[tip:x86/cpu] x86/intel_rdt/mba: Add info directory files for Memory Bandwidth Allocation

[tip-bot for Vikas Shivappa]

Commit-ID:  db69ef65636e6da135680d75d8646bd7e76136bc
Gitweb:     http://git.kernel.org/tip/db69ef65636e6da135680d75d8646bd7e76136bc
Author:     Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
AuthorDate: Fri, 7 Apr 2017 17:33:55 -0700
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 14 Apr 2017 16:10:08 +0200

x86/intel_rdt/mba: Add info directory files for Memory Bandwidth Allocation

The files in the info directory for MBA are as follows:

 num_closids
 	The maximum number of CLOSids available for MBA

 min_bandwidth
 	The minimum memory bandwidth percentage value

 bandwidth_gran
 	The granularity of the bandwidth control in percent for the
	particular CPU SKU. Intermediate values entered are rounded off
	to the previous control step available. Available bandwidth
	control steps are minimum_bandwidth + N * bandwidth_gran.

 delay_linear
 	When set, the OS writes a linear percentage based value to the
	control MSRs ranging from minimum_bandwidth to 100 percent.

	This value is informational and has no influence on the values
	written to the schemata files. The values written to the
	schemata are always bandwidth percentage that is requested.

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
Cc: ravi.v.shankar@xxxxxxxxx
Cc: tony.luck@xxxxxxxxx
Cc: fenghua.yu@xxxxxxxxx
Cc: vikas.shivappa@xxxxxxxxx
Link: http://lkml.kernel.org/r/1491611637-20417-7-git-send-email-vikas.shivappa@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
 arch/x86/include/asm/intel_rdt.h         |  1 +
 arch/x86/kernel/cpu/intel_rdt.c          |  1 +
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 62 ++++++++++++++++++++++++++++++--
 3 files changed, 62 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index b0f0a60..167fe10 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -174,6 +174,7 @@ struct rdt_resource {
 };
 
 void rdt_get_cache_infofile(struct rdt_resource *r);
+void rdt_get_mba_infofile(struct rdt_resource *r);
 
 extern struct mutex rdtgroup_mutex;
 
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index b387e04..438efef 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -203,6 +203,7 @@ static bool rdt_get_mem_config(struct rdt_resource *r)
 			return false;
 	}
 	r->data_width = 3;
+	rdt_get_mba_infofile(r);
 
 	r->capable = true;
 	r->enabled = true;
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 65d957b..f5af0cc 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -515,7 +515,6 @@ static int rdt_num_closids_show(struct kernfs_open_file *of,
 	struct rdt_resource *r = of->kn->parent->priv;
 
 	seq_printf(seq, "%d\n", r->num_closid);
-
 	return 0;
 }
 
@@ -525,7 +524,6 @@ static int rdt_default_ctrl_show(struct kernfs_open_file *of,
 	struct rdt_resource *r = of->kn->parent->priv;
 
 	seq_printf(seq, "%x\n", r->default_ctrl);
-
 	return 0;
 }
 
@@ -535,7 +533,33 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
 	struct rdt_resource *r = of->kn->parent->priv;
 
 	seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
+	return 0;
+}
+
+static int rdt_min_bw_show(struct kernfs_open_file *of,
+			     struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
 
+	seq_printf(seq, "%u\n", r->membw.min_bw);
+	return 0;
+}
+
+static int rdt_bw_gran_show(struct kernfs_open_file *of,
+			     struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	seq_printf(seq, "%u\n", r->membw.bw_gran);
+	return 0;
+}
+
+static int rdt_delay_linear_show(struct kernfs_open_file *of,
+			     struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	seq_printf(seq, "%u\n", r->membw.delay_linear);
 	return 0;
 }
 
@@ -561,6 +585,40 @@ static struct rftype res_cache_info_files[] = {
 	},
 };
 
+/* rdtgroup information files for memory bandwidth. */
+static struct rftype res_mba_info_files[] = {
+	{
+		.name		= "num_closids",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_num_closids_show,
+	},
+	{
+		.name		= "min_bandwidth",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_min_bw_show,
+	},
+	{
+		.name		= "bandwidth_gran",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_bw_gran_show,
+	},
+	{
+		.name		= "delay_linear",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_delay_linear_show,
+	},
+};
+
+void rdt_get_mba_infofile(struct rdt_resource *r)
+{
+	r->info_files = res_mba_info_files;
+	r->nr_info_files = ARRAY_SIZE(res_mba_info_files);
+}
+
 void rdt_get_cache_infofile(struct rdt_resource *r)
 {
 	r->info_files = res_cache_info_files;