Commit 7db15418 authored by Helge Deller's avatar Helge Deller Committed by Andrew Morton
Browse files

nios2: fix flush_dcache_page() for usage from irq context 

Since at least kernel 6.1, flush_dcache_page() is called with IRQs
disabled, e.g.  from aio_complete().

But the current implementation for flush_dcache_page() on NIOS2
unintentionally re-enables IRQs, which may lead to deadlocks.

Fix it by using xa_lock_irqsave() and xa_unlock_irqrestore() for the
flush_dcache_mmap_*lock() macros instead.

Link: https://lkml.kernel.org/r/ZOTF5WWURQNH9+iw@p100


Signed-off-by: default avatarHelge Deller <deller@gmx.de>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8cfd014e

arch/nios2/include/asm/cacheflush.h

+4 −0
Original line number Diff line number Diff line
@@ -52,5 +52,9 @@ extern void invalidate_dcache_range(unsigned long start, unsigned long end); 


#define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)

#define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)

#define flush_dcache_mmap_lock_irqsave(mapping, flags)		\

		xa_lock_irqsave(&mapping->i_pages, flags)

#define flush_dcache_mmap_unlock_irqrestore(mapping, flags)	\

		xa_unlock_irqrestore(&mapping->i_pages, flags)



#endif /* _ASM_NIOS2_CACHEFLUSH_H */

arch/nios2/mm/cacheflush.c

+3 −2
Original line number Diff line number Diff line
@@ -75,12 +75,13 @@ static void flush_aliases(struct address_space *mapping, struct folio *folio) 
{

	struct mm_struct *mm = current->active_mm;

	struct vm_area_struct *vma;

	unsigned long flags;

	pgoff_t pgoff;

	unsigned long nr = folio_nr_pages(folio);



	pgoff = folio->index;



	flush_dcache_mmap_lock(mapping);

	flush_dcache_mmap_lock_irqsave(mapping, flags);

	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) {

		unsigned long start;
@@ -92,7 +93,7 @@ static void flush_aliases(struct address_space *mapping, struct folio *folio) 
		start = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);

		flush_cache_range(vma, start, start + nr * PAGE_SIZE);

	}

	flush_dcache_mmap_unlock(mapping);

	flush_dcache_mmap_unlock_irqrestore(mapping, flags);

}



void flush_cache_all(void)