1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/export.h>
3 #include <linux/types.h>
4 #include <linux/io.h>
5 #include <linux/spinlock.h>
6
7 static DEFINE_RAW_SPINLOCK(__io_lock);
8
9 /*
10 * Generic atomic MMIO modify.
11 *
12 * Allows thread-safe access to registers shared by unrelated subsystems.
13 * The access is protected by a single MMIO-wide lock.
14 */
atomic_io_modify_relaxed(void __iomem * reg,u32 mask,u32 set)15 void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
16 {
17 unsigned long flags;
18 u32 value;
19
20 raw_spin_lock_irqsave(&__io_lock, flags);
21 value = readl_relaxed(reg) & ~mask;
22 value |= (set & mask);
23 writel_relaxed(value, reg);
24 raw_spin_unlock_irqrestore(&__io_lock, flags);
25 }
26 EXPORT_SYMBOL(atomic_io_modify_relaxed);
27
atomic_io_modify(void __iomem * reg,u32 mask,u32 set)28 void atomic_io_modify(void __iomem *reg, u32 mask, u32 set)
29 {
30 unsigned long flags;
31 u32 value;
32
33 raw_spin_lock_irqsave(&__io_lock, flags);
34 value = readl_relaxed(reg) & ~mask;
35 value |= (set & mask);
36 writel(value, reg);
37 raw_spin_unlock_irqrestore(&__io_lock, flags);
38 }
39 EXPORT_SYMBOL(atomic_io_modify);
40
41 /*
42 * Copy data from IO memory space to "real" memory space.
43 * This needs to be optimized.
44 */
_memcpy_fromio(void * to,const volatile void __iomem * from,size_t count)45 void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
46 {
47 unsigned char *t = to;
48 while (count) {
49 count--;
50 *t = readb(from);
51 t++;
52 from++;
53 }
54 }
55 EXPORT_SYMBOL(_memcpy_fromio);
56
57 /*
58 * Copy data from "real" memory space to IO memory space.
59 * This needs to be optimized.
60 */
_memcpy_toio(volatile void __iomem * to,const void * from,size_t count)61 void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
62 {
63 const unsigned char *f = from;
64 while (count) {
65 count--;
66 writeb(*f, to);
67 f++;
68 to++;
69 }
70 }
71 EXPORT_SYMBOL(_memcpy_toio);
72
73 /*
74 * "memset" on IO memory space.
75 * This needs to be optimized.
76 */
_memset_io(volatile void __iomem * dst,int c,size_t count)77 void _memset_io(volatile void __iomem *dst, int c, size_t count)
78 {
79 while (count) {
80 count--;
81 writeb(c, dst);
82 dst++;
83 }
84 }
85 EXPORT_SYMBOL(_memset_io);
86