From: Paul Burton <paul.burton@mips.com>
Date: Sat, 28 Jul 2018 01:23:19 +0000 (-0700)
Subject: MIPS: Fix ISA virt/bus conversion for non-zero PHYS_OFFSET
X-Git-Tag: v5.15~8277^2~21
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=0494d7ffdcebc6935410ea0719b24ab626675351;p=mirror_ubuntu-kernels.git

MIPS: Fix ISA virt/bus conversion for non-zero PHYS_OFFSET

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@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20047/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
---

diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index cd170d920d55..54c730aed327 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -143,14 +143,14 @@ 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