Commit 316ec062 authored by John David Anglin's avatar John David Anglin Committed by Helge Deller
Browse files

parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range 



The previously submitted patch did not resolve the random segmentation
faults observed on the phantom buildd system.  There are still
unresolved problems with the Debian 4.8 and 4.9 kernels on C8000.

The attached patch removes the flush of the offset map pages and does a
whole data cache flush for large ranges.  No other arch flushes the
offset map in these routines as far as I can tell.

I have not observed any random segmentation faults on rp3440 in two
weeks of testing with 4.10.0 and 4.10.1.

Signed-off-by: default avatarJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org      # v4.8+
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 5f655322

arch/parisc/include/asm/cacheflush.h

+2 −21
Original line number Original line Diff line number Diff line
@@ -43,28 +43,9 @@ static inline void flush_kernel_dcache_page(struct page *page) 




#define flush_kernel_dcache_range(start,size) \

#define flush_kernel_dcache_range(start,size) \

	flush_kernel_dcache_range_asm((start), (start)+(size));

	flush_kernel_dcache_range_asm((start), (start)+(size));

/* vmap range flushes and invalidates.  Architecturally, we don't need

 * the invalidate, because the CPU should refuse to speculate once an

 * area has been flushed, so invalidate is left empty */

static inline void flush_kernel_vmap_range(void *vaddr, int size)

{

	unsigned long start = (unsigned long)vaddr;



	flush_kernel_dcache_range_asm(start, start + size);

}

static inline void invalidate_kernel_vmap_range(void *vaddr, int size)

{

	unsigned long start = (unsigned long)vaddr;

	void *cursor = vaddr;





	for ( ; cursor < vaddr + size; cursor += PAGE_SIZE) {

void flush_kernel_vmap_range(void *vaddr, int size);

		struct page *page = vmalloc_to_page(cursor);

void invalidate_kernel_vmap_range(void *vaddr, int size);



		if (test_and_clear_bit(PG_dcache_dirty, &page->flags))

			flush_kernel_dcache_page(page);

	}

	flush_kernel_dcache_range_asm(start, start + size);

}





#define flush_cache_vmap(start, end)		flush_cache_all()

#define flush_cache_vmap(start, end)		flush_cache_all()

#define flush_cache_vunmap(start, end)		flush_cache_all()

#define flush_cache_vunmap(start, end)		flush_cache_all()

arch/parisc/kernel/cache.c

+22 −0
Original line number Original line Diff line number Diff line
@@ -616,3 +616,25 @@ flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long 
		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));

		__flush_cache_page(vma, vmaddr, PFN_PHYS(pfn));

	}

	}

}

}



void flush_kernel_vmap_range(void *vaddr, int size)

{

	unsigned long start = (unsigned long)vaddr;



	if ((unsigned long)size > parisc_cache_flush_threshold)

		flush_data_cache();

	else

		flush_kernel_dcache_range_asm(start, start + size);

}

EXPORT_SYMBOL(flush_kernel_vmap_range);



void invalidate_kernel_vmap_range(void *vaddr, int size)

{

	unsigned long start = (unsigned long)vaddr;



	if ((unsigned long)size > parisc_cache_flush_threshold)

		flush_data_cache();

	else

		flush_kernel_dcache_range_asm(start, start + size);

}

EXPORT_SYMBOL(invalidate_kernel_vmap_range);

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