[PATCH v7 05/12] x86/resctrl: Detect and configure Slow Memory Bandwidth allocation

Babu Moger
2022-10-17T22:27:19Z

The QoS slow memory configuration details are available via
CPUID_Fn80000020_EDX_x02. Detect the available details and
initialize the rest to defaults.

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
arch/x86/kernel/cpu/resctrl/core.c | 29 +++++++++++++++++++++++++++--
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 2 +-
arch/x86/kernel/cpu/resctrl/internal.h | 1 +
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++------
4 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index c7561c613209..d79f494a4e91 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -231,9 +231,15 @@ static bool __rdt_get_mem_config_amd(struct rdt_resource *r)
struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
union cpuid_0x10_3_eax eax;
union cpuid_0x10_x_edx edx;
- u32 ebx, ecx;
+ u32 ebx, ecx, subleaf;
+
+ /*
+ * Query CPUID_Fn80000020_EDX_x01 for MBA and
+ * CPUID_Fn80000020_EDX_x02 for SMBA
+ */
+ subleaf = (r->rid == RDT_RESOURCE_SMBA) ? 2 : 1;

- cpuid_count(0x80000020, 1, &eax.full, &ebx, &ecx, &edx.full);
+ cpuid_count(0x80000020, subleaf, &eax.full, &ebx, &ecx, &edx.full);
hw_res->num_closid = edx.split.cos_max + 1;
r->default_ctrl = MAX_MBA_BW_AMD;

@@ -756,6 +762,19 @@ static __init bool get_mem_config(void)
return false;
}

+static __init bool get_slow_mem_config(void)
+{
+ struct rdt_hw_resource *hw_res = &rdt_resources_all[RDT_RESOURCE_SMBA];
+
+ if (!rdt_cpu_has(X86_FEATURE_SMBA))
+ return false;
+
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+ return __rdt_get_mem_config_amd(&hw_res->r_resctrl);
+
+ return false;
+}
+
static __init bool get_rdt_alloc_resources(void)
{
struct rdt_resource *r;
@@ -786,6 +805,9 @@ static __init bool get_rdt_alloc_resources(void)
if (get_mem_config())
ret = true;

+ if (get_slow_mem_config())
+ ret = true;
+
return ret;
}

@@ -875,6 +897,9 @@ static __init void rdt_init_res_defs_amd(void)
} else if (r->rid == RDT_RESOURCE_MBA) {
hw_res->msr_base = MSR_IA32_MBA_BW_BASE;
hw_res->msr_update = mba_wrmsr_amd;
+ } else if (r->rid == RDT_RESOURCE_SMBA) {
+ hw_res->msr_base = MSR_IA32_SMBA_BW_BASE;
+ hw_res->msr_update = mba_wrmsr_amd;
}
}
}
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 1dafbdc5ac31..42e2ef6fbdb8 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -210,7 +210,7 @@ static int parse_line(char *line, struct resctrl_schema *s,
unsigned long dom_id;

if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
- r->rid == RDT_RESOURCE_MBA) {
+ (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)) {
rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
return -EINVAL;
}
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 43d9f6f5a931..16e3c6e03c79 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -14,6 +14,7 @@
#define MSR_IA32_L2_CBM_BASE 0xd10
#define MSR_IA32_MBA_THRTL_BASE 0xd50
#define MSR_IA32_MBA_BW_BASE 0xc0000200
+#define MSR_IA32_SMBA_BW_BASE 0xc0000280

#define MSR_IA32_QM_CTR 0x0c8e
#define MSR_IA32_QM_EVTSEL 0x0c8d
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index e5a48f05e787..1271fd1ae2f3 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1213,7 +1213,7 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgroup *rdtgrp)

list_for_each_entry(s, &resctrl_schema_all, list) {
r = s->res;
- if (r->rid == RDT_RESOURCE_MBA)
+ if (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA)
continue;
has_cache = true;
list_for_each_entry(d, &r->domains, list) {
@@ -1402,7 +1402,8 @@ static int rdtgroup_size_show(struct kernfs_open_file *of,
ctrl = resctrl_arch_get_config(r, d,
closid,
type);
- if (r->rid == RDT_RESOURCE_MBA)
+ if (r->rid == RDT_RESOURCE_MBA ||
+ r->rid == RDT_RESOURCE_SMBA)
size = ctrl;
else
size = rdtgroup_cbm_to_size(r, d, ctrl);
@@ -2845,7 +2846,8 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)

list_for_each_entry(s, &resctrl_schema_all, list) {
r = s->res;
- if (r->rid == RDT_RESOURCE_MBA) {
+ if (r->rid == RDT_RESOURCE_MBA ||
+ r->rid == RDT_RESOURCE_SMBA) {
rdtgroup_init_mba(r, rdtgrp->closid);
if (is_mba_sc(r))
continue;
@@ -3287,7 +3289,8 @@ void resctrl_offline_domain(struct rdt_resource *r, struct rdt_domain *d)
{
lockdep_assert_held(&rdtgroup_mutex);

- if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
+ if (supports_mba_mbps() &&
+ (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_SMBA))
mba_sc_domain_destroy(r, d);

if (!r->mon_capable)
@@ -3354,8 +3357,9 @@ int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d)

lockdep_assert_held(&rdtgroup_mutex);

- if (supports_mba_mbps() && r->rid == RDT_RESOURCE_MBA)
- /* RDT_RESOURCE_MBA is never mon_capable */
+ if (supports_mba_mbps() &&
+ (r->rid == RDT_RESOURCE_MBA || r->rid == RDT_RESOURCE_MBA))
+ /* RDT_RESOURCE_MBA (or SMBA) is never mon_capable */
return mba_sc_domain_allocate(r, d);

if (!r->mon_capable)