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Commit 2464212f authored by Stuart Brady's avatar Stuart Brady Committed by Kyle McMartin
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[PARISC] Fix parisc_setup_cache_timing to choose a better flush threshold 



update comment about CAFL_STRIDE

Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>

Fixed a bug in parisc_setup_cache_timing() which caused it to calculate
a poor value for parisc_cache_flush_threshold.

Thanks to Joel Soete for spotting the bug.
Thanks to James Bottomley for pointing out the clean way to fix this.

Signed-off-by: default avatarStuart Brady <sdb@parisc-linux.org>

Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent f053725b

arch/parisc/kernel/cache.c

+6 −4
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <asm/page.h>

#include <asm/pgalloc.h>

#include <asm/processor.h>

#include <asm/sections.h>



int split_tlb;

int dcache_stride;
@@ -207,6 +208,9 @@ parisc_cache_init(void) 


	/* "New and Improved" version from Jim Hull 

	 *	(1 << (cc_block-1)) * (cc_line << (4 + cnf.cc_shift))

	 * The following CAFL_STRIDE is an optimized version, see

	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023625.html

	 * http://lists.parisc-linux.org/pipermail/parisc-linux/2004-June/023671.html

	 */

#define CAFL_STRIDE(cnf) (cnf.cc_line << (3 + cnf.cc_block + cnf.cc_shift))

	dcache_stride = CAFL_STRIDE(cache_info.dc_conf);
@@ -339,17 +343,15 @@ int parisc_cache_flush_threshold = FLUSH_THRESHOLD; 
void parisc_setup_cache_timing(void)

{

	unsigned long rangetime, alltime;

	extern char _text;	/* start of kernel code, defined by linker */

	extern char _end;	/* end of BSS, defined by linker */

	unsigned long size;



	alltime = mfctl(16);

	flush_data_cache();

	alltime = mfctl(16) - alltime;



	size = (unsigned long)(&_end - _text);

	size = (unsigned long)(_end - _text);

	rangetime = mfctl(16);

	flush_kernel_dcache_range((unsigned long)&_text, size);

	flush_kernel_dcache_range((unsigned long)_text, size);

	rangetime = mfctl(16) - rangetime;



	printk(KERN_DEBUG "Whole cache flush %lu cycles, flushing %lu bytes %lu cycles\n",