Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / arch / arm / kernel / io.c
blob60b621295d6cbee114dedb1ce710086178d656ea
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>
7 static DEFINE_RAW_SPINLOCK(__io_lock);
9 /*
10 * Generic atomic MMIO modify.
12 * Allows thread-safe access to registers shared by unrelated subsystems.
13 * The access is protected by a single MMIO-wide lock.
15 void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
17 unsigned long flags;
18 u32 value;
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);
26 EXPORT_SYMBOL(atomic_io_modify_relaxed);
28 void atomic_io_modify(void __iomem *reg, u32 mask, u32 set)
30 unsigned long flags;
31 u32 value;
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);
39 EXPORT_SYMBOL(atomic_io_modify);
42 * Copy data from IO memory space to "real" memory space.
43 * This needs to be optimized.
45 void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
47 unsigned char *t = to;
48 while (count) {
49 count--;
50 *t = readb(from);
51 t++;
52 from++;
55 EXPORT_SYMBOL(_memcpy_fromio);
58 * Copy data from "real" memory space to IO memory space.
59 * This needs to be optimized.
61 void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
63 const unsigned char *f = from;
64 while (count) {
65 count--;
66 writeb(*f, to);
67 f++;
68 to++;
71 EXPORT_SYMBOL(_memcpy_toio);
74 * "memset" on IO memory space.
75 * This needs to be optimized.
77 void _memset_io(volatile void __iomem *dst, int c, size_t count)
79 while (count) {
80 count--;
81 writeb(c, dst);
82 dst++;
85 EXPORT_SYMBOL(_memset_io);