diff options
| author | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2012-09-10 16:06:30 +0100 |
|---|---|---|
| committer | Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> | 2012-10-09 15:00:15 +0100 |
| commit | 4d101a06748ec5f3bcb27c9fe0a9d7dcf4866fb7 (patch) | |
| tree | 201946ebc3db39c9bce13824181e24a5cb5051d5 | |
| parent | 0173bc374bd66f6102dc856e878028fcb26648b7 (diff) | |
ARM: kernel: provide cluster to logical cpu mask mapping API
Some device drivers like PMU require to retrieve the logical cpu mask
that corresponds to a given cluster id. This patch provides a hook in
the topology code that, given an existing cluster id as input,
initializes the corresponding cpumask passed as a pointer, reusing all
existing topology information required by sched domains in the kernel.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
| -rw-r--r-- | arch/arm/include/asm/topology.h | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/topology.c | 27 |
2 files changed, 30 insertions, 0 deletions
diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index 58b8b84adcd..611edefaeaf 100644 --- a/arch/arm/include/asm/topology.h +++ b/arch/arm/include/asm/topology.h @@ -26,11 +26,14 @@ extern struct cputopo_arm cpu_topology[NR_CPUS]; void init_cpu_topology(void); void store_cpu_topology(unsigned int cpuid); const struct cpumask *cpu_coregroup_mask(int cpu); +int cluster_to_logical_mask(unsigned int socket_id, cpumask_t *cluster_mask); #else static inline void init_cpu_topology(void) { } static inline void store_cpu_topology(unsigned int cpuid) { } +static inline int cluster_to_logical_mask(unsigned int socket_id, + cpumask_t *cluster_mask) { return -EINVAL; } #endif diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index 26c12c6440f..d25a59657d5 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -318,6 +318,33 @@ void store_cpu_topology(unsigned int cpuid) } /* + * cluster_to_logical_mask - return cpu logical mask of CPUs in a cluster + * @socket_id: cluster HW identifier + * @cluster_mask: the cpumask location to be initialized, modified by the + * function only if return value == 0 + * + * Return: + * + * 0 on success + * -EINVAL if cluster_mask is NULL or there is no record matching socket_id + */ +int cluster_to_logical_mask(unsigned int socket_id, cpumask_t *cluster_mask) +{ + int cpu; + + if (!cluster_mask) + return -EINVAL; + + for_each_online_cpu(cpu) + if (socket_id == topology_physical_package_id(cpu)) { + cpumask_copy(cluster_mask, topology_core_cpumask(cpu)); + return 0; + } + + return -EINVAL; +} + +/* * init_cpu_topology is called at boot when only one cpu is running * which prevent simultaneous write access to cpu_topology array */ |