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authorJeremy Linton <jeremy.linton@arm.com>2019-08-08 15:40:06 -0500
committerWill Deacon <will@kernel.org>2019-08-12 12:59:15 +0100
commitbbd1b70639f785a970d998f35155c713f975e3ac (patch)
tree900720fcc2f594cd91330c9005ce3b6a58e89bf0 /drivers/acpi
parente21a712a9685488f5ce80495b37b9fdbe96c230d (diff)
downloadlinux-bbd1b70639f785a970d998f35155c713f975e3ac.tar.bz2
ACPI/PPTT: Add support for ACPI 6.3 thread flag
ACPI 6.3 adds a flag to the CPU node to indicate whether the given PE is a thread. Add a function to return that information for a given linux logical CPU. Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Robert Richter <rrichter@marvell.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/pptt.c53
1 files changed, 52 insertions, 1 deletions
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 1e7ac0bd0d3a..f31544d3656e 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -541,6 +541,44 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
}
/**
+ * check_acpi_cpu_flag() - Determine if CPU node has a flag set
+ * @cpu: Kernel logical CPU number
+ * @rev: The minimum PPTT revision defining the flag
+ * @flag: The flag itself
+ *
+ * Check the node representing a CPU for a given flag.
+ *
+ * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or
+ * the table revision isn't new enough.
+ * 1, any passed flag set
+ * 0, flag unset
+ */
+static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
+{
+ struct acpi_table_header *table;
+ acpi_status status;
+ u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
+ struct acpi_pptt_processor *cpu_node = NULL;
+ int ret = -ENOENT;
+
+ status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
+ if (ACPI_FAILURE(status)) {
+ acpi_pptt_warn_missing();
+ return ret;
+ }
+
+ if (table->revision >= rev)
+ cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
+
+ if (cpu_node)
+ ret = (cpu_node->flags & flag) != 0;
+
+ acpi_put_table(table);
+
+ return ret;
+}
+
+/**
* acpi_find_last_cache_level() - Determines the number of cache levels for a PE
* @cpu: Kernel logical CPU number
*
@@ -605,6 +643,20 @@ int cache_setup_acpi(unsigned int cpu)
}
/**
+ * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread
+ * @cpu: Kernel logical CPU number
+ *
+ * Return: 1, a thread
+ * 0, not a thread
+ * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or
+ * the table revision isn't new enough.
+ */
+int acpi_pptt_cpu_is_thread(unsigned int cpu)
+{
+ return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD);
+}
+
+/**
* find_acpi_cpu_topology() - Determine a unique topology value for a given CPU
* @cpu: Kernel logical CPU number
* @level: The topological level for which we would like a unique ID
@@ -664,7 +716,6 @@ int find_acpi_cpu_cache_topology(unsigned int cpu, int level)
return ret;
}
-
/**
* find_acpi_cpu_topology_package() - Determine a unique CPU package value
* @cpu: Kernel logical CPU number