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Subject[tip: perf/core] perf/x86: Expose CPUID enumeration bits for arch LBR
The following commit has been merged into the perf/core branch of tip:

Commit-ID: af6cf129706b2f79e12f97e62d977e7f653cdfd1
Gitweb: https://git.kernel.org/tip/af6cf129706b2f79e12f97e62d977e7f653cdfd1
Author: Kan Liang <kan.liang@linux.intel.com>
AuthorDate: Fri, 03 Jul 2020 05:49:14 -07:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 08 Jul 2020 11:38:53 +02:00

perf/x86: Expose CPUID enumeration bits for arch LBR

The LBR capabilities of Architecture LBR are retrieved from the CPUID
enumeration once at boot time. The capabilities have to be saved for
future usage.

Several new fields are added into structure x86_pmu to indicate the
capabilities. The fields will be used in the following patches.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/1593780569-62993-9-git-send-email-kan.liang@linux.intel.com
---
arch/x86/events/perf_event.h | 13 ++++++++++-
arch/x86/include/asm/perf_event.h | 40 ++++++++++++++++++++++++++++++-
2 files changed, 53 insertions(+)

diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 7dbf148..cc81177 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -693,6 +693,19 @@ struct x86_pmu {
bool lbr_double_abort; /* duplicated lbr aborts */
bool lbr_pt_coexist; /* (LBR|BTS) may coexist with PT */

+ /*
+ * Intel Architectural LBR CPUID Enumeration
+ */
+ unsigned int lbr_depth_mask:8;
+ unsigned int lbr_deep_c_reset:1;
+ unsigned int lbr_lip:1;
+ unsigned int lbr_cpl:1;
+ unsigned int lbr_filter:1;
+ unsigned int lbr_call_stack:1;
+ unsigned int lbr_mispred:1;
+ unsigned int lbr_timed_lbr:1;
+ unsigned int lbr_br_type:1;
+
void (*lbr_reset)(void);
void (*lbr_read)(struct cpu_hw_events *cpuc);
void (*lbr_save)(void *ctx);
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 2df7073..9ffce7d 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -142,6 +142,46 @@ union cpuid10_edx {
unsigned int full;
};

+/*
+ * Intel Architectural LBR CPUID detection/enumeration details:
+ */
+union cpuid28_eax {
+ struct {
+ /* Supported LBR depth values */
+ unsigned int lbr_depth_mask:8;
+ unsigned int reserved:22;
+ /* Deep C-state Reset */
+ unsigned int lbr_deep_c_reset:1;
+ /* IP values contain LIP */
+ unsigned int lbr_lip:1;
+ } split;
+ unsigned int full;
+};
+
+union cpuid28_ebx {
+ struct {
+ /* CPL Filtering Supported */
+ unsigned int lbr_cpl:1;
+ /* Branch Filtering Supported */
+ unsigned int lbr_filter:1;
+ /* Call-stack Mode Supported */
+ unsigned int lbr_call_stack:1;
+ } split;
+ unsigned int full;
+};
+
+union cpuid28_ecx {
+ struct {
+ /* Mispredict Bit Supported */
+ unsigned int lbr_mispred:1;
+ /* Timed LBRs Supported */
+ unsigned int lbr_timed_lbr:1;
+ /* Branch Type Field Supported */
+ unsigned int lbr_br_type:1;
+ } split;
+ unsigned int full;
+};
+
struct x86_pmu_capability {
int version;
int num_counters_gp;
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