Patch "x86/cpu: Move resctrl CPUID code to resctrl/" has been added to the 5.7-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    x86/cpu: Move resctrl CPUID code to resctrl/

to the 5.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-cpu-move-resctrl-cpuid-code-to-resctrl.patch
and it can be found in the queue-5.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 51c4c3cc86d5776ae81bcd298ed7c236ed109dfc
Author: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Date:   Tue May 5 15:36:13 2020 -0700

    x86/cpu: Move resctrl CPUID code to resctrl/
    
    [ Upstream commit 0118ad82c2a64ebcf15d7565ed35361407efadfa ]
    
    The function determining a platform's support and properties of cache
    occupancy and memory bandwidth monitoring (properties of
    X86_FEATURE_CQM_LLC) can be found among the common CPU code. After
    the feature's properties is populated in the per-CPU data the resctrl
    subsystem is the only consumer (via boot_cpu_data).
    
    Move the function that obtains the CPU information used by resctrl to
    the resctrl subsystem and rename it from init_cqm() to
    resctrl_cpu_detect(). The function continues to be called from the
    common CPU code. This move is done in preparation of the addition of some
    vendor specific code.
    
    No functional change.
    
    Suggested-by: Borislav Petkov <bp@xxxxxxx>
    Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
    Signed-off-by: Borislav Petkov <bp@xxxxxxx>
    Link: https://lkml.kernel.org/r/38433b99f9d16c8f4ee796f8cc42b871531fa203.1588715690.git.reinette.chatre@xxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/x86/include/asm/resctrl_sched.h b/arch/x86/include/asm/resctrl_sched.h
index f6b7fe2833cc7..c8a27cbbdae29 100644
--- a/arch/x86/include/asm/resctrl_sched.h
+++ b/arch/x86/include/asm/resctrl_sched.h
@@ -84,9 +84,12 @@ static inline void resctrl_sched_in(void)
 		__resctrl_sched_in();
 }
 
+void resctrl_cpu_detect(struct cpuinfo_x86 *c);
+
 #else
 
 static inline void resctrl_sched_in(void) {}
+static inline void resctrl_cpu_detect(struct cpuinfo_x86 *c) {}
 
 #endif /* CONFIG_X86_CPU_RESCTRL */
 
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8293ee5149758..1a74a22bfe44a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -56,6 +56,7 @@
 #include <asm/intel-family.h>
 #include <asm/cpu_device_id.h>
 #include <asm/uv/uv.h>
+#include <asm/resctrl.h>
 
 #include "cpu.h"
 
@@ -854,30 +855,6 @@ static void init_speculation_control(struct cpuinfo_x86 *c)
 	}
 }
 
-static void init_cqm(struct cpuinfo_x86 *c)
-{
-	if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {
-		c->x86_cache_max_rmid  = -1;
-		c->x86_cache_occ_scale = -1;
-		return;
-	}
-
-	/* will be overridden if occupancy monitoring exists */
-	c->x86_cache_max_rmid = cpuid_ebx(0xf);
-
-	if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC) ||
-	    cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL) ||
-	    cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)) {
-		u32 eax, ebx, ecx, edx;
-
-		/* QoS sub-leaf, EAX=0Fh, ECX=1 */
-		cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
-
-		c->x86_cache_max_rmid  = ecx;
-		c->x86_cache_occ_scale = ebx;
-	}
-}
-
 void get_cpu_cap(struct cpuinfo_x86 *c)
 {
 	u32 eax, ebx, ecx, edx;
@@ -945,7 +922,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 
 	init_scattered_cpuid_features(c);
 	init_speculation_control(c);
-	init_cqm(c);
+	resctrl_cpu_detect(c);
 
 	/*
 	 * Clear/Set all flags overridden by options, after probe.
diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index d8cc5223b7ce8..49599733fa94d 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -958,6 +958,30 @@ static __init void rdt_init_res_defs(void)
 
 static enum cpuhp_state rdt_online;
 
+void resctrl_cpu_detect(struct cpuinfo_x86 *c)
+{
+	if (!cpu_has(c, X86_FEATURE_CQM_LLC)) {
+		c->x86_cache_max_rmid  = -1;
+		c->x86_cache_occ_scale = -1;
+		return;
+	}
+
+	/* will be overridden if occupancy monitoring exists */
+	c->x86_cache_max_rmid = cpuid_ebx(0xf);
+
+	if (cpu_has(c, X86_FEATURE_CQM_OCCUP_LLC) ||
+	    cpu_has(c, X86_FEATURE_CQM_MBM_TOTAL) ||
+	    cpu_has(c, X86_FEATURE_CQM_MBM_LOCAL)) {
+		u32 eax, ebx, ecx, edx;
+
+		/* QoS sub-leaf, EAX=0Fh, ECX=1 */
+		cpuid_count(0xf, 1, &eax, &ebx, &ecx, &edx);
+
+		c->x86_cache_max_rmid  = ecx;
+		c->x86_cache_occ_scale = ebx;
+	}
+}
+
 static int __init resctrl_late_init(void)
 {
 	struct rdt_resource *r;