From f0edfea8ef93ed6cc5f747c46c85c8e53e0798a0 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 24 Aug 2018 10:31:08 +0200
Subject: [PATCH] dma-mapping: move the remap helpers to a separate file
The dma remap code only makes sense for not cache coherent architectures
(or possibly the corner case of highmem CMA allocations) and currently
is only used by arm, arm64, csky and xtensa. Split it out into a
separate file with a separate Kconfig symbol, which gets the right
copyright notice given that this code was written by Laura Abbott
working for Code Aurora at that point.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
arch/arm/Kconfig | 1 +
arch/arm64/Kconfig | 1 +
arch/csky/Kconfig | 1 +
arch/xtensa/Kconfig | 1 +
kernel/dma/Kconfig | 4 ++
kernel/dma/Makefile | 2 +-
kernel/dma/mapping.c | 84 ------------------------------------------
kernel/dma/remap.c | 88 ++++++++++++++++++++++++++++++++++++++++++++
8 files changed, 97 insertions(+), 85 deletions(-)
create mode 100644 kernel/dma/remap.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 91be74d8df658c..3b2852df6eb32b 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -30,6 +30,7 @@ config ARM
select CPU_PM if (SUSPEND || CPU_IDLE)
select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
select DMA_DIRECT_OPS if !MMU
+ select DMA_REMAP if MMU
select EDAC_SUPPORT
select EDAC_ATOMIC_SCRUB
select GENERIC_ALLOCATOR
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 787d7850e0643d..5d065acb6d1060 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -82,6 +82,7 @@ config ARM64
select CRC32
select DCACHE_WORD_ACCESS
select DMA_DIRECT_OPS
+ select DMA_REMAP
select EDAC_SUPPORT
select FRAME_POINTER
select GENERIC_ALLOCATOR
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index cb64f8dacd08ee..8a30e006a845e4 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -9,6 +9,7 @@ config CSKY
select CLKSRC_OF
select DMA_DIRECT_OPS
select DMA_NONCOHERENT_OPS
+ select DMA_REMAP
select IRQ_DOMAIN
select HANDLE_DOMAIN_IRQ
select DW_APB_TIMER_OF
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d29b7365da8d9f..239bfb16c58b67 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -11,6 +11,7 @@ config XTENSA
select CLONE_BACKWARDS
select COMMON_CLK
select DMA_DIRECT_OPS
+ select DMA_REMAP if MMU
select GENERIC_ATOMIC64
select GENERIC_CLOCKEVENTS
select GENERIC_IRQ_SHOW
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 645c7a2ecde8bf..c92e08173ed8c2 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -51,3 +51,7 @@ config SWIOTLB
bool
select DMA_DIRECT_OPS
select NEED_DMA_MAP_STATE
+
+config DMA_REMAP
+ depends on MMU
+ bool
diff --git a/kernel/dma/Makefile b/kernel/dma/Makefile
index 7d581e4eea4a2f..f4feeceb802005 100644
--- a/kernel/dma/Makefile
+++ b/kernel/dma/Makefile
@@ -7,4 +7,4 @@ obj-$(CONFIG_DMA_DIRECT_OPS) += direct.o
obj-$(CONFIG_DMA_VIRT_OPS) += virt.o
obj-$(CONFIG_DMA_API_DEBUG) += debug.o
obj-$(CONFIG_SWIOTLB) += swiotlb.o
-
+obj-$(CONFIG_DMA_REMAP) += remap.o
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 58dec7a92b7b51..dfbc3deb95cdce 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -262,87 +262,3 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
}
EXPORT_SYMBOL(dma_common_mmap);
-
-#ifdef CONFIG_MMU
-static struct vm_struct *__dma_common_pages_remap(struct page **pages,
- size_t size, unsigned long vm_flags, pgprot_t prot,
- const void *caller)
-{
- struct vm_struct *area;
-
- area = get_vm_area_caller(size, vm_flags, caller);
- if (!area)
- return NULL;
-
- if (map_vm_area(area, prot, pages)) {
- vunmap(area->addr);
- return NULL;
- }
-
- return area;
-}
-
-/*
- * remaps an array of PAGE_SIZE pages into another vm_area
- * Cannot be used in non-sleeping contexts
- */
-void *dma_common_pages_remap(struct page **pages, size_t size,
- unsigned long vm_flags, pgprot_t prot,
- const void *caller)
-{
- struct vm_struct *area;
-
- area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
- if (!area)
- return NULL;
-
- area->pages = pages;
-
- return area->addr;
-}
-
-/*
- * remaps an allocated contiguous region into another vm_area.
- * Cannot be used in non-sleeping contexts
- */
-
-void *dma_common_contiguous_remap(struct page *page, size_t size,
- unsigned long vm_flags,
- pgprot_t prot, const void *caller)
-{
- int i;
- struct page **pages;
- struct vm_struct *area;
-
- pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
- if (!pages)
- return NULL;
-
- for (i = 0; i < (size >> PAGE_SHIFT); i++)
- pages[i] = nth_page(page, i);
-
- area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
-
- kfree(pages);
-
- if (!area)
- return NULL;
- return area->addr;
-}
-
-/*
- * unmaps a range previously mapped by dma_common_*_remap
- */
-void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
-{
- struct vm_struct *area = find_vm_area(cpu_addr);
-
- if (!area || (area->flags & vm_flags) != vm_flags) {
- WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
- return;
- }
-
- unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
- vunmap(cpu_addr);
-}
-#endif
diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c
new file mode 100644
index 00000000000000..a15c393ea4e58a
--- /dev/null
+++ b/kernel/dma/remap.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 The Linux Foundation
+ */
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+static struct vm_struct *__dma_common_pages_remap(struct page **pages,
+ size_t size, unsigned long vm_flags, pgprot_t prot,
+ const void *caller)
+{
+ struct vm_struct *area;
+
+ area = get_vm_area_caller(size, vm_flags, caller);
+ if (!area)
+ return NULL;
+
+ if (map_vm_area(area, prot, pages)) {
+ vunmap(area->addr);
+ return NULL;
+ }
+
+ return area;
+}
+
+/*
+ * Remaps an array of PAGE_SIZE pages into another vm_area.
+ * Cannot be used in non-sleeping contexts
+ */
+void *dma_common_pages_remap(struct page **pages, size_t size,
+ unsigned long vm_flags, pgprot_t prot,
+ const void *caller)
+{
+ struct vm_struct *area;
+
+ area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+ if (!area)
+ return NULL;
+
+ area->pages = pages;
+
+ return area->addr;
+}
+
+/*
+ * Remaps an allocated contiguous region into another vm_area.
+ * Cannot be used in non-sleeping contexts
+ */
+void *dma_common_contiguous_remap(struct page *page, size_t size,
+ unsigned long vm_flags,
+ pgprot_t prot, const void *caller)
+{
+ int i;
+ struct page **pages;
+ struct vm_struct *area;
+
+ pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
+ if (!pages)
+ return NULL;
+
+ for (i = 0; i < (size >> PAGE_SHIFT); i++)
+ pages[i] = nth_page(page, i);
+
+ area = __dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+
+ kfree(pages);
+
+ if (!area)
+ return NULL;
+ return area->addr;
+}
+
+/*
+ * Unmaps a range previously mapped by dma_common_*_remap
+ */
+void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
+{
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (!area || (area->flags & vm_flags) != vm_flags) {
+ WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+ return;
+ }
+
+ unmap_kernel_range((unsigned long)cpu_addr, PAGE_ALIGN(size));
+ vunmap(cpu_addr);
+}
--
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