// SPDX-License-Identifier: GPL-2.0#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);