[PATCH AUTOSEL 4.4 17/47] MIPS: Fix ISA virt/bus conversion for non-zero PHYS_OFFSET

From: Sasha Levin
Date: Sun Sep 02 2018 - 09:19:40 EST


From: Paul Burton <paul.burton@xxxxxxxx>

[ Upstream commit 0494d7ffdcebc6935410ea0719b24ab626675351 ]

isa_virt_to_bus() & isa_bus_to_virt() claim to treat ISA bus addresses
as being identical to physical addresses, but they fail to do so in the
presence of a non-zero PHYS_OFFSET.

Correct this by having them use virt_to_phys() & phys_to_virt(), which
consolidates the calculations to one place & ensures that ISA bus
addresses do indeed match physical addresses.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxx>
Patchwork: https://patchwork.linux-mips.org/patch/20047/
Cc: James Hogan <jhogan@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: Vladimir Kondratiev <vladimir.kondratiev@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
arch/mips/include/asm/io.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 75fa296836fc..ab1df19b0957 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -141,14 +141,14 @@ static inline void * phys_to_virt(unsigned long address)
/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
*/
-static inline unsigned long isa_virt_to_bus(volatile void * address)
+static inline unsigned long isa_virt_to_bus(volatile void *address)
{
- return (unsigned long)address - PAGE_OFFSET;
+ return virt_to_phys(address);
}

-static inline void * isa_bus_to_virt(unsigned long address)
+static inline void *isa_bus_to_virt(unsigned long address)
{
- return (void *)(address + PAGE_OFFSET);
+ return phys_to_virt(address);
}

#define isa_page_to_bus page_to_phys
--
2.17.1