--- zzzz-none-000/linux-3.10.107/arch/arm/kernel/topology.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/arch/arm/kernel/topology.c 2021-02-04 17:41:59.000000000 +0000 @@ -26,30 +26,30 @@ #include /* - * cpu power scale management + * cpu capacity scale management */ /* - * cpu power table + * cpu capacity table * This per cpu data structure describes the relative capacity of each core. * On a heteregenous system, cores don't have the same computation capacity - * and we reflect that difference in the cpu_power field so the scheduler can - * take this difference into account during load balance. A per cpu structure - * is preferred because each CPU updates its own cpu_power field during the - * load balance except for idle cores. One idle core is selected to run the - * rebalance_domains for all idle cores and the cpu_power can be updated - * during this sequence. + * and we reflect that difference in the cpu_capacity field so the scheduler + * can take this difference into account during load balance. A per cpu + * structure is preferred because each CPU updates its own cpu_capacity field + * during the load balance except for idle cores. One idle core is selected + * to run the rebalance_domains for all idle cores and the cpu_capacity can be + * updated during this sequence. */ static DEFINE_PER_CPU(unsigned long, cpu_scale); -unsigned long arch_scale_freq_power(struct sched_domain *sd, int cpu) +unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) { return per_cpu(cpu_scale, cpu); } -static void set_power_scale(unsigned int cpu, unsigned long power) +static void set_capacity_scale(unsigned int cpu, unsigned long capacity) { - per_cpu(cpu_scale, cpu) = power; + per_cpu(cpu_scale, cpu) = capacity; } #ifdef CONFIG_OF @@ -62,53 +62,53 @@ * Table of relative efficiency of each processors * The efficiency value must fit in 20bit and the final * cpu_scale value must be in the range - * 0 < cpu_scale < 3*SCHED_POWER_SCALE/2 + * 0 < cpu_scale < 3*SCHED_CAPACITY_SCALE/2 * in order to return at most 1 when DIV_ROUND_CLOSEST * is used to compute the capacity of a CPU. * Processors that are not defined in the table, - * use the default SCHED_POWER_SCALE value for cpu_scale. + * use the default SCHED_CAPACITY_SCALE value for cpu_scale. */ -struct cpu_efficiency table_efficiency[] = { +static const struct cpu_efficiency table_efficiency[] = { {"arm,cortex-a15", 3891}, {"arm,cortex-a7", 2048}, {NULL, }, }; -struct cpu_capacity { - unsigned long hwid; - unsigned long capacity; -}; - -struct cpu_capacity *cpu_capacity; +static unsigned long *__cpu_capacity; +#define cpu_capacity(cpu) __cpu_capacity[cpu] -unsigned long middle_capacity = 1; +static unsigned long middle_capacity = 1; /* * Iterate all CPUs' descriptor in DT and compute the efficiency * (as per table_efficiency). Also calculate a middle efficiency * as close as possible to (max{eff_i} - min{eff_i}) / 2 - * This is later used to scale the cpu_power field such that an - * 'average' CPU is of middle power. Also see the comments near - * table_efficiency[] and update_cpu_power(). + * This is later used to scale the cpu_capacity field such that an + * 'average' CPU is of middle capacity. Also see the comments near + * table_efficiency[] and update_cpu_capacity(). */ static void __init parse_dt_topology(void) { - struct cpu_efficiency *cpu_eff; + const struct cpu_efficiency *cpu_eff; struct device_node *cn = NULL; - unsigned long min_capacity = (unsigned long)(-1); + unsigned long min_capacity = ULONG_MAX; unsigned long max_capacity = 0; unsigned long capacity = 0; - int alloc_size, cpu = 0; + int cpu = 0; - alloc_size = nr_cpu_ids * sizeof(struct cpu_capacity); - cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT); + __cpu_capacity = kcalloc(nr_cpu_ids, sizeof(*__cpu_capacity), + GFP_NOWAIT); - while ((cn = of_find_node_by_type(cn, "cpu"))) { - const u32 *rate, *reg; + for_each_possible_cpu(cpu) { + const u32 *rate; int len; - if (cpu >= num_possible_cpus()) - break; + /* too early to use cpu->of_node */ + cn = of_get_cpu_node(cpu, NULL); + if (!cn) { + pr_err("missing device node for CPU %d\n", cpu); + continue; + } for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++) if (of_device_is_compatible(cn, cpu_eff->compatible)) @@ -124,12 +124,6 @@ continue; } - reg = of_get_property(cn, "reg", &len); - if (!reg || len != 4) { - pr_err("%s missing reg property\n", cn->full_name); - continue; - } - capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency; /* Save min capacity of the system */ @@ -140,28 +134,22 @@ if (capacity > max_capacity) max_capacity = capacity; - cpu_capacity[cpu].capacity = capacity; - cpu_capacity[cpu++].hwid = be32_to_cpup(reg); + cpu_capacity(cpu) = capacity; } - if (cpu < num_possible_cpus()) - cpu_capacity[cpu].hwid = (unsigned long)(-1); - /* If min and max capacities are equals, we bypass the update of the * cpu_scale because all CPUs have the same capacity. Otherwise, we * compute a middle_capacity factor that will ensure that the capacity * of an 'average' CPU of the system will be as close as possible to - * SCHED_POWER_SCALE, which is the default value, but with the + * SCHED_CAPACITY_SCALE, which is the default value, but with the * constraint explained near table_efficiency[]. */ - if (min_capacity == max_capacity) - cpu_capacity[0].hwid = (unsigned long)(-1); - else if (4*max_capacity < (3*(max_capacity + min_capacity))) + if (4*max_capacity < (3*(max_capacity + min_capacity))) middle_capacity = (min_capacity + max_capacity) - >> (SCHED_POWER_SHIFT+1); + >> (SCHED_CAPACITY_SHIFT+1); else middle_capacity = ((max_capacity / 3) - >> (SCHED_POWER_SHIFT-1)) + 1; + >> (SCHED_CAPACITY_SHIFT-1)) + 1; } @@ -170,31 +158,20 @@ * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the * function returns directly for SMP system. */ -void update_cpu_power(unsigned int cpu, unsigned long hwid) +static void update_cpu_capacity(unsigned int cpu) { - unsigned int idx = 0; - - /* look for the cpu's hwid in the cpu capacity table */ - for (idx = 0; idx < num_possible_cpus(); idx++) { - if (cpu_capacity[idx].hwid == hwid) - break; - - if (cpu_capacity[idx].hwid == -1) - return; - } - - if (idx == num_possible_cpus()) + if (!cpu_capacity(cpu)) return; - set_power_scale(cpu, cpu_capacity[idx].capacity / middle_capacity); + set_capacity_scale(cpu, cpu_capacity(cpu) / middle_capacity); - printk(KERN_INFO "CPU%u: update cpu_power %lu\n", - cpu, arch_scale_freq_power(NULL, cpu)); + pr_info("CPU%u: update cpu_capacity %lu\n", + cpu, arch_scale_cpu_capacity(NULL, cpu)); } #else static inline void parse_dt_topology(void) {} -static inline void update_cpu_power(unsigned int cpuid, unsigned int mpidr) {} +static inline void update_cpu_capacity(unsigned int cpuid) {} #endif /* @@ -208,7 +185,16 @@ return &cpu_topology[cpu].core_sibling; } -void update_siblings_masks(unsigned int cpuid) +/* + * The current assumption is that we can power gate each core independently. + * This will be superseded by DT binding once available. + */ +const struct cpumask *cpu_corepower_mask(int cpu) +{ + return &cpu_topology[cpu].thread_sibling; +} + +static void update_siblings_masks(unsigned int cpuid) { struct cputopo_arm *cpu_topo, *cpuid_topo = &cpu_topology[cpuid]; int cpu; @@ -281,14 +267,28 @@ update_siblings_masks(cpuid); - update_cpu_power(cpuid, mpidr & MPIDR_HWID_BITMASK); + update_cpu_capacity(cpuid); - printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n", + pr_info("CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n", cpuid, cpu_topology[cpuid].thread_id, cpu_topology[cpuid].core_id, cpu_topology[cpuid].socket_id, mpidr); } +static inline int cpu_corepower_flags(void) +{ + return SD_SHARE_PKG_RESOURCES | SD_SHARE_POWERDOMAIN; +} + +static struct sched_domain_topology_level arm_topology[] = { +#ifdef CONFIG_SCHED_MC + { cpu_corepower_mask, cpu_corepower_flags, SD_INIT_NAME(GMC) }, + { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, +#endif + { cpu_cpu_mask, SD_INIT_NAME(DIE) }, + { NULL, }, +}; + /* * init_cpu_topology is called at boot when only one cpu is running * which prevent simultaneous write access to cpu_topology array @@ -297,7 +297,7 @@ { unsigned int cpu; - /* init core mask and power*/ + /* init core mask and capacity */ for_each_possible_cpu(cpu) { struct cputopo_arm *cpu_topo = &(cpu_topology[cpu]); @@ -307,9 +307,12 @@ cpumask_clear(&cpu_topo->core_sibling); cpumask_clear(&cpu_topo->thread_sibling); - set_power_scale(cpu, SCHED_POWER_SCALE); + set_capacity_scale(cpu, SCHED_CAPACITY_SCALE); } smp_wmb(); parse_dt_topology(); + + /* Set scheduler topology descriptor */ + set_sched_topology(arm_topology); }