[PATCH 1/9] cpu/SMT: Move SMT prototypes into cpu_smt.h

Michael Ellerman
2023-05-24T15:57:59Z

A subsequent patch would like to use the cpuhp_smt_control enum as part
of the interface between generic and arch code.

Currently that leads to circular header dependencies. So split the enum
and related declarations into a separate header.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/x86/include/asm/topology.h | 2 ++
include/linux/cpu.h | 25 +------------------------
include/linux/cpu_smt.h | 29 +++++++++++++++++++++++++++++
3 files changed, 32 insertions(+), 24 deletions(-)
create mode 100644 include/linux/cpu_smt.h

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 458c891a8273..66927a59e822 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -136,6 +136,8 @@ static inline int topology_max_smt_threads(void)
return __max_smt_threads;
}

+#include <linux/cpu_smt.h>
+
int topology_update_package_map(unsigned int apicid, unsigned int cpu);
int topology_update_die_map(unsigned int dieid, unsigned int cpu);
int topology_phys_to_logical_pkg(unsigned int pkg);
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index 8582a7142623..40548f3c201c 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -18,6 +18,7 @@
#include <linux/compiler.h>
#include <linux/cpumask.h>
#include <linux/cpuhotplug.h>
+#include <linux/cpu_smt.h>

struct device;
struct device_node;
@@ -202,30 +203,6 @@ void cpuhp_report_idle_dead(void);
static inline void cpuhp_report_idle_dead(void) { }
#endif /* #ifdef CONFIG_HOTPLUG_CPU */

-enum cpuhp_smt_control {
- CPU_SMT_ENABLED,
- CPU_SMT_DISABLED,
- CPU_SMT_FORCE_DISABLED,
- CPU_SMT_NOT_SUPPORTED,
- CPU_SMT_NOT_IMPLEMENTED,
-};
-
-#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
-extern enum cpuhp_smt_control cpu_smt_control;
-extern void cpu_smt_disable(bool force);
-extern void cpu_smt_check_topology(void);
-extern bool cpu_smt_possible(void);
-extern int cpuhp_smt_enable(void);
-extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
-#else
-# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
-static inline void cpu_smt_disable(bool force) { }
-static inline void cpu_smt_check_topology(void) { }
-static inline bool cpu_smt_possible(void) { return false; }
-static inline int cpuhp_smt_enable(void) { return 0; }
-static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
-#endif
-
extern bool cpu_mitigations_off(void);
extern bool cpu_mitigations_auto_nosmt(void);

diff --git a/include/linux/cpu_smt.h b/include/linux/cpu_smt.h
new file mode 100644
index 000000000000..17e105b52d85
--- /dev/null
+++ b/include/linux/cpu_smt.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CPU_SMT_H_
+#define _LINUX_CPU_SMT_H_
+
+enum cpuhp_smt_control {
+ CPU_SMT_ENABLED,
+ CPU_SMT_DISABLED,
+ CPU_SMT_FORCE_DISABLED,
+ CPU_SMT_NOT_SUPPORTED,
+ CPU_SMT_NOT_IMPLEMENTED,
+};
+
+#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
+extern enum cpuhp_smt_control cpu_smt_control;
+extern void cpu_smt_disable(bool force);
+extern void cpu_smt_check_topology(void);
+extern bool cpu_smt_possible(void);
+extern int cpuhp_smt_enable(void);
+extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
+#else
+# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
+static inline void cpu_smt_disable(bool force) { }
+static inline void cpu_smt_check_topology(void) { }
+static inline bool cpu_smt_possible(void) { return false; }
+static inline int cpuhp_smt_enable(void) { return 0; }
+static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
+#endif
+
+#endif /* _LINUX_CPU_SMT_H_ */
--
2.40.1