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Commit 681a4991 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[ARM] Optimise VFP thread notify function a little 



The common case for the thread notifier is a context switch.  Tell
gcc that this is the most likely condition so it can optimise the
function for this case.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent b36e4758

arch/arm/vfp/vfpmodule.c

+16 −24
Original line number Diff line number Diff line
@@ -40,10 +40,19 @@ unsigned int VFP_arch; 
static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)

{

	struct thread_info *thread = v;

	union vfp_state *vfp = &thread->vfpstate;

	union vfp_state *vfp;



	switch (cmd) {

	case THREAD_NOTIFY_FLUSH:

	if (likely(cmd == THREAD_NOTIFY_SWITCH)) {

		/*

		 * Always disable VFP so we can lazily save/restore the

		 * old state.

		 */

		fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);

		return NOTIFY_DONE;

	}



	vfp = &thread->vfpstate;

	if (cmd == THREAD_NOTIFY_FLUSH) {

		/*

		 * Per-thread VFP initialisation.

		 */
@@ -56,28 +65,11 @@ static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v) 
		 * Disable VFP to ensure we initialise it first.

		 */

		fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);

	}



		/*

		 * FALLTHROUGH: Ensure we don't try to overwrite our newly

		 * initialised state information on the first fault.

		 */



	case THREAD_NOTIFY_RELEASE:

		/*

		 * Per-thread VFP cleanup.

		 */

	/* flush and release case: Per-thread VFP cleanup. */

	if (last_VFP_context == vfp)

		last_VFP_context = NULL;

		break;



	case THREAD_NOTIFY_SWITCH:

		/*

		 * Always disable VFP so we can lazily save/restore the

		 * old state.

		 */

		fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);

		break;

	}



	return NOTIFY_DONE;

}