[PATCH v1 08/14] fs/resctrl: Extend schemata write for priority partition control

[Amit Singh Tomar]

Currently, Users can pass the configurations for CPBM, and MBA through
schemata file. For instance, CPBM can be passed using:

echo L3:0=ffff > schemata

This change allows, users to pass a new configuration for downstream
priority. For instance, dspri value of "0xa" can be passed as:

echo L3DSPRI:0=a > schemata

Signed-off-by: Amit Singh Tomar <amitsinght@xxxxxxxxxxx>
---
Changes since RFC:
		* As suggested by Fenghua Yu, Parse for DSPRI is called
		  from parse_line().
		* Decluttering code from rdtgroup_schemata_write().
---
 fs/resctrl/ctrlmondata.c | 59 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 56 insertions(+), 3 deletions(-)

diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
index 78f9fb1c52fa..f1f57bbfa094 100644
--- a/fs/resctrl/ctrlmondata.c
+++ b/fs/resctrl/ctrlmondata.c
@@ -30,6 +30,55 @@ typedef int (ctrlval_parser_t)(struct rdt_parse_data *data,
 			       struct resctrl_schema *s,
 			       struct rdt_domain *d);
 
+static bool dspri_validate(char *buf, unsigned long *data, struct rdt_resource *r)
+{
+
+	unsigned long dspri_val;
+	bool success = true;
+	int ret;
+
+	ret = kstrtoul(buf, 16, &dspri_val);
+	if (ret) {
+		pr_info("Non-hex character in the mask %s\n", buf);
+		success = false;
+		goto out;
+	}
+
+	if (dspri_val > r->default_dspri_ctrl) {
+		pr_info("dspri value %ld out of range [%d-%d]\n", dspri_val,
+					0, r->default_dspri_ctrl);
+		success = false;
+		goto out;
+	}
+
+	*data = dspri_val;
+
+out:
+	return success;
+}
+
+static int parse_dspri(struct rdt_parse_data *data, struct resctrl_schema *s,
+			struct rdt_domain *d)
+{
+	struct resctrl_staged_config *cfg;
+	struct rdt_resource *r = s->res;
+	unsigned long pri_val;
+
+	cfg = &d->staged_config[s->conf_type];
+	if (cfg->have_new_ctrl) {
+		pr_info("Duplicate domain %d\n", d->id);
+		return -EINVAL;
+	}
+
+	if (!dspri_validate(data->buf, &pri_val, r))
+		return -EINVAL;
+
+	cfg->new_ctrl = pri_val;
+	cfg->have_new_ctrl = true;
+
+	return 0;
+}
+
 /*
  * Check whether MBA bandwidth percentage value is correct. The value is
  * checked against the minimum and max bandwidth values specified by the
@@ -201,10 +250,14 @@ static int parse_cbm(struct rdt_parse_data *data, struct resctrl_schema *s,
 	return 0;
 }
 
-static ctrlval_parser_t *get_parser(struct rdt_resource *res)
+static ctrlval_parser_t *get_parser(struct resctrl_schema *s)
 {
-	if (res->fflags & RFTYPE_RES_CACHE)
+	struct rdt_resource *res = s->res;
+
+	if (res->fflags & RFTYPE_RES_CACHE && !s->ctrl_type)
 		return &parse_cbm;
+	else if (s->ctrl_type == SCHEMA_DSPRI)
+		return &parse_dspri;
 	else
 		return &parse_bw;
 }
@@ -218,7 +271,7 @@ static ctrlval_parser_t *get_parser(struct rdt_resource *res)
 static int parse_line(char *line, struct resctrl_schema *s,
 		      struct rdtgroup *rdtgrp)
 {
-	ctrlval_parser_t *parse_ctrlval = get_parser(s->res);
+	ctrlval_parser_t *parse_ctrlval = get_parser(s);
 	enum resctrl_conf_type t = s->conf_type;
 	struct resctrl_staged_config *cfg;
 	struct rdt_resource *r = s->res;
-- 
2.25.1