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Subject[PATCH] csky: Fixup io-range page attribute for mmap("/dev/mem")
Date
From: Guo Ren <ren_guo@c-sky.com>

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 <ren_guo@c-sky.com>
Reported-by: Fan Xiaodong <xiaodong.fan@boyahualu.com>
---
arch/csky/include/asm/pgtable.h | 5 +++++
arch/csky/mm/ioremap.c | 14 ++++++++++++++
2 files changed, 19 insertions(+)

diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index af7a7fa..dcea277 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -241,6 +241,11 @@ static inline pte_t pte_mkyoung(pte_t pte)

#define pgd_index(address) ((address) >> PGDIR_SHIFT)

+#define __HAVE_PHYS_MEM_ACCESS_PROT
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot);
+
/*
* Macro to make mark a page protection value as "uncacheable". Note
* that "protection" is really a misnomer here as the protection value
diff --git a/arch/csky/mm/ioremap.c b/arch/csky/mm/ioremap.c
index cb7c03e..8473b6b 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);
--
2.7.4
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