From mboxrd@z Thu Jan 1 00:00:00 1970 From: lorenzo.pieralisi@arm.com (Lorenzo Pieralisi) Date: Mon, 24 Mar 2014 15:36:11 +0000 Subject: [PATCH 2/4] arm64: topology: Add support for topology DT bindings In-Reply-To: <1395422881-10029-2-git-send-email-broonie@kernel.org> References: <1395422881-10029-1-git-send-email-broonie@kernel.org> <1395422881-10029-2-git-send-email-broonie@kernel.org> Message-ID: <20140324153611.GA16245@red-moon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Mark, On Fri, Mar 21, 2014 at 05:27:59PM +0000, Mark Brown wrote: > From: Mark Brown > > Add support for parsing the explicit topology bindings to discover the > topology of the system. > > Since it is not currently clear how to map multi-level clusters for the > scheduler all leaf clusters are presented to the scheduler at the same > level. This should be enough to provide good support for current systems. > > Signed-off-by: Mark Brown Please apply the patches attached, that fix some stale comments and add of_node_put in paths that could otherwise be broken by return statements. Patch "arm64: kernel: topology: removed stale comment" applies to patch 1 of this series. Patch "arm64: kernel: topology updates" applies to patch 2 of this series. Both should be squashed into your original patches. Please have a final look and test them, they work for me. Having said that, on the updated patch 1 and 2 of this series: Reviewed-by: Lorenzo Pieralisi > --- > > - Discard the DT data if any CPUs are omitted from the topology. > - Call of_node_put() where required. > > arch/arm64/kernel/topology.c | 192 +++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 186 insertions(+), 6 deletions(-) > > diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c > index ff662b23af5f..d0cb687fb7f5 100644 > --- a/arch/arm64/kernel/topology.c > +++ b/arch/arm64/kernel/topology.c > @@ -17,10 +17,183 @@ > #include > #include > #include > +#include > #include > > #include > > +static int __init get_cpu_for_node(struct device_node *node) > +{ > + struct device_node *cpu_node; > + int cpu; > + > + cpu_node = of_parse_phandle(node, "cpu", 0); > + if (!cpu_node) > + return -1; > + > + for_each_possible_cpu(cpu) { > + if (of_get_cpu_node(cpu, NULL) == cpu_node) > + return cpu; > + } > + > + pr_crit("Unable to find CPU node for %s\n", cpu_node->full_name); > + return -1; > +} > + > +static int __init parse_core(struct device_node *core, int cluster_id, > + int core_id) > +{ > + char name[10]; > + bool leaf = true; > + int i = 0; > + int cpu; > + struct device_node *t; > + > + do { > + snprintf(name, sizeof(name), "thread%d", i); > + t = of_get_child_by_name(core, name); > + if (t) { > + leaf = false; > + cpu = get_cpu_for_node(t); > + if (cpu >= 0) { > + cpu_topology[cpu].cluster_id = cluster_id; > + cpu_topology[cpu].core_id = core_id; > + cpu_topology[cpu].thread_id = i; > + } else { > + pr_err("%s: Can't get CPU for thread\n", > + t->full_name); > + return -EINVAL; > + } > + of_node_put(t); > + } > + i++; > + } while (t); > + > + cpu = get_cpu_for_node(core); > + if (cpu >= 0) { > + if (!leaf) { > + pr_err("%s: Core has both threads and CPU\n", > + core->full_name); > + return -EINVAL; > + } > + > + cpu_topology[cpu].cluster_id = cluster_id; > + cpu_topology[cpu].core_id = core_id; > + } else if (leaf) { > + pr_err("%s: Can't get CPU for leaf core\n", core->full_name); > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int __init parse_cluster(struct device_node *cluster, int depth) > +{ > + char name[10]; > + bool leaf = true; > + bool has_cores = false; > + struct device_node *c; > + static int cluster_id __initdata; > + int core_id = 0; > + int i, ret; > + > + /* > + * First check for child clusters; we currently ignore any > + * information about the nesting of clusters and present the > + * scheduler with a flat list of them. > + */ > + i = 0; > + do { > + snprintf(name, sizeof(name), "cluster%d", i); > + c = of_get_child_by_name(cluster, name); > + if (c) { > + ret = parse_cluster(c, depth + 1); > + if (ret != 0) > + return ret; > + leaf = false; > + of_node_put(c); > + } > + i++; > + } while (c); > + > + /* Now check for cores */ > + i = 0; > + do { > + snprintf(name, sizeof(name), "core%d", i); > + c = of_get_child_by_name(cluster, name); > + if (c) { > + has_cores = true; > + > + if (depth == 0) > + pr_err("%s: cpu-map children should be clusters\n", > + c->full_name); > + > + if (leaf) { > + ret = parse_core(c, cluster_id, core_id++); > + if (ret != 0) > + return ret; > + } else { > + pr_err("%s: Non-leaf cluster with core %s\n", > + cluster->full_name, name); > + return -EINVAL; > + } > + of_node_put(c); > + } > + i++; > + } while (c); > + > + if (leaf && !has_cores) > + pr_warn("%s: empty cluster\n", cluster->full_name); > + > + if (leaf) > + cluster_id++; > + > + return 0; > +} > + > +static int __init parse_dt_topology(void) > +{ > + struct device_node *cn, *map; > + int ret = 0; > + int cpu; > + > + cn = of_find_node_by_path("/cpus"); > + if (!cn) { > + pr_err("No CPU information found in DT\n"); > + return 0; > + } > + > + /* > + * When topology is provided cpu-map is essentially a root > + * cluster with restricted subnodes. > + */ > + map = of_get_child_by_name(cn, "cpu-map"); > + if (!map) > + goto out; > + > + ret = parse_cluster(map, 0); > + if (ret != 0) > + goto out; > + > + of_node_put(map); > + > + /* > + * Check that all cores are in the topology; the SMP code will > + * only mark cores described in the DT as possible. > + */ > + for_each_possible_cpu(cpu) { > + if (cpu_topology[cpu].cluster_id == -1) { > + pr_err("CPU%d: No topology information specified\n", > + cpu); > + ret = -EINVAL; > + } > + } > + > +out: > + of_node_put(cn); > + return ret; > +} > + > /* > * cpu topology table > */ > @@ -71,15 +244,10 @@ void store_cpu_topology(unsigned int cpuid) > update_siblings_masks(cpuid); > } > > -/* > - * init_cpu_topology is called at boot when only one cpu is running > - * which prevent simultaneous write access to cpu_topology array > - */ > -void __init init_cpu_topology(void) > +static void __init reset_cpu_topology(void) > { > unsigned int cpu; > > - /* init core mask and power*/ > for_each_possible_cpu(cpu) { > struct cpu_topology *cpu_topo = &cpu_topology[cpu]; > > @@ -93,3 +261,15 @@ void __init init_cpu_topology(void) > cpumask_set_cpu(cpu, &cpu_topo->thread_sibling); > } > } > + > +void __init init_cpu_topology(void) > +{ > + reset_cpu_topology(); > + > + /* > + * Discard anything that was parsed if we hit an error so we > + * don't use partial information. > + */ > + if (parse_dt_topology()) > + reset_cpu_topology(); > +} > -- > 1.9.1 > > -------------- next part -------------- A non-text attachment was scrubbed... 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