aboutsummaryrefslogtreecommitdiffstats
path: root/arch/ia64/ia32/ia32_support.c
blob: 896b1ebbfb268381bc87eb2e766e9c75e7d75f84 (plain) (blame)
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
/*
 * IA32 helper functions
 *
 * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
 * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
 * Copyright (C) 2001-2002 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 06/16/00	A. Mallick	added csd/ssd/tssd for ia32 thread context
 * 02/19/01	D. Mosberger	dropped tssd; it's not needed
 * 09/14/01	D. Mosberger	fixed memory management for gdt/tss page
 * 09/29/01	D. Mosberger	added ia32_load_segment_descriptors()
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/personality.h>
#include <linux/sched.h>

#include <asm/intrinsics.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/uaccess.h>

#include "ia32priv.h"

extern int die_if_kernel (char *str, struct pt_regs *regs, long err);

struct exec_domain ia32_exec_domain;
struct page *ia32_shared_page[NR_CPUS];
unsigned long *ia32_boot_gdt;
unsigned long *cpu_gdt_table[NR_CPUS];
struct page *ia32_gate_page;

static unsigned long
load_desc (u16 selector)
{
	unsigned long *table, limit, index;

	if (!selector)
		return 0;
	if (selector & IA32_SEGSEL_TI) {
		table = (unsigned long *) IA32_LDT_OFFSET;
		limit = IA32_LDT_ENTRIES;
	} else {
		table = cpu_gdt_table[smp_processor_id()];
		limit = IA32_PAGE_SIZE / sizeof(ia32_boot_gdt[0]);
	}
	index = selector >> IA32_SEGSEL_INDEX_SHIFT;
	if (index >= limit)
		return 0;
	return IA32_SEG_UNSCRAMBLE(table[index]);
}

void
ia32_load_segment_descriptors (struct task_struct *task)
{
	struct pt_regs *regs = task_pt_regs(task);

	/* Setup the segment descriptors */
	regs->r24 = load_desc(regs->r16 >> 16);		/* ESD */
	regs->r27 = load_desc(regs->r16 >>  0);		/* DSD */
	regs->r28 = load_desc(regs->r16 >> 32);		/* FSD */
	regs->r29 = load_desc(regs->r16 >> 48);		/* GSD */
	regs->ar_csd = load_desc(regs->r17 >>  0);	/* CSD */
	regs->ar_ssd = load_desc(regs->r17 >> 16);	/* SSD */
}

int
ia32_clone_tls (struct task_struct *child, struct pt_regs *childregs)
{
	struct desc_struct *desc;
	struct ia32_user_desc info;
	int idx;

	if (copy_from_user(&info, (void __user *)(childregs->r14 & 0xffffffff), sizeof(info)))
		return -EFAULT;
	if (LDT_empty(&info))
		return -EINVAL;

	idx = info.entry_number;
	if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
		return -EINVAL;

	desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
	desc->a = LDT_entry_a(&info);
	desc->b = LDT_entry_b(&info);

	/* XXX: can this be done in a cleaner way ? */
	load_TLS(&child->thread, smp_processor_id());
	ia32_load_segment_descriptors(child);
	load_TLS(&current->thread, smp_processor_id());

	return 0;
}

void
ia32_save_state (struct task_struct *t)
{
	t->thread.eflag = ia64_getreg(_IA64_REG_AR_EFLAG);
	t->thread.fsr   = ia64_getreg(_IA64_REG_AR_FSR);
	t->thread.fcr   = ia64_getreg(_IA64_REG_AR_FCR);
	t->thread.fir   = ia64_getreg(_IA64_REG_AR_FIR);
	t->thread.fdr   = ia64_getreg(_IA64_REG_AR_FDR);
	ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob);
	ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1);
}

void
ia32_load_state (struct task_struct *t)
{
	unsigned long eflag, fsr, fcr, fir, fdr, tssd;
	struct pt_regs *regs = task_pt_regs(t);

	eflag = t->thread.eflag;
	fsr = t->thread.fsr;
	fcr = t->thread.fcr;
	fir = t->thread.fir;
	fdr = t->thread.fdr;
	tssd = load_desc(_TSS);					/* TSSD */

	ia64_setreg(_IA64_REG_AR_EFLAG, eflag);
	ia64_setreg(_IA64_REG_AR_FSR, fsr);
	ia64_setreg(_IA64_REG_AR_FCR, fcr);
	ia64_setreg(_IA64_REG_AR_FIR, fir);
	ia64_setreg(_IA64_REG_AR_FDR, fdr);
	current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE);
	current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD);
	ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE);
	ia64_set_kr(IA64_KR_TSSD, tssd);

	regs->r17 = (_TSS << 48) | (_LDT << 32) | (__u32) regs->r17;
	regs->r30 = load_desc(_LDT);				/* LDTD */
	load_TLS(&t->thread, smp_processor_id());
}

/*
 * Setup IA32 GDT and TSS
 */
void
ia32_gdt_init (void)
{
	int cpu = smp_processor_id();

	ia32_shared_page[cpu] = alloc_page(GFP_KERNEL);
	if (!ia32_shared_page[cpu])
		panic("failed to allocate ia32_shared_page[%d]\n", cpu);

	cpu_gdt_table[cpu] = page_address(ia32_shared_page[cpu]);

	/* Copy from the boot cpu's GDT */
	memcpy(cpu_gdt_table[cpu], ia32_boot_gdt, PAGE_SIZE);
}


/*
 * Setup IA32 GDT and TSS
 */
static void
ia32_boot_gdt_init (void)
{
	unsigned long ldt_size;

	ia32_shared_page[0] = alloc_page(GFP_KERNEL);
	if (!ia32_shared_page[0])
		panic("failed to allocate ia32_shared_page[0]\n");

	ia32_boot_gdt = page_address(ia32_shared_page[0]);
	cpu_gdt_table[0] = ia32_boot_gdt;

	/* CS descriptor in IA-32 (scrambled) format */
	ia32_boot_gdt[__USER_CS >> 3]
		= IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
				      0xb, 1, 3, 1, 1, 1, 1);

	/* DS descriptor in IA-32 (scrambled) format */
	ia32_boot_gdt[__USER_DS >> 3]
		= IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
				      0x3, 1, 3, 1, 1, 1, 1);

	ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
	ia32_boot_gdt[TSS_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235,
						       0xb, 0, 3, 1, 1, 1, 0);
	ia32_boot_gdt[LDT_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1,
						       0x2, 0, 3, 1, 1, 1, 0);
}

static void
ia32_gate_page_init(void)
{
	unsigned long *sr;

	ia32_gate_page = alloc_page(GFP_KERNEL);
	sr = page_address(ia32_gate_page);
	/* This is popl %eax ; movl $,%eax ; int $0x80 */
	*sr++ = 0xb858 | (__IA32_NR_sigreturn << 16) | (0x80cdUL << 48);

	/* This is movl $,%eax ; int $0x80 */
	*sr = 0xb8 | (__IA32_NR_rt_sigreturn << 8) | (0x80cdUL << 40);
}

void
ia32_mem_init(void)
{
	ia32_boot_gdt_init();
	ia32_gate_page_init();
}

/*
 * Handle bad IA32 interrupt via syscall
 */
void
ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
{
	siginfo_t siginfo;

	if (die_if_kernel("Bad IA-32 interrupt", regs, int_num))
		return;

	siginfo.si_signo = SIGTRAP;
	siginfo.si_errno = int_num;	/* XXX is it OK to abuse si_errno like this? */
	siginfo.si_flags = 0;
	siginfo.si_isr = 0;
	siginfo.si_addr = NULL;
	siginfo.si_imm = 0;
	siginfo.si_code = TRAP_BRKPT;
	force_sig_info(SIGTRAP, &siginfo, current);
}

void
ia32_cpu_init (void)
{
	/* initialize global ia32 state - CR0 and CR4 */
	ia64_setreg(_IA64_REG_AR_CFLAG, (((ulong) IA32_CR4 << 32) | IA32_CR0));
}

static int __init
ia32_init (void)
{
	ia32_exec_domain.name = "Linux/x86";
	ia32_exec_domain.handler = NULL;
	ia32_exec_domain.pers_low = PER_LINUX32;
	ia32_exec_domain.pers_high = PER_LINUX32;
	ia32_exec_domain.signal_map = default_exec_domain.signal_map;
	ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
	register_exec_domain(&ia32_exec_domain);

#if PAGE_SHIFT > IA32_PAGE_SHIFT
	{
		extern struct kmem_cache *ia64_partial_page_cachep;

		ia64_partial_page_cachep = kmem_cache_create("ia64_partial_page_cache",
					sizeof(struct ia64_partial_page),
					0, SLAB_PANIC, NULL);
	}
#endif
	return 0;
}

__initcall(ia32_init);