| Message ID | 1398432017-8506-8-git-send-email-hanjun.guo@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 25, 2014 at 09:20:13PM +0800, Hanjun Guo wrote: > +/* > + * Use the CPU slot number provided by ACPI to update the physical > + * package id, then we can get the right value in the "physical id" > + * field of /proc/cpuinfo. > + */ > +void arch_fix_phys_package_id(int num, u32 slot) > +{ > + struct cpu_topology *cpuid_topo = &cpu_topology[num]; > + > + if (cpuid_topo->cluster_id == -1) > + cpuid_topo->cluster_id = slot; > +} > +EXPORT_SYMBOL_GPL(arch_fix_phys_package_id); This isn't going to work once we parse the MPIDR - we will always have a cluster ID from MPIDR unless the system is uniprocessor (which doesn't seem like it's going to be a common or useful case). We'll either need to have something in the topology parsing path which goes out and queries ACPI before we try to parse MPIDR or this will need to just set whatever it's told to set unconditionally.
Hi Mark, On 2014-4-25 22:52, Mark Brown wrote: > On Fri, Apr 25, 2014 at 09:20:13PM +0800, Hanjun Guo wrote: > >> +/* >> + * Use the CPU slot number provided by ACPI to update the physical >> + * package id, then we can get the right value in the "physical id" >> + * field of /proc/cpuinfo. >> + */ >> +void arch_fix_phys_package_id(int num, u32 slot) >> +{ >> + struct cpu_topology *cpuid_topo = &cpu_topology[num]; >> + >> + if (cpuid_topo->cluster_id == -1) >> + cpuid_topo->cluster_id = slot; >> +} >> +EXPORT_SYMBOL_GPL(arch_fix_phys_package_id); > > This isn't going to work once we parse the MPIDR - we will always have a > cluster ID from MPIDR unless the system is uniprocessor (which doesn't > seem like it's going to be a common or useful case). We'll either need > to have something in the topology parsing path which goes out and > queries ACPI before we try to parse MPIDR or this will need to just set > whatever it's told to set unconditionally. I prefer the latter way. Since platform software (firmware) knows the topology of the system, if ACPI describes a slot number for this CPU, I think we can use it unconditionally. Thanks Hanjun
On Mon, Apr 28, 2014 at 11:00:01AM +0800, Hanjun Guo wrote: > Since platform software (firmware) knows the topology of the system, if > ACPI describes a slot number for this CPU, I think we can use it > unconditionally. Right, the only concern with that is upsetting the scheduler but since x86 does the same thing presumably this is safe.
diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h index 0172e6d..0b0e24f 100644 --- a/arch/arm64/include/asm/topology.h +++ b/arch/arm64/include/asm/topology.h @@ -26,11 +26,13 @@ extern struct cpu_topology cpu_topology[NR_CPUS]; void init_cpu_topology(void); void store_cpu_topology(unsigned int cpuid); const struct cpumask *cpu_coregroup_mask(int cpu); +void arch_fix_phys_package_id(int num, u32 slot); #else static inline void init_cpu_topology(void) { } static inline void store_cpu_topology(unsigned int cpuid) { } +static inline void arch_fix_phys_package_id(int num, u32 slot) { } #endif diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 3e06b0b..51ea4a1 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -93,3 +93,17 @@ void __init init_cpu_topology(void) cpumask_clear(&cpu_topo->thread_sibling); } } + +/* + * Use the CPU slot number provided by ACPI to update the physical + * package id, then we can get the right value in the "physical id" + * field of /proc/cpuinfo. + */ +void arch_fix_phys_package_id(int num, u32 slot) +{ + struct cpu_topology *cpuid_topo = &cpu_topology[num]; + + if (cpuid_topo->cluster_id == -1) + cpuid_topo->cluster_id = slot; +} +EXPORT_SYMBOL_GPL(arch_fix_phys_package_id);
arch_fix_phys_package_id() will be called in ACPI core to use the slot number provided by ACPI to update the physical package id, then we can get the right value in the "physical id" field of /proc/cpuinfo. Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> --- arch/arm64/include/asm/topology.h | 2 ++ arch/arm64/kernel/topology.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+)