x86/cpu: Move resctrl CPUID code to resctrl/

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@suse.de>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/38433b99f9d16c8f4ee796f8cc42b871531fa203.1588715690.git.reinette.chatre@intel.com

1 files changed, 24 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 6f38c88226af..861c6d1ba9ab 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;