From 366001345f62d151aa95499fa4ed49f7d952b253 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 10 Sep 2012 16:06:30 +0100 Subject: [PATCH] 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 --- arch/arm/include/asm/topology.h | 3 +++ arch/arm/kernel/topology.c | 27 +++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index 58b8b84adcd2..611edefaeaf1 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 c5a59546a256..e9ac11c85922 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -289,6 +289,33 @@ void store_cpu_topology(unsigned int cpuid) cpu_topology[cpuid].socket_id, mpidr); } +/* + * 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 -- 2.34.1