[PATCH 1/1] nios2: implement flush_dcache_mmap_lock/unlock

[Julien Beraud]

Use spin_lock/unlock_irq instead of doing nothing. This fixes corruptions
of the vma_interval_tree causing the kernel to be stuck in an
infinite loop in vma_interval_tree_foreach.

Signed-off-by: Julien Beraud <julien.beraud@xxxxxxxxxxxxxxxxxxxxx>
---
 arch/nios2/include/asm/cacheflush.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/nios2/include/asm/cacheflush.h b/arch/nios2/include/asm/cacheflush.h
index 52abba973dc2..55e383c173f7 100644
--- a/arch/nios2/include/asm/cacheflush.h
+++ b/arch/nios2/include/asm/cacheflush.h
@@ -46,7 +46,9 @@ extern void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
 extern void flush_dcache_range(unsigned long start, unsigned long end);
 extern void invalidate_dcache_range(unsigned long start, unsigned long end);
 
-#define flush_dcache_mmap_lock(mapping)		do { } while (0)
-#define flush_dcache_mmap_unlock(mapping)	do { } while (0)
+#define flush_dcache_mmap_lock(mapping) \
+	spin_lock_irq(&(mapping)->tree_lock)
+#define flush_dcache_mmap_unlock(mapping) \
+	spin_unlock_irq(&(mapping)->tree_lock)
 
 #endif /* _ASM_NIOS2_CACHEFLUSH_H */
-- 
2.11.0