csky: Fixup update_mmu_cache called with user io mapping

The function update_mmu_cache could be called by user-io mapping.
There is no space of struct page in mem_map for the pte. Just
ignore the user-io mmaping in update_mmu_cache.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>

diff --git a/arch/csky/abiv2/cacheflush.c b/arch/csky/abiv2/cacheflush.c
index 790f1ebfba44ba925ccd94f1927b61e03137dbc6..39c51399dd81da57ef4d9c580bd31bdf5e2b6f0b 100644 (file)
--- a/arch/csky/abiv2/cacheflush.c
+++ b/arch/csky/abiv2/cacheflush.c
@@ -12,6 +12,9 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
        unsigned long addr;
        struct page *page;
 
+       if (!pfn_valid(pte_pfn(*pte)))
+               return;
+
        page = pfn_to_page(pte_pfn(*pte));
        if (page == ZERO_PAGE(0))
                return;