Hi,
Thanks for looking at this.
On 8/1/19 10:57 AM, Sudeep Holla wrote:
Hi Jeremy,
On Wed, Jul 31, 2019 at 10:46:33PM -0500, Jeremy Linton wrote:
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.
Apart from few minor nits,
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Jeremy Linton <jeremy.linton@xxxxxxx>
---
drivers/acpi/pptt.c | 54 +++++++++++++++++++++++++++++++++++++++++++-
include/linux/acpi.h | 5 ++++
2 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c
index 1e7ac0bd0d3a..84718f6cb741 100644
--- a/drivers/acpi/pptt.c
+++ b/drivers/acpi/pptt.c
@@ -540,6 +540,44 @@ static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
return retval;
}
+/**
+ * check_acpi_cpu_flag() - Determine if CPU node has a flag set
+ * @cpu: Kernel logical CPU number
+ * @rev: The PPTT revision defining the flag
[nit] I would rather put it as minimum PPTT revision that supports the
flag. It aligns with the code too as we are not looking for exact match.
Ok, sure.
+ * @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
@@ -604,6 +642,21 @@ int cache_setup_acpi(unsigned int cpu)
return status;
}
+/**
+ * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread
+ * @cpu: Kernel logical CPU number
+ *
[nit] If you spin the patch again, you can drop extra line space here.
Sure..
--
Regards,
Sudeep
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