1 #include <linux/kernel.h> 2 #include <linux/module.h> 3 #include <linux/init.h> 4 #include <linux/bootmem.h> 5 #include <linux/percpu.h> 6 #include <linux/kexec.h> 7 #include <linux/crash_dump.h> 8 #include <linux/smp.h> 9 #include <linux/topology.h> 10 #include <linux/pfn.h> 11 #include <asm/sections.h> 12 #include <asm/processor.h> 13 #include <asm/setup.h> 14 #include <asm/mpspec.h> 15 #include <asm/apicdef.h> 16 #include <asm/highmem.h> 17 #include <asm/proto.h> 18 #include <asm/cpumask.h> 19 #include <asm/cpu.h> 20 #include <asm/stackprotector.h> 21 22 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 23 # define DBG(x...) printk(KERN_DEBUG x) 24 #else 25 # define DBG(x...) 26 #endif 27 28 DEFINE_PER_CPU(int, cpu_number); 29 EXPORT_PER_CPU_SYMBOL(cpu_number); 30 31 #ifdef CONFIG_X86_64 32 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load) 33 #else 34 #define BOOT_PERCPU_OFFSET 0 35 #endif 36 37 DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET; 38 EXPORT_PER_CPU_SYMBOL(this_cpu_off); 39 40 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = { 41 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET, 42 }; 43 EXPORT_SYMBOL(__per_cpu_offset); 44 45 /* 46 * On x86_64 symbols referenced from code should be reachable using 47 * 32bit relocations. Reserve space for static percpu variables in 48 * modules so that they are always served from the first chunk which 49 * is located at the percpu segment base. On x86_32, anything can 50 * address anywhere. No need to reserve space in the first chunk. 51 */ 52 #ifdef CONFIG_X86_64 53 #define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE 54 #else 55 #define PERCPU_FIRST_CHUNK_RESERVE 0 56 #endif 57 58 #ifdef CONFIG_X86_32 59 /** 60 * pcpu_need_numa - determine percpu allocation needs to consider NUMA 61 * 62 * If NUMA is not configured or there is only one NUMA node available, 63 * there is no reason to consider NUMA. This function determines 64 * whether percpu allocation should consider NUMA or not. 65 * 66 * RETURNS: 67 * true if NUMA should be considered; otherwise, false. 68 */ 69 static bool __init pcpu_need_numa(void) 70 { 71 #ifdef CONFIG_NEED_MULTIPLE_NODES 72 pg_data_t *last = NULL; 73 unsigned int cpu; 74 75 for_each_possible_cpu(cpu) { 76 int node = early_cpu_to_node(cpu); 77 78 if (node_online(node) && NODE_DATA(node) && 79 last && last != NODE_DATA(node)) 80 return true; 81 82 last = NODE_DATA(node); 83 } 84 #endif 85 return false; 86 } 87 #endif 88 89 /** 90 * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu 91 * @cpu: cpu to allocate for 92 * @size: size allocation in bytes 93 * @align: alignment 94 * 95 * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper 96 * does the right thing for NUMA regardless of the current 97 * configuration. 98 * 99 * RETURNS: 100 * Pointer to the allocated area on success, NULL on failure. 101 */ 102 static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, 103 unsigned long align) 104 { 105 const unsigned long goal = __pa(MAX_DMA_ADDRESS); 106 #ifdef CONFIG_NEED_MULTIPLE_NODES 107 int node = early_cpu_to_node(cpu); 108 void *ptr; 109 110 if (!node_online(node) || !NODE_DATA(node)) { 111 ptr = __alloc_bootmem_nopanic(size, align, goal); 112 pr_info("cpu %d has no node %d or node-local memory\n", 113 cpu, node); 114 pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n", 115 cpu, size, __pa(ptr)); 116 } else { 117 ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node), 118 size, align, goal); 119 pr_debug("per cpu data for cpu%d %lu bytes on node%d at " 120 "%016lx\n", cpu, size, node, __pa(ptr)); 121 } 122 return ptr; 123 #else 124 return __alloc_bootmem_nopanic(size, align, goal); 125 #endif 126 } 127 128 /* 129 * Helpers for first chunk memory allocation 130 */ 131 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align) 132 { 133 return pcpu_alloc_bootmem(cpu, size, align); 134 } 135 136 static void __init pcpu_fc_free(void *ptr, size_t size) 137 { 138 free_bootmem(__pa(ptr), size); 139 } 140 141 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to) 142 { 143 #ifdef CONFIG_NEED_MULTIPLE_NODES 144 if (early_cpu_to_node(from) == early_cpu_to_node(to)) 145 return LOCAL_DISTANCE; 146 else 147 return REMOTE_DISTANCE; 148 #else 149 return LOCAL_DISTANCE; 150 #endif 151 } 152 153 static void __init pcpup_populate_pte(unsigned long addr) 154 { 155 populate_extra_pte(addr); 156 } 157 158 static inline void setup_percpu_segment(int cpu) 159 { 160 #ifdef CONFIG_X86_32 161 struct desc_struct gdt; 162 163 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF, 164 0x2 | DESCTYPE_S, 0x8); 165 gdt.s = 1; 166 write_gdt_entry(get_cpu_gdt_table(cpu), 167 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S); 168 #endif 169 } 170 171 void __init setup_per_cpu_areas(void) 172 { 173 unsigned int cpu; 174 unsigned long delta; 175 int rc; 176 177 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n", 178 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids); 179 180 /* 181 * Allocate percpu area. Embedding allocator is our favorite; 182 * however, on NUMA configurations, it can result in very 183 * sparse unit mapping and vmalloc area isn't spacious enough 184 * on 32bit. Use page in that case. 185 */ 186 #ifdef CONFIG_X86_32 187 if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa()) 188 pcpu_chosen_fc = PCPU_FC_PAGE; 189 #endif 190 rc = -EINVAL; 191 if (pcpu_chosen_fc != PCPU_FC_PAGE) { 192 const size_t atom_size = cpu_has_pse ? PMD_SIZE : PAGE_SIZE; 193 const size_t dyn_size = PERCPU_MODULE_RESERVE + 194 PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE; 195 196 rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, 197 dyn_size, atom_size, 198 pcpu_cpu_distance, 199 pcpu_fc_alloc, pcpu_fc_free); 200 if (rc < 0) 201 pr_warning("PERCPU: %s allocator failed (%d), " 202 "falling back to page size\n", 203 pcpu_fc_names[pcpu_chosen_fc], rc); 204 } 205 if (rc < 0) 206 rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, 207 pcpu_fc_alloc, pcpu_fc_free, 208 pcpup_populate_pte); 209 if (rc < 0) 210 panic("cannot initialize percpu area (err=%d)", rc); 211 212 /* alrighty, percpu areas up and running */ 213 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; 214 for_each_possible_cpu(cpu) { 215 per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu]; 216 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); 217 per_cpu(cpu_number, cpu) = cpu; 218 setup_percpu_segment(cpu); 219 setup_stack_canary_segment(cpu); 220 /* 221 * Copy data used in early init routines from the 222 * initial arrays to the per cpu data areas. These 223 * arrays then become expendable and the *_early_ptr's 224 * are zeroed indicating that the static arrays are 225 * gone. 226 */ 227 #ifdef CONFIG_X86_LOCAL_APIC 228 per_cpu(x86_cpu_to_apicid, cpu) = 229 early_per_cpu_map(x86_cpu_to_apicid, cpu); 230 per_cpu(x86_bios_cpu_apicid, cpu) = 231 early_per_cpu_map(x86_bios_cpu_apicid, cpu); 232 #endif 233 #ifdef CONFIG_X86_64 234 per_cpu(irq_stack_ptr, cpu) = 235 per_cpu(irq_stack_union.irq_stack, cpu) + 236 IRQ_STACK_SIZE - 64; 237 #ifdef CONFIG_NUMA 238 per_cpu(x86_cpu_to_node_map, cpu) = 239 early_per_cpu_map(x86_cpu_to_node_map, cpu); 240 #endif 241 #endif 242 /* 243 * Up to this point, the boot CPU has been using .data.init 244 * area. Reload any changed state for the boot CPU. 245 */ 246 if (cpu == boot_cpu_id) 247 switch_to_new_gdt(cpu); 248 } 249 250 /* indicate the early static arrays will soon be gone */ 251 #ifdef CONFIG_X86_LOCAL_APIC 252 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL; 253 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL; 254 #endif 255 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) 256 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL; 257 #endif 258 259 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA) 260 /* 261 * make sure boot cpu node_number is right, when boot cpu is on the 262 * node that doesn't have mem installed 263 */ 264 per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id); 265 #endif 266 267 /* Setup node to cpumask map */ 268 setup_node_to_cpumask_map(); 269 270 /* Setup cpu initialized, callin, callout masks */ 271 setup_cpu_local_masks(); 272 } 273