From 7adfb58fbd0a27469d26536f99b66391c4c8e2a0 Mon Sep 17 00:00:00 2001 From: Bernd Schmidt Date: Thu, 21 Jun 2007 11:34:16 +0800 Subject: Blackfin arch: defines and provides entry points for certain user space functions at fixed addresses This patch defines (and provides) entry points for certain user space functions at fixed addresses. The Blackfin has no usable atomic instructions, but we can ensure that these code sequences appear atomic from a user space point of view by detecting when we're in the process of executing them during the interrupt handler return path. This allows much more efficient pthread lock implementations than the bfin_spinlock syscall we're currently using. Also provided is a small sys_rt_sigreturn stub which can be used by the signal handler setup code. The signal.c part will be committed separately. Signed-off-by: Bernd Schmidt Signed-off-by: Bryan Wu --- arch/blackfin/mach-common/entry.S | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/blackfin/mach-common') diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S index 40045b1386a..c4a32ea06c4 100644 --- a/arch/blackfin/mach-common/entry.S +++ b/arch/blackfin/mach-common/entry.S @@ -741,6 +741,10 @@ _schedule_and_signal_from_int: r0 = [p0]; sti r0; + r0 = sp; + sp += -12; + call _finish_atomic_sections; + sp += 12; jump.s .Lresume_userspace; _schedule_and_signal: -- cgit v1.2.3-70-g09d2