15 #include <linux/cpu.h>
29 #include <asm/cpu.h>
34  * cpu capacity scale management
38  * cpu capacity table
39  * This per cpu data structure describes the relative capacity of each core.
40  * On a heteregenous system, cores don't have the same computation capacity
42  * can take this difference into account during load balance. A per cpu
43  * structure is preferred because each CPU updates its own cpu_capacity field
61  * is used to compute the capacity of a CPU.
66 	{"arm,cortex-a15", 3891},
67 	{"arm,cortex-a7",  2048},
72 #define cpu_capacity(cpu)	__cpu_capacity[cpu]  argument
80  * as close as possible to  (max{eff_i} - min{eff_i}) / 2
82  * 'average' CPU is of middle capacity. Also see the comments near
91 	unsigned long capacity = 0;  in parse_dt_topology()  local
92 	int cpu = 0;  in parse_dt_topology()  local
97 	for_each_possible_cpu(cpu) {  in parse_dt_topology()
101 		/* too early to use cpu->of_node */  in parse_dt_topology()
102 		cn = of_get_cpu_node(cpu, NULL);  in parse_dt_topology()
104 			pr_err("missing device node for CPU %d\n", cpu);  in parse_dt_topology()
108 		if (topology_parse_cpu_capacity(cn, cpu)) {  in parse_dt_topology()
115 		for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++)  in parse_dt_topology()
116 			if (of_device_is_compatible(cn, cpu_eff->compatible))  in parse_dt_topology()
119 		if (cpu_eff->compatible == NULL)  in parse_dt_topology()
122 		rate = of_get_property(cn, "clock-frequency", &len);  in parse_dt_topology()
124 			pr_err("%pOF missing clock-frequency property\n", cn);  in parse_dt_topology()
128 		capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;  in parse_dt_topology()
130 		/* Save min capacity of the system */  in parse_dt_topology()
131 		if (capacity < min_capacity)  in parse_dt_topology()
132 			min_capacity = capacity;  in parse_dt_topology()
134 		/* Save max capacity of the system */  in parse_dt_topology()
135 		if (capacity > max_capacity)  in parse_dt_topology()
136 			max_capacity = capacity;  in parse_dt_topology()
138 		cpu_capacity(cpu) = capacity;  in parse_dt_topology()
142 	 * cpu_scale because all CPUs have the same capacity. Otherwise, we  in parse_dt_topology()
143 	 * compute a middle_capacity factor that will ensure that the capacity  in parse_dt_topology()
144 	 * of an 'average' CPU of the system will be as close as possible to  in parse_dt_topology()
153 				>> (SCHED_CAPACITY_SHIFT-1)) + 1;  in parse_dt_topology()
160  * Look for a customed capacity of a CPU in the cpu_capacity table during the
164 static void update_cpu_capacity(unsigned int cpu)  in update_cpu_capacity()  argument
166 	if (!cpu_capacity(cpu) || cap_from_dt)  in update_cpu_capacity()
169 	topology_set_cpu_scale(cpu, cpu_capacity(cpu) / middle_capacity);  in update_cpu_capacity()
171 	pr_info("CPU%u: update cpu_capacity %lu\n",  in update_cpu_capacity()
172 		cpu, topology_get_cpu_scale(cpu));  in update_cpu_capacity()
181  * store_cpu_topology is called at boot when only one cpu is running
190 	if (cpuid_topo->package_id != -1)  in store_cpu_topology()
195 	/* create cpu topology mapping */  in store_cpu_topology()
204 			cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);  in store_cpu_topology()
205 			cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);  in store_cpu_topology()
206 			cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 2);  in store_cpu_topology()
209 			cpuid_topo->thread_id = -1;  in store_cpu_topology()
210 			cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);  in store_cpu_topology()
211 			cpuid_topo->package_id = MPIDR_AFFINITY_LEVEL(mpidr, 1);  in store_cpu_topology()
219 		cpuid_topo->thread_id = -1;  in store_cpu_topology()
220 		cpuid_topo->core_id = 0;  in store_cpu_topology()
221 		cpuid_topo->package_id = -1;  in store_cpu_topology()
226 	pr_info("CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",  in store_cpu_topology()
236  * init_cpu_topology is called at boot when only one cpu is running