On Sun, 9 Jan 2022 17:30:07 +0000
Andre Przywara <andre.przyw...@arm.com> wrote:
Hi Rick, Leo:
> 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 - removing outdated comments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.
it looks like arch/risc-v/include/asm/io.h is a copy of the ARM
version, and includes the same pointless legacy. You might want to
remove those parts there as well.
Cheers,
Andre
> Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
> ---
> arch/arm/include/asm/io.h | 98 +--------------------------------------
> 1 file changed, 2 insertions(+), 96 deletions(-)
>
> diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
> index 36b840378a9..89b1015bc4d 100644
> --- a/arch/arm/include/asm/io.h
> +++ b/arch/arm/include/asm/io.h
> @@ -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>
>
