base/node / acpi: Change 'node_hmem_attrs' to 'access_coordinates'

Dan Williams suggested changing the struct 'node_hmem_attrs' to
'access_coordinates' [1]. The struct is a container of r/w-latency and
r/w-bandwidth numbers. Moving forward, this container will also be used by
CXL to store the performance characteristics of each link hop in
the PCIE/CXL topology. So, where node_hmem_attrs is just the access
parameters of a memory-node, access_coordinates applies more broadly
to hardware topology characteristics. The observation is that seemed like
an exercise in having the application identify "where" it falls on a
spectrum of bandwidth and latency needs. For the tuple of
read/write-latency and read/write-bandwidth, "coordinates" is not a perfect
fit. Sometimes it is just conveying values in isolation and not a
"location" relative to other performance points, but in the end this data
is used to identify the performance operation point of a given memory-node.
[2]

Link: http://lore.kernel.org/r/64471313421f7_1b66294d5@dwillia2-xfh.jf.intel.com.notmuch/
Link: https://lore.kernel.org/linux-cxl/645e6215ee0de_1e6f2945e@dwillia2-xfh.jf.intel.com.notmuch/
Suggested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/170319615734.2212653.15319394025985499185.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index 1e39d27bee41..69e781900082 100644
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -33,7 +33,7 @@ struct memory_dev_type {
 	struct kref kref;
 };
 
-struct node_hmem_attrs;
+struct access_coordinate;
 
 #ifdef CONFIG_NUMA
 extern bool numa_demotion_enabled;
@@ -45,9 +45,9 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype);
 int register_mt_adistance_algorithm(struct notifier_block *nb);
 int unregister_mt_adistance_algorithm(struct notifier_block *nb);
 int mt_calc_adistance(int node, int *adist);
-int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
+int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
 			     const char *source);
-int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist);
+int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
 #ifdef CONFIG_MIGRATION
 int next_demotion_node(int node);
 void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
@@ -126,13 +126,13 @@ static inline int mt_calc_adistance(int node, int *adist)
 	return NOTIFY_DONE;
 }
 
-static inline int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
+static inline int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
 					   const char *source)
 {
 	return -EIO;
 }
 
-static inline int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist)
+static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adist)
 {
 	return -EIO;
 }