#include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/bootmem.h> #include <linux/percpu.h> #include <linux/kexec.h> #include <linux/crash_dump.h> #include <linux/smp.h> #include <linux/topology.h> #include <linux/pfn.h> #include <asm/sections.h> #include <asm/processor.h> #include <asm/setup.h> #include <asm/mpspec.h> #include <asm/apicdef.h> #include <asm/highmem.h> #include <asm/proto.h> #include <asm/cpumask.h> #include <asm/cpu.h> #include <asm/stackprotector.h> #ifdef CONFIG_DEBUG_PER_CPU_MAPS # define DBG(x...) printk(KERN_DEBUG x) #else # define DBG(x...) #endif DEFINE_PER_CPU(int, cpu_number); EXPORT_PER_CPU_SYMBOL(cpu_number); #ifdef CONFIG_X86_64 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load) #else #define BOOT_PERCPU_OFFSET 0 #endif DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET; EXPORT_PER_CPU_SYMBOL(this_cpu_off); unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET, }; EXPORT_SYMBOL(__per_cpu_offset); /* * On x86_64 symbols referenced from code should be reachable using * 32bit relocations. Reserve space for static percpu variables in * modules so that they are always served from the first chunk which * is located at the percpu segment base. On x86_32, anything can * address anywhere. No need to reserve space in the first chunk. */ #ifdef CONFIG_X86_64 #define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE #else #define PERCPU_FIRST_CHUNK_RESERVE 0 #endif #ifdef CONFIG_X86_32 /** * pcpu_need_numa - determine percpu allocation needs to consider NUMA * * If NUMA is not configured or there is only one NUMA node available, * there is no reason to consider NUMA. This function determines * whether percpu allocation should consider NUMA or not. * * RETURNS: * true if NUMA should be considered; otherwise, false. */ static bool __init pcpu_need_numa(void) { #ifdef CONFIG_NEED_MULTIPLE_NODES pg_data_t *last = NULL; unsigned int cpu; for_each_possible_cpu(cpu) { int node = early_cpu_to_node(cpu); if (node_online(node) && NODE_DATA(node) && last && last != NODE_DATA(node)) return true; last = NODE_DATA(node); } #endif return false; } #endif /** * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu * @cpu: cpu to allocate for * @size: size allocation in bytes * @align: alignment * * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper * does the right thing for NUMA regardless of the current * configuration. * * RETURNS: * Pointer to the allocated area on success, NULL on failure. */ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, unsigned long align) { const unsigned long goal = __pa(MAX_DMA_ADDRESS); #ifdef CONFIG_NEED_MULTIPLE_NODES int node = early_cpu_to_node(cpu); void *ptr; if (!node_online(node) || !NODE_DATA(node)) { ptr = __alloc_bootmem_nopanic(size, align, goal); pr_info("cpu %d has no node %d or node-local memory\n", cpu, node); pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n", cpu, size, __pa(ptr)); } else { ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node), size, align, goal); pr_debug("per cpu data for cpu%d %lu bytes on node%d at " "%016lx\n", cpu, size, node, __pa(ptr)); } return ptr; #else return __alloc_bootmem_nopanic(size, align, goal); #endif } /* * Helpers for first chunk memory allocation */ static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align) { return pcpu_alloc_bootmem(cpu, size, align); } static void __init pcpu_fc_free(void *ptr, size_t size) { free_bootmem(__pa(ptr), size); } static int __init pcpu_cpu_distance(unsigned int from, unsigned int to) { #ifdef CONFIG_NEED_MULTIPLE_NODES if (early_cpu_to_node(from) == early_cpu_to_node(to)) return LOCAL_DISTANCE; else return REMOTE_DISTANCE; #else return LOCAL_DISTANCE; #endif } static void __init pcpup_populate_pte(unsigned long addr) { populate_extra_pte(addr); } static inline void setup_percpu_segment(int cpu) { #ifdef CONFIG_X86_32 struct desc_struct gdt; pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF, 0x2 | DESCTYPE_S, 0x8); gdt.s = 1; write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S); #endif } void __init setup_per_cpu_areas(void) { unsigned int cpu; unsigned long delta; int rc; pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n", NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids); /* * Allocate percpu area. Embedding allocator is our favorite; * however, on NUMA configurations, it can result in very * sparse unit mapping and vmalloc area isn't spacious enough * on 32bit. Use page in that case. */ #ifdef CONFIG_X86_32 if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa()) pcpu_chosen_fc = PCPU_FC_PAGE; #endif rc = -EINVAL; if (pcpu_chosen_fc != PCPU_FC_PAGE) { const size_t atom_size = cpu_has_pse ? PMD_SIZE : PAGE_SIZE; const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE; rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, dyn_size, atom_size, pcpu_cpu_distance, pcpu_fc_alloc, pcpu_fc_free); if (rc < 0) pr_warning("PERCPU: %s allocator failed (%d), " "falling back to page size\n", pcpu_fc_names[pcpu_chosen_fc], rc); } if (rc < 0) rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, pcpu_fc_alloc, pcpu_fc_free, pcpup_populate_pte); if (rc < 0) panic("cannot initialize percpu area (err=%d)", rc); /* alrighty, percpu areas up and running */ delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; for_each_possible_cpu(cpu) { per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu]; per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); per_cpu(cpu_number, cpu) = cpu; setup_percpu_segment(cpu); setup_stack_canary_segment(cpu); /* * Copy data used in early init routines from the * initial arrays to the per cpu data areas. These * arrays then become expendable and the *_early_ptr's * are zeroed indicating that the static arrays are * gone. */ #ifdef CONFIG_X86_LOCAL_APIC per_cpu(x86_cpu_to_apicid, cpu) = early_per_cpu_map(x86_cpu_to_apicid, cpu); per_cpu(x86_bios_cpu_apicid, cpu) = early_per_cpu_map(x86_bios_cpu_apicid, cpu); #endif #ifdef CONFIG_X86_64 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack_union.irq_stack, cpu) + IRQ_STACK_SIZE - 64; #ifdef CONFIG_NUMA per_cpu(x86_cpu_to_node_map, cpu) = early_per_cpu_map(x86_cpu_to_node_map, cpu); #endif #endif /* * Up to this point, the boot CPU has been using .data.init * area. Reload any changed state for the boot CPU. */ if (cpu == boot_cpu_id) switch_to_new_gdt(cpu); } /* indicate the early static arrays will soon be gone */ #ifdef CONFIG_X86_LOCAL_APIC early_per_cpu_ptr(x86_cpu_to_apicid) = NULL; early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL; #endif #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) early_per_cpu_ptr(x86_cpu_to_node_map) = NULL; #endif #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) /* * make sure boot cpu node_number is right, when boot cpu is on the * node that doesn't have mem installed */ per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id); #endif /* Setup node to cpumask map */ setup_node_to_cpumask_map(); /* Setup cpu initialized, callin, callout masks */ setup_cpu_local_masks(); }