1#include <linux/export.h>
2#include <linux/types.h>
3#include <linux/io.h>
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);
39
40/*
41 * Copy data from IO memory space to "real" memory space.
42 * This needs to be optimized.
43 */
44void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
45{
46	unsigned char *t = to;
47	while (count) {
48		count--;
49		*t = readb(from);
50		t++;
51		from++;
52	}
53}
54EXPORT_SYMBOL(_memcpy_fromio);
55
56/*
57 * Copy data from "real" memory space to IO memory space.
58 * This needs to be optimized.
59 */
60void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
61{
62	const unsigned char *f = from;
63	while (count) {
64		count--;
65		writeb(*f, to);
66		f++;
67		to++;
68	}
69}
70EXPORT_SYMBOL(_memcpy_toio);
71
72/*
73 * "memset" on IO memory space.
74 * This needs to be optimized.
75 */
76void _memset_io(volatile void __iomem *dst, int c, size_t count)
77{
78	while (count) {
79		count--;
80		writeb(c, dst);
81		dst++;
82	}
83}
84EXPORT_SYMBOL(_memset_io);
85