From 63d8d3e8d54326842677bc3d3a3e43a133846a71 Mon Sep 17 00:00:00 2001
From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Date: Tue, 15 Dec 2020 12:07:38 +0100
Subject: [PATCH 51/55] lscpu: use cluster on aarch64 machine which doesn't
 have ACPI PPTT

lscpu may show the wrong number of sockets if the machine is aarch64 and
doesn't have ACPI PPTT.

That's because lscpu show the number of sockets by using a sysfs entry
(cpu/cpuX/topology/core_siblings). The sysfs entry is set by MPIDR_EL1
register if the machine doesn't have ACPI PPTT. MPIDR_EL1 doesn't show
the physical socket information directly. It shows the affinity level.

According to linux/arch/arm64/kernel/topology.c:store_cpu_topology(),
the top level of affinity is called as 'Cluster'.

Use Cluster instead of Socket on the machine which doesn't have ACPI PPTT.

Note, ARM SBBR v1.2 requires ACPI PPTT, so this patch is needed for the
machine which is based on SBBR v1.0 and v1.1.

[kzak@redhat.com: - port to old code
                  - change semantic to be same as current upstream]

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1883056
Upstream: 73c0a766ffbe60e013b55cfd716d531b5a6ae22a
Upstream: https://marc.info/?l=util-linux-ng&m=159984070611464&w=2
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
 sys-utils/lscpu.1 |  3 +++
 sys-utils/lscpu.c | 65 ++++++++++++++++++++++++++++++++++++++++++-----
 sys-utils/lscpu.h |  3 +++
 3 files changed, 65 insertions(+), 6 deletions(-)

diff --git a/sys-utils/lscpu.1 b/sys-utils/lscpu.1
index b70f2e151..cf981d708 100644
--- a/sys-utils/lscpu.1
+++ b/sys-utils/lscpu.1
@@ -47,6 +47,9 @@ The logical core number.  A core can contain several CPUs.
 .B SOCKET
 The logical socket number.  A socket can contain several cores.
 .TP
+.B CLUSTER
+The logical cluster number.  A cluster can contain several cores.
+.TP
 .B BOOK
 The logical book number.  A book can contain several sockets.
 .TP
diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 748d545b6..a8b448fa0 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -70,6 +70,7 @@
 #define _PATH_SYS_HYP_FEATURES "/sys/hypervisor/properties/features"
 #define _PATH_SYS_CPU		_PATH_SYS_SYSTEM "/cpu"
 #define _PATH_SYS_NODE		_PATH_SYS_SYSTEM "/node"
+#define _PATH_ACPI_PPTT		"/sys/firmware/acpi/tables/PPTT"
 #define _PATH_PROC_XEN		"/proc/xen"
 #define _PATH_PROC_XENCAP	_PATH_PROC_XEN "/capabilities"
 #define _PATH_PROC_CPUINFO	"/proc/cpuinfo"
@@ -168,6 +169,7 @@ enum {
 	COL_CPU,
 	COL_CORE,
 	COL_SOCKET,
+	COL_CLUSTER,
 	COL_NODE,
 	COL_BOOK,
 	COL_DRAWER,
@@ -194,6 +196,7 @@ static struct lscpu_coldesc coldescs[] =
 	[COL_CPU]          = { "CPU", N_("logical CPU number"), 1 },
 	[COL_CORE]         = { "CORE", N_("logical core number") },
 	[COL_SOCKET]       = { "SOCKET", N_("logical socket number") },
+	[COL_CLUSTER]      = { "CLUSTER", N_("logical cluster number") },
 	[COL_NODE]         = { "NODE", N_("logical NUMA node number") },
 	[COL_BOOK]         = { "BOOK", N_("logical book number") },
 	[COL_DRAWER]       = { "DRAWER", N_("logical drawer number") },
@@ -383,6 +386,26 @@ static void read_physical_info_powerpc(
 }
 #endif
 
+static int is_fallback_to_cluster(struct lscpu_desc *desc)
+{
+	char *arch;
+	struct stat st;
+	struct utsname utsbuf;
+
+	if (desc)
+		arch = desc->arch;
+	else {
+		if (uname(&utsbuf) == -1)
+			err(EXIT_FAILURE, _("error: uname failed"));
+		arch = utsbuf.machine;
+	}
+
+	if (!(strcmp(arch, "aarch64")) && (stat(_PATH_ACPI_PPTT, &st) < 0))
+		return 1;
+	else
+		return 0;
+}
+
 
 static void
 read_basicinfo(struct lscpu_desc *desc, struct lscpu_modifier *mod)
@@ -1344,6 +1367,10 @@ get_cell_data(struct lscpu_desc *desc, int idx, int col,
 				snprintf(buf, bufsz, "%zu", i);
 		}
 		break;
+	case COL_CLUSTER:
+		if (!desc->is_cluster)
+			break;
+		/* fallthrough */
 	case COL_SOCKET:
 		if (mod->physical) {
 			if (desc->socketids[idx] ==  -1)
@@ -1799,12 +1826,18 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 			if (fd)
 				fclose(fd);
 		}
+
+
 		if (desc->mtid)
 			threads_per_core = atoi(desc->mtid) + 1;
 		add_summary_n(tb, _("Thread(s) per core:"),
 			threads_per_core ?: desc->nthreads / desc->ncores);
-		add_summary_n(tb, _("Core(s) per socket:"),
-			cores_per_socket ?: desc->ncores / desc->nsockets);
+		if (desc->is_cluster)
+			add_summary_n(tb, _("Core(s) per cluster:"),
+				cores_per_socket ?: desc->ncores / desc->nsockets);
+		else
+			add_summary_n(tb, _("Core(s) per socket:"),
+				cores_per_socket ?: desc->ncores / desc->nsockets);
 		if (desc->nbooks) {
 			add_summary_n(tb, _("Socket(s) per book:"),
 				sockets_per_book ?: desc->nsockets / desc->nbooks);
@@ -1816,7 +1849,17 @@ print_summary(struct lscpu_desc *desc, struct lscpu_modifier *mod)
 				add_summary_n(tb, _("Book(s):"), books_per_drawer ?: desc->nbooks);
 			}
 		} else {
-			add_summary_n(tb, _("Socket(s):"), sockets_per_book ?: desc->nsockets);
+			if (desc->is_cluster) {
+				if (desc->nr_socket_on_cluster > 0)
+					add_summary_n(tb, _("Socket(s):"), desc->nr_socket_on_cluster);
+				else
+					add_summary_s(tb, _("Socket(s):"), "-");
+
+				add_summary_n(tb, _("Cluster(s):"),
+						sockets_per_book ?: desc->nsockets);
+			} else
+				add_summary_n(tb, _("Socket(s):"),
+						sockets_per_book ?: desc->nsockets);
 		}
 	}
 	if (desc->nnodes)
@@ -2060,10 +2103,13 @@ int main(int argc, char *argv[])
 		qsort(desc->ecaches, desc->necaches,
 				sizeof(struct cpu_cache), cachecmp);
 
+	desc->is_cluster = is_fallback_to_cluster(desc);
+
 	read_nodes(desc);
 	read_hypervisor(desc, mod);
 	arm_cpu_decode(desc);
 
+
 	switch(mod->mode) {
 	case OUTPUT_SUMMARY:
 		print_summary(desc, mod);
@@ -2072,7 +2118,10 @@ int main(int argc, char *argv[])
 		if (!ncolumns) {
 			columns[ncolumns++] = COL_CPU;
 			columns[ncolumns++] = COL_CORE;
-			columns[ncolumns++] = COL_SOCKET;
+			if (desc->is_cluster)
+				columns[ncolumns++] = COL_CLUSTER;
+			else
+				columns[ncolumns++] = COL_SOCKET;
 			columns[ncolumns++] = COL_NODE;
 			columns[ncolumns++] = COL_CACHE;
 			mod->compat = 1;
@@ -2089,8 +2138,12 @@ int main(int argc, char *argv[])
 				columns[ncolumns++] = COL_DRAWER;
 			if (desc->bookmaps)
 				columns[ncolumns++] = COL_BOOK;
-			if (desc->socketmaps)
-				columns[ncolumns++] = COL_SOCKET;
+			if (desc->socketmaps) {
+				if (desc->is_cluster)
+					columns[ncolumns++] = COL_CLUSTER;
+				else
+					columns[ncolumns++] = COL_SOCKET;
+			}
 			if (desc->coremaps)
 				columns[ncolumns++] = COL_CORE;
 			if (desc->caches)
diff --git a/sys-utils/lscpu.h b/sys-utils/lscpu.h
index 3d1885a3e..bffa9df60 100644
--- a/sys-utils/lscpu.h
+++ b/sys-utils/lscpu.h
@@ -158,6 +158,9 @@ struct lscpu_desc {
 	int		physsockets;	/* Physical sockets (modules) */
 	int		physchips;	/* Physical chips */
 	int		physcoresperchip;	/* Physical cores per chip */
+
+	int		is_cluster;
+	int		nr_socket_on_cluster;
 };
 
 enum {
-- 
2.29.2