On 6/17/19 7:34 AM, Valentin Schneider wrote:
Hi Jeremy,
Few nits below.
Also, I had a look at the other PPTT processor flags that were introduced
in 6.3, and the only other one being used is ACPI_LEAF_NODE in
acpi_pptt_leaf_node(). However that one already has a handle on the table
header, so the check_acpi_cpu_flag() isn't of much help there.
I don't believe the other existing flags will benefit from the helper since
they are more about describing the PPTT tree, but I think it doesn't hurt
to keep it around for potential future flags.
That was the thought process.
On 14/06/2019 23:31, Jeremy Linton wrote:
[...]
@@ -517,6 +517,43 @@ 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
+ * @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.
+ * Otherwise returns flag value
+ */
Nit: strictly speaking we're not returning the flag value but its mask
applied to the flags field. I don't think anyone will care about getting
the actual flag value, but it should be made obvious in the doc:
Or I clarify the code to actually do what the comments says. Maybe that
is what John G was also pointing out too?
-ENOENT if ...
0 if the flag isn't set
0 if it is set.
[...]
@@ -581,6 +618,21 @@ 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: extra newline
+ * 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
@@ -641,7 +693,6 @@ int find_acpi_cpu_cache_topology(unsigned int cpu, int level)
[...]
