2 * X86-64 specific CPU setup.
3 * Copyright (C) 1995 Linus Torvalds
4 * Copyright 2001, 2002, 2003 SuSE Labs / Andi Kleen.
5 * See setup.c for older changelog.
6 * $Id: setup64.c,v 1.12 2002/03/21 10:09:17 ak Exp $
8 #include <linux/config.h>
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/string.h>
13 #include <linux/bootmem.h>
14 #include <linux/bitops.h>
16 #include <asm/pgtable.h>
17 #include <asm/processor.h>
19 #include <asm/atomic.h>
20 #include <asm/mmu_context.h>
23 #include <asm/percpu.h>
25 #include <asm/proto.h>
29 char x86_boot_params[2048] __initdata = {0,};
31 cpumask_t cpu_initialized __initdata = CPU_MASK_NONE;
33 struct x8664_pda cpu_pda[NR_CPUS] __cacheline_aligned;
35 extern struct task_struct init_task;
37 extern unsigned char __per_cpu_start[], __per_cpu_end[];
39 extern struct desc_ptr cpu_gdt_descr[];
40 struct desc_ptr idt_descr = { 256 * 16, (unsigned long) idt_table };
42 char boot_cpu_stack[IRQSTACKSIZE] __attribute__((section(".bss.page_aligned")));
44 unsigned long __supported_pte_mask = ~0UL;
45 static int do_not_nx __initdata = 0;
48 Control non executable mappings for 64bit processes.
53 int __init nonx_setup(char *str)
55 if (!strncmp(str, "on", 2)) {
56 __supported_pte_mask |= _PAGE_NX;
58 } else if (!strncmp(str, "off", 3)) {
60 __supported_pte_mask &= ~_PAGE_NX;
64 __setup("noexec=", nonx_setup); /* parsed early actually */
66 int force_personality32 = READ_IMPLIES_EXEC;
69 Control non executable heap for 32bit processes.
70 To control the stack too use noexec=off
72 on PROT_READ does not imply PROT_EXEC for 32bit processes
73 off PROT_READ implies PROT_EXEC (default)
75 static int __init nonx32_setup(char *str)
77 if (!strcmp(str, "on"))
78 force_personality32 &= ~READ_IMPLIES_EXEC;
79 else if (!strcmp(str, "off"))
80 force_personality32 |= READ_IMPLIES_EXEC;
83 __setup("noexec32=", nonx32_setup);
87 * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
88 * Always point %gs to its beginning
90 void __init setup_per_cpu_areas(void)
95 /* Copy section for each CPU (we discard the original) */
96 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
98 if (size < PERCPU_ENOUGH_ROOM)
99 size = PERCPU_ENOUGH_ROOM;
102 for (i = 0; i < NR_CPUS; i++) {
105 if (!NODE_DATA(cpu_to_node(i))) {
106 printk("cpu with no node %d, num_online_nodes %d\n",
107 i, num_online_nodes());
108 ptr = alloc_bootmem(size);
110 ptr = alloc_bootmem_node(NODE_DATA(cpu_to_node(i)), size);
113 panic("Cannot allocate cpu data for CPU %d\n", i);
114 cpu_pda[i].data_offset = ptr - __per_cpu_start;
115 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
119 void pda_init(int cpu)
121 struct x8664_pda *pda = &cpu_pda[cpu];
123 /* Setup up data that may be needed in __get_free_pages early */
124 asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
125 wrmsrl(MSR_GS_BASE, cpu_pda + cpu);
128 pda->cpunumber = cpu;
131 (unsigned long)stack_thread_info() - PDA_STACKOFFSET + THREAD_SIZE;
132 pda->active_mm = &init_mm;
136 /* others are initialized in smpboot.c */
137 pda->pcurrent = &init_task;
138 pda->irqstackptr = boot_cpu_stack;
140 pda->irqstackptr = (char *)
141 __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
142 if (!pda->irqstackptr)
143 panic("cannot allocate irqstack for cpu %d", cpu);
146 asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt)));
148 pda->irqstackptr += IRQSTACKSIZE-64;
151 char boot_exception_stacks[N_EXCEPTION_STACKS * EXCEPTION_STKSZ]
152 __attribute__((section(".bss.page_aligned")));
154 /* May not be marked __init: used by software suspend */
155 void syscall_init(void)
158 * LSTAR and STAR live in a bit strange symbiosis.
159 * They both write to the same internal register. STAR allows to set CS/DS
160 * but only a 32bit target. LSTAR sets the 64bit rip.
162 wrmsrl(MSR_STAR, ((u64)__USER32_CS)<<48 | ((u64)__KERNEL_CS)<<32);
163 wrmsrl(MSR_LSTAR, system_call);
165 #ifdef CONFIG_IA32_EMULATION
166 syscall32_cpu_init ();
169 /* Flags to clear on syscall */
170 wrmsrl(MSR_SYSCALL_MASK, EF_TF|EF_DF|EF_IE|0x3000);
173 void __init check_efer(void)
177 rdmsrl(MSR_EFER, efer);
178 if (!(efer & EFER_NX) || do_not_nx) {
179 __supported_pte_mask &= ~_PAGE_NX;
184 * cpu_init() initializes state that is per-CPU. Some data is already
185 * initialized (naturally) in the bootstrap process, such as the GDT
186 * and IDT. We reload them nevertheless, this function acts as a
187 * 'CPU state barrier', nothing should get across.
188 * A lot of state is already set up in PDA init.
190 void __init cpu_init (void)
193 int cpu = stack_smp_processor_id();
195 int cpu = smp_processor_id();
197 struct tss_struct *t = &per_cpu(init_tss, cpu);
199 char *estacks = NULL;
200 struct task_struct *me;
203 /* CPU 0 is initialised in head64.c */
207 estacks = boot_exception_stacks;
211 if (cpu_test_and_set(cpu, cpu_initialized))
212 panic("CPU#%d already initialized!\n", cpu);
214 printk("Initializing CPU#%d\n", cpu);
216 clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);
219 * Initialize the per-CPU GDT with the boot GDT,
220 * and set up the GDT descriptor:
223 memcpy(cpu_gdt_table[cpu], cpu_gdt_table[0], GDT_SIZE);
226 cpu_gdt_descr[cpu].size = GDT_SIZE;
227 cpu_gdt_descr[cpu].address = (unsigned long)cpu_gdt_table[cpu];
228 asm volatile("lgdt %0" :: "m" (cpu_gdt_descr[cpu]));
229 asm volatile("lidt %0" :: "m" (idt_descr));
231 memcpy(me->thread.tls_array, cpu_gdt_table[cpu], GDT_ENTRY_TLS_ENTRIES * 8);
237 asm volatile("pushfq ; popq %%rax ; btr $14,%%rax ; pushq %%rax ; popfq" ::: "eax");
241 wrmsrl(MSR_FS_BASE, 0);
242 wrmsrl(MSR_KERNEL_GS_BASE, 0);
248 * set up and load the per-CPU TSS
250 for (v = 0; v < N_EXCEPTION_STACKS; v++) {
252 estacks = (char *)__get_free_pages(GFP_ATOMIC,
253 EXCEPTION_STACK_ORDER);
255 panic("Cannot allocate exception stack %ld %d\n",
258 estacks += EXCEPTION_STKSZ;
259 t->ist[v] = (unsigned long)estacks;
262 t->io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
264 * <= is required because the CPU will access up to
265 * 8 bits beyond the end of the IO permission bitmap.
267 for (i = 0; i <= IO_BITMAP_LONGS; i++)
268 t->io_bitmap[i] = ~0UL;
270 atomic_inc(&init_mm.mm_count);
271 me->active_mm = &init_mm;
274 enter_lazy_tlb(&init_mm, me);
276 set_tss_desc(cpu, t);
278 load_LDT(&init_mm.context);
281 * Clear all 6 debug registers: