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Commit 7f3f1d01 authored by Ralf Baechle's avatar Ralf Baechle
Browse files

[MIPS] Fix deadlock on MP with cache aliases. 



A proper fix would involve introducing the notion of shared caches but
at this stage of 2.6.17 that's going to be too intrusive and not needed
for current hardware; aside I think some discussion will be needed.

So for now on the affected SMP configurations which happen to suffer from
cache aliases we make use of the fact that a single cache will be shared
by all processors.  This solves the deadlock issue and will improve
performance by getting rid of the smp_call_function overhead.

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 78665aaa

arch/mips/mm/c-r4k.c

+30 −9
Original line number Original line Diff line number Diff line
@@ -29,6 +29,27 @@ 
#include <asm/war.h>

#include <asm/war.h>

#include <asm/cacheflush.h> /* for run_uncached() */

#include <asm/cacheflush.h> /* for run_uncached() */







/*

 * Special Variant of smp_call_function for use by cache functions:

 *

 *  o No return value

 *  o collapses to normal function call on UP kernels

 *  o collapses to normal function call on systems with a single shared

 *    primary cache.

 */

static inline void r4k_on_each_cpu(void (*func) (void *info), void *info,

                                   int retry, int wait)

{

	preempt_disable();



#if !defined(CONFIG_MIPS_MT_SMP) && !defined(CONFIG_MIPS_MT_SMTC)

	smp_call_function(func, info, retry, wait);

#endif

	func(info);

	preempt_enable();

}



/*

/*

 * Must die.

 * Must die.

 */

 */
@@ -299,7 +320,7 @@ static void r4k_flush_cache_all(void) 
	if (!cpu_has_dc_aliases)

	if (!cpu_has_dc_aliases)

		return;

		return;





	on_each_cpu(local_r4k_flush_cache_all, NULL, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_cache_all, NULL, 1, 1);

}

}





static inline void local_r4k___flush_cache_all(void * args)

static inline void local_r4k___flush_cache_all(void * args)
@@ -320,7 +341,7 @@ static inline void local_r4k___flush_cache_all(void * args) 




static void r4k___flush_cache_all(void)

static void r4k___flush_cache_all(void)

{

{

	on_each_cpu(local_r4k___flush_cache_all, NULL, 1, 1);

	r4k_on_each_cpu(local_r4k___flush_cache_all, NULL, 1, 1);

}

}





static inline void local_r4k_flush_cache_range(void * args)

static inline void local_r4k_flush_cache_range(void * args)
@@ -341,7 +362,7 @@ static inline void local_r4k_flush_cache_range(void * args) 
static void r4k_flush_cache_range(struct vm_area_struct *vma,

static void r4k_flush_cache_range(struct vm_area_struct *vma,

	unsigned long start, unsigned long end)

	unsigned long start, unsigned long end)

{

{

	on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_cache_range, vma, 1, 1);

}

}





static inline void local_r4k_flush_cache_mm(void * args)

static inline void local_r4k_flush_cache_mm(void * args)
@@ -370,7 +391,7 @@ static void r4k_flush_cache_mm(struct mm_struct *mm) 
	if (!cpu_has_dc_aliases)

	if (!cpu_has_dc_aliases)

		return;

		return;





	on_each_cpu(local_r4k_flush_cache_mm, mm, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_cache_mm, mm, 1, 1);

}

}





struct flush_cache_page_args {

struct flush_cache_page_args {
@@ -461,7 +482,7 @@ static void r4k_flush_cache_page(struct vm_area_struct *vma, 
	args.addr = addr;

	args.addr = addr;

	args.pfn = pfn;

	args.pfn = pfn;





	on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_cache_page, &args, 1, 1);

}

}





static inline void local_r4k_flush_data_cache_page(void * addr)

static inline void local_r4k_flush_data_cache_page(void * addr)
@@ -471,7 +492,7 @@ static inline void local_r4k_flush_data_cache_page(void * addr) 




static void r4k_flush_data_cache_page(unsigned long addr)

static void r4k_flush_data_cache_page(unsigned long addr)

{

{

	on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_data_cache_page, (void *) addr, 1, 1);

}

}





struct flush_icache_range_args {

struct flush_icache_range_args {
@@ -514,7 +535,7 @@ static void r4k_flush_icache_range(unsigned long start, unsigned long end) 
	args.start = start;

	args.start = start;

	args.end = end;

	args.end = end;





	on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_icache_range, &args, 1, 1);

	instruction_hazard();

	instruction_hazard();

}

}
@@ -590,7 +611,7 @@ static void r4k_flush_icache_page(struct vm_area_struct *vma, 
	args.vma = vma;

	args.vma = vma;

	args.page = page;

	args.page = page;





	on_each_cpu(local_r4k_flush_icache_page, &args, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_icache_page, &args, 1, 1);

}

}
@@ -689,7 +710,7 @@ static void local_r4k_flush_cache_sigtramp(void * arg) 




static void r4k_flush_cache_sigtramp(unsigned long addr)

static void r4k_flush_cache_sigtramp(unsigned long addr)

{

{

	on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1);

	r4k_on_each_cpu(local_r4k_flush_cache_sigtramp, (void *) addr, 1, 1);

}

}





static void r4k_flush_icache_all(void)

static void r4k_flush_icache_all(void)