linux-stable/arch/arm/kernel/io.c

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#include <linux/export.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/spinlock.h>
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.
* This needs to be optimized.
*/
void _memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
{
unsigned char *t = to;
while (count) {
count--;
*t = readb(from);
t++;
from++;
}
}
EXPORT_SYMBOL(_memcpy_fromio);
/*
* Copy data from "real" memory space to IO memory space.
* This needs to be optimized.
*/
void _memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
{
const unsigned char *f = from;
while (count) {
count--;
writeb(*f, to);
f++;
to++;
}
}
EXPORT_SYMBOL(_memcpy_toio);
/*
* "memset" on IO memory space.
* This needs to be optimized.
*/
void _memset_io(volatile void __iomem *dst, int c, size_t count)
{
while (count) {
count--;
writeb(c, dst);
dst++;
}
}
EXPORT_SYMBOL(_memset_io);