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, 7 insertions, 1 deletions

diff --git a/arch/frv/kernel/entry-table.S b/arch/frv/kernel/entry-table.S
index d3b9253d862a..bf35f33e48c9 100644
--- a/arch/frv/kernel/entry-table.S
+++ b/arch/frv/kernel/entry-table.S
@@ -316,8 +316,14 @@ __trap_fixup_kernel_data_tlb_miss:
         .section        .trap.vector
         .org            TBR_TT_TRAP0 >> 2
         .long           system_call
-        .rept           126
+        .rept           119
         .long           __entry_unsupported_trap
         .endr
+
+        # userspace atomic op emulation, traps 120-126
+        .rept           7
+        .long           __entry_atomic_op
+        .endr
+        
         .org            TBR_TT_BREAK >> 2
         .long           __entry_debug_exception