android_kernel_samsung_hero.../arch/arm/kernel/io.c
2016-08-17 16:41:52 +08:00

130 lines
2.5 KiB
C

#include <linux/export.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#define IO_CHECK_ALIGN(v, a) ((((unsigned long)(v)) & ((a) - 1)) == 0)
static DEFINE_RAW_SPINLOCK(__io_lock);
/*
* Generic atomic MMIO modify.
*
* Allows thread-safe access to registers shared by unrelated subsystems.
* The access is protected by a single MMIO-wide lock.
*/
void atomic_io_modify_relaxed(void __iomem *reg, u32 mask, u32 set)
{
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&__io_lock, flags);
value = readl_relaxed(reg) & ~mask;
value |= (set & mask);
writel_relaxed(value, reg);
raw_spin_unlock_irqrestore(&__io_lock, flags);
}
EXPORT_SYMBOL(atomic_io_modify_relaxed);
void atomic_io_modify(void __iomem *reg, u32 mask, u32 set)
{
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&__io_lock, flags);
value = readl_relaxed(reg) & ~mask;
value |= (set & mask);
writel(value, reg);
raw_spin_unlock_irqrestore(&__io_lock, flags);
}
EXPORT_SYMBOL(atomic_io_modify);
/*
* Copy data from IO memory space to "real" memory space.
*/
void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
{
while (count && (!IO_CHECK_ALIGN(from, 8) || !IO_CHECK_ALIGN(to, 8))) {
*(u8 *)to = readb_relaxed_no_log(from);
from++;
to++;
count--;
}
while (count >= 8) {
*(u64 *)to = readq_relaxed_no_log(from);
from += 8;
to += 8;
count -= 8;
}
while (count) {
*(u8 *)to = readb_relaxed_no_log(from);
from++;
to++;
count--;
}
}
EXPORT_SYMBOL(_memcpy_fromio);
/*
* Copy data from "real" memory space to IO memory space.
*/
void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
{
void *p = (void __force *)to;
while (count && (!IO_CHECK_ALIGN(p, 8) || !IO_CHECK_ALIGN(from, 8))) {
writeb_relaxed_no_log(*(volatile u8 *)from, p);
from++;
p++;
count--;
}
while (count >= 8) {
writeq_relaxed_no_log(*(volatile u64 *)from, p);
from += 8;
p += 8;
count -= 8;
}
while (count) {
writeb_relaxed_no_log(*(volatile u8 *)from, p);
from++;
p++;
count--;
}
}
EXPORT_SYMBOL(_memcpy_toio);
/*
* "memset" on IO memory space.
*/
void _memset_io(volatile void __iomem *dst, int c, size_t count)
{
void *p = (void __force *)dst;
u64 qc = c;
qc |= qc << 8;
qc |= qc << 16;
qc |= qc << 32;
while (count && !IO_CHECK_ALIGN(p, 8)) {
writeb_relaxed_no_log(c, p);
p++;
count--;
}
while (count >= 8) {
writeq_relaxed_no_log(qc, p);
p += 8;
count -= 8;
}
while (count) {
writeb_relaxed_no_log(c, p);
p++;
count--;
}
}
EXPORT_SYMBOL(_memset_io);