From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: will.deacon@arm.com, marc.zyngier@arm.com, mark.rutland@arm.com,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
robh@kernel.org, frowand.list@gmail.com,
mathieu.poirier@linaro.org, peterz@infradead.org,
Jonathan.Cameron@huawei.com,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Sudeep Holla <sudeep.holla@arm.com>
Subject: [PATCH v6 2/6] of: Add helper for mapping device node to logical CPU number
Date: Mon, 21 Aug 2017 18:55:05 +0100 [thread overview]
Message-ID: <1503338109-32540-3-git-send-email-suzuki.poulose@arm.com> (raw)
In-Reply-To: <1503338109-32540-1-git-send-email-suzuki.poulose@arm.com>
Add a helper to map a device node to a logical CPU number to avoid
duplication. Currently this is open coded in different places (e.g
gic-v3, coresight). The helper tries to map device node to a "possible"
logical CPU id, which may not be online yet. It is the responsibility
of the user to make sure that the CPU is online. The helper uses
of_get_cpu_node() which uses arch specific backends to match the phyiscal
ids.
Cc: devicetree@vger.kernel.org
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since V3:
- Renamed the helper to of_cpu_node_to_id(), suggested by Rob
- Return -ENODEV on failure than nr_cpus_id
---
drivers/of/base.c | 26 ++++++++++++++++++++++++++
include/linux/of.h | 7 +++++++
2 files changed, 33 insertions(+)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 686628d..e8625ff 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -420,6 +420,32 @@ struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
EXPORT_SYMBOL(of_get_cpu_node);
/**
+ * of_cpu_node_to_id: Get the logical CPU number for a given device_node
+ *
+ * @cpu_node: Pointer to the device_node for CPU.
+ *
+ * Returns the logical CPU number of the given CPU device_node.
+ * Returns -ENODEV if the CPU is not found.
+ */
+int of_cpu_node_to_id(struct device_node *cpu_node)
+{
+ int cpu;
+ bool found = false;
+ struct device_node *np;
+
+ for_each_possible_cpu(cpu) {
+ np = of_get_cpu_node(cpu, NULL);
+ found = (cpu_node == np);
+ of_node_put(np);
+ if (found)
+ return cpu;
+ }
+
+ return -ENODEV;
+}
+EXPORT_SYMBOL(of_cpu_node_to_id);
+
+/**
* __of_device_is_compatible() - Check if the node matches given constraints
* @device: pointer to node
* @compat: required compatible string, NULL or "" for any match
diff --git a/include/linux/of.h b/include/linux/of.h
index 4a8a709..23cf02d 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -539,6 +539,8 @@ const char *of_prop_next_string(struct property *prop, const char *cur);
bool of_console_check(struct device_node *dn, char *name, int index);
+extern int of_cpu_node_to_id(struct device_node *np);
+
#else /* CONFIG_OF */
static inline void of_core_init(void)
@@ -863,6 +865,11 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag
{
}
+static inline int of_cpu_node_to_id(struct device_node *np)
+{
+ return -ENODEV;
+}
+
#define of_match_ptr(_ptr) NULL
#define of_match_node(_matches, _node) NULL
#endif /* CONFIG_OF */
--
2.7.5
next prev parent reply other threads:[~2017-08-21 17:56 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-21 17:55 [PATCH v6 0/6] perf: Support for ARM DynamIQ Shared Unit Suzuki K Poulose
2017-08-21 17:55 ` [PATCH v6 1/6] perf: Export perf_event_update_userpage Suzuki K Poulose
2017-08-21 17:55 ` Suzuki K Poulose [this message]
2017-08-21 17:55 ` [PATCH v6 3/6] coresight: of: Use of_cpu_node_to_id helper Suzuki K Poulose
2017-08-21 17:55 ` [PATCH v6 4/6] irqchip: gic-v3: " Suzuki K Poulose
2017-08-21 17:55 ` [PATCH v6 5/6] dt-bindings: Document devicetree binding for ARM DSU PMU Suzuki K Poulose
2017-08-21 17:55 ` [PATCH v6 6/6] perf: ARM DynamIQ Shared Unit PMU support Suzuki K Poulose
2017-08-22 11:17 ` Jonathan Cameron
2017-08-22 15:35 ` Suzuki K Poulose
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