[tip: perf/core] x86/cpu: Add helper function get_llc_id

[tip-bot2 for Kim Phillips]

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     f644500512b6b3838091ddc2cfe61a4110e7778e
Gitweb:        https://git.kernel.org/tip/f644500512b6b3838091ddc2cfe61a4110e7778e
Author:        Kim Phillips <kim.phillips@xxxxxxx>
AuthorDate:    Tue, 17 Aug 2021 17:10:46 -05:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Fri, 20 Aug 2021 12:33:13 +02:00

x86/cpu: Add helper function get_llc_id

Factor out a helper function rather than export cpu_llc_id, which is
needed in order to be able to build the AMD uncore driver as a module.

Signed-off-by: Kim Phillips <kim.phillips@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210817221048.88063-7-kim.phillips@xxxxxxx
---
 arch/x86/events/amd/uncore.c     | 2 +-
 arch/x86/include/asm/processor.h | 2 ++
 arch/x86/kernel/cpu/amd.c        | 2 +-
 arch/x86/kernel/cpu/common.c     | 6 ++++++
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/events/amd/uncore.c b/arch/x86/events/amd/uncore.c
index 7fb50ad..a01f9f1 100644
--- a/arch/x86/events/amd/uncore.c
+++ b/arch/x86/events/amd/uncore.c
@@ -452,7 +452,7 @@ static int amd_uncore_cpu_starting(unsigned int cpu)
 
 	if (amd_uncore_llc) {
 		uncore = *per_cpu_ptr(amd_uncore_llc, cpu);
-		uncore->id = per_cpu(cpu_llc_id, cpu);
+		uncore->id = get_llc_id(cpu);
 
 		uncore = amd_uncore_find_online_sibling(uncore, amd_uncore_llc);
 		*per_cpu_ptr(amd_uncore_llc, cpu) = uncore;
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 154321d..fa2f7ee 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -785,6 +785,8 @@ extern int set_tsc_mode(unsigned int val);
 
 DECLARE_PER_CPU(u64, msr_misc_features_shadow);
 
+extern u16 get_llc_id(unsigned int cpu);
+
 #ifdef CONFIG_CPU_SUP_AMD
 extern u32 amd_get_nodes_per_socket(void);
 #else
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 2d11384..1d83024 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -438,7 +438,7 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
 
 	node = numa_cpu_node(cpu);
 	if (node == NUMA_NO_NODE)
-		node = per_cpu(cpu_llc_id, cpu);
+		node = get_llc_id(cpu);
 
 	/*
 	 * On multi-fabric platform (e.g. Numascale NumaChip) a
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index a1b756c..684d4e1 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -78,6 +78,12 @@ EXPORT_SYMBOL(smp_num_siblings);
 /* Last level cache ID of each logical CPU */
 DEFINE_PER_CPU_READ_MOSTLY(u16, cpu_llc_id) = BAD_APICID;
 
+u16 get_llc_id(unsigned int cpu)
+{
+	return per_cpu(cpu_llc_id, cpu);
+}
+EXPORT_SYMBOL_GPL(get_llc_id);
+
 /* correctly size the local cpu masks */
 void __init setup_cpu_local_masks(void)
 {