From 5685d7fcb55fd729d7e0452c157a0ac8d72ca7b6 Mon Sep 17 00:00:00 2001 From: Tiezhu Yang Date: Tue, 14 May 2024 12:24:18 +0800 Subject: [PATCH] LoongArch: Give a chance to build with !CONFIG_SMP In the current code, SMP is selected in Kconfig for LoongArch, the users can not unset it, this is reasonable for a multi-processor machine. But as the help info of config SMP said, if you have a system with only one CPU, say N. On a uni-processor machine, the kernel will run faster if you say N here. Loongson-2K0500 is a single-core CPU for applications like industrial control, printing terminals, and BMC (Baseboard Management Controller), there are many development boards, products and solutions on the market, so it is better and necessary to give a chance to build with !CONFIG_SMP for a uni-processor machine. First of all, do not select SMP for config LOONGARCH in Kconfig to make it possible to unset CONFIG_SMP. Then, do some changes to fix warnings and errors if CONFIG_SMP is not set. (1) Define get_ipi_irq() only if CONFIG_SMP is set to fix the warning: arch/loongarch/kernel/irq.c:90:19: warning: 'get_ipi_irq' defined but not used [-Wunused-function] (2) Add "#ifdef CONFIG_SMP" in asm/smp.h to fix the warning: ./arch/loongarch/include/asm/smp.h:49:9: warning: "raw_smp_processor_id" redefined 49 | #define raw_smp_processor_id raw_smp_processor_id | ^~~~~~~~~~~~~~~~~~~~ ./include/linux/smp.h:198:9: note: this is the location of the previous definition 198 | #define raw_smp_processor_id() 0 (3) Define machine_shutdown() as empty under !CONFIG_SMP to fix the error: arch/loongarch/kernel/machine_kexec.c: In function 'machine_shutdown': arch/loongarch/kernel/machine_kexec.c:233:25: error: implicit declaration of function 'cpu_device_up'; did you mean 'put_device'? [-Wimplicit-function-declaration] (4) Make config SCHED_SMT depends on SMP to fix many errors such as: kernel/sched/core.c: In function 'sched_core_find': kernel/sched/core.c:310:43: error: 'struct rq' has no member named 'cpu' (5) Define cpu_logical_map(cpu) as 0 under !CONFIG_SMP in asm/smp.h, then include asm/smp.h in asm/acpi.h (because acpi.h is included in linux/irq.h indirectly) to fix many build errors under drivers/irqchip such as: drivers/irqchip/irq-loongson-eiointc.c: In function 'cpu_to_eio_node': drivers/irqchip/irq-loongson-eiointc.c:59:16: error: implicit declaration of function 'cpu_logical_map' [-Wimplicit-function-declaration] (6) Do not write per_cpu_offset(0) to PERCPU_BASE_KS when resume because the per_cpu_offset(x) macro is defined as (__per_cpu_offset[x]) only under CONFIG_SMP in include/asm-generic/percpu.h. Just save the value of PERCPU_BASE_KS when suspend and restore it when resume to fix the error: arch/loongarch/power/suspend.c: In function 'loongarch_common_resume': arch/loongarch/power/suspend.c:47:21: error: implicit declaration of function 'per_cpu_offset' [-Wimplicit-function-declaration] (7) Fix huge page handling under !CONFIG_SMP in tlbex.S. When running the UnixBench tests with "-c 1" single-streamed pass, the improvement of performance is about 9 percent with this patch. By the way, it is helpful to debug and analysis the kernel issues of multi-processor system under !CONFIG_SMP. Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen --- arch/loongarch/Kconfig | 2 +- arch/loongarch/include/asm/acpi.h | 1 + arch/loongarch/include/asm/smp.h | 6 ++++++ arch/loongarch/kernel/irq.c | 2 ++ arch/loongarch/kernel/machine_kexec.c | 2 +- arch/loongarch/mm/tlbex.S | 9 ++++++--- arch/loongarch/power/suspend.c | 4 +++- 7 files changed, 20 insertions(+), 6 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index e22330064e98..73246b21aae8 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -178,7 +178,6 @@ config LOONGARCH select PCI_QUIRKS select PERF_USE_VMALLOC select RTC_LIB - select SMP select SPARSE_IRQ select SYSCTL_ARCH_UNALIGN_ALLOW select SYSCTL_ARCH_UNALIGN_NO_WARN @@ -424,6 +423,7 @@ config EFI_STUB config SCHED_SMT bool "SMT scheduler support" + depends on SMP default y help Improves scheduler's performance when there are multiple diff --git a/arch/loongarch/include/asm/acpi.h b/arch/loongarch/include/asm/acpi.h index 49e29b29996f..313f66f7913a 100644 --- a/arch/loongarch/include/asm/acpi.h +++ b/arch/loongarch/include/asm/acpi.h @@ -8,6 +8,7 @@ #ifndef _ASM_LOONGARCH_ACPI_H #define _ASM_LOONGARCH_ACPI_H +#include #include #ifdef CONFIG_ACPI diff --git a/arch/loongarch/include/asm/smp.h b/arch/loongarch/include/asm/smp.h index f81e5f01d619..b3a0868d29ea 100644 --- a/arch/loongarch/include/asm/smp.h +++ b/arch/loongarch/include/asm/smp.h @@ -6,6 +6,8 @@ #ifndef __ASM_SMP_H #define __ASM_SMP_H +#ifdef CONFIG_SMP + #include #include #include @@ -101,4 +103,8 @@ static inline void __cpu_die(unsigned int cpu) } #endif +#else /* !CONFIG_SMP */ +#define cpu_logical_map(cpu) 0 +#endif /* CONFIG_SMP */ + #endif /* __ASM_SMP_H */ diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c index 883e5066ae44..e791fa275ec5 100644 --- a/arch/loongarch/kernel/irq.c +++ b/arch/loongarch/kernel/irq.c @@ -87,6 +87,7 @@ static void __init init_vec_parent_group(void) acpi_table_parse(ACPI_SIG_MCFG, early_pci_mcfg_parse); } +#ifdef CONFIG_SMP static int __init get_ipi_irq(void) { struct irq_domain *d = irq_find_matching_fwnode(cpuintc_handle, DOMAIN_BUS_ANY); @@ -96,6 +97,7 @@ static int __init get_ipi_irq(void) return -EINVAL; } +#endif void __init init_IRQ(void) { diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/machine_kexec.c index 2dcb9e003657..8ae641dc53bb 100644 --- a/arch/loongarch/kernel/machine_kexec.c +++ b/arch/loongarch/kernel/machine_kexec.c @@ -225,6 +225,7 @@ void crash_smp_send_stop(void) void machine_shutdown(void) { +#ifdef CONFIG_SMP int cpu; /* All CPUs go to reboot_code_buffer */ @@ -232,7 +233,6 @@ void machine_shutdown(void) if (!cpu_online(cpu)) cpu_device_up(get_cpu_device(cpu)); -#ifdef CONFIG_SMP smp_call_function(kexec_shutdown_secondary, NULL, 0); #endif } diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S index a44387b838af..c08682a89c58 100644 --- a/arch/loongarch/mm/tlbex.S +++ b/arch/loongarch/mm/tlbex.S @@ -125,6 +125,8 @@ vmalloc_load: tlb_huge_update_load: #ifdef CONFIG_SMP ll.d ra, t1, 0 +#else + rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) #endif andi t0, ra, _PAGE_PRESENT beqz t0, nopage_tlb_load @@ -135,7 +137,6 @@ tlb_huge_update_load: beqz t0, tlb_huge_update_load ori t0, ra, _PAGE_VALID #else - rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) ori t0, ra, _PAGE_VALID st.d t0, t1, 0 #endif @@ -281,6 +282,8 @@ vmalloc_store: tlb_huge_update_store: #ifdef CONFIG_SMP ll.d ra, t1, 0 +#else + rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) #endif andi t0, ra, _PAGE_PRESENT | _PAGE_WRITE xori t0, t0, _PAGE_PRESENT | _PAGE_WRITE @@ -292,7 +295,6 @@ tlb_huge_update_store: beqz t0, tlb_huge_update_store ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) #else - rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) st.d t0, t1, 0 #endif @@ -438,6 +440,8 @@ vmalloc_modify: tlb_huge_update_modify: #ifdef CONFIG_SMP ll.d ra, t1, 0 +#else + rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) #endif andi t0, ra, _PAGE_WRITE beqz t0, nopage_tlb_modify @@ -448,7 +452,6 @@ tlb_huge_update_modify: beqz t0, tlb_huge_update_modify ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) #else - rotri.d ra, ra, 64 - (_PAGE_HUGE_SHIFT + 1) ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED) st.d t0, t1, 0 #endif diff --git a/arch/loongarch/power/suspend.c b/arch/loongarch/power/suspend.c index 166d9e06a64b..c9e594925c47 100644 --- a/arch/loongarch/power/suspend.c +++ b/arch/loongarch/power/suspend.c @@ -24,6 +24,7 @@ struct saved_registers { u64 kpgd; u32 pwctl0; u32 pwctl1; + u64 pcpu_base; }; static struct saved_registers saved_regs; @@ -36,6 +37,7 @@ void loongarch_common_suspend(void) saved_regs.pwctl1 = csr_read32(LOONGARCH_CSR_PWCTL1); saved_regs.ecfg = csr_read32(LOONGARCH_CSR_ECFG); saved_regs.euen = csr_read32(LOONGARCH_CSR_EUEN); + saved_regs.pcpu_base = csr_read64(PERCPU_BASE_KS); loongarch_suspend_addr = loongson_sysconf.suspend_addr; } @@ -44,7 +46,6 @@ void loongarch_common_resume(void) { sync_counter(); local_flush_tlb_all(); - csr_write64(per_cpu_offset(0), PERCPU_BASE_KS); csr_write64(eentry, LOONGARCH_CSR_EENTRY); csr_write64(eentry, LOONGARCH_CSR_MERRENTRY); csr_write64(tlbrentry, LOONGARCH_CSR_TLBRENTRY); @@ -55,6 +56,7 @@ void loongarch_common_resume(void) csr_write32(saved_regs.pwctl1, LOONGARCH_CSR_PWCTL1); csr_write32(saved_regs.ecfg, LOONGARCH_CSR_ECFG); csr_write32(saved_regs.euen, LOONGARCH_CSR_EUEN); + csr_write64(saved_regs.pcpu_base, PERCPU_BASE_KS); } int loongarch_acpi_suspend(void)