Merge branch 'drm-rockchip-next-fixes-2016-03-28' of https://github.com/markyzq/kerne...
[deliverable/linux.git] / arch / arm / kernel / io.c
CommitLineData
ecea4ab6 1#include <linux/export.h>
1da177e4 2#include <linux/types.h>
fced80c7 3#include <linux/io.h>
c5ca95b5
EG
4#include <linux/spinlock.h>
5
6static DEFINE_RAW_SPINLOCK(__io_lock);
7
8/*
9 * Generic atomic MMIO modify.
10 *
11 * Allows thread-safe access to registers shared by unrelated subsystems.
12 * The access is protected by a single MMIO-wide lock.
13 */
14void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
15{
16 unsigned long flags;
17 u32 value;
18
19 raw_spin_lock_irqsave(&__io_lock, flags);
20 value = readl_relaxed(reg) & ~mask;
21 value |= (set & mask);
22 writel_relaxed(value, reg);
23 raw_spin_unlock_irqrestore(&__io_lock, flags);
24}
25EXPORT_SYMBOL(atomic_io_modify_relaxed);
26
27void atomic_io_modify(void __iomem *reg, u32 mask, u32 set)
28{
29 unsigned long flags;
30 u32 value;
31
32 raw_spin_lock_irqsave(&__io_lock, flags);
33 value = readl_relaxed(reg) & ~mask;
34 value |= (set & mask);
35 writel(value, reg);
36 raw_spin_unlock_irqrestore(&__io_lock, flags);
37}
38EXPORT_SYMBOL(atomic_io_modify);
1da177e4
LT
39
40/*
41 * Copy data from IO memory space to "real" memory space.
42 * This needs to be optimized.
43 */
d2f60748 44void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
1da177e4
LT
45{
46 unsigned char *t = to;
47 while (count) {
48 count--;
49 *t = readb(from);
50 t++;
51 from++;
52 }
53}
296630c9 54EXPORT_SYMBOL(_memcpy_fromio);
1da177e4
LT
55
56/*
57 * Copy data from "real" memory space to IO memory space.
58 * This needs to be optimized.
59 */
d2f60748 60void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
1da177e4
LT
61{
62 const unsigned char *f = from;
63 while (count) {
64 count--;
65 writeb(*f, to);
66 f++;
67 to++;
68 }
69}
296630c9 70EXPORT_SYMBOL(_memcpy_toio);
1da177e4
LT
71
72/*
73 * "memset" on IO memory space.
74 * This needs to be optimized.
75 */
d2f60748 76void _memset_io(volatile void __iomem *dst, int c, size_t count)
1da177e4
LT
77{
78 while (count) {
79 count--;
80 writeb(c, dst);
81 dst++;
82 }
83}
1da177e4 84EXPORT_SYMBOL(_memset_io);
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