These APIs take logical cpu number as input
Change cpu_first_thread_in_core() to cpu_leftmost_thread_sibling()
Change cpu_last_thread_in_core() to cpu_rightmost_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_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 APIs are now clearly named to
distinguish 'core number' versus first and last 'logical cpu
number' in that core.
The new APIs cpu_{left,right}most_thread_sibling() work on
logical cpu numbers. While cpu_first_thread_of_core() and
cpu_core_of_thread() work on core index.
Example usage: (4 threads per core system)
cpu_leftmost_thread_sibling(5) = 4
cpu_rightmost_thread_sibling(5) = 7
cpu_core_of_thread(5) = 1
cpu_first_thread_of_core(1) = 4
cpu_core_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.
Made API changes to few callers. Exported symbols for use
in modules.
Signed-off-by: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com>
---
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..26dc6bd 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_of_thread(int cpu);
+int cpu_first_thread_of_core(int core);
+#else
+static inline int cpu_core_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_leftmost_thread_sibling(int cpu)
{
return cpu & ~(threads_per_core - 1);
}
-static inline int cpu_last_thread_in_core(int cpu)
+static inline int cpu_rightmost_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 5c196d1..da4c2f8 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -468,7 +468,20 @@ 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_of_thread(int cpu)
+{
+ return cpu >> threads_shift;
+}
+EXPORT_SYMBOL_GPL(cpu_core_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)
@@ -527,7 +540,7 @@ 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_leftmost_thread_sibling(cpu);
for (i = 0; i < threads_per_core; i++) {
if (cpu_is_offline(base + i))
continue;
@@ -606,7 +619,7 @@ int __cpu_disable(void)
return err;
/* Update sibling maps */
- base = cpu_first_thread_in_core(cpu);
+ base = cpu_leftmost_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..22f3bc5 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_leftmost_thread_sibling(cpu);
+ i <= cpu_rightmost_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_leftmost_thread_sibling(cpu),
+ cpu_rightmost_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_leftmost_thread_sibling(cpu);
+ i <= cpu_rightmost_thread_sibling(cpu); i++) {
__clear_bit(id, stale_map[i]);
}
}
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
