# \[PATCH 7/8\] perf/amd/uncore: Allow the driver to be built as a module

- From: Kim Phillips \<hidden\>
- Date: 2021-08-17 22:12:49 
- List: linux-perf-users
- Page: https://ratatoskr.run/linux-perf-users/2021/08/1480938
- Thread: https://ratatoskr.run/linux-perf-users/2021/08/1480931/t.md

```text
Add support to build the AMD uncore driver as a module.
This is in order to facilitate development.

Signed-off-by: Kim Phillips <redacted>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Murray <redacted>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <redacted>
Cc: Joao Martins <redacted>
Cc: Konrad Rzeszutek Wilk <redacted>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <redacted>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <redacted>
Cc: Stephane Eranian <redacted>
Cc: Thomas Gleixner <redacted>
Cc: <redacted>
Cc: <redacted>
Cc: x86@kernel.org
---
 arch/x86/events/Kconfig      | 10 ++++++++++
 arch/x86/events/amd/Makefile |  6 +++---
 arch/x86/events/amd/uncore.c | 28 +++++++++++++++++++++++++++-
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/Kconfig b/arch/x86/events/Kconfig
index 39d9ded9e25a..d6cdfe631674 100644
--- a/arch/x86/events/Kconfig
+++ b/arch/x86/events/Kconfig
@@ -34,4 +34,14 @@ config PERF_EVENTS_AMD_POWER
 	  (CPUID Fn8000_0007_EDX[12]) interface to calculate the
 	  average power consumption on Family 15h processors.
 
+config PERF_EVENTS_AMD_UNCORE
+	tristate "AMD Uncore performance events"
+	depends on PERF_EVENTS && CPU_SUP_AMD
+	default y
+	help
+	  Include support for AMD uncore performance events for use with
+	  e.g., perf stat -e amd_l3/.../,amd_df/.../.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called 'amd-uncore'.
 endmenu
diff --git a/arch/x86/events/amd/Makefile b/arch/x86/events/amd/Makefile
index fe8795a67385..ec45a12deb8b 100644
--- a/arch/x86/events/amd/Makefile
+++ b/arch/x86/events/amd/Makefile
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_CPU_SUP_AMD)		+= core.o uncore.o
+obj-$(CONFIG_CPU_SUP_AMD)		+= core.o ibs.o
 obj-$(CONFIG_PERF_EVENTS_AMD_POWER)	+= power.o
-obj-$(CONFIG_X86_LOCAL_APIC)		+= ibs.o
+obj-$(CONFIG_PERF_EVENTS_AMD_UNCORE)	+= amd-uncore.o
+amd-uncore-objs				:= uncore.o
 ifdef CONFIG_AMD_IOMMU
 obj-$(CONFIG_CPU_SUP_AMD)		+= iommu.o
 endif
-
diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index a01f9f1016d9..0d04414b97d2 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -347,6 +347,7 @@ static struct pmu amd_nb_pmu = {
 	.stop		= amd_uncore_stop,
 	.read		= amd_uncore_read,
 	.capabilities	= PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
+	.module		= THIS_MODULE,
 };
 
 static struct pmu amd_llc_pmu = {
@@ -360,6 +361,7 @@ static struct pmu amd_llc_pmu = {
 	.stop		= amd_uncore_stop,
 	.read		= amd_uncore_read,
 	.capabilities	= PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT,
+	.module		= THIS_MODULE,
 };
 
 static struct amd_uncore *amd_uncore_alloc(unsigned int cpu)
@@ -665,4 +667,28 @@ static int __init amd_uncore_init(void)
 
 	return ret;
 }
-device_initcall(amd_uncore_init);
+
+static void __exit amd_uncore_exit(void)
+{
+	cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE);
+	cpuhp_remove_state(CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING);
+	cpuhp_remove_state(CPUHP_PERF_X86_AMD_UNCORE_PREP);
+
+	if (boot_cpu_has(X86_FEATURE_PERFCTR_LLC)) {
+		perf_pmu_unregister(&amd_llc_pmu);
+		free_percpu(amd_uncore_llc);
+		amd_uncore_llc = NULL;
+	}
+
+	if (boot_cpu_has(X86_FEATURE_PERFCTR_NB)) {
+		perf_pmu_unregister(&amd_nb_pmu);
+		free_percpu(amd_uncore_nb);
+		amd_uncore_nb = NULL;
+	}
+}
+
+module_init(amd_uncore_init);
+module_exit(amd_uncore_exit);
+
+MODULE_DESCRIPTION("AMD Uncore Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.31.1

```