History log of /arch/mips/kernel/pm-cps.c
Revision Date Author Comments
c90e49f26466d1733558b8385f4755a6ee3ddafc 09-Jul-2014 Paul Burton <paul.burton@imgtec.com> MIPS: {pm,smp}-cps: use cpu_vpe_id macro

When determining the VPE ID of a CPU, make use of the cpu_vpe_id macro
which will return 0 in a non-MT kernel build. Most code is already doing
so but a couple of places weren't. Fixing this prevents a build failure
for non-MT kernels where struct cpuinfo_mips does not contain the vpe_id
field:

arch/mips/kernel/pm-cps.c: In function 'cps_pm_enter_state':
arch/mips/kernel/pm-cps.c:153:51: error: 'struct cpuinfo_mips' has no
member named 'vpe_id'
vpe_cfg = &core_cfg->vpe_config[current_cpu_data.vpe_id];

arch/mips/kernel/smp-cps.c: In function 'wait_for_sibling_halt':
arch/mips/kernel/smp-cps.c:363:33: error: 'struct cpuinfo_mips' has no
member named 'vpe_id'
unsigned vpe_id = cpu_data[cpu].vpe_id;

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
064231e548d0ef90453081f424ced7b3ffffffe9 09-Jul-2014 Paul Burton <paul.burton@imgtec.com> MIPS: pm-cps: Prevent use of mips_cps_* without CPS SMP

These symbols will not be defined when CONFIG_MIPS_CPS=n, but although
the CPS_PM_POWER_GATED state will never be used in that case the
compiler doesn't have enough information to figure that out. Add checks
which evaluate to a constant false for CONFIG_MIPS_CPS=n cases in order
to help the compiler out & eliminate the symbol references.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7278/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
7c5491b808d8ea0781c4402792b21a103151135f 11-Jun-2014 Paul Burton <paul.burton@imgtec.com> MIPS: pm-cps: convert smp_mb__*()

Commit 91bbefe6b0fc "arch,mips: Convert smp_mb__*()" replaced the
smp_mb__* functions with a simpler API, whilst commit 3179d37ee1ed
"MIPS: pm-cps: add PM state entry code for CPS systems" introduced
new uses of smp_mb__before_atomic_inc & smp_mb__after_clear_bit.
Replace those calls with the corresponding before & after atomic
functions of the new, simpler API in order to avoid a build failure:

arch/mips/kernel/pm-cps.c: In function 'coupled_barrier':
arch/mips/kernel/pm-cps.c:104:2: error: 'smp_mb__before_atomic_inc' is
deprecated (declared at include/linux/atomic.h:11)
[-Werror=deprecated-declarations]

arch/mips/kernel/pm-cps.c: In function 'cps_pm_enter_state':
arch/mips/kernel/pm-cps.c:161:2: error: 'smp_mb__after_clear_bit' is
deprecated (declared at include/linux/bitops.h:48)
[-Werror=deprecated-declarations]

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7086/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
3179d37ee1ed602770a8b8ed975bd30faa85b4a3 14-Apr-2014 Paul Burton <paul.burton@imgtec.com> MIPS: pm-cps: add PM state entry code for CPS systems

This patch adds code to generate entry & exit code for various low power
states available on systems based around the MIPS Coherent Processing
System architecture (ie. those with a Coherence Manager, Global
Interrupt Controller & for >=CM2 a Cluster Power Controller). States
supported are:

- Non-coherent wait. This state first leaves the coherent domain and
then executes a regular MIPS wait instruction. Power savings are
found from the elimination of coherency interventions between the
core and any other coherent requestors in the system.

- Clock gated. This state leaves the coherent domain and then gates
the clock input to the core. This removes all dynamic power from the
core but leaves the core at the mercy of another to restart its
clock. Register state is preserved, but the core can not service
interrupts whilst its clock is gated.

- Power gated. This deepest state removes all power input to the core.
All register state is lost and the core will restart execution from
its BEV when another core powers it back up. Because register state
is lost this state requires cooperation with the CONFIG_MIPS_CPS SMP
implementation in order for the core to exit the state successfully.

The code will detect which states are available on the current system
during boot & generate the entry/exit code for those states. This will
be used by cpuidle & hotplug implementations.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>