[PATCH v5 1/2] powerpc: cleanup APIs for cpu/thread/core mappings
From: Vaidyanathan Srinivasan <hidden>
Date: 2010-10-06 18:37:29
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
These APIs take logical cpu number as input
Change cpu_first_thread_in_core() to cpu_first_thread_sibling()
Change cpu_last_thread_in_core() to cpu_last_thread_sibling()
These APIs convert core number (index) to logical cpu/thread numbers
Add cpu_first_thread_of_core(int core)
Changed cpu_thread_to_core() to cpu_core_index_of_thread(int cpu)
The goal is to make 'threads_per_core' accessible to the
pseries_energy module. Instead of making an API to read
threads_per_core, this is a higher level wrapper function to
convert from logical cpu number to core number.
The current APIs cpu_first_thread_in_core() and
cpu_last_thread_in_core() returns logical CPU number while
cpu_thread_to_core() returns core number or index which is
not a logical CPU number. The new APIs are now clearly named to
distinguish 'core number' versus first and last 'logical cpu
number' in that core.
The new APIs cpu_{first,last}_thread_sibling() work on
logical cpu numbers. While cpu_first_thread_of_core() and
cpu_core_index_of_thread() work on core index.
Example usage: (4 threads per core system)
cpu_first_thread_sibling(5) = 4
cpu_last_thread_sibling(5) = 7
cpu_core_index_of_thread(5) = 1
cpu_first_thread_of_core(1) = 4
cpu_core_index_of_thread() is used in cpu_to_drc_index() in the
module and cpu_first_thread_of_core() is used in
drc_index_to_cpu() in the module.
Make API changes to few callers. Export symbols for use in modules.
Signed-off-by: Vaidyanathan Srinivasan <redacted>
---
arch/powerpc/include/asm/cputhreads.h | 15 +++++++++------
arch/powerpc/kernel/smp.c | 19 ++++++++++++++++---
arch/powerpc/mm/mmu_context_nohash.c | 12 ++++++------
3 files changed, 31 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h
index a8e1844..f71bb4c 100644
--- a/arch/powerpc/include/asm/cputhreads.h
+++ b/arch/powerpc/include/asm/cputhreads.h@@ -61,22 +61,25 @@ static inline cpumask_t cpu_online_cores_map(void) return cpu_thread_mask_to_cores(cpu_online_map); } -static inline int cpu_thread_to_core(int cpu) -{ - return cpu >> threads_shift; -} +#ifdef CONFIG_SMP +int cpu_core_index_of_thread(int cpu); +int cpu_first_thread_of_core(int core); +#else +static inline int cpu_core_index_of_thread(int cpu) { return cpu; } +static inline int cpu_first_thread_of_core(int core) { return core; } +#endif static inline int cpu_thread_in_core(int cpu) { return cpu & (threads_per_core - 1); } -static inline int cpu_first_thread_in_core(int cpu) +static inline int cpu_first_thread_sibling(int cpu) { return cpu & ~(threads_per_core - 1); } -static inline int cpu_last_thread_in_core(int cpu) +static inline int cpu_last_thread_sibling(int cpu) { return cpu | (threads_per_core - 1); }
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 0008bc5..012d6e2 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c@@ -466,7 +466,20 @@ out: return id; } -/* Must be called when no change can occur to cpu_present_mask, +/* Helper routines for cpu to core mapping */ +int cpu_core_index_of_thread(int cpu) +{ + return cpu >> threads_shift; +} +EXPORT_SYMBOL_GPL(cpu_core_index_of_thread); + +int cpu_first_thread_of_core(int core) +{ + return core << threads_shift; +} +EXPORT_SYMBOL_GPL(cpu_first_thread_of_core); + +/* Must be called when no change can occur to cpu_present_map, * i.e. during cpu online or offline. */ static struct device_node *cpu_to_l2cache(int cpu)
@@ -517,7 +530,7 @@ int __devinit start_secondary(void *unused) notify_cpu_starting(cpu); set_cpu_online(cpu, true); /* Update sibling maps */ - base = cpu_first_thread_in_core(cpu); + base = cpu_first_thread_sibling(cpu); for (i = 0; i < threads_per_core; i++) { if (cpu_is_offline(base + i)) continue;
@@ -596,7 +609,7 @@ int __cpu_disable(void) return err; /* Update sibling maps */ - base = cpu_first_thread_in_core(cpu); + base = cpu_first_thread_sibling(cpu); for (i = 0; i < threads_per_core; i++) { cpumask_clear_cpu(cpu, cpu_sibling_mask(base + i)); cpumask_clear_cpu(base + i, cpu_sibling_mask(cpu));
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index ddfd7ad..9aa754c 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c@@ -111,8 +111,8 @@ static unsigned int steal_context_smp(unsigned int id) * a core map instead but this will do for now. */ for_each_cpu(cpu, mm_cpumask(mm)) { - for (i = cpu_first_thread_in_core(cpu); - i <= cpu_last_thread_in_core(cpu); i++) + for (i = cpu_first_thread_sibling(cpu); + i <= cpu_last_thread_sibling(cpu); i++) __set_bit(id, stale_map[i]); cpu = i - 1; }
@@ -264,14 +264,14 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next) */ if (test_bit(id, stale_map[cpu])) { pr_hardcont(" | stale flush %d [%d..%d]", - id, cpu_first_thread_in_core(cpu), - cpu_last_thread_in_core(cpu)); + id, cpu_first_thread_sibling(cpu), + cpu_last_thread_sibling(cpu)); local_flush_tlb_mm(next); /* XXX This clear should ultimately be part of local_flush_tlb_mm */ - for (i = cpu_first_thread_in_core(cpu); - i <= cpu_last_thread_in_core(cpu); i++) { + for (i = cpu_first_thread_sibling(cpu); + i <= cpu_last_thread_sibling(cpu); i++) { __clear_bit(id, stale_map[i]); } }