From 76d21d186a65523b08ea5f70302e2c29ee8f6a8d Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Wed, 30 Jan 2019 20:13:11 +0800 Subject: csky: Fixup io-range page attribute for mmap("/dev/mem") Some user space drivers need accessing IO address and IO remap need SO(strong order) page-attribute to make IO operation correct. So we need add SO-page-attr for all non-memory address. Signed-off-by: Guo Ren Reported-by: Fan Xiaodong --- arch/csky/mm/ioremap.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'arch/csky/mm') diff --git a/arch/csky/mm/ioremap.c b/arch/csky/mm/ioremap.c index cb7c03e5cd21..8473b6bdf512 100644 --- a/arch/csky/mm/ioremap.c +++ b/arch/csky/mm/ioremap.c @@ -46,3 +46,17 @@ void iounmap(void __iomem *addr) vunmap((void *)((unsigned long)addr & PAGE_MASK)); } EXPORT_SYMBOL(iounmap); + +pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) +{ + if (!pfn_valid(pfn)) { + vma_prot.pgprot |= _PAGE_SO; + return pgprot_noncached(vma_prot); + } else if (file->f_flags & O_SYNC) { + return pgprot_noncached(vma_prot); + } + + return vma_prot; +} +EXPORT_SYMBOL(phys_mem_access_prot); -- cgit