS allows mixing "slightly different" Cacheability and Coherency + # Attribute bits. It is believed that the uncached access through + # KSEG1 and the implementation specific "uncached accelerated" used + # by pgprot_writcombine can be mixed, and the latter sometimes provides + # significant advantages. + # select ARCH_HAS_DMA_WRITE_COMBINE select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_HAS_UNCACHED_SEGMENT