FRV: Add support for emulation of userspace atomic ops [try #2]

Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/asm-frv/spr-regs.h b/include/asm-frv/spr-regs.h
index c2a541ef828d..01e6af5e99b8 100644
--- a/include/asm-frv/spr-regs.h
+++ b/include/asm-frv/spr-regs.h
@@ -99,9 +99,23 @@
 #define TBR_TT_TRAP1            (0x81 << 4)
 #define TBR_TT_TRAP2            (0x82 << 4)
 #define TBR_TT_TRAP3            (0x83 << 4)
+#define TBR_TT_TRAP120          (0xf8 << 4)
+#define TBR_TT_TRAP121          (0xf9 << 4)
+#define TBR_TT_TRAP122          (0xfa << 4)
+#define TBR_TT_TRAP123          (0xfb << 4)
+#define TBR_TT_TRAP124          (0xfc << 4)
+#define TBR_TT_TRAP125          (0xfd << 4)
 #define TBR_TT_TRAP126          (0xfe << 4)
 #define TBR_TT_BREAK            (0xff << 4)
 
+#define TBR_TT_ATOMIC_CMPXCHG32 TBR_TT_TRAP120
+#define TBR_TT_ATOMIC_XCHG32    TBR_TT_TRAP121
+#define TBR_TT_ATOMIC_XOR       TBR_TT_TRAP122
+#define TBR_TT_ATOMIC_OR        TBR_TT_TRAP123
+#define TBR_TT_ATOMIC_AND       TBR_TT_TRAP124
+#define TBR_TT_ATOMIC_SUB       TBR_TT_TRAP125
+#define TBR_TT_ATOMIC_ADD       TBR_TT_TRAP126
+
 #define __get_TBR()     ({ unsigned long x; asm volatile("movsg tbr,%0" : "=r"(x)); x; })
 
 /*