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| author |   Michael Neuling <mikey@neuling.org> | 2014-06-11 15:59:28 +1000 |
|---|---|---|
| committer |   Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2014-06-11 17:05:12 +1000 |
| commit | d4e58e5928f8c6c49228451dd03e0714cbab299a (patch) | |
| tree | 34add9a16b4dbe03da04191f51588f3f6a6bdbf9 /arch/powerpc/kernel/cpu_setup_power.S | |
| parent | powerpc/cpuidle: Only clear LPCR decrementer wakeup bit on fast sleep entry (diff) | |
| download | linux-dev-d4e58e5928f8c6c49228451dd03e0714cbab299a.tar.xz linux-dev-d4e58e5928f8c6c49228451dd03e0714cbab299a.zip | |
powerpc/powernv: Enable POWER8 doorbell IPIs
This patch enables POWER8 doorbell IPIs on powernv.
Since doorbells can only IPI within a core, we test to see when we can use
doorbells and if not we fall back to XICS. This also enables hypervisor
doorbells to wakeup us up from nap/sleep via the LPCR PECEDH bit.
Based on tests by Anton, the best case IPI latency between two threads dropped
from 894ns to 512ns.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/cpu_setup_power.S')
| -rw-r--r-- | arch/powerpc/kernel/cpu_setup_power.S | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S index 1557e7c2c7e1..46733535cc0b 100644 --- a/arch/powerpc/kernel/cpu_setup_power.S +++ b/arch/powerpc/kernel/cpu_setup_power.S @@ -56,6 +56,7 @@ _GLOBAL(__setup_cpu_power8) li r0,0 mtspr SPRN_LPID,r0 mfspr r3,SPRN_LPCR + ori r3, r3, LPCR_PECEDH bl __init_LPCR bl __init_HFSCR bl __init_tlb_power8 @@ -74,6 +75,7 @@ _GLOBAL(__restore_cpu_power8) li r0,0 mtspr SPRN_LPID,r0 mfspr r3,SPRN_LPCR + ori r3, r3, LPCR_PECEDH bl __init_LPCR bl __init_HFSCR bl __init_tlb_power8 |