Other arches have ioremap_wt() to map IO areas write-through.
Implement it on PPC as well in order to avoid drivers using
__ioremap(_PAGE_WRITETHRU)
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
---
v2: no change
arch/powerpc/include/asm/io.h | 6 ++++++
arch/powerpc/mm/pgtable_32.c | 8 ++++++++
2 files changed, 14 insertions(+)
diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index e0331e754568..3380b5b22450 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -3,6 +3,9 @@
#ifdef __KERNEL__
#define ARCH_HAS_IOREMAP_WC
+#ifdef CONFIG_PPC32
+#define ARCH_HAS_IOREMAP_WT
+#endif
/*
* This program is free software; you can redistribute it and/or
@@ -746,6 +749,8 @@ static inline void iosync(void)
*
* * ioremap_wc enables write combining
*
+ * * ioremap_wt enables write through
+ *
* * iounmap undoes such a mapping and can be hooked
*
* * __ioremap_at (and the pending __iounmap_at) are low level functions to
@@ -767,6 +772,7 @@ extern void __iomem *ioremap(phys_addr_t address, unsigned long size);
extern void __iomem *ioremap_prot(phys_addr_t address, unsigned long size,
unsigned long flags);
extern void __iomem *ioremap_wc(phys_addr_t address, unsigned long size);
+void __iomem *ioremap_wt(phys_addr_t address, unsigned long size);
#define ioremap_nocache(addr, size) ioremap((addr), (size))
#define ioremap_uc(addr, size) ioremap((addr), (size))
#define ioremap_cache(addr, size) \
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index 120a49bfb9c6..528999738645 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -90,6 +90,14 @@ ioremap_wc(phys_addr_t addr, unsigned long size)
EXPORT_SYMBOL(ioremap_wc);
void __iomem *
+ioremap_wt(phys_addr_t addr, unsigned long size)
+{
+ return __ioremap_caller(addr, size, _PAGE_WRITETHRU,
+ __builtin_return_address(0));
+}
+EXPORT_SYMBOL(ioremap_wt);
+
+void __iomem *
ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
{
/* writeable implies dirty for kernel addresses */
--
2.13.3
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