lib/iomap_copy.c

Source file repositories/reference/linux-study-clean/lib/iomap_copy.c

File Facts

System
Linux kernel
Corpus path
lib/iomap_copy.c
Extension
.c
Size
2209 bytes
Lines
79
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2006 PathScale, Inc.  All Rights Reserved.
 */

#include <linux/export.h>
#include <linux/io.h>

/**
 * __iowrite32_copy - copy data to MMIO space, in 32-bit units
 * @to: destination, in MMIO space (must be 32-bit aligned)
 * @from: source (must be 32-bit aligned)
 * @count: number of 32-bit quantities to copy
 *
 * Copy data from kernel space to MMIO space, in units of 32 bits at a
 * time.  Order of access is not guaranteed, nor is a memory barrier
 * performed afterwards.
 */
#ifndef __iowrite32_copy
void __iowrite32_copy(void __iomem *to, const void *from, size_t count)
{
	u32 __iomem *dst = to;
	const u32 *src = from;
	const u32 *end = src + count;

	while (src < end)
		__raw_writel(*src++, dst++);
}
EXPORT_SYMBOL_GPL(__iowrite32_copy);
#endif

/**
 * __ioread32_copy - copy data from MMIO space, in 32-bit units
 * @to: destination (must be 32-bit aligned)
 * @from: source, in MMIO space (must be 32-bit aligned)
 * @count: number of 32-bit quantities to copy
 *
 * Copy data from MMIO space to kernel space, in units of 32 bits at a
 * time.  Order of access is not guaranteed, nor is a memory barrier
 * performed afterwards.
 */
void __ioread32_copy(void *to, const void __iomem *from, size_t count)
{
	u32 *dst = to;
	const u32 __iomem *src = from;
	const u32 __iomem *end = src + count;

	while (src < end)
		*dst++ = __raw_readl(src++);
}
EXPORT_SYMBOL_GPL(__ioread32_copy);

/**
 * __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units
 * @to: destination, in MMIO space (must be 64-bit aligned)
 * @from: source (must be 64-bit aligned)
 * @count: number of 64-bit quantities to copy
 *
 * Copy data from kernel space to MMIO space, in units of 32 or 64 bits at a
 * time.  Order of access is not guaranteed, nor is a memory barrier
 * performed afterwards.
 */
#ifndef __iowrite64_copy
void __iowrite64_copy(void __iomem *to, const void *from, size_t count)
{
#ifdef CONFIG_64BIT
	u64 __iomem *dst = to;
	const u64 *src = from;
	const u64 *end = src + count;

	while (src < end)
		__raw_writeq(*src++, dst++);
#else
	__iowrite32_copy(to, from, count * 2);
#endif
}
EXPORT_SYMBOL_GPL(__iowrite64_copy);
#endif

Annotation

Implementation Notes