summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/setup64.c
blob: 309366f8f6030f100322cdc2ca63f001d6bc3ac5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
/* 
 * 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>

#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
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);

/*
 * Copy data used in early init routines from the initial arrays to the
 * per cpu data areas.  These arrays then become expendable and the
 * *_early_ptr's are zeroed indicating that the static arrays are gone.
 */
static void __init setup_per_cpu_maps(void)
{
	int cpu;

	for_each_possible_cpu(cpu) {
#ifdef CONFIG_SMP
		if (per_cpu_offset(cpu)) {
#endif
			per_cpu(x86_cpu_to_apicid, cpu) =
						x86_cpu_to_apicid_init[cpu];
			per_cpu(x86_bios_cpu_apicid, cpu) =
						x86_bios_cpu_apicid_init[cpu];
#ifdef CONFIG_NUMA
			per_cpu(x86_cpu_to_node_map, cpu) =
						x86_cpu_to_node_map_init[cpu];
#endif
#ifdef CONFIG_SMP
		}
		else
			printk(KERN_NOTICE "per_cpu_offset zero for cpu %d\n",
									cpu);
#endif
	}

	/* indicate the early static arrays will soon be gone */
	x86_cpu_to_apicid_early_ptr = NULL;
	x86_bios_cpu_apicid_early_ptr = NULL;
#ifdef CONFIG_NUMA
	x86_cpu_to_node_map_early_ptr = NULL;
#endif
}

/*
 * 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(early_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(early_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);
	}

	/* setup percpu data maps early */
	setup_per_cpu_maps();
} 

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);

	/*
	 * 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);
}
OpenPOWER on IntegriCloud