Commit Graph

4 Commits

Author SHA1 Message Date
Paul Burton c90e49f264 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>
2014-07-30 20:48:42 +02:00
Paul Burton 064231e548 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>
2014-07-30 20:47:39 +02:00
Paul Burton 7c5491b808 MIPS: pm-cps: convert smp_mb__*()
Commit 91bbefe6b0 "arch,mips: Convert smp_mb__*()" replaced the
smp_mb__* functions with a simpler API, whilst commit 3179d37ee1
"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>
2014-06-16 12:47:47 +01:00
Paul Burton 3179d37ee1 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>
2014-05-28 16:20:31 +01:00