[U-Boot] [PATCH 3/3 v2] ARM: ARM926EJS - Add cache operations

[Marek Vasut]

On Friday, August 19, 2011 11:37:29 AM Aneesh V wrote:
> Hi Hong,
> 
> On Friday 19 August 2011 02:53 PM, Hong Xu wrote:
> > Add a new file arch/arm/cpu/arm926ejs/cache.c and put cache operations
> > into this file.
> 
> How about converting as much as possible of these to armv5/armv6 generic
> code as I mentioned in this thread:
> 
> http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/105385/focus=105526
> 
> On a quick look everything below except the "flush_dcache_all()" seems
> to be armv5 generic.

I'd be _VERY_ careful here. And this "seems" doesn't sound very convincing. Are 
you dead sure it won't break any v5 CPU we support?

Cheers

> 
> best regards,
> Aneesh
> 
> > Signed-off-by: Hong Xu <hong.xu at atmel.com>
> > Tested-by: Elen Song <elen.song at atmel.com>
> > CC: Albert Aribaud <albert.u.boot at aribaud.net>
> > ---
> > Since V1
> > 
> >     Modified copyright line
> >     Fix for compiling warnings
> >     Changed the way to use CONFIG_SYS_CACHELINE_SIZE
> >     When unaligned buffer detected, emit ERROR instead of WARNING
> >     
> >     Do not make a common v5,v6 cache file. It seems arm946 is lack of
> >     Test-and-Clean DCache operation. And maybe more differents...
> >  
> >  arch/arm/cpu/arm926ejs/Makefile |    2 +-
> >  arch/arm/cpu/arm926ejs/cache.c  |  135
> >  +++++++++++++++++++++++++++++++++++++++ 2 files changed, 136
> >  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..756c9b1
> > --- /dev/null
> > +++ b/arch/arm/cpu/arm926ejs/cache.c
> > @@ -0,0 +1,135 @@
> > +/*
> > + * (C) Copyright 2011 Atmel Corporation
> > + *
> > + * 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_CACHELINE_SIZE
> > +/*
> > + * ARM926EJ-S Technical Reference Manual, Chap 2.3.1 Table 2-9
> > + * only b'10, aka. 32 bytes cache line len is valid
> > + */
> > +#define CONFIG_SYS_CACHELINE_SIZE 32
> > +#endif
> > +
> > +#ifndef CONFIG_SYS_DCACHE_OFF
> > +/*
> > + * Flush or Invalidate DCache respectively
> > + */
> > +static void cache_range_op(unsigned long start, unsigned long stop, int
> > op) +{
> > +	unsigned long mva;
> > +
> > +	if (op > INVALIDATE_CACHE_OP) {
> > +		printf("ERROR: %s - Invalid cache operation, op: %d!\n",
> > +			__func__, op);
> > +		return;
> > +	}
> > +
> > +	mva = start;
> > +	if ((mva & (CONFIG_SYS_CACHELINE_SIZE - 1)) != 0) {
> > +		printf("ERROR: %s op: %d - start address 0x%08lx not aligned "
> > +			"to cache line size(%d bytes)\n", __func__, op, start,
> > +			CONFIG_SYS_CACHELINE_SIZE);
> > +		/* Round up starting address */
> > +		mva = (mva | (CONFIG_SYS_CACHELINE_SIZE - 1)) + 1;
> > +	}
> > +	if ((stop & (CONFIG_SYS_CACHELINE_SIZE - 1)) != 0) {
> > +		printf("ERROR: %s op: %d - stop address 0x%08lx not aligned "
> > +			"to cache line size(%d bytes)\n", __func__, op, stop,
> > +			CONFIG_SYS_CACHELINE_SIZE);
> > +		/* Round down ending address */
> > +		stop &= ~(CONFIG_SYS_CACHELINE_SIZE - 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 += CONFIG_SYS_CACHELINE_SIZE;
> > +	}
> > +
> > +	/* 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