Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp8061286imu; Tue, 4 Dec 2018 02:11:10 -0800 (PST) X-Google-Smtp-Source: AFSGD/X3NbqRpagYOPFVtZMHUU3xSfdjs/KPiWTV7wdwdFjlSQtJDTebxBBBUF0sWU1E6WX3ySgd X-Received: by 2002:a63:c447:: with SMTP id m7mr16207768pgg.27.1543918270872; Tue, 04 Dec 2018 02:11:10 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1543918270; cv=none; d=google.com; s=arc-20160816; b=qxN0FEc6CqLo5Nx3ns9QXMCsrNe56GT9e77TOc0zzrkCrAAcqQOwq67RAZI9rFf4vG R+ZVMzZJQ5yfqLiBYnZavjdLySg2qkmuNpCow53Mli+VXqYKdYC5fmmjffNoYjkTJMLZ hq2i33GzsemgAa5tdg/JNehMFgH/Spl9Beag3KOE+bJEKyd9Inmq0bJXDWnpeznYXGz3 aEDHNle5+b/8FQ83wvumEsU4xNY4kd2poZKMDUFvSaDARtFKYvPQweSg1eJPB6vBrBgd Kg4PhN78+dHtSxYQWytf7GZCmb9Fi0+tLwKtz1H+FJUuNqV0+gi+YNt94SsbihZ3o4La gnrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=DngtDs3xglHGJCWya0z1rBDau6L08+tGX8e4XGKLDQA=; b=sq96AuwWy02OsdqafCtykp+a5iR+UhwgvR7jTcZo2PxlCEj5iZjsmB7fIxkQLkPT8z BVcYCiA3W3DYp3XljxZ5EAGvhHwEefw6Qa1F4DD+OTXlLKai+SPAIrUxiDFY5RjEx9w1 Wzcx7jHTsvX8aQ9/7mcIIypH2tBIZfL7o42N1udpZz7W4/c9wsSC9DVGNR3Kkn9tK6RQ qOoe679EVEHArqwcq8lsWWoyrB/pbiq81VHb4ZnGT/J34aFc74qT7yZ8gdsGr4xuxWxH kWeMIUqh+21sdJyhXYmzmtgpLRkiUAxxnQFebTxEwN+DuLXHNWtqJJPgd9yjfPMGKAH9 B0xg== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@armlinux.org.uk header.s=pandora-2014 header.b=MjtHPTSx; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=armlinux.org.uk Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 14si15835719pgo.511.2018.12.04.02.10.55; Tue, 04 Dec 2018 02:11:10 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@armlinux.org.uk header.s=pandora-2014 header.b=MjtHPTSx; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=armlinux.org.uk Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725955AbeLDKKK (ORCPT + 99 others); Tue, 4 Dec 2018 05:10:10 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:33022 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725764AbeLDKKJ (ORCPT ); Tue, 4 Dec 2018 05:10:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=DngtDs3xglHGJCWya0z1rBDau6L08+tGX8e4XGKLDQA=; b=MjtHPTSx2CsjiKBucgM7TQLLy AWLXCGZgC9BR/IVDpwBajclmYHSDs5Hg8kW/9kWEiFQV/lf8Lb+nX5A8SvNy/gxQ4xeEsPWXzjU6b KdA0w2mql+NMS2AlPqiJCe4iN0qAfqseF+ILN6OJAkg2bqapuppXOF8Wf4f5xHAfcrICY=; Received: from n2100.armlinux.org.uk ([fd8f:7570:feb6:1:214:fdff:fe10:4f86]:60412) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gU7eQ-0005Wh-MC; Tue, 04 Dec 2018 10:09:58 +0000 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1gU7eO-0003bn-2V; Tue, 04 Dec 2018 10:09:56 +0000 Date: Tue, 4 Dec 2018 10:09:54 +0000 From: Russell King - ARM Linux To: Christoph Hellwig Cc: iommu@lists.linux-foundation.org, Catalin Marinas , Will Deacon , linux-kernel@vger.kernel.org, Guo Ren , Laura Abbott , Robin Murphy , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 4/9] dma-mapping: move the arm64 ncoherent alloc/free support to common code Message-ID: <20181204100954.GN30658@n2100.armlinux.org.uk> References: <20181105121931.13481-1-hch@lst.de> <20181105121931.13481-5-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181105121931.13481-5-hch@lst.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 05, 2018 at 01:19:26PM +0100, Christoph Hellwig wrote: > The arm64 codebase to implement coherent dma allocation for architectures > with non-coherent DMA is a good start for a generic implementation, given > that is uses the generic remap helpers, provides the atomic pool for > allocations that can't sleep and still is realtively simple and well > tested. Move it to kernel/dma and allow architectures to opt into it > using a config symbol. Architectures just need to provide a new > arch_dma_prep_coherent helper to writeback an invalidate the caches > for any memory that gets remapped for uncached access. > > Signed-off-by: Christoph Hellwig > --- > arch/arm64/Kconfig | 2 +- > arch/arm64/mm/dma-mapping.c | 184 ++------------------------------ > include/linux/dma-mapping.h | 5 + > include/linux/dma-noncoherent.h | 2 + > kernel/dma/Kconfig | 6 ++ > kernel/dma/remap.c | 158 ++++++++++++++++++++++++++- > 6 files changed, 181 insertions(+), 176 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 5d065acb6d10..2e645ea693ea 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -82,7 +82,7 @@ config ARM64 > select CRC32 > select DCACHE_WORD_ACCESS > select DMA_DIRECT_OPS > - select DMA_REMAP > + select DMA_DIRECT_REMAP > select EDAC_SUPPORT > select FRAME_POINTER > select GENERIC_ALLOCATOR > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index a3ac26284845..e2e7e5d0f94e 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -33,113 +33,6 @@ > > #include > > -static struct gen_pool *atomic_pool __ro_after_init; > - > -#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K > -static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE; > - > -static int __init early_coherent_pool(char *p) > -{ > - atomic_pool_size = memparse(p, &p); > - return 0; > -} > -early_param("coherent_pool", early_coherent_pool); > - > -static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) > -{ > - unsigned long val; > - void *ptr = NULL; > - > - if (!atomic_pool) { > - WARN(1, "coherent pool not initialised!\n"); > - return NULL; > - } > - > - val = gen_pool_alloc(atomic_pool, size); > - if (val) { > - phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val); > - > - *ret_page = phys_to_page(phys); > - ptr = (void *)val; > - memset(ptr, 0, size); > - } > - > - return ptr; > -} > - > -static bool __in_atomic_pool(void *start, size_t size) > -{ > - return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); > -} > - > -static int __free_from_pool(void *start, size_t size) > -{ > - if (!__in_atomic_pool(start, size)) > - return 0; > - > - gen_pool_free(atomic_pool, (unsigned long)start, size); > - > - return 1; > -} > - > -void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, > - gfp_t flags, unsigned long attrs) > -{ > - struct page *page; > - void *ptr, *coherent_ptr; > - pgprot_t prot = pgprot_writecombine(PAGE_KERNEL); > - > - size = PAGE_ALIGN(size); > - > - if (!gfpflags_allow_blocking(flags)) { > - struct page *page = NULL; > - void *addr = __alloc_from_pool(size, &page, flags); > - > - if (addr) > - *dma_handle = phys_to_dma(dev, page_to_phys(page)); > - > - return addr; > - } > - > - ptr = dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs); > - if (!ptr) > - goto no_mem; > - > - /* remove any dirty cache lines on the kernel alias */ > - __dma_flush_area(ptr, size); > - > - /* create a coherent mapping */ > - page = virt_to_page(ptr); > - coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP, > - prot, __builtin_return_address(0)); > - if (!coherent_ptr) > - goto no_map; > - > - return coherent_ptr; > - > -no_map: > - dma_direct_free_pages(dev, size, ptr, *dma_handle, attrs); > -no_mem: > - return NULL; > -} > - > -void arch_dma_free(struct device *dev, size_t size, void *vaddr, > - dma_addr_t dma_handle, unsigned long attrs) > -{ > - if (!__free_from_pool(vaddr, PAGE_ALIGN(size))) { > - void *kaddr = phys_to_virt(dma_to_phys(dev, dma_handle)); > - > - vunmap(vaddr); > - dma_direct_free_pages(dev, size, kaddr, dma_handle, attrs); > - } > -} > - > -long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, > - dma_addr_t dma_addr) > -{ > - return __phys_to_pfn(dma_to_phys(dev, dma_addr)); > -} > - > pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, > unsigned long attrs) > { > @@ -160,6 +53,11 @@ void arch_sync_dma_for_cpu(struct device *dev, phys_addr_t paddr, > __dma_unmap_area(phys_to_virt(paddr), size, dir); > } > > +void arch_dma_prep_coherent(struct page *page, size_t size) > +{ > + __dma_flush_area(page_address(page), size); > +} > + > #ifdef CONFIG_IOMMU_DMA > static int __swiotlb_get_sgtable_page(struct sg_table *sgt, > struct page *page, size_t size) > @@ -191,67 +89,6 @@ static int __swiotlb_mmap_pfn(struct vm_area_struct *vma, > } > #endif /* CONFIG_IOMMU_DMA */ > > -static int __init atomic_pool_init(void) > -{ > - pgprot_t prot = __pgprot(PROT_NORMAL_NC); > - unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; > - struct page *page; > - void *addr; > - unsigned int pool_size_order = get_order(atomic_pool_size); > - > - if (dev_get_cma_area(NULL)) > - page = dma_alloc_from_contiguous(NULL, nr_pages, > - pool_size_order, false); > - else > - page = alloc_pages(GFP_DMA32, pool_size_order); > - > - if (page) { > - int ret; > - void *page_addr = page_address(page); > - > - memset(page_addr, 0, atomic_pool_size); > - __dma_flush_area(page_addr, atomic_pool_size); > - > - atomic_pool = gen_pool_create(PAGE_SHIFT, -1); > - if (!atomic_pool) > - goto free_page; > - > - addr = dma_common_contiguous_remap(page, atomic_pool_size, > - VM_USERMAP, prot, atomic_pool_init); > - > - if (!addr) > - goto destroy_genpool; > - > - ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr, > - page_to_phys(page), > - atomic_pool_size, -1); > - if (ret) > - goto remove_mapping; > - > - gen_pool_set_algo(atomic_pool, > - gen_pool_first_fit_order_align, > - NULL); > - > - pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n", > - atomic_pool_size / 1024); > - return 0; > - } > - goto out; > - > -remove_mapping: > - dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP); > -destroy_genpool: > - gen_pool_destroy(atomic_pool); > - atomic_pool = NULL; > -free_page: > - if (!dma_release_from_contiguous(NULL, page, nr_pages)) > - __free_pages(page, pool_size_order); > -out: > - pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n", > - atomic_pool_size / 1024); > - return -ENOMEM; > -} > - > /******************************************** > * The following APIs are for dummy DMA ops * > ********************************************/ > @@ -350,8 +187,7 @@ static int __init arm64_dma_init(void) > TAINT_CPU_OUT_OF_SPEC, > "ARCH_DMA_MINALIGN smaller than CTR_EL0.CWG (%d < %d)", > ARCH_DMA_MINALIGN, cache_line_size()); > - > - return atomic_pool_init(); > + return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC)); > } > arch_initcall(arm64_dma_init); > > @@ -397,7 +233,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, > page = alloc_pages(gfp, get_order(size)); > addr = page ? page_address(page) : NULL; > } else { > - addr = __alloc_from_pool(size, &page, gfp); > + addr = dma_alloc_from_pool(size, &page, gfp); > } > if (!addr) > return NULL; > @@ -407,7 +243,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, > if (coherent) > __free_pages(page, get_order(size)); > else > - __free_from_pool(addr, size); > + dma_free_from_pool(addr, size); > addr = NULL; > } > } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > @@ -471,9 +307,9 @@ static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, > * coherent devices. > * Hence how dodgy the below logic looks... > */ > - if (__in_atomic_pool(cpu_addr, size)) { > + if (dma_in_atomic_pool(cpu_addr, size)) { > iommu_dma_unmap_page(dev, handle, iosize, 0, 0); > - __free_from_pool(cpu_addr, size); > + dma_free_from_pool(cpu_addr, size); > } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > struct page *page = vmalloc_to_page(cpu_addr); > > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h > index 15bd41447025..56ed94b99963 100644 > --- a/include/linux/dma-mapping.h > +++ b/include/linux/dma-mapping.h > @@ -455,6 +455,11 @@ 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); > + > /** > * dma_mmap_attrs - map a coherent DMA allocation into user space > * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices > diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h > index 9051b055beec..306557331d7d 100644 > --- a/include/linux/dma-noncoherent.h > +++ b/include/linux/dma-noncoherent.h > @@ -69,4 +69,6 @@ static inline void arch_sync_dma_for_cpu_all(struct device *dev) > } > #endif /* CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL */ > > +void arch_dma_prep_coherent(struct page *page, size_t size); > + > #endif /* _LINUX_DMA_NONCOHERENT_H */ > diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig > index c92e08173ed8..fb045ebb0713 100644 > --- a/kernel/dma/Kconfig > +++ b/kernel/dma/Kconfig > @@ -55,3 +55,9 @@ config SWIOTLB > config DMA_REMAP > depends on MMU > bool > + > +config DMA_DIRECT_REMAP > + bool > + depends on DMA_DIRECT_OPS > + select DMA_REMAP > + > diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c > index 456f7cc3414d..bc42766f52df 100644 > --- a/kernel/dma/remap.c > +++ b/kernel/dma/remap.c > @@ -1,8 +1,13 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > + * Copyright (C) 2012 ARM Ltd. > * Copyright (c) 2014 The Linux Foundation > */ > -#include > +#include > +#include > +#include > +#include > +#include > #include > #include > > @@ -86,3 +91,154 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) > unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size)); > vunmap(cpu_addr); > } > + > +#ifdef CONFIG_DMA_DIRECT_REMAP > +static struct gen_pool *atomic_pool __ro_after_init; > + > +#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K > +static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE; > + > +static int __init early_coherent_pool(char *p) > +{ > + atomic_pool_size = memparse(p, &p); > + return 0; > +} > +early_param("coherent_pool", early_coherent_pool); > + > +int __init dma_atomic_pool_init(gfp_t gfp, pgprot_t prot) > +{ > + unsigned int pool_size_order = get_order(atomic_pool_size); > + unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; > + struct page *page; > + void *addr; > + int ret; > + > + if (dev_get_cma_area(NULL)) > + page = dma_alloc_from_contiguous(NULL, nr_pages, > + pool_size_order, false); > + else > + page = alloc_pages(gfp, pool_size_order); > + if (!page) > + goto out; > + > + memset(page_address(page), 0, atomic_pool_size); Note that this won't work if 'page' is a highmem page - should there be a check for that, or a check for the gfp flags? Also, is this memset() actually useful, or a waste of cycles - when we allocate from this pool (see dma_alloc_from_pool()), we always memset() the buffer. > + arch_dma_prep_coherent(page, atomic_pool_size); > + > + atomic_pool = gen_pool_create(PAGE_SHIFT, -1); > + if (!atomic_pool) > + goto free_page; > + > + addr = dma_common_contiguous_remap(page, atomic_pool_size, VM_USERMAP, > + prot, __builtin_return_address(0)); > + if (!addr) > + goto destroy_genpool; > + > + ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr, > + page_to_phys(page), atomic_pool_size, -1); > + if (ret) > + goto remove_mapping; > + gen_pool_set_algo(atomic_pool, gen_pool_first_fit_order_align, NULL); > + > + pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n", > + atomic_pool_size / 1024); > + return 0; > + > +remove_mapping: > + dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP); > +destroy_genpool: > + gen_pool_destroy(atomic_pool); > + atomic_pool = NULL; > +free_page: > + if (!dma_release_from_contiguous(NULL, page, nr_pages)) > + __free_pages(page, pool_size_order); > +out: > + pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n", > + atomic_pool_size / 1024); > + return -ENOMEM; > +} > + > +bool dma_in_atomic_pool(void *start, size_t size) > +{ > + return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); > +} > + > +void *dma_alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) > +{ > + unsigned long val; > + void *ptr = NULL; > + > + if (!atomic_pool) { > + WARN(1, "coherent pool not initialised!\n"); > + return NULL; > + } > + > + val = gen_pool_alloc(atomic_pool, size); > + if (val) { > + phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val); > + > + *ret_page = phys_to_page(phys); > + ptr = (void *)val; > + memset(ptr, 0, size); > + } > + > + return ptr; > +} > + > +bool dma_free_from_pool(void *start, size_t size) > +{ > + if (!dma_in_atomic_pool(start, size)) > + return false; > + gen_pool_free(atomic_pool, (unsigned long)start, size); > + return true; > +} > + > +void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, > + gfp_t flags, unsigned long attrs) > +{ > + struct page *page = NULL; > + void *ret, *kaddr; > + > + size = PAGE_ALIGN(size); > + > + if (!gfpflags_allow_blocking(flags)) { > + ret = dma_alloc_from_pool(size, &page, flags); > + if (!ret) > + return NULL; > + *dma_handle = phys_to_dma(dev, page_to_phys(page)); > + return ret; > + } > + > + kaddr = dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs); > + if (!kaddr) > + return NULL; > + page = virt_to_page(kaddr); > + > + /* remove any dirty cache lines on the kernel alias */ > + arch_dma_prep_coherent(page, size); > + > + /* create a coherent mapping */ > + ret = dma_common_contiguous_remap(page, size, VM_USERMAP, > + arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs), > + __builtin_return_address(0)); > + if (!ret) > + dma_direct_free_pages(dev, size, kaddr, *dma_handle, attrs); > + return ret; > +} > + > +void arch_dma_free(struct device *dev, size_t size, void *vaddr, > + dma_addr_t dma_handle, unsigned long attrs) > +{ > + if (!dma_free_from_pool(vaddr, PAGE_ALIGN(size))) { > + void *kaddr = phys_to_virt(dma_to_phys(dev, dma_handle)); > + > + vunmap(vaddr); > + dma_direct_free_pages(dev, size, kaddr, dma_handle, attrs); > + } > +} > + > +long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr, > + dma_addr_t dma_addr) > +{ > + return __phys_to_pfn(dma_to_phys(dev, dma_addr)); > +} > +#endif /* CONFIG_DMA_DIRECT_REMAP */ > -- > 2.19.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up