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 3e5d82e744ac12dd4ee1b651754b8993ee2df146..863f958c126c9a3df533c02fa1fb3def4a8e738f 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"