diff options
| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2006-08-27 12:38:34 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-09-20 14:58:35 +0100 |
| commit | 681a4991f83742a0d2325afbf7b7f22045ad5b30 (patch) | |
| tree | 8665ef5bba53d53759c34e6e8c0fa08c98c8e4f2 | |
| parent | b36e4758dc1b9ff1f6d97e951edba22366230d11 (diff) | |
[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: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/vfp/vfpmodule.c | 40 |
1 files changed, 16 insertions, 24 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 4178f6cc3d3..dedbb449632 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -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. */ @@ -56,29 +65,12 @@ 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. - */ - 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; } + /* flush and release case: Per-thread VFP cleanup. */ + if (last_VFP_context == vfp) + last_VFP_context = NULL; + return NOTIFY_DONE; } |