Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756555Ab3GVOZP (ORCPT ); Mon, 22 Jul 2013 10:25:15 -0400 Received: from mail-qe0-f42.google.com ([209.85.128.42]:43247 "EHLO mail-qe0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755657Ab3GVOZL (ORCPT ); Mon, 22 Jul 2013 10:25:11 -0400 Date: Mon, 22 Jul 2013 10:25:08 -0400 (EDT) From: Nicolas Pitre To: Sudeep KarkadaNagesha cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, Russell King , Shawn Guo , Gregory Clement , Greg Kroah-Hartman , Viresh Kumar , "Rafael J. Wysocki" , Grant Likely , Rob Herring , Lorenzo Pieralisi , Olof Johansson , Arnd Bergmann Subject: Re: [PATCH v3 04/16] ARM: topology: remove hwid/MPIDR dependency from cpu_capacity In-Reply-To: <1374492747-13879-5-git-send-email-Sudeep.KarkadaNagesha@arm.com> Message-ID: References: <1374069984-20567-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1374492747-13879-1-git-send-email-Sudeep.KarkadaNagesha@arm.com> <1374492747-13879-5-git-send-email-Sudeep.KarkadaNagesha@arm.com> User-Agent: Alpine 2.03 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5890 Lines: 171 On Mon, 22 Jul 2013, Sudeep KarkadaNagesha wrote: > From: Sudeep KarkadaNagesha > > Currently the topology code computes cpu capacity and stores it in > the list along with hwid(which is MPIDR) as it parses the CPU nodes > in the device tree. This is required as it needs to be mapped to the > logical CPU later. > > Since the CPU device nodes can be retrieved in the logical ordering > using DT/OF helpers, its possible to store cpu_capacity also in logical > ordering and avoid storing hwid for each entry. > > This patch removes hwid by making use of of_get_cpu_node. > > Cc: Russell King > Cc: Lorenzo Pieralisi > Acked-by: Rob Herring > Signed-off-by: Sudeep KarkadaNagesha Acked-by: Nicolas Pitre > --- > arch/arm/kernel/topology.c | 61 +++++++++++++++------------------------------- > 1 file changed, 19 insertions(+), 42 deletions(-) > > diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c > index c5a5954..28ef27a 100644 > --- a/arch/arm/kernel/topology.c > +++ b/arch/arm/kernel/topology.c > @@ -74,12 +74,8 @@ struct cpu_efficiency table_efficiency[] = { > {NULL, }, > }; > > -struct cpu_capacity { > - unsigned long hwid; > - unsigned long capacity; > -}; > - > -struct cpu_capacity *cpu_capacity; > +unsigned long *__cpu_capacity; > +#define cpu_capacity(cpu) __cpu_capacity[cpu] > > unsigned long middle_capacity = 1; > > @@ -100,15 +96,19 @@ static void __init parse_dt_topology(void) > unsigned long capacity = 0; > int alloc_size, cpu = 0; > > - alloc_size = nr_cpu_ids * sizeof(struct cpu_capacity); > - cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT); > + alloc_size = nr_cpu_ids * sizeof(*__cpu_capacity); > + __cpu_capacity = kzalloc(alloc_size, 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); > + 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 @@ static void __init parse_dt_topology(void) > 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 */ > @@ -140,13 +134,9 @@ static void __init parse_dt_topology(void) > 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 > @@ -154,9 +144,7 @@ static void __init parse_dt_topology(void) > * SCHED_POWER_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); > else > @@ -170,23 +158,12 @@ static void __init parse_dt_topology(void) > * 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) > +void update_cpu_power(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_power_scale(cpu, cpu_capacity(cpu) / middle_capacity); > > printk(KERN_INFO "CPU%u: update cpu_power %lu\n", > cpu, arch_scale_freq_power(NULL, cpu)); > @@ -194,7 +171,7 @@ void update_cpu_power(unsigned int cpu, unsigned long hwid) > > #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_power(unsigned int cpuid) {} > #endif > > /* > @@ -281,7 +258,7 @@ void store_cpu_topology(unsigned int cpuid) > > update_siblings_masks(cpuid); > > - update_cpu_power(cpuid, mpidr & MPIDR_HWID_BITMASK); > + update_cpu_power(cpuid); > > printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n", > cpuid, cpu_topology[cpuid].thread_id, > -- > 1.8.1.2 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/