diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/loongarch/Kconfig | 9 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/hardirq.h | 1 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/paravirt.h | 30 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/paravirt_api_clock.h | 1 | ||||
| -rw-r--r-- | arch/loongarch/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/loongarch/kernel/irq.c | 2 | ||||
| -rw-r--r-- | arch/loongarch/kernel/paravirt.c | 151 | ||||
| -rw-r--r-- | arch/loongarch/kernel/smp.c | 4 |
8 files changed, 197 insertions, 2 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 54ad04dacdee..42331d9a8dd7 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -632,6 +632,15 @@ config RANDOMIZE_BASE_MAX_OFFSET source "kernel/livepatch/Kconfig" +config PARAVIRT + bool "Enable paravirtualization code" + depends on AS_HAS_LVZ_EXTENSION + help + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. However, when run without a hypervisor + the kernel is theoretically slower and slightly larger. + endmenu config ARCH_SELECT_MEMORY_MODEL diff --git a/arch/loongarch/include/asm/hardirq.h b/arch/loongarch/include/asm/hardirq.h index 08eb72e01b1a..d41138abcf26 100644 --- a/arch/loongarch/include/asm/hardirq.h +++ b/arch/loongarch/include/asm/hardirq.h @@ -22,6 +22,7 @@ enum ipi_msg_type { typedef struct { unsigned int ipi_irqs[NR_IPI]; unsigned int __softirq_pending; + atomic_t message ____cacheline_aligned_in_smp; } ____cacheline_aligned irq_cpustat_t; DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); diff --git a/arch/loongarch/include/asm/paravirt.h b/arch/loongarch/include/asm/paravirt.h new file mode 100644 index 000000000000..0965710f47f2 --- /dev/null +++ b/arch/loongarch/include/asm/paravirt.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_LOONGARCH_PARAVIRT_H +#define _ASM_LOONGARCH_PARAVIRT_H + +#ifdef CONFIG_PARAVIRT + +#include <linux/static_call_types.h> +struct static_key; +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +u64 dummy_steal_clock(int cpu); +DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock); + +static inline u64 paravirt_steal_clock(int cpu) +{ + return static_call(pv_steal_clock)(cpu); +} + +int __init pv_ipi_init(void); + +#else + +static inline int pv_ipi_init(void) +{ + return 0; +} + +#endif // CONFIG_PARAVIRT +#endif diff --git a/arch/loongarch/include/asm/paravirt_api_clock.h b/arch/loongarch/include/asm/paravirt_api_clock.h new file mode 100644 index 000000000000..65ac7cee0dad --- /dev/null +++ b/arch/loongarch/include/asm/paravirt_api_clock.h @@ -0,0 +1 @@ +#include <asm/paravirt.h> diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 3a7620b66bc6..c9bfeda89e40 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -51,6 +51,7 @@ obj-$(CONFIG_MODULES) += module.o module-sections.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_PROC_FS) += proc.o +obj-$(CONFIG_PARAVIRT) += paravirt.o obj-$(CONFIG_SMP) += smp.o diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c index dcb1faf2c2b7..f4991c03514f 100644 --- a/arch/loongarch/kernel/irq.c +++ b/arch/loongarch/kernel/irq.c @@ -113,5 +113,5 @@ void __init init_IRQ(void) per_cpu(irq_stack, i), per_cpu(irq_stack, i) + IRQ_STACK_SIZE); } - set_csr_ecfg(ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC); + set_csr_ecfg(ECFGF_SIP0 | ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC); } diff --git a/arch/loongarch/kernel/paravirt.c b/arch/loongarch/kernel/paravirt.c new file mode 100644 index 000000000000..1633ed4f692f --- /dev/null +++ b/arch/loongarch/kernel/paravirt.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/export.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/jump_label.h> +#include <linux/kvm_para.h> +#include <linux/static_call.h> +#include <asm/paravirt.h> + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +static u64 native_steal_clock(int cpu) +{ + return 0; +} + +DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); + +#ifdef CONFIG_SMP +static void pv_send_ipi_single(int cpu, unsigned int action) +{ + int min, old; + irq_cpustat_t *info = &per_cpu(irq_stat, cpu); + + old = atomic_fetch_or(BIT(action), &info->message); + if (old) + return; + + min = cpu_logical_map(cpu); + kvm_hypercall3(KVM_HCALL_FUNC_IPI, 1, 0, min); +} + +#define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG) + +static void pv_send_ipi_mask(const struct cpumask *mask, unsigned int action) +{ + int i, cpu, min = 0, max = 0, old; + __uint128_t bitmap = 0; + irq_cpustat_t *info; + + if (cpumask_empty(mask)) + return; + + action = BIT(action); + for_each_cpu(i, mask) { + info = &per_cpu(irq_stat, i); + old = atomic_fetch_or(action, &info->message); + if (old) + continue; + + cpu = cpu_logical_map(i); + if (!bitmap) { + min = max = cpu; + } else if (cpu < min && cpu > (max - KVM_IPI_CLUSTER_SIZE)) { + /* cpu < min, and bitmap still enough */ + bitmap <<= min - cpu; + min = cpu; + } else if (cpu > min && cpu < (min + KVM_IPI_CLUSTER_SIZE)) { + /* cpu > min, and bitmap still enough */ + max = cpu > max ? cpu : max; + } else { + /* + * With cpu, bitmap will exceed KVM_IPI_CLUSTER_SIZE, + * send IPI here directly and skip the remaining CPUs. + */ + kvm_hypercall3(KVM_HCALL_FUNC_IPI, (unsigned long)bitmap, + (unsigned long)(bitmap >> BITS_PER_LONG), min); + min = max = cpu; + bitmap = 0; + } + __set_bit(cpu - min, (unsigned long *)&bitmap); + } + + if (bitmap) + kvm_hypercall3(KVM_HCALL_FUNC_IPI, (unsigned long)bitmap, + (unsigned long)(bitmap >> BITS_PER_LONG), min); +} + +static irqreturn_t pv_ipi_interrupt(int irq, void *dev) +{ + u32 action; + irq_cpustat_t *info; + + /* Clear SWI interrupt */ + clear_csr_estat(1 << INT_SWI0); + info = this_cpu_ptr(&irq_stat); + action = atomic_xchg(&info->message, 0); + + if (action & SMP_RESCHEDULE) { + scheduler_ipi(); + info->ipi_irqs[IPI_RESCHEDULE]++; + } + + if (action & SMP_CALL_FUNCTION) { + generic_smp_call_function_interrupt(); + info->ipi_irqs[IPI_CALL_FUNCTION]++; + } + + return IRQ_HANDLED; +} + +static void pv_init_ipi(void) +{ + int r, swi; + + swi = get_percpu_irq(INT_SWI0); + if (swi < 0) + panic("SWI0 IRQ mapping failed\n"); + irq_set_percpu_devid(swi); + r = request_percpu_irq(swi, pv_ipi_interrupt, "SWI0-IPI", &irq_stat); + if (r < 0) + panic("SWI0 IRQ request failed\n"); +} +#endif + +static bool kvm_para_available(void) +{ + int config; + static int hypervisor_type; + + if (!hypervisor_type) { + config = read_cpucfg(CPUCFG_KVM_SIG); + if (!memcmp(&config, KVM_SIGNATURE, 4)) + hypervisor_type = HYPERVISOR_KVM; + } + + return hypervisor_type == HYPERVISOR_KVM; +} + +int __init pv_ipi_init(void) +{ + int feature; + + if (!cpu_has_hypervisor) + return 0; + if (!kvm_para_available()) + return 0; + + feature = read_cpucfg(CPUCFG_KVM_FEATURE); + if (!(feature & KVM_FEATURE_IPI)) + return 0; + +#ifdef CONFIG_SMP + mp_ops.init_ipi = pv_init_ipi; + mp_ops.send_ipi_single = pv_send_ipi_single; + mp_ops.send_ipi_mask = pv_send_ipi_mask; +#endif + + return 0; +} diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c index 15b75e671bcd..0dfe2388ef41 100644 --- a/arch/loongarch/kernel/smp.c +++ b/arch/loongarch/kernel/smp.c @@ -29,6 +29,7 @@ #include <asm/loongson.h> #include <asm/mmu_context.h> #include <asm/numa.h> +#include <asm/paravirt.h> #include <asm/processor.h> #include <asm/setup.h> #include <asm/time.h> @@ -299,6 +300,7 @@ void __init loongson_smp_setup(void) cpu_data[0].core = cpu_logical_map(0) % loongson_sysconf.cores_per_package; cpu_data[0].package = cpu_logical_map(0) / loongson_sysconf.cores_per_package; + pv_ipi_init(); iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_EN); pr_info("Detected %i available CPU(s)\n", loongson_sysconf.nr_cpus); } @@ -343,7 +345,7 @@ void loongson_init_secondary(void) { unsigned int cpu = smp_processor_id(); unsigned int imask = ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | - ECFGF_IPI | ECFGF_PMC | ECFGF_TIMER; + ECFGF_IPI | ECFGF_PMC | ECFGF_TIMER | ECFGF_SIP0; change_csr_ecfg(ECFG0_IM, imask); |