[PATCH 6/8] x86/intel_rdt/mba: Add info directory files for MBA

[Vikas Shivappa]

Add the files in info directory for MBA.
The files in the info directory are as follows :
 - num_closids: max number of closids for MBA which represents the max
 class of service user can configure.
 - max_thrtl_by: the max throttle by values.

Throttle by can have a linear scale and non linear scale.  In linear
scale, if a throttle_by value is 40%, it means that the memory b/w is
throttled 'by' 40% or in other words a max of 60% b/w is allowed to
pass. In non-linear scale, the throttle_by values are in 2^n
granularity. The h/w does not guarantee a curve of actual throttle w.r.t
the configured values. But if a throttle_by value of x > y, then x is
guaranteed to throttle more b/w than y.
 - throttle granularity: Shows the throttle granularity of the throttle
 values that can be configured.

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/intel_rdt.h         |  8 ++-
 arch/x86/kernel/cpu/intel_rdt.c          |  2 +
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 84 ++++++++++++++++++++++++++++++--
 3 files changed, 89 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index 49ae832..88725b6 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -5,7 +5,6 @@
 
 #include <linux/kernfs.h>
 #include <linux/jump_label.h>
-
 #include <asm/intel_rdt_common.h>
 
 #define IA32_L3_QOS_CFG		0xc81
@@ -77,6 +76,8 @@ struct rftype {
  * @no_ctrl:			Specifies max cache cbm or min mem b/w delay.
  * @min_cbm_bits:		Minimum number of consecutive bits to be set
  *				in a cache bit mask
+ * @info_files:		resctrl info files for the resource
+ * @infofiles_len:		Number of info files
  * @max_delay:		Max throttle delay
  * @delay_gran:		Throttle delay granularity
  * @delay_linear:		true if delay is in linear scale
@@ -98,6 +99,8 @@ struct rdt_resource {
 	int			cbm_len;
 	int			min_cbm_bits;
 	u32			no_ctrl;
+	struct rftype		*info_files;
+	int			infofiles_len;
 	u32			max_delay;
 	u32			delay_gran;
 	u32			delay_linear;
@@ -137,6 +140,9 @@ struct msr_param {
 	int			high;
 };
 
+void rdt_get_cache_infofile(struct rdt_resource *r);
+void rdt_get_mbe_infofile(struct rdt_resource *r);
+
 extern struct mutex rdtgroup_mutex;
 
 extern struct rdt_resource rdt_resources_all[];
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index 6736e1d..bdfbd1d 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -154,6 +154,7 @@ static void rdt_get_mem_config(struct rdt_resource *r)
 	if (r->delay_linear)
 		r->delay_gran = MAX_MBA_THRTL - r->max_delay;
 
+	rdt_get_mbe_infofile(r);
 	r->capable = true;
 	r->enabled = true;
 }
@@ -168,6 +169,7 @@ static void rdt_get_cache_config(int idx, struct rdt_resource *r)
 	r->num_closid = edx.split.cos_max + 1;
 	r->cbm_len = eax.split.cbm_len + 1;
 	r->no_ctrl = BIT_MASK(eax.split.cbm_len + 1) - 1;
+	rdt_get_cache_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 53f1917..9d9b7f4 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -517,9 +517,41 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
 
 	return 0;
 }
+static int rdt_max_delay_show(struct kernfs_open_file *of,
+			     struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	seq_printf(seq, "%d\n", r->max_delay);
+
+	return 0;
+}
+
+static int rdt_delay_gran_show(struct kernfs_open_file *of,
+			     struct seq_file *seq, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+
+	if (r->delay_linear)
+		seq_printf(seq, "%d\n", r->delay_gran);
+	else
+		seq_printf(seq, "power of 2\n");
+
+	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, "%d\n", r->delay_linear);
+
+	return 0;
+}
 
 /* rdtgroup information files for one cache resource. */
-static struct rftype res_info_files[] = {
+static struct rftype res_cache_info_files[] = {
 	{
 		.name		= "num_closids",
 		.mode		= 0444,
@@ -540,11 +572,52 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
 	},
 };
 
+/* rdtgroup information files for MBE. */
+static struct rftype res_mbe_info_files[] = {
+	{
+		.name		= "num_closids",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_num_closids_show,
+	},
+	{
+		.name		= "max_thrtl_by",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_max_delay_show,
+	},
+	{
+		.name		= "thrtl_by_gran",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_delay_gran_show,
+	},
+	{
+		.name		= "thrtl_by_linear",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdt_delay_linear_show,
+	},
+};
+
+void rdt_get_mbe_infofile(struct rdt_resource *r)
+{
+	r->info_files = &res_mbe_info_files[0];
+	r->infofiles_len = ARRAY_SIZE(res_mbe_info_files);
+}
+
+void rdt_get_cache_infofile(struct rdt_resource *r)
+{
+	r->info_files = &res_cache_info_files[0];
+	r->infofiles_len = ARRAY_SIZE(res_cache_info_files);
+}
+
 static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
 {
 	struct kernfs_node *kn_subdir;
+	struct rftype *res_info_files;
 	struct rdt_resource *r;
-	int ret;
+	int ret, len;
 
 	/* create the directory */
 	kn_info = kernfs_create_dir(parent_kn, "info", parent_kn->mode, NULL);
@@ -563,8 +636,11 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
 		ret = rdtgroup_kn_set_ugid(kn_subdir);
 		if (ret)
 			goto out_destroy;
-		ret = rdtgroup_add_files(kn_subdir, res_info_files,
-					 ARRAY_SIZE(res_info_files));
+
+		res_info_files = r->info_files;
+		len = r->infofiles_len;
+
+		ret = rdtgroup_add_files(kn_subdir, res_info_files, len);
 		if (ret)
 			goto out_destroy;
 		kernfs_activate(kn_subdir);
-- 
1.9.1