On Mon, Dec 07 2015 at 07:53 -0700, Lorenzo Pieralisi wrote:
Hi Lina,
On Tue, Nov 17, 2015 at 03:37:45PM -0700, Lina Iyer wrote:
Architectures that support CPU domain control in the firmware specify
the domain heirarchy as part of the topology nodes. Parse and initialize
domains from the topology node for such architectures.
Cc: Rob Herring <robherri...@gmail.com>
Cc: Stephen Boyd <sb...@codeaurora.org>
Cc: Kevin Hilman <khil...@linaro.org>
Cc: Ulf Hansson <ulf.hans...@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Signed-off-by: Lina Iyer <lina.i...@linaro.org>
---
drivers/base/power/cpu-pd.c | 76 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/cpu-pd.h | 1 +
2 files changed, 77 insertions(+)
diff --git a/drivers/base/power/cpu-pd.c b/drivers/base/power/cpu-pd.c
index e331ae6..2872c18 100644
--- a/drivers/base/power/cpu-pd.c
+++ b/drivers/base/power/cpu-pd.c
@@ -429,3 +429,79 @@ int of_attach_cpu_pm_domain(struct device_node *dn)
return 0;
}
EXPORT_SYMBOL(of_attach_cpu_pm_domain);
+
+static int of_parse_cpu_pd(struct device_node *cluster,
+ const struct cpu_pd_ops *ops)
+{
+ struct device_node *domain_node;
+ struct generic_pm_domain *genpd;
+ char name[10];
+ struct device_node *c;
+ int i, ret;
+
+ for (i = 0; ; i++) {
+ snprintf(name, sizeof(name), "cluster%d", i);
+ c = of_get_child_by_name(cluster, name);
+ if (!c)
+ break;
+
+ domain_node = of_parse_phandle(c, "cluster", 0);
+ if (!domain_node)
+ return -1;
+
+ /* Initialize CPU PM domain domain at this level */
+ genpd = of_init_cpu_pm_domain(domain_node, ops);
+ if (IS_ERR(genpd))
+ return -1;
+
+ /* Initialize and attach child domains */
+ ret = of_parse_cpu_pd(c, ops);
+
+ /*
+ * Attach the domain to its parent after reading
+ * the children, so the mask of CPUs in this domain
+ * are setup correctly.
+ */
+ if (!ret)
+ of_attach_cpu_pm_domain(domain_node);
+
+ of_node_put(c);
+ if (ret != 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * of_setup_cpu_domain_topology() - Setup the CPU domains from the CPU
+ * topology node in DT.
+ *
+ * @ops: The PM domain suspend/resume ops for all the domains in the topology
+ */
+int of_setup_cpu_domain_topology(const struct cpu_pd_ops *ops)
+{
+ struct device_node *cn, *map;
+ int ret = 0;
+
+ cn = of_find_node_by_path("/cpus");
+ if (!cn) {
+ pr_err("No CPU information found in DT\n");
+ return 0;
+ }
+
+ map = of_get_child_by_name(cn, "cpu-map");
+ if (!map)
+ goto out;
I commented on this before, is this reliance on cpu-map necessary ?
Could not you just rely on the "power-domains" phandle in the cpu
nodes to build the cpumask for a specific power domain ? I think
you should try to decouple the concept of power domain from the cpu-map
cluster and I think this would also simplify your code in the process.
Sorry, I missed seeing your comment on this earlier.
Hmm, it can be done, but I felt out of place to define just power
domains that have no devices in Linux, since they are handled in PSCI,
but also have no relation to PSCI. Hence, I felt cpu-map to be a good
place for the cluster domain. But I am not strongly inclined. I can
remove them from the cpu-map and keep them as separate nodes. However,
it would be nice to have a way to say these nodes are PSCI controlled.
Thanks,
Lina
So to sum it up, I'd suggest you build the power domain cpumask by
enumerating the cpus pointing at a specific power-domain node.
+
+ ret = of_parse_cpu_pd(map, ops);
+ if (ret != 0)
+ goto out_map;
+
+out_map:
+ of_node_put(map);
+out:
+ of_node_put(cn);
+ return ret;
+}
+EXPORT_SYMBOL(of_setup_cpu_domain_topology);
diff --git a/include/linux/cpu-pd.h b/include/linux/cpu-pd.h
index 489ee2f..e8290db 100644
--- a/include/linux/cpu-pd.h
+++ b/include/linux/cpu-pd.h
@@ -32,4 +32,5 @@ struct cpu_pm_domain {
struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn,
const struct cpu_pd_ops *ops);
int of_attach_cpu_pm_domain(struct device_node *dn);
+int of_setup_cpu_domain_topology(const struct cpu_pd_ops *ops);
#endif /* __CPU_PD_H__ */
--
2.1.4
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