From: Anshuman Khandual <anshuman.khandual@arm.com>
Date: Wed, 24 Aug 2022 04:48:17 +0000 (+0530)
Subject: perf: Capture branch privilege information
X-Git-Tag: v6.1-rc1~97^2~60
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5402d25aa5710d240040f73fb13d7d5c303ef071;p=thirdparty%2Fkernel%2Flinux.git

perf: Capture branch privilege information

Platforms like arm64 could capture privilege level information for all the
branch records. Hence this adds a new element in the struct branch_entry to
record the privilege level information, which could be requested through a
new event.attr.branch_sample_type based flag PERF_SAMPLE_BRANCH_PRIV_SAVE.
This flag helps user choose whether privilege information is captured.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lkml.kernel.org/r/20220824044822.70230-4-anshuman.khandual@arm.com
---

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index fed60e6b10e52..1a258d45a3fa6 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift {
 
 	PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT	= 17, /* save low level index of raw branch records */
 
+	PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT	= 18, /* save privilege mode */
+
 	PERF_SAMPLE_BRANCH_MAX_SHIFT		/* non-ABI */
 };
 
@@ -233,6 +235,8 @@ enum perf_branch_sample_type {
 
 	PERF_SAMPLE_BRANCH_HW_INDEX	= 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT,
 
+	PERF_SAMPLE_BRANCH_PRIV_SAVE	= 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT,
+
 	PERF_SAMPLE_BRANCH_MAX		= 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT,
 };
 
@@ -282,6 +286,13 @@ enum {
 	PERF_BR_NEW_MAX,
 };
 
+enum {
+	PERF_BR_PRIV_UNKNOWN	= 0,
+	PERF_BR_PRIV_USER	= 1,
+	PERF_BR_PRIV_KERNEL	= 2,
+	PERF_BR_PRIV_HV		= 3,
+};
+
 #define PERF_SAMPLE_BRANCH_PLM_ALL \
 	(PERF_SAMPLE_BRANCH_USER|\
 	 PERF_SAMPLE_BRANCH_KERNEL|\
@@ -1402,7 +1413,8 @@ struct perf_branch_entry {
 		type:4,     /* branch type */
 		spec:2,     /* branch speculation info */
 		new_type:4, /* additional branch type */
-		reserved:34;
+		priv:3,     /* privilege level */
+		reserved:31;
 };
 
 union perf_sample_weight {