[PATCH 7/8] x86/intel_rdt: schemata file support for MBA prepare

[Vikas Shivappa]

Add support to introduce generic APIs for control validation and writing
QOS_MSRs for RDT resources. The control validation api is meant to
validate the control values like cache bit mask for CAT and memory b/w
percentage for MBA. A resource generic display format is also added and
used for the resources depending on whether its displayed in
hex/decimal.

Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/intel_rdt.h         |  8 +++++++
 arch/x86/kernel/cpu/intel_rdt.c          | 33 +++++++++++++++++++++-----
 arch/x86/kernel/cpu/intel_rdt_schemata.c | 40 ++++++++++++++++++--------------
 3 files changed, 58 insertions(+), 23 deletions(-)

diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index 24de64c..8748b0d 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -77,6 +77,9 @@ struct rftype {
  * @default_ctrl:		Specifies default cache cbm or mem b/w percent.
  * @min_cbm_bits:		Minimum number of consecutive bits to be set
  *				in a cache bit mask
+ * @format_str:		Per resource format string to show domain val
+ * @parse_ctrlval:		Per resource API to parse the ctrl values
+ * @msr_update:		API to update QOS MSRs
  * @info_files:		resctrl info files for the resource
  * @infofiles_len:		Number of info files
  * @max_delay:			Max throttle delay. Delay is the hardware
@@ -105,6 +108,9 @@ struct rdt_resource {
 	int			cbm_len;
 	int			min_cbm_bits;
 	u32			default_ctrl;
+	const char		*format_str;
+	int (*parse_ctrlval)	(char *buf, struct rdt_resource *r);
+	void (*msr_update)	(void *a1, void *a2, struct rdt_resource *r);
 	struct rftype		*info_files;
 	int			infofiles_len;
 	u32			max_delay;
@@ -150,6 +156,8 @@ struct msr_param {
 
 void rdt_get_cache_infofile(struct rdt_resource *r);
 void rdt_get_mba_infofile(struct rdt_resource *r);
+int parse_cbm(char *buf, struct rdt_resource *r);
+void cqm_wrmsr(void *a1, void *a2, 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 353c476b4..7ce4453 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -44,6 +44,9 @@ struct rdt_resource rdt_resources_all[] = {
 		.name		= "L3",
 		.domains	= domain_init(RDT_RESOURCE_L3),
 		.msr_base	= IA32_L3_CBM_BASE,
+		.parse_ctrlval	= parse_cbm,
+		.msr_update	= cqm_wrmsr,
+		.format_str	= "%d=%x",
 		.min_cbm_bits	= 1,
 		.cache_level	= 3,
 		.cbm_idx_multi	= 1,
@@ -53,6 +56,9 @@ struct rdt_resource rdt_resources_all[] = {
 		.name		= "L3DATA",
 		.domains	= domain_init(RDT_RESOURCE_L3DATA),
 		.msr_base	= IA32_L3_CBM_BASE,
+		.parse_ctrlval	= parse_cbm,
+		.msr_update	= cqm_wrmsr,
+		.format_str	= "%d=%x",
 		.min_cbm_bits	= 1,
 		.cache_level	= 3,
 		.cbm_idx_multi	= 2,
@@ -62,6 +68,9 @@ struct rdt_resource rdt_resources_all[] = {
 		.name		= "L3CODE",
 		.domains	= domain_init(RDT_RESOURCE_L3CODE),
 		.msr_base	= IA32_L3_CBM_BASE,
+		.parse_ctrlval	= parse_cbm,
+		.msr_update	= cqm_wrmsr,
+		.format_str	= "%d=%x",
 		.min_cbm_bits	= 1,
 		.cache_level	= 3,
 		.cbm_idx_multi	= 2,
@@ -71,6 +80,9 @@ struct rdt_resource rdt_resources_all[] = {
 		.name		= "L2",
 		.domains	= domain_init(RDT_RESOURCE_L2),
 		.msr_base	= IA32_L2_CBM_BASE,
+		.parse_ctrlval	= parse_cbm,
+		.msr_update	= cqm_wrmsr,
+		.format_str	= "%d=%x",
 		.min_cbm_bits	= 1,
 		.cache_level	= 2,
 		.cbm_idx_multi	= 1,
@@ -258,11 +270,24 @@ static int get_cache_id(int cpu, int level)
 	return -1;
 }
 
+void cqm_wrmsr(void *a1, void *a2, struct rdt_resource *r)
+{
+	struct rdt_domain *d = (struct rdt_domain *)a2;
+	struct msr_param *m = (struct msr_param *)a1;
+	int i;
+
+	for (i = m->low; i < m->high; i++) {
+		int idx = cbm_idx(r, i);
+
+		wrmsrl(r->msr_base + idx, d->ctrl_val[i]);
+	}
+}
+
 void rdt_ctrl_update(void *arg)
 {
 	struct msr_param *m = (struct msr_param *)arg;
 	struct rdt_resource *r = m->res;
-	int i, cpu = smp_processor_id();
+	int cpu = smp_processor_id();
 	struct rdt_domain *d;
 
 	list_for_each_entry(d, &r->domains, list) {
@@ -276,11 +301,7 @@ void rdt_ctrl_update(void *arg)
 	return;
 
 found:
-	for (i = m->low; i < m->high; i++) {
-		int idx = cbm_idx(r, i);
-
-		wrmsrl(r->msr_base + idx, d->ctrl_val[i]);
-	}
+	r->msr_update(m, d, r);
 }
 
 /*
diff --git a/arch/x86/kernel/cpu/intel_rdt_schemata.c b/arch/x86/kernel/cpu/intel_rdt_schemata.c
index 3cde1e8..4141662 100644
--- a/arch/x86/kernel/cpu/intel_rdt_schemata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -34,41 +34,46 @@
  *	are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
  * Additionally Haswell requires at least two bits set.
  */
-static bool cbm_validate(unsigned long var, struct rdt_resource *r)
+static int cbm_validate(char *buf, unsigned long *data, struct rdt_resource *r)
 {
-	unsigned long first_bit, zero_bit;
+	unsigned long first_bit, zero_bit, var;
+	int ret;
+
+	ret = kstrtoul(buf, 16, &var);
+	if (ret)
+		return ret;
 
 	if (var == 0 || var > r->default_ctrl)
-		return false;
+		return -EINVAL;
 
 	first_bit = find_first_bit(&var, r->cbm_len);
 	zero_bit = find_next_zero_bit(&var, r->cbm_len, first_bit);
 
 	if (find_next_bit(&var, r->cbm_len, zero_bit) < r->cbm_len)
-		return false;
+		return -EINVAL;
 
 	if ((zero_bit - first_bit) < r->min_cbm_bits)
-		return false;
-	return true;
+		return -EINVAL;
+
+	*data = var;
+
+	return 0;
 }
 
 /*
- * Read one cache bit mask (hex). Check that it is valid for the current
- * resource type.
+ * Read the user RDT control value into tempory buffer:
+ * Cache bit mask (hex) or Memory b/w throttle (decimal).
+ * Check that it is valid for the current resource type.
  */
-static int parse_cbm(char *buf, struct rdt_resource *r)
+int parse_cbm(char *buf, struct rdt_resource *r)
 {
 	unsigned long data;
 	int ret;
 
-	ret = kstrtoul(buf, 16, &data);
-	if (ret)
-		return ret;
-	if (!cbm_validate(data, r))
-		return -EINVAL;
+	ret = cbm_validate(buf, &data, r);
 	r->tmp_ctrl[r->num_tmp_ctrl++] = data;
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -90,7 +95,7 @@ static int parse_line(char *line, struct rdt_resource *r)
 		id = strsep(&dom, "=");
 		if (kstrtoul(id, 10, &dom_id) || dom_id != d->id)
 			return -EINVAL;
-		if (parse_cbm(dom, r))
+		if (r->parse_ctrlval(dom, r))
 			return -EINVAL;
 	}
 
@@ -240,7 +245,8 @@ static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
 	list_for_each_entry(dom, &r->domains, list) {
 		if (sep)
 			seq_puts(s, ";");
-		seq_printf(s, "%d=%x", dom->id, dom->ctrl_val[closid]);
+
+		seq_printf(s, r->format_str, dom->id, dom->ctrl_val[closid]);
 		sep = true;
 	}
 	seq_puts(s, "\n");
-- 
1.9.1