blob: c187743965a02029df7090843ae30e2059afe4d6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * IA32 helper functions
3 *
4 * Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
5 * Copyright (C) 2000 Asit K. Mallick <asit.k.mallick@intel.com>
6 * Copyright (C) 2001-2002 Hewlett-Packard Co
7 * David Mosberger-Tang <davidm@hpl.hp.com>
8 *
9 * 06/16/00 A. Mallick added csd/ssd/tssd for ia32 thread context
10 * 02/19/01 D. Mosberger dropped tssd; it's not needed
11 * 09/14/01 D. Mosberger fixed memory management for gdt/tss page
12 * 09/29/01 D. Mosberger added ia32_load_segment_descriptors()
13 */
14
15#include <linux/kernel.h>
16#include <linux/init.h>
17#include <linux/mm.h>
18#include <linux/personality.h>
19#include <linux/sched.h>
20
21#include <asm/intrinsics.h>
22#include <asm/page.h>
23#include <asm/pgtable.h>
24#include <asm/system.h>
25#include <asm/processor.h>
26#include <asm/uaccess.h>
27
28#include "ia32priv.h"
29
30extern void die_if_kernel (char *str, struct pt_regs *regs, long err);
31
32struct exec_domain ia32_exec_domain;
33struct page *ia32_shared_page[NR_CPUS];
34unsigned long *ia32_boot_gdt;
35unsigned long *cpu_gdt_table[NR_CPUS];
36struct page *ia32_gate_page;
37
38static unsigned long
39load_desc (u16 selector)
40{
41 unsigned long *table, limit, index;
42
43 if (!selector)
44 return 0;
45 if (selector & IA32_SEGSEL_TI) {
46 table = (unsigned long *) IA32_LDT_OFFSET;
47 limit = IA32_LDT_ENTRIES;
48 } else {
49 table = cpu_gdt_table[smp_processor_id()];
50 limit = IA32_PAGE_SIZE / sizeof(ia32_boot_gdt[0]);
51 }
52 index = selector >> IA32_SEGSEL_INDEX_SHIFT;
53 if (index >= limit)
54 return 0;
55 return IA32_SEG_UNSCRAMBLE(table[index]);
56}
57
58void
59ia32_load_segment_descriptors (struct task_struct *task)
60{
Al Viro64505782006-01-12 01:06:06 -080061 struct pt_regs *regs = task_pt_regs(task);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63 /* Setup the segment descriptors */
64 regs->r24 = load_desc(regs->r16 >> 16); /* ESD */
65 regs->r27 = load_desc(regs->r16 >> 0); /* DSD */
66 regs->r28 = load_desc(regs->r16 >> 32); /* FSD */
67 regs->r29 = load_desc(regs->r16 >> 48); /* GSD */
68 regs->ar_csd = load_desc(regs->r17 >> 0); /* CSD */
69 regs->ar_ssd = load_desc(regs->r17 >> 16); /* SSD */
70}
71
72int
73ia32_clone_tls (struct task_struct *child, struct pt_regs *childregs)
74{
75 struct desc_struct *desc;
76 struct ia32_user_desc info;
77 int idx;
78
79 if (copy_from_user(&info, (void __user *)(childregs->r14 & 0xffffffff), sizeof(info)))
80 return -EFAULT;
81 if (LDT_empty(&info))
82 return -EINVAL;
83
84 idx = info.entry_number;
85 if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
86 return -EINVAL;
87
88 desc = child->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
89 desc->a = LDT_entry_a(&info);
90 desc->b = LDT_entry_b(&info);
91
92 /* XXX: can this be done in a cleaner way ? */
93 load_TLS(&child->thread, smp_processor_id());
94 ia32_load_segment_descriptors(child);
95 load_TLS(&current->thread, smp_processor_id());
96
97 return 0;
98}
99
100void
101ia32_save_state (struct task_struct *t)
102{
103 t->thread.eflag = ia64_getreg(_IA64_REG_AR_EFLAG);
104 t->thread.fsr = ia64_getreg(_IA64_REG_AR_FSR);
105 t->thread.fcr = ia64_getreg(_IA64_REG_AR_FCR);
106 t->thread.fir = ia64_getreg(_IA64_REG_AR_FIR);
107 t->thread.fdr = ia64_getreg(_IA64_REG_AR_FDR);
108 ia64_set_kr(IA64_KR_IO_BASE, t->thread.old_iob);
109 ia64_set_kr(IA64_KR_TSSD, t->thread.old_k1);
110}
111
112void
113ia32_load_state (struct task_struct *t)
114{
115 unsigned long eflag, fsr, fcr, fir, fdr, tssd;
Al Viro64505782006-01-12 01:06:06 -0800116 struct pt_regs *regs = task_pt_regs(t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
118 eflag = t->thread.eflag;
119 fsr = t->thread.fsr;
120 fcr = t->thread.fcr;
121 fir = t->thread.fir;
122 fdr = t->thread.fdr;
123 tssd = load_desc(_TSS); /* TSSD */
124
125 ia64_setreg(_IA64_REG_AR_EFLAG, eflag);
126 ia64_setreg(_IA64_REG_AR_FSR, fsr);
127 ia64_setreg(_IA64_REG_AR_FCR, fcr);
128 ia64_setreg(_IA64_REG_AR_FIR, fir);
129 ia64_setreg(_IA64_REG_AR_FDR, fdr);
130 current->thread.old_iob = ia64_get_kr(IA64_KR_IO_BASE);
131 current->thread.old_k1 = ia64_get_kr(IA64_KR_TSSD);
132 ia64_set_kr(IA64_KR_IO_BASE, IA32_IOBASE);
133 ia64_set_kr(IA64_KR_TSSD, tssd);
134
135 regs->r17 = (_TSS << 48) | (_LDT << 32) | (__u32) regs->r17;
136 regs->r30 = load_desc(_LDT); /* LDTD */
137 load_TLS(&t->thread, smp_processor_id());
138}
139
140/*
141 * Setup IA32 GDT and TSS
142 */
143void
144ia32_gdt_init (void)
145{
146 int cpu = smp_processor_id();
147
148 ia32_shared_page[cpu] = alloc_page(GFP_KERNEL);
149 if (!ia32_shared_page[cpu])
150 panic("failed to allocate ia32_shared_page[%d]\n", cpu);
151
152 cpu_gdt_table[cpu] = page_address(ia32_shared_page[cpu]);
153
154 /* Copy from the boot cpu's GDT */
155 memcpy(cpu_gdt_table[cpu], ia32_boot_gdt, PAGE_SIZE);
156}
157
158
159/*
160 * Setup IA32 GDT and TSS
161 */
162static void
163ia32_boot_gdt_init (void)
164{
165 unsigned long ldt_size;
166
167 ia32_shared_page[0] = alloc_page(GFP_KERNEL);
168 if (!ia32_shared_page[0])
169 panic("failed to allocate ia32_shared_page[0]\n");
170
171 ia32_boot_gdt = page_address(ia32_shared_page[0]);
172 cpu_gdt_table[0] = ia32_boot_gdt;
173
174 /* CS descriptor in IA-32 (scrambled) format */
175 ia32_boot_gdt[__USER_CS >> 3]
176 = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
177 0xb, 1, 3, 1, 1, 1, 1);
178
179 /* DS descriptor in IA-32 (scrambled) format */
180 ia32_boot_gdt[__USER_DS >> 3]
181 = IA32_SEG_DESCRIPTOR(0, (IA32_GATE_END-1) >> IA32_PAGE_SHIFT,
182 0x3, 1, 3, 1, 1, 1, 1);
183
184 ldt_size = PAGE_ALIGN(IA32_LDT_ENTRIES*IA32_LDT_ENTRY_SIZE);
185 ia32_boot_gdt[TSS_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_TSS_OFFSET, 235,
186 0xb, 0, 3, 1, 1, 1, 0);
187 ia32_boot_gdt[LDT_ENTRY] = IA32_SEG_DESCRIPTOR(IA32_LDT_OFFSET, ldt_size - 1,
188 0x2, 0, 3, 1, 1, 1, 0);
189}
190
191static void
192ia32_gate_page_init(void)
193{
194 unsigned long *sr;
195
196 ia32_gate_page = alloc_page(GFP_KERNEL);
197 sr = page_address(ia32_gate_page);
198 /* This is popl %eax ; movl $,%eax ; int $0x80 */
199 *sr++ = 0xb858 | (__IA32_NR_sigreturn << 16) | (0x80cdUL << 48);
200
201 /* This is movl $,%eax ; int $0x80 */
202 *sr = 0xb8 | (__IA32_NR_rt_sigreturn << 8) | (0x80cdUL << 40);
203}
204
205void
206ia32_mem_init(void)
207{
208 ia32_boot_gdt_init();
209 ia32_gate_page_init();
210}
211
212/*
213 * Handle bad IA32 interrupt via syscall
214 */
215void
216ia32_bad_interrupt (unsigned long int_num, struct pt_regs *regs)
217{
218 siginfo_t siginfo;
219
220 die_if_kernel("Bad IA-32 interrupt", regs, int_num);
221
222 siginfo.si_signo = SIGTRAP;
223 siginfo.si_errno = int_num; /* XXX is it OK to abuse si_errno like this? */
224 siginfo.si_flags = 0;
225 siginfo.si_isr = 0;
226 siginfo.si_addr = NULL;
227 siginfo.si_imm = 0;
228 siginfo.si_code = TRAP_BRKPT;
229 force_sig_info(SIGTRAP, &siginfo, current);
230}
231
232void
233ia32_cpu_init (void)
234{
235 /* initialize global ia32 state - CR0 and CR4 */
236 ia64_setreg(_IA64_REG_AR_CFLAG, (((ulong) IA32_CR4 << 32) | IA32_CR0));
237}
238
239static int __init
240ia32_init (void)
241{
242 ia32_exec_domain.name = "Linux/x86";
243 ia32_exec_domain.handler = NULL;
244 ia32_exec_domain.pers_low = PER_LINUX32;
245 ia32_exec_domain.pers_high = PER_LINUX32;
246 ia32_exec_domain.signal_map = default_exec_domain.signal_map;
247 ia32_exec_domain.signal_invmap = default_exec_domain.signal_invmap;
248 register_exec_domain(&ia32_exec_domain);
249
250#if PAGE_SHIFT > IA32_PAGE_SHIFT
251 {
252 extern kmem_cache_t *partial_page_cachep;
253
254 partial_page_cachep = kmem_cache_create("partial_page_cache",
255 sizeof(struct partial_page), 0, 0,
256 NULL, NULL);
257 if (!partial_page_cachep)
258 panic("Cannot create partial page SLAB cache");
259 }
260#endif
261 return 0;
262}
263
264__initcall(ia32_init);