The MBA feature details like minimum bandwidth supported, b/w
granularity etc are obtained via executing CPUID with EAX=10H
,ECX=3.
Setup and initialize the MBA specific extensions to data structures like
global list of RDT resources, RDT resource structure and RDT domain
structure.
Signed-off-by: Vikas Shivappa <vikas.shiva...@linux.intel.com>
---
arch/x86/include/asm/intel_rdt.h | 17 +++++++
arch/x86/kernel/cpu/intel_rdt.c | 95 ++++++++++++++++++++++++++++++++++------
2 files changed, 99 insertions(+), 13 deletions(-)
diff --git a/arch/x86/include/asm/intel_rdt.h b/arch/x86/include/asm/intel_rdt.h
index d2eee45..af65b2a 100644
--- a/arch/x86/include/asm/intel_rdt.h
+++ b/arch/x86/include/asm/intel_rdt.h
@@ -11,6 +11,9 @@
#define IA32_L3_QOS_CFG 0xc81
#define IA32_L3_CBM_BASE 0xc90
#define IA32_L2_CBM_BASE 0xd10
+#define IA32_MBA_THRTL_BASE 0xd50
+#define MAX_MBA_THRTL 100u
+#define MBA_IS_LINEAR 0x4
#define L3_QOS_CDP_ENABLE 0x01ULL
@@ -74,6 +77,14 @@ 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
+ * @max_delay: Max throttle delay. Delay is the hardware
+ * understandable value for memory b/w.
+ * @min_bw: Minimum memory bandwidth in percentage
+ * user can request
+ * @bw_gran: Bandwidth granularity
+ * @delay_linear: True if Mem b/w delay is in linear scale
+ * @mb_map: Mapping of mem b/w delay to
+ * b/w throttle percentage
* @domains: All domains for this resource
* @num_domains: Number of domains active
* @msr_base: Base MSR address for CBMs
@@ -92,6 +103,11 @@ struct rdt_resource {
int cbm_len;
int min_cbm_bits;
u32 default_ctrl;
+ u32 max_delay;
+ u32 min_bw;
+ u32 bw_gran;
+ u32 delay_linear;
+ u32 *mb_map;
struct list_head domains;
int num_domains;
int msr_base;
@@ -141,6 +157,7 @@ enum {
RDT_RESOURCE_L3DATA,
RDT_RESOURCE_L3CODE,
RDT_RESOURCE_L2,
+ RDT_RESOURCE_MBA,
/* Must be the last */
RDT_NUM_RESOURCES,
diff --git a/arch/x86/kernel/cpu/intel_rdt.c b/arch/x86/kernel/cpu/intel_rdt.c
index b76a518..130ce98 100644
--- a/arch/x86/kernel/cpu/intel_rdt.c
+++ b/arch/x86/kernel/cpu/intel_rdt.c
@@ -76,6 +76,14 @@ struct rdt_resource rdt_resources_all[] = {
.cbm_idx_multi = 1,
.cbm_idx_offset = 0
},
+ {
+ .name = "MB",
+ .domains = domain_init(RDT_RESOURCE_MBA),
+ .msr_base = IA32_MBA_THRTL_BASE,
+ .cache_level = 3,
+ .cbm_idx_multi = 1,
+ .cbm_idx_offset = 0
+ },
};
static int cbm_idx(struct rdt_resource *r, int closid)
@@ -130,6 +138,51 @@ static inline bool cache_alloc_hsw_probe(void)
return false;
}
+/*
+ * rdt_get_mb_table() - get a mapping of b/w percentage values
+ * exposed to user interface and the h/w understandable delay values.
+ *
+ * The non-linear delay values have the granularity of power of two
+ * and also the h/w does not guarantee a curve for configured delay
+ * values vs. actual b/w throttled.
+ * Hence we need a mapping that is pre caliberated for user to express
+ * the b/w in terms of any sensible number.
+ */
+static inline int rdt_get_mb_table(struct rdt_resource *r)
+{
+ /*
+ * There are no Intel SKUs as of now to support non-linear delay.
+ */
+ r->mb_map = NULL;
+
+ return -ENODEV;
+}
+
+static bool rdt_get_mem_config(struct rdt_resource *r)
+{
+ union cpuid_0x10_3_eax eax;
+ union cpuid_0x10_x_edx edx;
+ u32 ebx, ecx;
+
+ cpuid_count(0x00000010, 3, &eax.full, &ebx, &ecx, &edx.full);
+ r->num_closid = edx.split.cos_max + 1;
+ r->max_delay = eax.split.max_delay + 1;
+ r->default_ctrl = MAX_MBA_THRTL;
+ if (ecx & MBA_IS_LINEAR) {
+ r->delay_linear = true;
+ r->min_bw = MAX_MBA_THRTL - r->max_delay;
+ r->bw_gran = MAX_MBA_THRTL - r->max_delay;
+ } else {
+ if (rdt_get_mb_table(r))
+ return false;
+ }
+
+ r->capable = true;
+ r->enabled = true;
+
+ return true;
+}
+
static void rdt_get_cache_config(int idx, struct rdt_resource *r)
{
union cpuid_0x10_1_eax eax;
@@ -184,9 +237,8 @@ static inline bool get_rdt_resources(void)
ret = true;
}
- if (boot_cpu_has(X86_FEATURE_MBA)) {
- ret = true;
- }
+ if (boot_cpu_has(X86_FEATURE_MBA))
+ ret = rdt_get_mem_config(&rdt_resources_all[RDT_RESOURCE_MBA]);
return ret;
}
@@ -262,6 +314,30 @@ static struct rdt_domain *rdt_find_domain(struct
rdt_resource *r, int id,
return NULL;
}
+static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d)
+{
+ int i;
+
+ d->ctrl_val = kmalloc_array(r->num_closid,
+ sizeof(*d->ctrl_val), GFP_KERNEL);
+ if (!d->ctrl_val)
+ return -ENOMEM;
+
+ /*
+ * Initialize the Control MSRs to having no control.
+ * For Cache Allocation: Set all bits in cbm
+ * For Memory Allocation: Set b/w requested to 100
+ */
+ for (i = 0; i < r->num_closid; i++) {
+ int idx = cbm_idx(r, i);
+
+ d->ctrl_val[i] = r->default_ctrl;
+ wrmsrl(r->msr_base + idx, d->ctrl_val[i]);
+ }
+
+ return 0;
+}
+
/*
* domain_add_cpu - Add a cpu to a resource's domain list.
*
@@ -277,7 +353,7 @@ static struct rdt_domain *rdt_find_domain(struct
rdt_resource *r, int id,
*/
static void domain_add_cpu(int cpu, struct rdt_resource *r)
{
- int i, id = get_cache_id(cpu, r->cache_level);
+ int id = get_cache_id(cpu, r->cache_level), ret;
struct list_head *add_pos = NULL;
struct rdt_domain *d;
@@ -298,19 +374,12 @@ static void domain_add_cpu(int cpu, struct rdt_resource
*r)
d->id = id;
- d->ctrl_val = kmalloc_array(r->num_closid, sizeof(*d->ctrl_val),
GFP_KERNEL);
- if (!d->ctrl_val) {
+ ret = domain_setup_ctrlval(r, d);
+ if (ret) {
kfree(d);
return;
}
- for (i = 0; i < r->num_closid; i++) {
- int idx = cbm_idx(r, i);
-
- d->ctrl_val[i] = r->default_ctrl;
- wrmsrl(r->msr_base + idx, d->ctrl_val[i]);
- }
-
cpumask_set_cpu(cpu, &d->cpu_mask);
list_add_tail(&d->list, add_pos);
r->num_domains++;
--
1.9.1
