u-boot/include/asm-generic/io.h
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

110 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Generic I/O functions.
*
* Copyright (c) 2016 Imagination Technologies Ltd.
*/
#ifndef __ASM_GENERIC_IO_H__
#define __ASM_GENERIC_IO_H__
/*
* This file should be included at the end of each architecture-specific
* asm/io.h such that we may provide generic implementations without
* conflicting with architecture-specific code.
*/
#ifndef __ASSEMBLY__
/**
* phys_to_virt() - Return a virtual address mapped to a given physical address
* @paddr: the physical address
*
* Returns a virtual address which the CPU can access that maps to the physical
* address @paddr. This should only be used where it is known that no dynamic
* mapping is required. In general, map_physmem should be used instead.
*
* Returns: a virtual address which maps to @paddr
*/
#ifndef phys_to_virt
static inline void *phys_to_virt(phys_addr_t paddr)
{
return (void *)(unsigned long)paddr;
}
#endif
/**
* virt_to_phys() - Return the physical address that a virtual address maps to
* @vaddr: the virtual address
*
* Returns the physical address which the CPU-accessible virtual address @vaddr
* maps to.
*
* Returns: the physical address which @vaddr maps to
*/
#ifndef virt_to_phys
static inline phys_addr_t virt_to_phys(void *vaddr)
{
return (phys_addr_t)((unsigned long)vaddr);
}
#endif
/*
* Flags for use with map_physmem() & unmap_physmem(). Architectures need not
* support all of these, in which case they will be defined as zero here &
* ignored. Callers that may run on multiple architectures should therefore
* treat them as hints rather than requirements.
*/
#ifndef MAP_NOCACHE
# define MAP_NOCACHE 0 /* Produce an uncached mapping */
#endif
#ifndef MAP_WRCOMBINE
# define MAP_WRCOMBINE 0 /* Allow write-combining on the mapping */
#endif
#ifndef MAP_WRBACK
# define MAP_WRBACK 0 /* Map using write-back caching */
#endif
#ifndef MAP_WRTHROUGH
# define MAP_WRTHROUGH 0 /* Map using write-through caching */
#endif
/**
* map_physmem() - Return a virtual address mapped to a given physical address
* @paddr: the physical address
* @len: the length of the required mapping
* @flags: flags affecting the type of mapping
*
* Return a virtual address through which the CPU may access the memory at
* physical address @paddr. The mapping will be valid for at least @len bytes,
* and may be affected by flags passed to the @flags argument. This function
* may create new mappings, so should generally be paired with a matching call
* to unmap_physmem once the caller is finished with the memory in question.
*
* Returns: a virtual address suitably mapped to @paddr
*/
#ifndef map_physmem
static inline void *map_physmem(phys_addr_t paddr, unsigned long len,
unsigned long flags)
{
return phys_to_virt(paddr);
}
#endif
/**
* unmap_physmem() - Remove mappings created by a prior call to map_physmem()
* @vaddr: the virtual address which map_physmem() previously returned
* @flags: flags matching those originally passed to map_physmem()
*
* Unmap memory which was previously mapped by a call to map_physmem(). If
* map_physmem() dynamically created a mapping for the memory in question then
* unmap_physmem() will remove that mapping.
*/
#ifndef unmap_physmem
static inline void unmap_physmem(void *vaddr, unsigned long flags)
{
}
#endif
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_GENERIC_IO_H__ */