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

From: Vikas Shivappa
Date: Fri Feb 17 2017 - 14:58:48 EST


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