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.
7 #include <linux/config.h>
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/string.h>
12 #include <linux/bootmem.h>
13 #include <linux/bitops.h>
14 #include <linux/module.h>
15 #include <asm/bootsetup.h>
17 #include <asm/pgtable.h>
18 #include <asm/processor.h>
20 #include <asm/atomic.h>
21 #include <asm/mmu_context.h>
24 #include <asm/percpu.h>
25 #include <asm/proto.h>
26 #include <asm/sections.h>
28 char x86_boot_params
[BOOT_PARAM_SIZE
] __initdata
= {0,};
30 cpumask_t cpu_initialized __cpuinitdata
= CPU_MASK_NONE
;
32 struct x8664_pda
*_cpu_pda
[NR_CPUS
] __read_mostly
;
33 EXPORT_SYMBOL(_cpu_pda
);
34 struct x8664_pda boot_cpu_pda
[NR_CPUS
] __cacheline_aligned
;
36 struct desc_ptr idt_descr
= { 256 * 16 - 1, (unsigned long) idt_table
};
38 char boot_cpu_stack
[IRQSTACKSIZE
] __attribute__((section(".bss.page_aligned")));
40 unsigned long __supported_pte_mask __read_mostly
= ~0UL;
41 EXPORT_SYMBOL(__supported_pte_mask
);
42 static int do_not_nx __cpuinitdata
= 0;
45 Control non executable mappings for 64bit processes.
50 int __init
nonx_setup(char *str
)
52 if (!strncmp(str
, "on", 2)) {
53 __supported_pte_mask
|= _PAGE_NX
;
55 } else if (!strncmp(str
, "off", 3)) {
57 __supported_pte_mask
&= ~_PAGE_NX
;
61 __setup("noexec=", nonx_setup
); /* parsed early actually */
63 int force_personality32
= 0;
66 Control non executable heap for 32bit processes.
67 To control the stack too use noexec=off
69 on PROT_READ does not imply PROT_EXEC for 32bit processes
70 off PROT_READ implies PROT_EXEC (default)
72 static int __init
nonx32_setup(char *str
)
74 if (!strcmp(str
, "on"))
75 force_personality32
&= ~READ_IMPLIES_EXEC
;
76 else if (!strcmp(str
, "off"))
77 force_personality32
|= READ_IMPLIES_EXEC
;
80 __setup("noexec32=", nonx32_setup
);
84 * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
85 * Always point %gs to its beginning
87 void __init
setup_per_cpu_areas(void)
92 #ifdef CONFIG_HOTPLUG_CPU
93 prefill_possible_map();
96 /* Copy section for each CPU (we discard the original) */
97 size
= ALIGN(__per_cpu_end
- __per_cpu_start
, SMP_CACHE_BYTES
);
99 if (size
< PERCPU_ENOUGH_ROOM
)
100 size
= PERCPU_ENOUGH_ROOM
;
103 for_each_cpu_mask (i
, cpu_possible_map
) {
106 if (!NODE_DATA(cpu_to_node(i
))) {
107 printk("cpu with no node %d, num_online_nodes %d\n",
108 i
, num_online_nodes());
109 ptr
= alloc_bootmem(size
);
111 ptr
= alloc_bootmem_node(NODE_DATA(cpu_to_node(i
)), size
);
114 panic("Cannot allocate cpu data for CPU %d\n", i
);
115 cpu_pda(i
)->data_offset
= ptr
- __per_cpu_start
;
116 memcpy(ptr
, __per_cpu_start
, __per_cpu_end
- __per_cpu_start
);
120 void pda_init(int cpu
)
122 struct x8664_pda
*pda
= cpu_pda(cpu
);
124 /* Setup up data that may be needed in __get_free_pages early */
125 asm volatile("movl %0,%%fs ; movl %0,%%gs" :: "r" (0));
126 wrmsrl(MSR_GS_BASE
, pda
);
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
);
147 pda
->irqstackptr
+= IRQSTACKSIZE
-64;
150 char boot_exception_stacks
[(N_EXCEPTION_STACKS
- 1) * EXCEPTION_STKSZ
+ DEBUG_STKSZ
]
151 __attribute__((section(".bss.page_aligned")));
153 /* May not be marked __init: used by software suspend */
154 void syscall_init(void)
157 * LSTAR and STAR live in a bit strange symbiosis.
158 * They both write to the same internal register. STAR allows to set CS/DS
159 * but only a 32bit target. LSTAR sets the 64bit rip.
161 wrmsrl(MSR_STAR
, ((u64
)__USER32_CS
)<<48 | ((u64
)__KERNEL_CS
)<<32);
162 wrmsrl(MSR_LSTAR
, system_call
);
164 #ifdef CONFIG_IA32_EMULATION
165 syscall32_cpu_init ();
168 /* Flags to clear on syscall */
169 wrmsrl(MSR_SYSCALL_MASK
, EF_TF
|EF_DF
|EF_IE
|0x3000);
172 void __cpuinit
check_efer(void)
176 rdmsrl(MSR_EFER
, efer
);
177 if (!(efer
& EFER_NX
) || do_not_nx
) {
178 __supported_pte_mask
&= ~_PAGE_NX
;
183 * cpu_init() initializes state that is per-CPU. Some data is already
184 * initialized (naturally) in the bootstrap process, such as the GDT
185 * and IDT. We reload them nevertheless, this function acts as a
186 * 'CPU state barrier', nothing should get across.
187 * A lot of state is already set up in PDA init.
189 void __cpuinit
cpu_init (void)
191 int cpu
= stack_smp_processor_id();
192 struct tss_struct
*t
= &per_cpu(init_tss
, cpu
);
194 char *estacks
= NULL
;
195 struct task_struct
*me
;
198 /* CPU 0 is initialised in head64.c */
201 zap_low_mappings(cpu
);
203 estacks
= boot_exception_stacks
;
207 if (cpu_test_and_set(cpu
, cpu_initialized
))
208 panic("CPU#%d already initialized!\n", cpu
);
210 printk("Initializing CPU#%d\n", cpu
);
212 clear_in_cr4(X86_CR4_VME
|X86_CR4_PVI
|X86_CR4_TSD
|X86_CR4_DE
);
215 * Initialize the per-CPU GDT with the boot GDT,
216 * and set up the GDT descriptor:
219 memcpy(cpu_gdt(cpu
), cpu_gdt_table
, GDT_SIZE
);
221 cpu_gdt_descr
[cpu
].size
= GDT_SIZE
;
222 asm volatile("lgdt %0" :: "m" (cpu_gdt_descr
[cpu
]));
223 asm volatile("lidt %0" :: "m" (idt_descr
));
225 memset(me
->thread
.tls_array
, 0, GDT_ENTRY_TLS_ENTRIES
* 8);
228 wrmsrl(MSR_FS_BASE
, 0);
229 wrmsrl(MSR_KERNEL_GS_BASE
, 0);
235 * set up and load the per-CPU TSS
237 for (v
= 0; v
< N_EXCEPTION_STACKS
; v
++) {
239 static const unsigned int order
[N_EXCEPTION_STACKS
] = {
240 [0 ... N_EXCEPTION_STACKS
- 1] = EXCEPTION_STACK_ORDER
,
241 [DEBUG_STACK
- 1] = DEBUG_STACK_ORDER
244 estacks
= (char *)__get_free_pages(GFP_ATOMIC
, order
[v
]);
246 panic("Cannot allocate exception stack %ld %d\n",
250 #if DEBUG_STKSZ > EXCEPTION_STKSZ
252 cpu_pda(cpu
)->debugstack
= (unsigned long)estacks
;
253 estacks
+= DEBUG_STKSZ
;
257 estacks
+= EXCEPTION_STKSZ
;
260 t
->ist
[v
] = (unsigned long)estacks
;
263 t
->io_bitmap_base
= offsetof(struct tss_struct
, io_bitmap
);
265 * <= is required because the CPU will access up to
266 * 8 bits beyond the end of the IO permission bitmap.
268 for (i
= 0; i
<= IO_BITMAP_LONGS
; i
++)
269 t
->io_bitmap
[i
] = ~0UL;
271 atomic_inc(&init_mm
.mm_count
);
272 me
->active_mm
= &init_mm
;
275 enter_lazy_tlb(&init_mm
, me
);
277 set_tss_desc(cpu
, t
);
279 load_LDT(&init_mm
.context
);
282 * Clear all 6 debug registers:
285 set_debugreg(0UL, 0);
286 set_debugreg(0UL, 1);
287 set_debugreg(0UL, 2);
288 set_debugreg(0UL, 3);
289 set_debugreg(0UL, 6);
290 set_debugreg(0UL, 7);