aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-07-28 21:14:24 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-07-28 21:14:24 -0400
commit1d9b9f6a53d77ed801ba875f937d6dabbfc381ce (patch)
tree36ea93b80a444c3b37111e352790ebc07f29379f /kernel
parenta3ad7f128c637b7612ebeacb1f85fec933bb1195 (diff)
parent12c0b20fa4afb5c8a377d6987fb2dcf353e1dce1 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (21 commits) x86/PCI: use dev_printk when possible PCI: add D3 power state avoidance quirk PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot PCI: add an option to allow ASPM enabled forcibly PCI: disable ASPM on pre-1.1 PCIe devices PCI: disable ASPM per ACPI FADT setting PCI MSI: Don't disable MSIs if the mask bit isn't supported PCI: handle 64-bit resources better on 32-bit machines PCI: rewrite PCI BAR reading code PCI: document pci_target_state PCI hotplug: fix typo in pcie hotplug output x86 gart: replace to_pages macro with iommu_num_pages x86, AMD IOMMU: replace to_pages macro with iommu_num_pages iommu: add iommu_num_pages helper function dma-coherent: add documentation to new interfaces Cris: convert to using generic dma-coherent mem allocator Sh: use generic per-device coherent dma allocator ARM: support generic per-device coherent dma mem Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE x86: use generic per-device dma coherent allocator ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/Makefile1
-rw-r--r--kernel/dma-coherent.c154
2 files changed, 155 insertions, 0 deletions
diff --git a/kernel/Makefile b/kernel/Makefile
index 54f69837d35a..4e1d7df7c3e2 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
84obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o 84obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
85obj-$(CONFIG_MARKERS) += marker.o 85obj-$(CONFIG_MARKERS) += marker.o
86obj-$(CONFIG_LATENCYTOP) += latencytop.o 86obj-$(CONFIG_LATENCYTOP) += latencytop.o
87obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
87obj-$(CONFIG_FTRACE) += trace/ 88obj-$(CONFIG_FTRACE) += trace/
88obj-$(CONFIG_TRACING) += trace/ 89obj-$(CONFIG_TRACING) += trace/
89obj-$(CONFIG_SMP) += sched_cpupri.o 90obj-$(CONFIG_SMP) += sched_cpupri.o
diff --git a/kernel/dma-coherent.c b/kernel/dma-coherent.c
new file mode 100644
index 000000000000..7517115a8cce
--- /dev/null
+++ b/kernel/dma-coherent.c
@@ -0,0 +1,154 @@
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
95/**
96 * Try to allocate memory from the per-device coherent area.
97 *
98 * @dev: device from which we allocate memory
99 * @size: size of requested memory area
100 * @dma_handle: This will be filled with the correct dma handle
101 * @ret: This pointer will be filled with the virtual address
102 * to allocated area.
103 *
104 * This function should be only called from per-arch %dma_alloc_coherent()
105 * to support allocation from per-device coherent memory pools.
106 *
107 * Returns 0 if dma_alloc_coherent should continue with allocating from
108 * generic memory areas, or !0 if dma_alloc_coherent should return %ret.
109 */
110int dma_alloc_from_coherent(struct device *dev, ssize_t size,
111 dma_addr_t *dma_handle, void **ret)
112{
113 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
114 int order = get_order(size);
115
116 if (mem) {
117 int page = bitmap_find_free_region(mem->bitmap, mem->size,
118 order);
119 if (page >= 0) {
120 *dma_handle = mem->device_base + (page << PAGE_SHIFT);
121 *ret = mem->virt_base + (page << PAGE_SHIFT);
122 memset(*ret, 0, size);
123 } else if (mem->flags & DMA_MEMORY_EXCLUSIVE)
124 *ret = NULL;
125 }
126 return (mem != NULL);
127}
128
129/**
130 * Try to free the memory allocated from per-device coherent memory pool.
131 * @dev: device from which the memory was allocated
132 * @order: the order of pages allocated
133 * @vaddr: virtual address of allocated pages
134 *
135 * This checks whether the memory was allocated from the per-device
136 * coherent memory pool and if so, releases that memory.
137 *
138 * Returns 1 if we correctly released the memory, or 0 if
139 * %dma_release_coherent() should proceed with releasing memory from
140 * generic pools.
141 */
142int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
143{
144 struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
145
146 if (mem && vaddr >= mem->virt_base && vaddr <
147 (mem->virt_base + (mem->size << PAGE_SHIFT))) {
148 int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
149
150 bitmap_release_region(mem->bitmap, page, order);
151 return 1;
152 }
153 return 0;
154}