MIPS: Fix mips_atomic_set() with EVA

EVA linked loads (LLE) and conditional stores (SCE) should be used on
EVA kernels for the MIPS_ATOMIC_SET operation of the sysmips system
call, or else the atomic set will apply to the kernel view of the
virtual address space (potentially unmapped on EVA kernels) rather than
the user view (TLB mapped).

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.15.x-
Patchwork: https://patchwork.linux-mips.org/patch/16151/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 3e5d82e..863f958 100644 (file)
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -29,6 +29,7 @@
 #include <linux/sched/task_stack.h>
 
 #include <asm/asm.h>
+#include <asm/asm-eva.h>
 #include <asm/branch.h>
 #include <asm/cachectl.h>
 #include <asm/cacheflush.h>
@@ -131,9 +132,11 @@ static inline int mips_atomic_set(unsigned long addr, unsigned long new)
                __asm__ __volatile__ (
                "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
                "       li      %[err], 0                               \n"
-               "1:     ll      %[old], (%[addr])                       \n"
+               "1:                                                     \n"
+               user_ll("%[old]", "(%[addr])")
                "       move    %[tmp], %[new]                          \n"
-               "2:     sc      %[tmp], (%[addr])                       \n"
+               "2:                                                     \n"
+               user_sc("%[tmp]", "(%[addr])")
                "       beqz    %[tmp], 4f                              \n"
                "3:                                                     \n"
                "       .insn                                           \n"