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From: Laurent Dufour <ldufour@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	mpe@ellerman.id.au, npiggin@gmail.com,
	christophe.leroy@csgroup.eu, tglx@linutronix.de,
	dave.hansen@linux.intel.com, mingo@redhat.com, bp@alien8.de
Subject: [PATCH v2 4/9] cpu/SMT: Remove topology_smt_supported()
Date: Wed, 28 Jun 2023 12:05:53 +0200	[thread overview]
Message-ID: <20230628100558.43482-5-ldufour@linux.ibm.com> (raw)
In-Reply-To: <20230628100558.43482-1-ldufour@linux.ibm.com>

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 <mpe@ellerman.id.au>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
---
 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


  parent reply	other threads:[~2023-06-28 10:12 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-28 10:05 [PATCH v2 0/9] Introduce SMT level and add PowerPC support Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 1/9] cpu/SMT: Move SMT prototypes into cpu_smt.h Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 2/9] cpu/SMT: Move smt/control simple exit cases earlier Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 3/9] cpu/SMT: Store the current/max number of threads Laurent Dufour
2023-06-28 10:05 ` Laurent Dufour [this message]
2023-06-28 10:05 ` [PATCH v2 5/9] cpu/SMT: Create topology_smt_thread_allowed() Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 6/9] cpu/SMT: Allow enabling partial SMT states via sysfs Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 7/9] powerpc/pseries: Initialise CPU hotplug callbacks earlier Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 8/9] powerpc: Add HOTPLUG_SMT support Laurent Dufour
2023-06-28 10:05 ` [PATCH v2 9/9] powerpc/pseries: Honour current SMT state when DLPAR onlining CPUs Laurent Dufour
2023-06-28 15:33 ` [PATCH v2 0/9] Introduce SMT level and add PowerPC support Sachin Sant
2023-06-29 11:10   ` Michael Ellerman
2023-06-29 12:04     ` Laurent Dufour
2023-06-29 13:31     ` Sachin Sant

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