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Commit 31058f84 authored by Pavankumar Kondeti's avatar Pavankumar Kondeti
Browse files

arm: topology: Allow specifying the CPU efficiency from device tree 



The efficiency of a CPU can vary across SoCs depending on the
cache size, bus interconnect frequencies etc. Allow specifying
this from the device tree. This value overrides the default
values hardcoded in the efficiency table.

Change-Id: If2885675ce3d7b43c3b2568fe1e29a76f48a5c3d
Signed-off-by: default avatarPavankumar Kondeti <pkondeti@codeaurora.org>
parent fd5704aa

arch/arm/kernel/topology.c

+20 −7
Original line number Diff line number Diff line
@@ -279,6 +279,7 @@ static int __init parse_dt_topology(void) 
	for_each_possible_cpu(cpu) {

		const u32 *rate;

		int len;

		u32 efficiency;



		/* too early to use cpu->of_node */

		cn = of_get_cpu_node(cpu, NULL);
@@ -287,14 +288,26 @@ static int __init parse_dt_topology(void) 
			continue;

		}



		for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++)

			if (of_device_is_compatible(cn, cpu_eff->compatible))

		/*

		 * The CPU efficiency value passed from the device tree

		 * overrides the value defined in the table_efficiency[]

		 */

		if (of_property_read_u32(cn, "efficiency", &efficiency) < 0) {



			for (cpu_eff = table_efficiency;

					cpu_eff->compatible; cpu_eff++)



				if (of_device_is_compatible(cn,

						cpu_eff->compatible))

					break;



			if (cpu_eff->compatible == NULL)

				continue;



		per_cpu(cpu_efficiency, cpu) = cpu_eff->efficiency;

			efficiency = cpu_eff->efficiency;

		}



		per_cpu(cpu_efficiency, cpu) = efficiency;



		rate = of_get_property(cn, "clock-frequency", &len);

		if (!rate || len != 4) {
@@ -303,7 +316,7 @@ static int __init parse_dt_topology(void) 
			continue;

		}



		capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;

		capacity = ((be32_to_cpup(rate)) >> 20) * efficiency;



		/* Save min capacity of the system */

		if (capacity < min_capacity)