From c8d2bcc467c8a1a85983c24e0331cf19fe94668f Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 12 May 2023 23:07:37 +0200 Subject: MIPS: SMP_CPS: Switch to hotplug core state synchronization Switch to the CPU hotplug core state tracking and synchronization mechanim. This unfortunately requires to add dead reporting to the non CPS platforms as CPS is the only user, but it allows an overall consolidation of this functionality. No functional change intended. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Michael Kelley Tested-by: Oleksandr Natalenko Tested-by: Helge Deller # parisc Tested-by: Guilherme G. Piccoli # Steam Deck Link: https://lore.kernel.org/r/20230512205256.803238859@linutronix.de --- arch/mips/kernel/smp.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/mips/kernel/smp.c') diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 1d93b85271ba..90c71d800b59 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -690,6 +690,14 @@ void flush_tlb_one(unsigned long vaddr) EXPORT_SYMBOL(flush_tlb_page); EXPORT_SYMBOL(flush_tlb_one); +#ifdef CONFIG_HOTPLUG_CORE_SYNC_DEAD +void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu) +{ + if (mp_ops->cleanup_dead_cpu) + mp_ops->cleanup_dead_cpu(cpu); +} +#endif + #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST static void tick_broadcast_callee(void *info) -- cgit v1.2.3 From 96cb8ae28c652e7ef0633b1c0786eb0f529ed516 Mon Sep 17 00:00:00 2001 From: Jiaxun Yang Date: Sun, 21 May 2023 23:31:22 +0100 Subject: MIPS: Rework smt cmdline parameters Provide a generic smt parameters interface aligned with s390 to allow users to limit smt usage and threads per core. It replaced previous undocumented "nothreads" parameter for smp-cps which is ambiguous and does not cover smp-mt. Signed-off-by: Jiaxun Yang Signed-off-by: Thomas Bogendoerfer --- Documentation/admin-guide/kernel-parameters.txt | 4 ++-- arch/mips/include/asm/smp.h | 2 ++ arch/mips/kernel/smp-cps.c | 13 +------------ arch/mips/kernel/smp-mt.c | 3 ++- arch/mips/kernel/smp.c | 18 ++++++++++++++++++ 5 files changed, 25 insertions(+), 15 deletions(-) (limited to 'arch/mips/kernel/smp.c') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9e5bab29685f..50439f410adc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3838,7 +3838,7 @@ nosmp [SMP] Tells an SMP kernel to act as a UP kernel, and disable the IO APIC. legacy for "maxcpus=0". - nosmt [KNL,S390] Disable symmetric multithreading (SMT). + nosmt [KNL,MIPS,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. [KNL,X86] Disable symmetric multithreading (SMT). @@ -5735,7 +5735,7 @@ 1: Fast pin select (default) 2: ATC IRMode - smt= [KNL,S390] Set the maximum number of threads (logical + smt= [KNL,MIPS,S390] Set the maximum number of threads (logical CPUs) to use per physical CPU on systems capable of symmetric multithreading (SMT). Will be capped to the actual hardware limit. diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h index aab8981bc32c..a40d8c0e4b87 100644 --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -57,6 +57,8 @@ extern int __cpu_logical_map[NR_CPUS]; /* Mask of CPUs which are currently definitely operating coherently */ extern cpumask_t cpu_coherent_mask; +extern unsigned int smp_max_threads __initdata; + extern asmlinkage void smp_bootstrap(void); extern void calculate_cpu_foreign_map(void); diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c index 62f677b2306f..bea6a13ea464 100644 --- a/arch/mips/kernel/smp-cps.c +++ b/arch/mips/kernel/smp-cps.c @@ -25,24 +25,13 @@ #include #include -static bool threads_disabled; static DECLARE_BITMAP(core_power, NR_CPUS); struct core_boot_config *mips_cps_core_bootcfg; -static int __init setup_nothreads(char *s) -{ - threads_disabled = true; - return 0; -} -early_param("nothreads", setup_nothreads); - static unsigned core_vpe_count(unsigned int cluster, unsigned core) { - if (threads_disabled) - return 1; - - return mips_cps_numvps(cluster, core); + return min(smp_max_threads, mips_cps_numvps(cluster, core)); } static void __init cps_smp_setup(void) diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c index 5f04a0141068..7729cc733421 100644 --- a/arch/mips/kernel/smp-mt.c +++ b/arch/mips/kernel/smp-mt.c @@ -46,7 +46,8 @@ static void __init smvp_copy_vpe_config(void) static unsigned int __init smvp_vpe_init(unsigned int tc, unsigned int mvpconf0, unsigned int ncpu) { - if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)) + if (tc >= smp_max_threads || + (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))) return ncpu; /* Deactivate all but VPE 0 */ diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 1d93b85271ba..280251ea8319 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -73,6 +73,24 @@ static cpumask_t cpu_core_setup_map; cpumask_t cpu_coherent_mask; +unsigned int smp_max_threads __initdata = UINT_MAX; + +static int __init early_nosmt(char *s) +{ + smp_max_threads = 1; + return 0; +} +early_param("nosmt", early_nosmt); + +static int __init early_smt(char *s) +{ + get_option(&s, &smp_max_threads); + /* Ensure at least one thread is available */ + smp_max_threads = clamp_val(smp_max_threads, 1U, UINT_MAX); + return 0; +} +early_param("smt", early_smt); + #ifdef CONFIG_GENERIC_IRQ_IPI static struct irq_desc *call_desc; static struct irq_desc *sched_desc; -- cgit v1.2.3