arm: Clean up asm/io.h

asm/io.h is the header file containing the central MMIO accessor macros.
Judging by the header and the comments, it was apparently once copied
from the Linux kernel, but has deviated since then *heavily*. There is
absolutely no point in staying close to the original Linux code anymore,
so just remove the old cruft, by:
- removing pointless Linux history
- removing commented code
- removing outdated comments
- removing unused definitions (for mem_isa)

This massively improves the readability of the file.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
This commit is contained in:
Andre Przywara 2022-02-11 11:29:37 +00:00 committed by Tom Rini
parent 7ed340a828
commit 7ab2e47d27

View file

@ -1,45 +1,26 @@
/*
* linux/include/asm-arm/io.h
* I/O device access primitives. Based on early versions from the Linux kernel.
*
* Copyright (C) 1996-2000 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Modifications:
* 16-Sep-1996 RMK Inlined the inx/outx functions & optimised for both
* constant addresses and variable addresses.
* 04-Dec-1997 RMK Moved a lot of this stuff to the new architecture
* specific IO header files.
* 27-Mar-1999 PJB Second parameter of memcpy_toio is const..
* 04-Apr-1999 PJB Added check_signature.
* 12-Dec-1999 RMK More cleanups
* 18-Jun-2000 RMK Removed virt_to_* and friends definitions
*/
#ifndef __ASM_ARM_IO_H
#define __ASM_ARM_IO_H
#ifdef __KERNEL__
#include <linux/types.h>
#include <linux/kernel.h>
#include <asm/byteorder.h>
#include <asm/memory.h>
#include <asm/barriers.h>
#if 0 /* XXX###XXX */
#include <asm/arch/hardware.h>
#endif /* XXX###XXX */
static inline void sync(void)
{
}
/*
* Generic virtual read/write. Note that we don't support half-word
* read/writes. We define __arch_*[bl] here, and leave __arch_*w
* to the architecture specific code.
*/
/* Generic virtual read/write. */
#define __arch_getb(a) (*(volatile unsigned char *)(a))
#define __arch_getw(a) (*(volatile unsigned short *)(a))
#define __arch_getl(a) (*(volatile unsigned int *)(a))
@ -247,13 +228,6 @@ static inline void __raw_readsl(unsigned long addr, void *data, int longlen)
#define setbits_64(addr, set) setbits(64, addr, set)
#define clrsetbits_64(addr, clear, set) clrsetbits(64, addr, clear, set)
/*
* Now, pick up the machine-defined IO definitions
*/
#if 0 /* XXX###XXX */
#include <asm/arch/io.h>
#endif /* XXX###XXX */
/*
* IO port access primitives
* -------------------------
@ -317,16 +291,6 @@ static inline void __raw_readsl(unsigned long addr, void *data, int longlen)
#define writesb(a, d, s) __raw_writesb((unsigned long)a, d, s)
#define readsb(a, d, s) __raw_readsb((unsigned long)a, d, s)
/*
* DMA-consistent mapping functions. These allocate/free a region of
* uncached, unwrite-buffered mapped memory space for use with DMA
* devices. This is the "generic" version. The PCI specific version
* is in pci.h
*/
extern void *consistent_alloc(int gfp, size_t size, dma_addr_t *handle);
extern void consistent_free(void *vaddr, size_t size, dma_addr_t handle);
extern void consistent_sync(void *vaddr, size_t size, int rw);
/*
* String version of IO memory access ops:
*/
@ -334,8 +298,6 @@ extern void _memcpy_fromio(void *, unsigned long, size_t);
extern void _memcpy_toio(unsigned long, const void *, size_t);
extern void _memset_io(unsigned long, int, size_t);
extern void __readwrite_bug(const char *fn);
/* Optimized copy functions to read from/write to IO sapce */
#ifdef CONFIG_ARM64
#include <cpu_func.h>
@ -441,62 +403,6 @@ void __memset_io(volatile void __iomem *dst, int c, size_t count)
#define memcpy_toio(a, b, c) memcpy((void *)(a), (b), (c))
#endif
/*
* If this architecture has ISA IO, then define the isa_read/isa_write
* macros.
*/
#ifdef __mem_isa
#define isa_readb(addr) __raw_readb(__mem_isa(addr))
#define isa_readw(addr) __raw_readw(__mem_isa(addr))
#define isa_readl(addr) __raw_readl(__mem_isa(addr))
#define isa_writeb(val,addr) __raw_writeb(val,__mem_isa(addr))
#define isa_writew(val,addr) __raw_writew(val,__mem_isa(addr))
#define isa_writel(val,addr) __raw_writel(val,__mem_isa(addr))
#define isa_memset_io(a,b,c) _memset_io(__mem_isa(a),(b),(c))
#define isa_memcpy_fromio(a,b,c) _memcpy_fromio((a),__mem_isa(b),(c))
#define isa_memcpy_toio(a,b,c) _memcpy_toio(__mem_isa((a)),(b),(c))
#define isa_eth_io_copy_and_sum(a,b,c,d) \
eth_copy_and_sum((a),__mem_isa(b),(c),(d))
static inline int
isa_check_signature(unsigned long io_addr, const unsigned char *signature,
int length)
{
int retval = 0;
do {
if (isa_readb(io_addr) != *signature)
goto out;
io_addr++;
signature++;
length--;
} while (length);
retval = 1;
out:
return retval;
}
#else /* __mem_isa */
#define isa_readb(addr) (__readwrite_bug("isa_readb"),0)
#define isa_readw(addr) (__readwrite_bug("isa_readw"),0)
#define isa_readl(addr) (__readwrite_bug("isa_readl"),0)
#define isa_writeb(val,addr) __readwrite_bug("isa_writeb")
#define isa_writew(val,addr) __readwrite_bug("isa_writew")
#define isa_writel(val,addr) __readwrite_bug("isa_writel")
#define isa_memset_io(a,b,c) __readwrite_bug("isa_memset_io")
#define isa_memcpy_fromio(a,b,c) __readwrite_bug("isa_memcpy_fromio")
#define isa_memcpy_toio(a,b,c) __readwrite_bug("isa_memcpy_toio")
#define isa_eth_io_copy_and_sum(a,b,c,d) \
__readwrite_bug("isa_eth_io_copy_and_sum")
#define isa_check_signature(io,sig,len) (0)
#endif /* __mem_isa */
#endif /* __KERNEL__ */
#include <asm-generic/io.h>
#include <iotrace.h>