[ARM] Add thread_notify infrastructure
Some machine classes need to allow VFP support to be built into the
kernel, but still allow the kernel to run even though VFP isn't
present. Unfortunately, the kernel hard-codes VFP instructions
into the thread switch, which prevents this being run-time selectable.
Solve this by introducing a notifier which things such as VFP can
hook into to be informed of events which affect the VFP subsystem
(eg, creation and destruction of threads, switches between threads.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index 24c7b04..af9e0ae 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -285,7 +285,7 @@
bne 1f @ yes: block them for next task
ldr r5, =concan_owner
- add r6, r2, #(TI_IWMMXT_STATE - TI_CPU_DOMAIN) @ get next task Concan save area
+ add r6, r2, #TI_IWMMXT_STATE @ get next task Concan save area
ldr r5, [r5] @ get current Concan owner
teq r5, r6 @ next task owns it?
movne pc, lr @ no: leave Concan disabled