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Subject: [PATCH v8 05/13] x86/resctrl: Detect and configure Slow Memory
 Bandwidth Allocation
From:   Babu Moger <babu.moger@amd.com>
To:     <corbet@lwn.net>, <reinette.chatre@intel.com>,
        <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>
CC:     <fenghua.yu@intel.com>, <dave.hansen@linux.intel.com>,
        <x86@kernel.org>, <hpa@zytor.com>, <paulmck@kernel.org>,
        <akpm@linux-foundation.org>, <quic_neeraju@quicinc.com>,
        <rdunlap@infradead.org>, <damien.lemoal@opensource.wdc.com>,
        <songmuchun@bytedance.com>, <peterz@infradead.org>,
        <jpoimboe@kernel.org>, <pbonzini@redhat.com>, <babu.moger@amd.com>,
        <chang.seok.bae@intel.com>, <pawan.kumar.gupta@linux.intel.com>,
        <jmattson@google.com>, <daniel.sneddon@linux.intel.com>,
        <sandipan.das@amd.com>, <tony.luck@intel.com>,
        <james.morse@arm.com>, <linux-doc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <bagasdotme@gmail.com>,
        <eranian@google.com>
Date:   Fri, 4 Nov 2022 15:00:29 -0500
Message-ID: <166759202922.3281208.6231300030834095574.stgit@bmoger-ubuntu>
In-Reply-To: <166759188265.3281208.11769277079826754455.stgit@bmoger-ubuntu>
References: <166759188265.3281208.11769277079826754455.stgit@bmoger-ubuntu>
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The QoS slow memory configuration details are available via=0A=
CPUID_Fn80000020_EDX_x02. Detect the available details and=0A=
initialize the rest to defaults.=0A=
=0A=
Signed-off-by: Babu Moger <babu.moger@amd.com>=0A=
---=0A=
 arch/x86/kernel/cpu/resctrl/core.c        |   36 +++++++++++++++++++++++++=
++--=0A=
 arch/x86/kernel/cpu/resctrl/ctrlmondata.c |    2 +-=0A=
 arch/x86/kernel/cpu/resctrl/internal.h    |    1 +=0A=
 arch/x86/kernel/cpu/resctrl/rdtgroup.c    |    8 ++++--=0A=
 4 files changed, 41 insertions(+), 6 deletions(-)=0A=
=0A=
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resct=
rl/core.c=0A=
index e31c98e2fafc..6571d08e2b0d 100644=0A=
--- a/arch/x86/kernel/cpu/resctrl/core.c=0A=
+++ b/arch/x86/kernel/cpu/resctrl/core.c=0A=
@@ -162,6 +162,13 @@ bool is_mba_sc(struct rdt_resource *r)=0A=
 	if (!r)=0A=
 		return rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.mba_sc;=0A=
 =0A=
+	/*=0A=
+	 * The software controller support is only applicable to MBA resource.=0A=
+	 * Make sure to check for resource type again.=0A=
+	 */=0A=
+	if (r->rid !=3D RDT_RESOURCE_MBA)=0A=
+		return false;=0A=
+=0A=
 	return r->membw.mba_sc;=0A=
 }=0A=
 =0A=
@@ -225,9 +232,15 @@ static bool __rdt_get_mem_config_amd(struct rdt_resour=
ce *r)=0A=
 	struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r);=0A=
 	union cpuid_0x10_3_eax eax;=0A=
 	union cpuid_0x10_x_edx edx;=0A=
-	u32 ebx, ecx;=0A=
+	u32 ebx, ecx, subleaf;=0A=
 =0A=
-	cpuid_count(0x80000020, 1, &eax.full, &ebx, &ecx, &edx.full);=0A=
+	/*=0A=
+	 * Query CPUID_Fn80000020_EDX_x01 for MBA and=0A=
+	 * CPUID_Fn80000020_EDX_x02 for SMBA=0A=
+	 */=0A=
+	subleaf =3D (r->rid =3D=3D RDT_RESOURCE_SMBA) ? 2 :  1;=0A=
+=0A=
+	cpuid_count(0x80000020, subleaf, &eax.full, &ebx, &ecx, &edx.full);=0A=
 	hw_res->num_closid =3D edx.split.cos_max + 1;=0A=
 	r->default_ctrl =3D MAX_MBA_BW_AMD;=0A=
 =0A=
@@ -750,6 +763,19 @@ static __init bool get_mem_config(void)=0A=
 	return false;=0A=
 }=0A=
 =0A=
+static __init bool get_slow_mem_config(void)=0A=
+{=0A=
+	struct rdt_hw_resource *hw_res =3D &rdt_resources_all[RDT_RESOURCE_SMBA];=
=0A=
+=0A=
+	if (!rdt_cpu_has(X86_FEATURE_SMBA))=0A=
+		return false;=0A=
+=0A=
+	if (boot_cpu_data.x86_vendor =3D=3D X86_VENDOR_AMD)=0A=
+		return __rdt_get_mem_config_amd(&hw_res->r_resctrl);=0A=
+=0A=
+	return false;=0A=
+}=0A=
+=0A=
 static __init bool get_rdt_alloc_resources(void)=0A=
 {=0A=
 	struct rdt_resource *r;=0A=
@@ -780,6 +806,9 @@ static __init bool get_rdt_alloc_resources(void)=0A=
 	if (get_mem_config())=0A=
 		ret =3D true;=0A=
 =0A=
+	if (get_slow_mem_config())=0A=
+		ret =3D true;=0A=
+=0A=
 	return ret;=0A=
 }=0A=
 =0A=
@@ -869,6 +898,9 @@ static __init void rdt_init_res_defs_amd(void)=0A=
 		} else if (r->rid =3D=3D RDT_RESOURCE_MBA) {=0A=
 			hw_res->msr_base =3D MSR_IA32_MBA_BW_BASE;=0A=
 			hw_res->msr_update =3D mba_wrmsr_amd;=0A=
+		} else if (r->rid =3D=3D RDT_RESOURCE_SMBA) {=0A=
+			hw_res->msr_base =3D MSR_IA32_SMBA_BW_BASE;=0A=
+			hw_res->msr_update =3D mba_wrmsr_amd;=0A=
 		}=0A=
 	}=0A=
 }=0A=
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cp=
u/resctrl/ctrlmondata.c=0A=
index 1df0e3262bca..2dd4b8c47f23 100644=0A=
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c=0A=
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c=0A=
@@ -209,7 +209,7 @@ static int parse_line(char *line, struct resctrl_schema=
 *s,=0A=
 	unsigned long dom_id;=0A=
 =0A=
 	if (rdtgrp->mode =3D=3D RDT_MODE_PSEUDO_LOCKSETUP &&=0A=
-	    r->rid =3D=3D RDT_RESOURCE_MBA) {=0A=
+	    (r->rid =3D=3D RDT_RESOURCE_MBA || r->rid =3D=3D RDT_RESOURCE_SMBA)) =
{=0A=
 		rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");=0A=
 		return -EINVAL;=0A=
 	}=0A=
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r=
esctrl/internal.h=0A=
index 43d9f6f5a931..16e3c6e03c79 100644=0A=
--- a/arch/x86/kernel/cpu/resctrl/internal.h=0A=
+++ b/arch/x86/kernel/cpu/resctrl/internal.h=0A=
@@ -14,6 +14,7 @@=0A=
 #define MSR_IA32_L2_CBM_BASE		0xd10=0A=
 #define MSR_IA32_MBA_THRTL_BASE		0xd50=0A=
 #define MSR_IA32_MBA_BW_BASE		0xc0000200=0A=
+#define MSR_IA32_SMBA_BW_BASE		0xc0000280=0A=
 =0A=
 #define MSR_IA32_QM_CTR			0x0c8e=0A=
 #define MSR_IA32_QM_EVTSEL		0x0c8d=0A=
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r=
esctrl/rdtgroup.c=0A=
index e5a48f05e787..8a3dafc0dbf7 100644=0A=
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c=0A=
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c=0A=
@@ -1213,7 +1213,7 @@ static bool rdtgroup_mode_test_exclusive(struct rdtgr=
oup *rdtgrp)=0A=
 =0A=
 	list_for_each_entry(s, &resctrl_schema_all, list) {=0A=
 		r =3D s->res;=0A=
-		if (r->rid =3D=3D RDT_RESOURCE_MBA)=0A=
+		if (r->rid =3D=3D RDT_RESOURCE_MBA || r->rid =3D=3D RDT_RESOURCE_SMBA)=
=0A=
 			continue;=0A=
 		has_cache =3D true;=0A=
 		list_for_each_entry(d, &r->domains, list) {=0A=
@@ -1402,7 +1402,8 @@ static int rdtgroup_size_show(struct kernfs_open_file=
 *of,=0A=
 					ctrl =3D resctrl_arch_get_config(r, d,=0A=
 								       closid,=0A=
 								       type);=0A=
-				if (r->rid =3D=3D RDT_RESOURCE_MBA)=0A=
+				if (r->rid =3D=3D RDT_RESOURCE_MBA ||=0A=
+				    r->rid =3D=3D RDT_RESOURCE_SMBA)=0A=
 					size =3D ctrl;=0A=
 				else=0A=
 					size =3D rdtgroup_cbm_to_size(r, d, ctrl);=0A=
@@ -2845,7 +2846,8 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgr=
p)=0A=
 =0A=
 	list_for_each_entry(s, &resctrl_schema_all, list) {=0A=
 		r =3D s->res;=0A=
-		if (r->rid =3D=3D RDT_RESOURCE_MBA) {=0A=
+		if (r->rid =3D=3D RDT_RESOURCE_MBA ||=0A=
+		    r->rid =3D=3D RDT_RESOURCE_SMBA) {=0A=
 			rdtgroup_init_mba(r, rdtgrp->closid);=0A=
 			if (is_mba_sc(r))=0A=
 				continue;=0A=
=0A=