| Message ID | 20170917164523.6970-4-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Sun, Sep 17, 2017 at 06:45:20PM +0200, Martin Blumenstingl wrote: > On Amlogic Meson8 / Meson8m2 (both Cortex-A9) and Meson8b (Cortex-A5) > the CPU hotplug code needs to wait until the SCU status of the CPU that > is being taken offline is SCU_PM_POWEROFF. > Provide a utility function (which can be invoked for example from > .cpu_kill()) which allows reading the SCU status of a CPU. > > While here, replace the magic number 0x3 with a preprocessor macro > (SCU_CPU_STATUS_MASK) so we don't have to duplicate this magic number in > the new function. > > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Russell King <rmk+kernel@armlinux.org.uk> > --- > arch/arm/include/asm/smp_scu.h | 6 ++++++ > arch/arm/kernel/smp_scu.c | 18 +++++++++++++++++- > 2 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h > index 4c47bdfd4f61..1529d1ae2f8d 100644 > --- a/arch/arm/include/asm/smp_scu.h > +++ b/arch/arm/include/asm/smp_scu.h > @@ -28,6 +28,7 @@ static inline unsigned long scu_a9_get_base(void) > unsigned int scu_get_core_count(void __iomem *); > int scu_power_mode(void __iomem *, unsigned int); > int scu_cpu_power_enable(void __iomem *, unsigned int); > +int scu_get_cpu_power_mode(void __iomem *scu_base, unsigned int logical_cpu); > #else > static inline unsigned int scu_get_core_count(void __iomem *scu_base) > { > @@ -42,6 +43,11 @@ static inline int scu_cpu_power_enable(void __iomem *scu_base, > { > return -EINVAL; > } > +static inline int scu_get_cpu_power_mode(void __iomem *scu_base, > + unsigned int logical_cpu) > +{ > + return -EINVAL; > +} > #endif > > #if defined(CONFIG_SMP) && defined(CONFIG_HAVE_ARM_SCU) > diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c > index 1d549c16b5fc..c6b33074c393 100644 > --- a/arch/arm/kernel/smp_scu.c > +++ b/arch/arm/kernel/smp_scu.c > @@ -21,6 +21,7 @@ > #define SCU_STANDBY_ENABLE (1 << 5) > #define SCU_CONFIG 0x04 > #define SCU_CPU_STATUS 0x08 > +#define SCU_CPU_STATUS_MASK GENMASK(1, 0) > #define SCU_INVALIDATE 0x0c > #define SCU_FPGA_REVISION 0x10 > > @@ -82,7 +83,8 @@ static int scu_set_power_mode_internal(void __iomem *scu_base, > if (mode > 3 || mode == 1 || cpu > 3) > return -EINVAL; > > - val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu) & ~0x03; > + val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu); > + val &= ~SCU_CPU_STATUS_MASK; > val |= mode; > writeb_relaxed(val, scu_base + SCU_CPU_STATUS + cpu); > > @@ -109,3 +111,17 @@ int scu_cpu_power_enable(void __iomem *scu_base, unsigned int cpu) > { > return scu_set_power_mode_internal(scu_base, cpu, SCU_PM_NORMAL); > } > + > +int scu_get_cpu_power_mode(void __iomem *scu_base, unsigned int logical_cpu) > +{ > + unsigned int val; > + int cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(logical_cpu), 0); > + > + if (cpu > 3) > + return -EINVAL; > + > + val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu); > + val &= SCU_CPU_STATUS_MASK; > + > + return val; > +} > -- > 2.14.1 >
diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h index 4c47bdfd4f61..1529d1ae2f8d 100644 --- a/arch/arm/include/asm/smp_scu.h +++ b/arch/arm/include/asm/smp_scu.h @@ -28,6 +28,7 @@ static inline unsigned long scu_a9_get_base(void) unsigned int scu_get_core_count(void __iomem *); int scu_power_mode(void __iomem *, unsigned int); int scu_cpu_power_enable(void __iomem *, unsigned int); +int scu_get_cpu_power_mode(void __iomem *scu_base, unsigned int logical_cpu); #else static inline unsigned int scu_get_core_count(void __iomem *scu_base) { @@ -42,6 +43,11 @@ static inline int scu_cpu_power_enable(void __iomem *scu_base, { return -EINVAL; } +static inline int scu_get_cpu_power_mode(void __iomem *scu_base, + unsigned int logical_cpu) +{ + return -EINVAL; +} #endif #if defined(CONFIG_SMP) && defined(CONFIG_HAVE_ARM_SCU) diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c index 1d549c16b5fc..c6b33074c393 100644 --- a/arch/arm/kernel/smp_scu.c +++ b/arch/arm/kernel/smp_scu.c @@ -21,6 +21,7 @@ #define SCU_STANDBY_ENABLE (1 << 5) #define SCU_CONFIG 0x04 #define SCU_CPU_STATUS 0x08 +#define SCU_CPU_STATUS_MASK GENMASK(1, 0) #define SCU_INVALIDATE 0x0c #define SCU_FPGA_REVISION 0x10 @@ -82,7 +83,8 @@ static int scu_set_power_mode_internal(void __iomem *scu_base, if (mode > 3 || mode == 1 || cpu > 3) return -EINVAL; - val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu) & ~0x03; + val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu); + val &= ~SCU_CPU_STATUS_MASK; val |= mode; writeb_relaxed(val, scu_base + SCU_CPU_STATUS + cpu); @@ -109,3 +111,17 @@ int scu_cpu_power_enable(void __iomem *scu_base, unsigned int cpu) { return scu_set_power_mode_internal(scu_base, cpu, SCU_PM_NORMAL); } + +int scu_get_cpu_power_mode(void __iomem *scu_base, unsigned int logical_cpu) +{ + unsigned int val; + int cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(logical_cpu), 0); + + if (cpu > 3) + return -EINVAL; + + val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu); + val &= SCU_CPU_STATUS_MASK; + + return val; +}
On Amlogic Meson8 / Meson8m2 (both Cortex-A9) and Meson8b (Cortex-A5) the CPU hotplug code needs to wait until the SCU status of the CPU that is being taken offline is SCU_PM_POWEROFF. Provide a utility function (which can be invoked for example from .cpu_kill()) which allows reading the SCU status of a CPU. While here, replace the magic number 0x3 with a preprocessor macro (SCU_CPU_STATUS_MASK) so we don't have to duplicate this magic number in the new function. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- arch/arm/include/asm/smp_scu.h | 6 ++++++ arch/arm/kernel/smp_scu.c | 18 +++++++++++++++++- 2 files changed, 23 insertions(+), 1 deletion(-)