#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #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> DEFINE_PER_CPU_READ_MOSTLY(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 dyn_size = PERCPU_MODULE_RESERVE +			PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;		size_t atom_size; 		/*		 * On 64bit, use PMD_SIZE for atom_size so that embedded		 * percpu areas are aligned to PMD.  This, in the future,		 * can also allow using PMD mappings in vmalloc area.  Use		 * PAGE_SIZE on 32bit as vmalloc space is highly contended		 * and large vmalloc area allocs can easily fail.		 */#ifdef CONFIG_X86_64		atom_size = PMD_SIZE;#else		atom_size = PAGE_SIZE;#endif		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("%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_32		per_cpu(x86_cpu_to_logical_apicid, cpu) =			early_per_cpu_map(x86_cpu_to_logical_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;#endif#ifdef CONFIG_NUMA		per_cpu(x86_cpu_to_node_map, cpu) =			early_per_cpu_map(x86_cpu_to_node_map, cpu);		/*		 * Ensure that the boot cpu numa_node is correct when the boot		 * cpu is on a node that doesn't have memory installed.		 * Also cpu_up() will call cpu_to_node() for APs when		 * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set		 * up later with c_init aka intel_init/amd_init.		 * So set them all (boot cpu and all APs).		 */		set_cpu_numa_node(cpu, early_cpu_to_node(cpu));#endif		/*		 * Up to this point, the boot CPU has been using .init.data		 * area.  Reload any changed state for the boot CPU.		 */		if (!cpu)			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#ifdef CONFIG_X86_32	early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;#endif#ifdef CONFIG_NUMA	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;#endif 	/* Setup node to cpumask map */	setup_node_to_cpumask_map(); 	/* Setup cpu initialized, callin, callout masks */	setup_cpu_local_masks();}