x86/intel_rdt/mba_sc: Add schemata support

Currently when user updates the "schemata" with new MBA percentage
values, kernel writes the corresponding bandwidth percentage values to
the IA32_MBA_THRTL_MSR.

When MBA is expressed in MBps, the schemata format is changed to have the
per package memory bandwidth in MBps instead of being specified in
percentage. Do not write the IA32_MBA_THRTL_MSRs when the schemata is
updated as that is handled separately.

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: hpa@zytor.com
Link: https://lkml.kernel.org/r/1524263781-14267-5-git-send-email-vikas.shivappa@linux.intel.com

diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index 8c09e9db2fc64adf13cb05f642145ff6435fc870..ad03d975883e4a5780fbc274bed9b72b950e96f9 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -179,7 +179,7 @@ struct rdt_resource rdt_resources_all[] = {
                .msr_update             = mba_wrmsr,
                .cache_level            = 3,
                .parse_ctrlval          = parse_bw,
-               .format_str             = "%d=%*d",
+               .format_str             = "%d=%*u",
                .fflags                 = RFTYPE_RES_MB,
        },
 };

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index 23e1d5c249c60bca179e2ede61a98366e426beec..116d57b248d3cae479c47848766a730e620aa253 100644 (file)
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -53,7 +53,8 @@ static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
                return false;
        }
 
-       if (bw < r->membw.min_bw || bw > r->default_ctrl) {
+       if ((bw < r->membw.min_bw || bw > r->default_ctrl) &&
+           !is_mba_sc(r)) {
                rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
                                    r->membw.min_bw, r->default_ctrl);
                return false;
@@ -179,6 +180,8 @@ static int update_domains(struct rdt_resource *r, int closid)
        struct msr_param msr_param;
        cpumask_var_t cpu_mask;
        struct rdt_domain *d;
+       bool mba_sc;
+       u32 *dc;
        int cpu;
 
        if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
@@ -188,13 +191,20 @@ static int update_domains(struct rdt_resource *r, int closid)
        msr_param.high = msr_param.low + 1;
        msr_param.res = r;
 
+       mba_sc = is_mba_sc(r);
        list_for_each_entry(d, &r->domains, list) {
-               if (d->have_new_ctrl && d->new_ctrl != d->ctrl_val[closid]) {
+               dc = !mba_sc ? d->ctrl_val : d->mbps_val;
+               if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
                        cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
-                       d->ctrl_val[closid] = d->new_ctrl;
+                       dc[closid] = d->new_ctrl;
                }
        }
-       if (cpumask_empty(cpu_mask))
+
+       /*
+        * Avoid writing the control msr with control values when
+        * MBA software controller is enabled
+        */
+       if (cpumask_empty(cpu_mask) || mba_sc)
                goto done;
        cpu = get_cpu();
        /* Update CBM on this cpu if it's in cpu_mask. */
@@ -282,13 +292,17 @@ static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
 {
        struct rdt_domain *dom;
        bool sep = false;
+       u32 ctrl_val;
 
        seq_printf(s, "%*s:", max_name_width, r->name);
        list_for_each_entry(dom, &r->domains, list) {
                if (sep)
                        seq_puts(s, ";");
+
+               ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
+                           dom->mbps_val[closid]);
                seq_printf(s, r->format_str, dom->id, max_data_width,
-                          dom->ctrl_val[closid]);
+                          ctrl_val);
                sep = true;
        }
        seq_puts(s, "\n");