Commit efcc4ea8 authored Apr 24, 2018 by Vincent Chen Committed by Greentime Hu May 23, 2018

nds32: Correct flush_dcache_page function



1. Disable local irq before d-cache write-back and invalidate.
   The cpu_dcache_wbinval_page function is composed of d-cache
write-back and invalidate. If the local irq is enabled when calling
cpu_dcache_wbinval_page, the content of d-cache is possibly updated
between write-back and invalidate. In this case, the updated data will
be dropped due to the following d-cache invalidation. Therefore, we
disable the local irq before calling cpu_dcache_wbinval_page.

2. Correct the data write-back for page aliasing case.
   Only the page whose (page->index << PAGE_SHIFT) is located at the
same page color as page_address(page) needs to execute data write-back
in flush_dcache_page function.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Reviewed-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

parent 1613de8a

arch/nds32/mm/cacheflush.c

+12 −9

Original line number	Diff line number	Diff line
		@@ -217,17 +217,20 @@ void flush_dcache_page(struct page *page)
		if (mapping && !mapping_mapped(mapping))
		set_bit(PG_dcache_dirty, &page->flags);
		else {
		int i, pc;
		unsigned long vto, kaddr, flags;
		unsigned long kaddr, flags;

		kaddr = (unsigned long)page_address(page);
		cpu_dcache_wbinval_page(kaddr);
		pc = CACHE_SET(DCACHE) * CACHE_LINE_SIZE(DCACHE) / PAGE_SIZE;
		local_irq_save(flags);
		for (i = 0; i < pc; i++) {
		vto =
		kremap0(kaddr + i * PAGE_SIZE, page_to_phys(page));
		cpu_dcache_wbinval_page(vto);
		kunmap01(vto);
		cpu_dcache_wbinval_page(kaddr);
		if (mapping) {
		unsigned long vaddr, kto;

		vaddr = page->index << PAGE_SHIFT;
		if (aliasing(vaddr, kaddr)) {
		kto = kremap0(vaddr, page_to_phys(page));
		cpu_dcache_wbinval_page(kto);
		kunmap01(kto);
		}
		}
		local_irq_restore(flags);
		}