From e31c243f984628d02f045dc4b622f1e2827860dc Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 10 Apr 2008 16:10:55 +0100 Subject: 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 Signed-off-by: Linus Torvalds --- arch/frv/kernel/entry.S | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'arch/frv/kernel/entry.S') diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S index f36d7f4a7c25..b8a4b94779b1 100644 --- a/arch/frv/kernel/entry.S +++ b/arch/frv/kernel/entry.S @@ -654,6 +654,26 @@ __entry_debug_exception: movgs gr4,psr jmpl @(gr5,gr0) ; call ill_insn(esfr1,epcr0,esr0) +############################################################################### +# +# handle atomic operation emulation for userspace +# +############################################################################### + .globl __entry_atomic_op +__entry_atomic_op: + LEDS 0x6012 + sethi.p %hi(atomic_operation),gr5 + setlo %lo(atomic_operation),gr5 + movsg esfr1,gr8 + movsg epcr0,gr9 + movsg esr0,gr10 + + # now that we've accessed the exception regs, we can enable exceptions + movsg psr,gr4 + ori gr4,#PSR_ET,gr4 + movgs gr4,psr + jmpl @(gr5,gr0) ; call atomic_operation(esfr1,epcr0,esr0) + ############################################################################### # # handle media exception -- cgit v1.2.3