/*
* 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 <linux/kgdb.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>
#include <asm/genapic.h>
#ifndef CONFIG_DEBUG_BOOT_PARAMS
struct boot_params __initdata boot_params;
#else
struct boot_params boot_params;
#endif
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;
EXPORT_SYMBOL_GPL(__supported_pte_mask);
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 (default)
off PROT_READ implies PROT_EXEC
*/
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);
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,
X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF|X86_EFLAGS_IOPL);
}
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(get_cpu_gdt_table(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->x86_tss.ist[v] = (unsigned long)estacks;
}
t->x86_tss.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);
#ifdef CONFIG_KGDB
/*
* If the kgdb is connected no debug regs should be altered. This
* is only applicable when KGDB and a KGDB I/O module are built
* into the kernel and you are using early debugging with
* kgdbwait. KGDB will control the kernel HW breakpoint registers.
*/
if (kgdb_connected && arch_kgdb_ops.correct_hw_break)
arch_kgdb_ops.correct_hw_break();
else {
#endif
/*
* 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);
#ifdef CONFIG_KGDB
/* If the kgdb is connected no debug regs should be altered. */
}
#endif
fpu_init();
raw_local_save_flags(kernel_eflags);
if (is_uv_system())
uv_cpu_init();
}
