POWER ISA v3 defines a new idle processor core mechanism. In summary,
a) new instruction named stop is added. This instruction replaces
instructions like nap, sleep, rvwinkle.
b) new per thread SPR named Processor Stop Status and Control Register
(PSSCR) is added which controls the behavior of stop instruction.
PSSCR layout:
----------------------------------------------------------
| PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL |
----------------------------------------------------------
0 4 41 42 43 44 48 54 56 60
PSSCR key fields:
Bits 0:3 - Power-Saving Level Status. This field indicates the lowest
power-saving state the thread entered since stop instruction was last
executed.
Bit 42 - Enable State Loss
0 - No state is lost irrespective of other fields
1 - Allows state loss
Bits 44:47 - Power-Saving Level Limit
This limits the power-saving level that can be entered into.
Bits 60:63 - Requested Level
Used to specify which power-saving level must be entered on executing
stop instruction
This patch adds support for stop instruction and PSSCR handling.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Create a function for saving SPRs before entering deep idle states.
This function can be reused for POWER9 deep idle states.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pnv_powersave_common does common steps needed before entering idle
state and eventually changes MSR to MSR_IDLE and does rfid to
pnv_enter_arch207_idle_mode.
Move the updation of HSTATE_HWTHREAD_STATE to pnv_powersave_common
from pnv_enter_arch207_idle_mode and make it more generic by passing the
rfid address as a function parameter.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Functions like power7_wakeup_loss, power7_wakeup_noloss,
power7_wakeup_tb_loss are used by POWER7 and POWER8 hardware. They can
also be used by POWER9. Hence rename these functions hardware agnostic
names.
Suggested-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
idle_power7.S handles idle entry/exit for POWER7, POWER8 and in next
patch for POWER9. Rename the file to a non-hardware specific
name.
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
