6.6-stable review patch. If anyone has any objections, please let me know.
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From: Nysal Jan K.A nysal@linux.ibm.com
[ Upstream commit 227bbaabe64b6f9cd98aa051454c1d4a194a8c6a ]
topology_is_core_online() checks if the core a CPU belongs to is online. The core is online if at least one of the sibling CPUs is online. The first CPU of an online core is also online in the common case, so this should be fairly quick.
Fixes: 73c58e7e1412 ("powerpc: Add HOTPLUG_SMT support") Signed-off-by: Nysal Jan K.A nysal@linux.ibm.com Reviewed-by: Shrikanth Hegde sshegde@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240731030126.956210-3-nysal@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/include/asm/topology.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h index f4e6f2dd04b73..16bacfe8c7a2c 100644 --- a/arch/powerpc/include/asm/topology.h +++ b/arch/powerpc/include/asm/topology.h @@ -145,6 +145,7 @@ static inline int cpu_to_coregroup_id(int cpu)
#ifdef CONFIG_HOTPLUG_SMT #include <linux/cpu_smt.h> +#include <linux/cpumask.h> #include <asm/cputhreads.h>
static inline bool topology_is_primary_thread(unsigned int cpu) @@ -156,6 +157,18 @@ static inline bool topology_smt_thread_allowed(unsigned int cpu) { return cpu_thread_in_core(cpu) < cpu_smt_num_threads; } + +#define topology_is_core_online topology_is_core_online +static inline bool topology_is_core_online(unsigned int cpu) +{ + int i, first_cpu = cpu_first_thread_sibling(cpu); + + for (i = first_cpu; i < first_cpu + threads_per_core; ++i) { + if (cpu_online(i)) + return true; + } + return false; +} #endif
#endif /* __KERNEL__ */