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| author | Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> | 2014-12-09 18:56:53 (GMT) |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2014-12-14 23:46:41 (GMT) |
| commit | 77b54e9f213f76a23736940cf94bcd765fc00f40 (patch) | |
| tree | c07273530b9f15c65b48ed147e0b1aabecf55f96 /arch/powerpc/include/asm/reg.h | |
| parent | 7cba160ad789a3ad7e68b92bf20eaad6ed171f80 (diff) | |
| download | linux-77b54e9f213f76a23736940cf94bcd765fc00f40.tar.xz | |
powernv/powerpc: Add winkle support for offline cpus
Winkle is a deep idle state supported in power8 chips. A core enters
winkle when all the threads of the core enter winkle. In this state
power supply to the entire chiplet i.e core, private L2 and private L3
is turned off. As a result it gives higher powersavings compared to
sleep.
But entering winkle results in a total hypervisor state loss. Hence the
hypervisor context has to be preserved before entering winkle and
restored upon wake up.
Power-on Reset Engine (PORE) is a dedicated engine which is responsible
for powering on the chiplet during wake up. It can be programmed to
restore the register contests of a few specific registers. This patch
uses PORE to restore register state wherever possible and uses stack to
save and restore rest of the necessary registers.
With hypervisor state restore things fall under three categories-
per-core state, per-subcore state and per-thread state. To manage this,
extend the infrastructure introduced for sleep. Mainly we add a paca
variable subcore_sibling_mask. Using this and the core_idle_state we can
distingush first thread in core and subcore.
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/reg.h')
| -rw-r--r-- | arch/powerpc/include/asm/reg.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index a68ee15..1c874fb 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -373,6 +373,7 @@ #define SPRN_DBAT7L 0x23F /* Data BAT 7 Lower Register */ #define SPRN_DBAT7U 0x23E /* Data BAT 7 Upper Register */ #define SPRN_PPR 0x380 /* SMT Thread status Register */ +#define SPRN_TSCR 0x399 /* Thread Switch Control Register */ #define SPRN_DEC 0x016 /* Decrement Register */ #define SPRN_DER 0x095 /* Debug Enable Regsiter */ @@ -730,6 +731,7 @@ #define SPRN_BESCR 806 /* Branch event status and control register */ #define BESCR_GE 0x8000000000000000ULL /* Global Enable */ #define SPRN_WORT 895 /* Workload optimization register - thread */ +#define SPRN_WORC 863 /* Workload optimization register - core */ #define SPRN_PMC1 787 #define SPRN_PMC2 788 |