Commit 9603aa79 authored by Sandipan Das's avatar Sandipan Das Committed by Peter Zijlstra
Browse files

perf/x86/amd/core: Refactor branch attributes 



AMD processors that are capable of recording branches support either Branch
Sampling (BRS) or Last Branch Record (LBR). In preparation for adding Last
Branch Record Extension Version 2 (LbrExtV2) support, reuse the "branches"
capability to advertise information about both BRS and LBR but make the
"branch-brs" event exclusive to Family 19h processors that support BRS.

Signed-off-by: default avatarSandipan Das <sandipan.das@amd.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ba4a4cde6db79b1c65c49834027bbdb8a915546b.1660211399.git.sandipan.das@amd.com
parent b40d0156

arch/x86/events/amd/core.c

+19 −6
Original line number Diff line number Diff line
@@ -1247,23 +1247,25 @@ static ssize_t branches_show(struct device *cdev, 


static DEVICE_ATTR_RO(branches);



static struct attribute *amd_pmu_brs_attrs[] = {

static struct attribute *amd_pmu_branches_attrs[] = {

	&dev_attr_branches.attr,

	NULL,

};



static umode_t

amd_brs_is_visible(struct kobject *kobj, struct attribute *attr, int i)

amd_branches_is_visible(struct kobject *kobj, struct attribute *attr, int i)

{

	return x86_pmu.lbr_nr ? attr->mode : 0;

}



static struct attribute_group group_caps_amd_brs = {

static struct attribute_group group_caps_amd_branches = {

	.name  = "caps",

	.attrs = amd_pmu_brs_attrs,

	.is_visible = amd_brs_is_visible,

	.attrs = amd_pmu_branches_attrs,

	.is_visible = amd_branches_is_visible,

};



#ifdef CONFIG_PERF_EVENTS_AMD_BRS



EVENT_ATTR_STR(branch-brs, amd_branch_brs,

	       "event=" __stringify(AMD_FAM19H_BRS_EVENT)"\n");
@@ -1272,15 +1274,26 @@ static struct attribute *amd_brs_events_attrs[] = { 
	NULL,

};



static umode_t

amd_brs_is_visible(struct kobject *kobj, struct attribute *attr, int i)

{

	return static_cpu_has(X86_FEATURE_BRS) && x86_pmu.lbr_nr ?

	       attr->mode : 0;

}



static struct attribute_group group_events_amd_brs = {

	.name       = "events",

	.attrs      = amd_brs_events_attrs,

	.is_visible = amd_brs_is_visible,

};



#endif	/* CONFIG_PERF_EVENTS_AMD_BRS */



static const struct attribute_group *amd_attr_update[] = {

	&group_caps_amd_brs,

	&group_caps_amd_branches,

#ifdef CONFIG_PERF_EVENTS_AMD_BRS

	&group_events_amd_brs,

#endif

	NULL,

};