[U-Boot] [PATCH 3/3 v3] ARM: ARM926EJS - Add cache operations

[Marek Vasut]

On Thursday, August 11, 2011 05:27:37 AM Hong Xu wrote:
> Add a new file arch/arm/cpu/arm926ejs/cache.c and put cache operations
> into this file.
> 
> Signed-off-by: Hong Xu <hong.xu at atmel.com>
> ---
> V2:
> 	Fixed a typo when CONFIG_SYS_DCACHE_OFF is defined
> V3:
> 	Undo changes in include/configs/at91sam9260ek.h
> 	It's for testing purpose
> 
>  arch/arm/cpu/arm926ejs/Makefile |    2 +-
>  arch/arm/cpu/arm926ejs/cache.c  |  142
> +++++++++++++++++++++++++++++++++++++++ 2 files changed, 143
> insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/cpu/arm926ejs/cache.c
> 
> diff --git a/arch/arm/cpu/arm926ejs/Makefile
> b/arch/arm/cpu/arm926ejs/Makefile index 930e0d1..5b5f330 100644
> --- a/arch/arm/cpu/arm926ejs/Makefile
> +++ b/arch/arm/cpu/arm926ejs/Makefile
> @@ -26,7 +26,7 @@ include $(TOPDIR)/config.mk
>  LIB	= $(obj)lib$(CPU).o
> 
>  START	= start.o
> -COBJS	= cpu.o
> +COBJS	= cpu.o cache.o
> 
>  SRCS	:= $(START:.o=.S) $(SOBJS:.o=.S) $(COBJS:.o=.c)
>  OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))
> diff --git a/arch/arm/cpu/arm926ejs/cache.c
> b/arch/arm/cpu/arm926ejs/cache.c new file mode 100644
> index 0000000..fc321f6
> --- /dev/null
> +++ b/arch/arm/cpu/arm926ejs/cache.c
> @@ -0,0 +1,142 @@
> +/*
> + * (C) Copyright 2002
> + * Wolfgang Denk, DENX Software Engineering, wd at denx.de.

Again ... really ?

> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +
> +#define FLUSH_CACHE_OP		0
> +#define INVALIDATE_CACHE_OP	1
> +
> +#ifndef CONFIG_SYS_DCACHE_OFF
> +/*
> + * Flush or Invalidate DCache respectively
> + */
> +static void cache_range_op(unsigned long start, unsigned long stop, int
> op) +{
> +	int cache_line_len;
> +	unsigned long mva;
> +	char *func_name;
> +
> +	if (op == FLUSH_CACHE_OP)
> +		func_name = "flush_dcache_range";
> +	else if (op == INVALIDATE_CACHE_OP)
> +		func_name = "invalidate_dcache_range";
> +	else {
> +		printf("WARNING: %s - Invalid cache operation!\n", __func__);
> +		return;
> +	}

hm...
if (op > 2)
 printf(warning);

otherwise, just declare an array of strings ...
char *name[] = { "flush", "invalidate" };

and access it where needed ... printf("%s", name[OP]); ... maybe ?

> +
> +#ifdef CONFIG_SYS_CACHELINE_SIZE
> +	cache_line_len = CONFIG_SYS_CACHELINE_SIZE;
> +#else
> +	/*
> +	 * ARM926EJ-S Technical Reference Manual, Chap 2.3.1 Table 2-9
> +	 * only b'10, aka. 32 bytes cache line len is valid
> +	 */
> +	cache_line_len = 32;
> +#endif

Move this at the begining of the file

#ifndef CONFIG_SYS...
#define
#endif

include the comment, just modify it a bit accordingly, explaining what it does 
here. Then use CONFIG_SYS... as it'll always be defined.

Otherwise looks good.

I need sleep badly :-) Good night !

> +	mva = start;
> +	if ((mva & (cache_line_len - 1)) != 0) {
> +		printf("WARNING: %s - start address 0x%08x not aligned to"
> +			"cache line size(%d bytes)\n", func_name, start,
> +			cache_line_len);
> +		/* Round up starting address */
> +		mva = (mva | (cache_line_len - 1)) + 1;
> +	}
> +	if ((stop & (cache_line_len - 1)) != 0) {
> +		printf("WARNING: %s - stop address 0x%08x not aligned to"
> +			"cache line size(%d bytes)\n", func_name, stop,
> +			cache_line_len);
> +		/* Round down ending address */
> +		stop &= ~(cache_line_len - 1);
> +	}
> +
> +	while (mva < stop) {
> +		if (op == FLUSH_CACHE_OP)
> +			asm("mcr p15, 0, %0, c7, c14, 1\n" : : "r"(mva));
> +		else
> +			asm("mcr p15, 0, %0, c7, c6, 1\n" : : "r"(mva));
> +
> +		mva += cache_line_len;
> +	}
> +
> +	/* Drain WB if necessary */
> +	if (op == FLUSH_CACHE_OP)
> +		asm("mcr p15, 0, %0, c7, c10, 4\n" : : "r" (0));
> +}
> +
> +/*
> + * The buffer range to be flushed is [start, stop)
> + */
> +void flush_dcache_range(unsigned long start, unsigned long stop)
> +{
> +	cache_range_op(start, stop, FLUSH_CACHE_OP);
> +}
> +
> +void flush_dcache_all(void)
> +{
> +	/*
> +	 * ARM926EJ-S Technical Reference Manual, Chap 2.3.8
> +	 * Clean & Invalidate the entire DCache
> +	 */
> +	asm("0: mrc p15, 0, r15, c7, c14, 3\n\t" "bne 0b\n" : : : "memory");
> +	/* Drain WB */
> +	asm("mcr p15, 0, %0, c7, c10, 4\n" : : "r" (0));
> +}
> +
> +void flush_cache(unsigned long start, unsigned long size)
> +{
> +	flush_dcache_range(start, start + size);
> +}
> +
> +/*
> + * The buffer range to be invalidated is [start, stop)
> + */
> +void invalidate_dcache_range(unsigned long start, unsigned long stop)
> +{
> +	cache_range_op(start, stop, INVALIDATE_CACHE_OP);
> +}
> +
> +void invalidate_dcache_all(void)
> +{
> +	asm("mcr p15, 0, %0, c7, c6, 0\n" : : "r" (0));
> +}
> +
> +#else /* #ifndef CONFIG_SYS_DCACHE_OFF */
> +
> +void flush_cache(unsigned long start, unsigned long size) {}
> +void flush_dcache_all(void) {}
> +void flush_dcache_range(unsigned long start, unsigned long stop) {}
> +void invalidate_dcache_range(unsigned long start, unsigned long stop) {}
> +void invalidate_dcache_all(void) {}
> +#endif
> +
> +#ifndef CONFIG_SYS_ICACHE_OFF
> +void invalidate_icache_all(void)
> +{
> +	asm("mcr p15, 0, %0, c7, c5, 0\n" : : "r" (0));
> +}
> +
> +#else /* #ifndef CONFIG_SYS_ICACHE_OFF */
> +
> +void invalidate_icache_all(void) {}
> +#endif