2023-06-15 15:56:44

by Laurent Dufour

[permalink] [raw]
Subject: [PATCH 04/10] cpu/SMT: Remove topology_smt_supported()

Since the maximum number of threads is now passed to
cpu_smt_set_num_threads(), checking that value is enough to know if SMT is
supported.

Cc: Michael Ellerman <[email protected]>
Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Laurent Dufour <[email protected]>
---
arch/x86/include/asm/topology.h | 2 --
arch/x86/kernel/smpboot.c | 8 --------
kernel/cpu.c | 2 +-
3 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 66927a59e822..87358a8fe843 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -143,7 +143,6 @@ int topology_update_die_map(unsigned int dieid, unsigned int cpu);
int topology_phys_to_logical_pkg(unsigned int pkg);
int topology_phys_to_logical_die(unsigned int die, unsigned int cpu);
bool topology_is_primary_thread(unsigned int cpu);
-bool topology_smt_supported(void);
#else
#define topology_max_packages() (1)
static inline int
@@ -156,7 +155,6 @@ static inline int topology_phys_to_logical_die(unsigned int die,
static inline int topology_max_die_per_package(void) { return 1; }
static inline int topology_max_smt_threads(void) { return 1; }
static inline bool topology_is_primary_thread(unsigned int cpu) { return true; }
-static inline bool topology_smt_supported(void) { return false; }
#endif

static inline void arch_fix_phys_package_id(int num, u32 slot)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 352f0ce1ece4..3052c171668d 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -278,14 +278,6 @@ bool topology_is_primary_thread(unsigned int cpu)
return apic_id_is_primary_thread(per_cpu(x86_cpu_to_apicid, cpu));
}

-/**
- * topology_smt_supported - Check whether SMT is supported by the CPUs
- */
-bool topology_smt_supported(void)
-{
- return smp_num_siblings > 1;
-}
-
/**
* topology_phys_to_logical_pkg - Map a physical package id to a logical
*
diff --git a/kernel/cpu.c b/kernel/cpu.c
index edca8b7bd400..e354af92b2b8 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -442,7 +442,7 @@ void __init cpu_smt_set_num_threads(unsigned int num_threads,
{
WARN_ON(!num_threads || (num_threads > max_threads));

- if (!topology_smt_supported())
+ if (max_threads == 1)
cpu_smt_control = CPU_SMT_NOT_SUPPORTED;

cpu_smt_max_threads = max_threads;
--
2.41.0