From mboxrd@z Thu Jan 1 00:00:00 1970 From: atish.patra@wdc.com (Atish Patra) Date: Thu, 8 Nov 2018 17:50:09 -0800 Subject: [RFC 3/3] RISC-V: Parse cpu topology during boot. In-Reply-To: <1541728209-3224-1-git-send-email-atish.patra@wdc.com> References: <1541728209-3224-1-git-send-email-atish.patra@wdc.com> Message-ID: <1541728209-3224-4-git-send-email-atish.patra@wdc.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Currently, there are no topology defined for RISC-V. Parse the cpu-map node from device tree and setup the cpu topology. CPU topology after applying the patch. $cat /sys/devices/system/cpu/cpu2/topology/core_siblings_list 0-3 $cat /sys/devices/system/cpu/cpu3/topology/core_siblings_list 0-3 $cat /sys/devices/system/cpu/cpu3/topology/physical_package_id 0 $cat /sys/devices/system/cpu/cpu3/topology/core_id 3 Signed-off-by: Atish Patra --- arch/riscv/Kconfig | 1 + arch/riscv/kernel/smpboot.c | 6 +++++- 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 55da93f4..e2d8ddb5 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -42,6 +42,7 @@ config RISCV select THREAD_INFO_IN_TASK select RISCV_TIMER select GENERIC_IRQ_MULTI_HANDLER + select GENERIC_ARCH_TOPOLOGY select ARCH_HAS_PTE_SPECIAL config MMU diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 18cda0e8..6fa95442 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -42,6 +43,7 @@ void *__cpu_up_task_pointer[NR_CPUS]; void __init smp_prepare_boot_cpu(void) { + init_cpu_topology(); } void __init smp_prepare_cpus(unsigned int max_cpus) @@ -108,13 +110,15 @@ void __init smp_cpus_done(unsigned int max_cpus) asmlinkage void __init smp_callin(void) { struct mm_struct *mm = &init_mm; + unsigned int cpu = smp_processor_id(); /* All kernel threads share the same mm context. */ mmgrab(mm); current->active_mm = mm; trap_init(); - notify_cpu_starting(smp_processor_id()); + notify_cpu_starting(cpu); + update_siblings_masks(cpu); set_cpu_online(smp_processor_id(), 1); /* * Remote TLB flushes are ignored while the CPU is offline, so emit -- 2.7.4