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-rw-r--r--include/asm-generic/dma-coherent.h32
-rw-r--r--init/Kconfig4
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/dma-coherent.c127
4 files changed, 164 insertions, 0 deletions
diff --git a/include/asm-generic/dma-coherent.h b/include/asm-generic/dma-coherent.h
new file mode 100644
index 000000000000..85a3ffaa0242
--- /dev/null
+++ b/include/asm-generic/dma-coherent.h
@@ -0,0 +1,32 @@
1#ifndef DMA_COHERENT_H
2#define DMA_COHERENT_H
3
4#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
5/*
6 * These two functions are only for dma allocator.
7 * Don't use them in device drivers.
8 */
9int dma_alloc_from_coherent(struct device *dev, ssize_t size,
10 dma_addr_t *dma_handle, void **ret);
11int dma_release_from_coherent(struct device *dev, int order, void *vaddr);
12
13/*
14 * Standard interface
15 */
16#define ARCH_HAS_DMA_DECLARE_COHERENT_MEMORY
17extern int
18dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
19 dma_addr_t device_addr, size_t size, int flags);
20
21extern void
22dma_release_declared_memory(struct device *dev);
23
24extern void *
25dma_mark_declared_memory_occupied(struct device *dev,
26 dma_addr_t device_addr, size_t size);
27#else
28#define dma_alloc_from_coherent(dev, size, handle, ret) (0)
29#define dma_release_from_coherent(dev, order, vaddr) (0)
30#endif
31
32#endif
diff --git a/init/Kconfig b/init/Kconfig
index 6199d1120900..63cdbd8bd3d5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -802,6 +802,10 @@ config PROC_PAGE_MONITOR
802 802
803endmenu # General setup 803endmenu # General setup
804 804
805config HAVE_GENERIC_DMA_COHERENT
806 bool
807 default n
808
805config SLABINFO 809config SLABINFO
806 bool 810 bool
807 depends on PROC_FS 811 depends on PROC_FS
diff --git a/kernel/Makefile b/kernel/Makefile
index 1c9938addb9d..9e287d8ab766 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
69obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o 69obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
70obj-$(CONFIG_MARKERS) += marker.o 70obj-$(CONFIG_MARKERS) += marker.o
71obj-$(CONFIG_LATENCYTOP) += latencytop.o 71obj-$(CONFIG_LATENCYTOP) += latencytop.o
72obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
72 73
73ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) 74ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y)
74# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is 75# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
new file mode 100644
index 000000000000..89a554cfd936
--- /dev/null
+++ b/kernel/dma-coherent.c
@@ -0,0 +1,127 @@
1/*
2 * Coherent per-device memory handling.
3 * Borrowed from i386
4 */
5#include <linux/kernel.h>
6#include <linux/dma-mapping.h>
7
8struct dma_coherent_mem {
9 void *virt_base;
10 u32 device_base;
11 int size;
12 int flags;
13 unsigned long *bitmap;
14};
15
16int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
17 dma_addr_t device_addr, size_t size, int flags)
18{
19 void __iomem *mem_base = NULL;
20 int pages = size >> PAGE_SHIFT;
21 int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
22
23 if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
24 goto out;
25 if (!size)
26 goto out;
27 if (dev->dma_mem)
28 goto out;
29
30 /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
31
32 mem_base = ioremap(bus_addr, size);
33 if (!mem_base)
34 goto out;
35
36 dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
37 if (!dev->dma_mem)
38 goto out;
39 dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
40 if (!dev->dma_mem->bitmap)
41 goto free1_out;
42
43 dev->dma_mem->virt_base = mem_base;
44 dev->dma_mem->device_base = device_addr;
45 dev->dma_mem->size = pages;
46 dev->dma_mem->flags = flags;
47
48 if (flags & DMA_MEMORY_MAP)
49 return DMA_MEMORY_MAP;
50
51 return DMA_MEMORY_IO;
52
53 free1_out:
54 kfree(dev->dma_mem);
55 out:
56 if (mem_base)
57 iounmap(mem_base);
58 return 0;
59}
60EXPORT_SYMBOL(dma_declare_coherent_memory);
61
62void dma_release_declared_memory(struct device *dev)
63{
64 struct dma_coherent_mem *mem = dev->dma_mem;
65
66 if (!mem)
67 return;
68 dev->dma_mem = NULL;
69 iounmap(mem->virt_base);
70 kfree(mem->bitmap);
71 kfree(mem);
72}
73EXPORT_SYMBOL(dma_release_declared_memory);
74
75void *dma_mark_declared_memory_occupied(struct device *dev,
76 dma_addr_t device_addr, size_t size)
77{
78 struct dma_coherent_mem *mem = dev->dma_mem;
79 int pos, err;
80 int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1);
81
82 pages >>= PAGE_SHIFT;
83
84 if (!mem)
85 return ERR_PTR(-EINVAL);
86
87 pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
88 err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
89 if (err != 0)
90 return ERR_PTR(err);
91 return mem->virt_base + (pos << PAGE_SHIFT);
92}
93EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
94
95int dma_alloc_from_coherent(struct device *dev, ssize_t size,
96 dma_addr_t *dma_handle, void **ret)
97{
98 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
99 int order = get_order(size);
100
101 if (mem) {
102 int page = bitmap_find_free_region(mem->bitmap, mem->size,
103 order);
104 if (page >= 0) {
105 *dma_handle = mem->device_base + (page << PAGE_SHIFT);
106 *ret = mem->virt_base + (page << PAGE_SHIFT);
107 memset(*ret, 0, size);
108 }
109 if (mem->flags & DMA_MEMORY_EXCLUSIVE)
110 *ret = NULL;
111 }
112 return (mem != NULL);
113}
114
115int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
116{
117 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
118
119 if (mem && vaddr >= mem->virt_base && vaddr <
120 (mem->virt_base + (mem->size << PAGE_SHIFT))) {
121 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
122
123 bitmap_release_region(mem->bitmap, page, order);
124 return 1;
125 }
126 return 0;
127}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-10 07:19:52 -0500