[PATCH v4 05/16] perf kvm: Use macro to replace variable 'decode_str_len'

[Leo Yan]

The variable 'decode_str_len' defines the string length for KVM event
name and every arch defines its own values.

This introduces complexity that the variable definition are spreading in
multiple source files under arch folder.  This patch refactors code to
use a macro KVM_EVENT_NAME_LEN to define event name length and thus
remove the definitions in arch files.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
 tools/perf/arch/arm64/util/kvm-stat.c   |  1 -
 tools/perf/arch/powerpc/util/kvm-stat.c |  3 +--
 tools/perf/arch/s390/util/kvm-stat.c    |  1 -
 tools/perf/arch/x86/util/kvm-stat.c     |  7 +++----
 tools/perf/builtin-kvm.c                | 10 +++++-----
 tools/perf/util/kvm-stat.h              |  3 ++-
 6 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/tools/perf/arch/arm64/util/kvm-stat.c b/tools/perf/arch/arm64/util/kvm-stat.c
index 73d18e0ed6f6..72ca9bb45804 100644
--- a/tools/perf/arch/arm64/util/kvm-stat.c
+++ b/tools/perf/arch/arm64/util/kvm-stat.c
@@ -11,7 +11,6 @@ define_exit_reasons_table(arm64_trap_exit_reasons, kvm_arm_exception_class);
 
 const char *kvm_trap_exit_reason = "esr_ec";
 const char *vcpu_id_str = "id";
-const int decode_str_len = 20;
 const char *kvm_exit_reason = "ret";
 const char *kvm_entry_trace = "kvm:kvm_entry";
 const char *kvm_exit_trace = "kvm:kvm_exit";
diff --git a/tools/perf/arch/powerpc/util/kvm-stat.c b/tools/perf/arch/powerpc/util/kvm-stat.c
index 1a9b40ea92a5..d04a08c9fd19 100644
--- a/tools/perf/arch/powerpc/util/kvm-stat.c
+++ b/tools/perf/arch/powerpc/util/kvm-stat.c
@@ -14,7 +14,6 @@
 #define NR_TPS 4
 
 const char *vcpu_id_str = "vcpu_id";
-const int decode_str_len = 40;
 const char *kvm_entry_trace = "kvm_hv:kvm_guest_enter";
 const char *kvm_exit_trace = "kvm_hv:kvm_guest_exit";
 
@@ -80,7 +79,7 @@ static void hcall_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 {
 	const char *hcall_reason = get_hcall_exit_reason(key->key);
 
-	scnprintf(decode, decode_str_len, "%s", hcall_reason);
+	scnprintf(decode, KVM_EVENT_NAME_LEN, "%s", hcall_reason);
 }
 
 static struct kvm_events_ops hcall_events = {
diff --git a/tools/perf/arch/s390/util/kvm-stat.c b/tools/perf/arch/s390/util/kvm-stat.c
index 34da89ced29a..0aed92df51ba 100644
--- a/tools/perf/arch/s390/util/kvm-stat.c
+++ b/tools/perf/arch/s390/util/kvm-stat.c
@@ -19,7 +19,6 @@ define_exit_reasons_table(sie_diagnose_codes, diagnose_codes);
 define_exit_reasons_table(sie_icpt_prog_codes, icpt_prog_codes);
 
 const char *vcpu_id_str = "id";
-const int decode_str_len = 40;
 const char *kvm_exit_reason = "icptcode";
 const char *kvm_entry_trace = "kvm:kvm_s390_sie_enter";
 const char *kvm_exit_trace = "kvm:kvm_s390_sie_exit";
diff --git a/tools/perf/arch/x86/util/kvm-stat.c b/tools/perf/arch/x86/util/kvm-stat.c
index c5dd54f6ef5e..ef513def03ba 100644
--- a/tools/perf/arch/x86/util/kvm-stat.c
+++ b/tools/perf/arch/x86/util/kvm-stat.c
@@ -18,7 +18,6 @@ static struct kvm_events_ops exit_events = {
 };
 
 const char *vcpu_id_str = "vcpu_id";
-const int decode_str_len = 20;
 const char *kvm_exit_reason = "exit_reason";
 const char *kvm_entry_trace = "kvm:kvm_entry";
 const char *kvm_exit_trace = "kvm:kvm_exit";
@@ -77,7 +76,7 @@ static void mmio_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 				  struct event_key *key,
 				  char *decode)
 {
-	scnprintf(decode, decode_str_len, "%#lx:%s",
+	scnprintf(decode, KVM_EVENT_NAME_LEN, "%#lx:%s",
 		  (unsigned long)key->key,
 		  key->info == KVM_TRACE_MMIO_WRITE ? "W" : "R");
 }
@@ -121,7 +120,7 @@ static void ioport_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 				    struct event_key *key,
 				    char *decode)
 {
-	scnprintf(decode, decode_str_len, "%#llx:%s",
+	scnprintf(decode, KVM_EVENT_NAME_LEN, "%#llx:%s",
 		  (unsigned long long)key->key,
 		  key->info ? "POUT" : "PIN");
 }
@@ -165,7 +164,7 @@ static void msr_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 				    struct event_key *key,
 				    char *decode)
 {
-	scnprintf(decode, decode_str_len, "%#llx:%s",
+	scnprintf(decode, KVM_EVENT_NAME_LEN, "%#llx:%s",
 		  (unsigned long long)key->key,
 		  key->info ? "W" : "R");
 }
diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index 4e9519390da6..d400434aa137 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -159,7 +159,7 @@ void exit_event_decode_key(struct perf_kvm_stat *kvm,
 	const char *exit_reason = get_exit_reason(kvm, key->exit_reasons,
 						  key->key);
 
-	scnprintf(decode, decode_str_len, "%s", exit_reason);
+	scnprintf(decode, KVM_EVENT_NAME_LEN, "%s", exit_reason);
 }
 
 static bool register_kvm_events_ops(struct perf_kvm_stat *kvm)
@@ -432,7 +432,7 @@ static bool handle_end_event(struct perf_kvm_stat *kvm,
 	time_diff = sample->time - time_begin;
 
 	if (kvm->duration && time_diff > kvm->duration) {
-		char decode[decode_str_len];
+		char decode[KVM_EVENT_NAME_LEN];
 
 		kvm->events_ops->decode_key(kvm, &event->key, decode);
 		if (!skip_event(decode)) {
@@ -603,7 +603,7 @@ static void show_timeofday(void)
 
 static void print_result(struct perf_kvm_stat *kvm)
 {
-	char decode[decode_str_len];
+	char decode[KVM_EVENT_NAME_LEN];
 	struct kvm_event *event;
 	int vcpu = kvm->trace_vcpu;
 
@@ -614,7 +614,7 @@ static void print_result(struct perf_kvm_stat *kvm)
 
 	pr_info("\n\n");
 	print_vcpu_info(kvm);
-	pr_info("%*s ", decode_str_len, kvm->events_ops->name);
+	pr_info("%*s ", KVM_EVENT_NAME_LEN, kvm->events_ops->name);
 	pr_info("%10s ", "Samples");
 	pr_info("%9s ", "Samples%");
 
@@ -633,7 +633,7 @@ static void print_result(struct perf_kvm_stat *kvm)
 		min = get_event_min(event, vcpu);
 
 		kvm->events_ops->decode_key(kvm, &event->key, decode);
-		pr_info("%*s ", decode_str_len, decode);
+		pr_info("%*s ", KVM_EVENT_NAME_LEN, decode);
 		pr_info("%10llu ", (unsigned long long)ecount);
 		pr_info("%8.2f%% ", (double)ecount / kvm->total_count * 100);
 		pr_info("%8.2f%% ", (double)etime / kvm->total_time * 100);
diff --git a/tools/perf/util/kvm-stat.h b/tools/perf/util/kvm-stat.h
index 40a4b66cfee6..e84f1cdcfe05 100644
--- a/tools/perf/util/kvm-stat.h
+++ b/tools/perf/util/kvm-stat.h
@@ -8,6 +8,8 @@
 #include "stat.h"
 #include "record.h"
 
+#define KVM_EVENT_NAME_LEN	40
+
 struct evsel;
 struct evlist;
 struct perf_session;
@@ -143,7 +145,6 @@ extern const char *kvm_events_tp[];
 extern struct kvm_reg_events_ops kvm_reg_events_ops[];
 extern const char * const kvm_skip_events[];
 extern const char *vcpu_id_str;
-extern const int decode_str_len;
 extern const char *kvm_exit_reason;
 extern const char *kvm_entry_trace;
 extern const char *kvm_exit_trace;
-- 
2.34.1