Logo Search packages:      
Sourcecode: linux version File versions  Download package

setup64.c

/* 
 * X86-64 specific CPU setup.
 * Copyright (C) 1995  Linus Torvalds
 * Copyright 2001, 2002, 2003 SuSE Labs / Andi Kleen.
 * See setup.c for older changelog.
 */ 
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/bootmem.h>
#include <linux/bitops.h>
#include <linux/module.h>
#include <asm/pda.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/desc.h>
#include <asm/atomic.h>
#include <asm/mmu_context.h>
#include <asm/smp.h>
#include <asm/i387.h>
#include <asm/percpu.h>
#include <asm/proto.h>
#include <asm/sections.h>
#include <asm/setup.h>

struct boot_params __initdata boot_params;

cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE;

struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(_cpu_pda);
struct x8664_pda boot_cpu_pda[NR_CPUS] __cacheline_aligned;

struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };

char boot_cpu_stack[IRQSTACKSIZE] __attribute__((section(".bss.page_aligned")));

unsigned long __supported_pte_mask __read_mostly = ~0UL;
static int do_not_nx __cpuinitdata = 0;

/* noexec=on|off
Control non executable mappings for 64bit processes.

on    Enable(default)
off   Disable
*/ 
static int __init nonx_setup(char *str)
{
      if (!str)
            return -EINVAL;
      if (!strncmp(str, "on", 2)) {
                __supported_pte_mask |= _PAGE_NX; 
            do_not_nx = 0; 
      } else if (!strncmp(str, "off", 3)) {
            do_not_nx = 1;
            __supported_pte_mask &= ~_PAGE_NX;
        }
      return 0;
} 
early_param("noexec", nonx_setup);

int force_personality32 = 0; 

/* noexec32=on|off
Control non executable heap for 32bit processes.
To control the stack too use noexec=off

on    PROT_READ does not imply PROT_EXEC for 32bit processes
off   PROT_READ implies PROT_EXEC (default)
*/
static int __init nonx32_setup(char *str)
{
      if (!strcmp(str, "on"))
            force_personality32 &= ~READ_IMPLIES_EXEC;
      else if (!strcmp(str, "off"))
            force_personality32 |= READ_IMPLIES_EXEC;
      return 1;
}
__setup("noexec32=", nonx32_setup);

/*
 * Great future plan:
 * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
 * Always point %gs to its beginning
 */
void __init setup_per_cpu_areas(void)
{ 
      int i;
      unsigned long size;

#ifdef CONFIG_HOTPLUG_CPU
      prefill_possible_map();
#endif

      /* Copy section for each CPU (we discard the original) */
      size = PERCPU_ENOUGH_ROOM;

      printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n", size);
      for_each_cpu_mask (i, cpu_possible_map) {
            char *ptr;

            if (!NODE_DATA(cpu_to_node(i))) {
                  printk("cpu with no node %d, num_online_nodes %d\n",
                         i, num_online_nodes());
                  ptr = alloc_bootmem_pages(size);
            } else { 
                  ptr = alloc_bootmem_pages_node(NODE_DATA(cpu_to_node(i)), size);
            }
            if (!ptr)
                  panic("Cannot allocate cpu data for CPU %d\n", i);
            cpu_pda(i)->data_offset = ptr - __per_cpu_start;
            memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
      }
} 

void pda_init(int cpu)
{ 
      struct x8664_pda *pda = cpu_pda(cpu);

      /* Setup up data that may be needed in __get_free_pages early */
      asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0)); 
      /* Memory clobbers used to order PDA accessed */
      mb();
      wrmsrl(MSR_GS_BASE, pda);
      mb();

      pda->cpunumber = cpu; 
      pda->irqcount = -1;
      pda->kernelstack = 
            (unsigned long)stack_thread_info() - PDA_STACKOFFSET + THREAD_SIZE; 
      pda->active_mm = &init_mm;
      pda->mmu_state = 0;

      if (cpu == 0) {
            /* others are initialized in smpboot.c */
            pda->pcurrent = &init_task;
            pda->irqstackptr = boot_cpu_stack; 
      } else {
            pda->irqstackptr = (char *)
                  __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
            if (!pda->irqstackptr)
                  panic("cannot allocate irqstack for cpu %d", cpu); 
      }


      pda->irqstackptr += IRQSTACKSIZE-64;
} 

char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]
__attribute__((section(".bss.page_aligned")));

extern asmlinkage void ignore_sysret(void);

/* May not be marked __init: used by software suspend */
void syscall_init(void)
{
      /* 
       * LSTAR and STAR live in a bit strange symbiosis.
       * They both write to the same internal register. STAR allows to set CS/DS
       * but only a 32bit target. LSTAR sets the 64bit rip.        
       */ 
      wrmsrl(MSR_STAR,  ((u64)__USER32_CS)<<48  | ((u64)__KERNEL_CS)<<32); 
      wrmsrl(MSR_LSTAR, system_call); 
      wrmsrl(MSR_CSTAR, ignore_sysret);

#ifdef CONFIG_IA32_EMULATION              
      syscall32_cpu_init ();
#endif

      /* Flags to clear on syscall */
      wrmsrl(MSR_SYSCALL_MASK, EF_TF|EF_DF|EF_IE|0x3000); 
}

void __cpuinit check_efer(void)
{
      unsigned long efer;

      rdmsrl(MSR_EFER, efer); 
        if (!(efer & EFER_NX) || do_not_nx) { 
                __supported_pte_mask &= ~_PAGE_NX; 
        }       
}

unsigned long kernel_eflags;

/*
 * Copies of the original ist values from the tss are only accessed during
 * debugging, no special alignment required.
 */
DEFINE_PER_CPU(struct orig_ist, orig_ist);

/*
 * cpu_init() initializes state that is per-CPU. Some data is already
 * initialized (naturally) in the bootstrap process, such as the GDT
 * and IDT. We reload them nevertheless, this function acts as a
 * 'CPU state barrier', nothing should get across.
 * A lot of state is already set up in PDA init.
 */
void __cpuinit cpu_init (void)
{
      int cpu = stack_smp_processor_id();
      struct tss_struct *t = &per_cpu(init_tss, cpu);
      struct orig_ist *orig_ist = &per_cpu(orig_ist, cpu);
      unsigned long v; 
      char *estacks = NULL; 
      struct task_struct *me;
      int i;

      /* CPU 0 is initialised in head64.c */
      if (cpu != 0) {
            pda_init(cpu);
      } else 
            estacks = boot_exception_stacks; 

      me = current;

      if (cpu_test_and_set(cpu, cpu_initialized))
            panic("CPU#%d already initialized!\n", cpu);

      printk("Initializing CPU#%d\n", cpu);

      clear_in_cr4(X86_CR4_VME|X86_CR4_PVI|X86_CR4_TSD|X86_CR4_DE);

      /*
       * Initialize the per-CPU GDT with the boot GDT,
       * and set up the GDT descriptor:
       */
      if (cpu)
            memcpy(cpu_gdt(cpu), cpu_gdt_table, GDT_SIZE);

      cpu_gdt_descr[cpu].size = GDT_SIZE;
      load_gdt((const struct desc_ptr *)&cpu_gdt_descr[cpu]);
      load_idt((const struct desc_ptr *)&idt_descr);

      memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
      syscall_init();

      wrmsrl(MSR_FS_BASE, 0);
      wrmsrl(MSR_KERNEL_GS_BASE, 0);
      barrier(); 

      check_efer();

      /*
       * set up and load the per-CPU TSS
       */
      for (v = 0; v < N_EXCEPTION_STACKS; v++) {
            static const unsigned int order[N_EXCEPTION_STACKS] = {
                  [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
                  [DEBUG_STACK - 1] = DEBUG_STACK_ORDER
            };
            if (cpu) {
                  estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
                  if (!estacks)
                        panic("Cannot allocate exception stack %ld %d\n",
                              v, cpu); 
            }
            estacks += PAGE_SIZE << order[v];
            orig_ist->ist[v] = t->ist[v] = (unsigned long)estacks;
      }

      t->io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
      /*
       * <= is required because the CPU will access up to
       * 8 bits beyond the end of the IO permission bitmap.
       */
      for (i = 0; i <= IO_BITMAP_LONGS; i++)
            t->io_bitmap[i] = ~0UL;

      atomic_inc(&init_mm.mm_count);
      me->active_mm = &init_mm;
      if (me->mm)
            BUG();
      enter_lazy_tlb(&init_mm, me);

      set_tss_desc(cpu, t);
      load_TR_desc();
      load_LDT(&init_mm.context);

      /*
       * Clear all 6 debug registers:
       */

      set_debugreg(0UL, 0);
      set_debugreg(0UL, 1);
      set_debugreg(0UL, 2);
      set_debugreg(0UL, 3);
      set_debugreg(0UL, 6);
      set_debugreg(0UL, 7);

      fpu_init(); 

      raw_local_save_flags(kernel_eflags);
}

Generated by  Doxygen 1.6.0   Back to index