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1 #ifndef _ASM_X86_DESC_H
2 #define _ASM_X86_DESC_H
3 
4 #include <asm/desc_defs.h>
5 #include <asm/ldt.h>
6 #include <asm/mmu.h>
7 
8 #include <linux/smp.h>
9 
fill_ldt(struct desc_struct * desc,const struct user_desc * info)10 static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *info)
11 {
12 	desc->limit0		= info->limit & 0x0ffff;
13 
14 	desc->base0		= (info->base_addr & 0x0000ffff);
15 	desc->base1		= (info->base_addr & 0x00ff0000) >> 16;
16 
17 	desc->type		= (info->read_exec_only ^ 1) << 1;
18 	desc->type	       |= info->contents << 2;
19 
20 	desc->s			= 1;
21 	desc->dpl		= 0x3;
22 	desc->p			= info->seg_not_present ^ 1;
23 	desc->limit		= (info->limit & 0xf0000) >> 16;
24 	desc->avl		= info->useable;
25 	desc->d			= info->seg_32bit;
26 	desc->g			= info->limit_in_pages;
27 
28 	desc->base2		= (info->base_addr & 0xff000000) >> 24;
29 	/*
30 	 * Don't allow setting of the lm bit. It would confuse
31 	 * user_64bit_mode and would get overridden by sysret anyway.
32 	 */
33 	desc->l			= 0;
34 }
35 
36 extern struct desc_ptr idt_descr;
37 extern gate_desc idt_table[];
38 extern struct desc_ptr nmi_idt_descr;
39 extern gate_desc nmi_idt_table[];
40 
41 struct gdt_page {
42 	struct desc_struct gdt[GDT_ENTRIES];
43 } __attribute__((aligned(PAGE_SIZE)));
44 
45 DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page);
46 
get_cpu_gdt_table(unsigned int cpu)47 static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
48 {
49 	return per_cpu(gdt_page, cpu).gdt;
50 }
51 
52 #ifdef CONFIG_X86_64
53 
pack_gate(gate_desc * gate,unsigned type,unsigned long func,unsigned dpl,unsigned ist,unsigned seg)54 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
55 			     unsigned dpl, unsigned ist, unsigned seg)
56 {
57 	gate->offset_low	= PTR_LOW(func);
58 	gate->segment		= __KERNEL_CS;
59 	gate->ist		= ist;
60 	gate->p			= 1;
61 	gate->dpl		= dpl;
62 	gate->zero0		= 0;
63 	gate->zero1		= 0;
64 	gate->type		= type;
65 	gate->offset_middle	= PTR_MIDDLE(func);
66 	gate->offset_high	= PTR_HIGH(func);
67 }
68 
69 #else
pack_gate(gate_desc * gate,unsigned char type,unsigned long base,unsigned dpl,unsigned flags,unsigned short seg)70 static inline void pack_gate(gate_desc *gate, unsigned char type,
71 			     unsigned long base, unsigned dpl, unsigned flags,
72 			     unsigned short seg)
73 {
74 	gate->a = (seg << 16) | (base & 0xffff);
75 	gate->b = (base & 0xffff0000) | (((0x80 | type | (dpl << 5)) & 0xff) << 8);
76 }
77 
78 #endif
79 
desc_empty(const void * ptr)80 static inline int desc_empty(const void *ptr)
81 {
82 	const u32 *desc = ptr;
83 
84 	return !(desc[0] | desc[1]);
85 }
86 
87 #ifdef CONFIG_PARAVIRT
88 #include <asm/paravirt.h>
89 #else
90 #define load_TR_desc()				native_load_tr_desc()
91 #define load_gdt(dtr)				native_load_gdt(dtr)
92 #define load_idt(dtr)				native_load_idt(dtr)
93 #define load_tr(tr)				asm volatile("ltr %0"::"m" (tr))
94 #define load_ldt(ldt)				asm volatile("lldt %0"::"m" (ldt))
95 
96 #define store_gdt(dtr)				native_store_gdt(dtr)
97 #define store_idt(dtr)				native_store_idt(dtr)
98 #define store_tr(tr)				(tr = native_store_tr())
99 
100 #define load_TLS(t, cpu)			native_load_tls(t, cpu)
101 #define set_ldt					native_set_ldt
102 
103 #define write_ldt_entry(dt, entry, desc)	native_write_ldt_entry(dt, entry, desc)
104 #define write_gdt_entry(dt, entry, desc, type)	native_write_gdt_entry(dt, entry, desc, type)
105 #define write_idt_entry(dt, entry, g)		native_write_idt_entry(dt, entry, g)
106 
paravirt_alloc_ldt(struct desc_struct * ldt,unsigned entries)107 static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries)
108 {
109 }
110 
paravirt_free_ldt(struct desc_struct * ldt,unsigned entries)111 static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries)
112 {
113 }
114 #endif	/* CONFIG_PARAVIRT */
115 
116 #define store_ldt(ldt) asm("sldt %0" : "=m"(ldt))
117 
native_write_idt_entry(gate_desc * idt,int entry,const gate_desc * gate)118 static inline void native_write_idt_entry(gate_desc *idt, int entry, const gate_desc *gate)
119 {
120 	memcpy(&idt[entry], gate, sizeof(*gate));
121 }
122 
native_write_ldt_entry(struct desc_struct * ldt,int entry,const void * desc)123 static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry, const void *desc)
124 {
125 	memcpy(&ldt[entry], desc, 8);
126 }
127 
128 static inline void
native_write_gdt_entry(struct desc_struct * gdt,int entry,const void * desc,int type)129 native_write_gdt_entry(struct desc_struct *gdt, int entry, const void *desc, int type)
130 {
131 	unsigned int size;
132 
133 	switch (type) {
134 	case DESC_TSS:	size = sizeof(tss_desc);	break;
135 	case DESC_LDT:	size = sizeof(ldt_desc);	break;
136 	default:	size = sizeof(*gdt);		break;
137 	}
138 
139 	memcpy(&gdt[entry], desc, size);
140 }
141 
pack_descriptor(struct desc_struct * desc,unsigned long base,unsigned long limit,unsigned char type,unsigned char flags)142 static inline void pack_descriptor(struct desc_struct *desc, unsigned long base,
143 				   unsigned long limit, unsigned char type,
144 				   unsigned char flags)
145 {
146 	desc->a = ((base & 0xffff) << 16) | (limit & 0xffff);
147 	desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
148 		(limit & 0x000f0000) | ((type & 0xff) << 8) |
149 		((flags & 0xf) << 20);
150 	desc->p = 1;
151 }
152 
153 
set_tssldt_descriptor(void * d,unsigned long addr,unsigned type,unsigned size)154 static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned type, unsigned size)
155 {
156 #ifdef CONFIG_X86_64
157 	struct ldttss_desc64 *desc = d;
158 
159 	memset(desc, 0, sizeof(*desc));
160 
161 	desc->limit0		= size & 0xFFFF;
162 	desc->base0		= PTR_LOW(addr);
163 	desc->base1		= PTR_MIDDLE(addr) & 0xFF;
164 	desc->type		= type;
165 	desc->p			= 1;
166 	desc->limit1		= (size >> 16) & 0xF;
167 	desc->base2		= (PTR_MIDDLE(addr) >> 8) & 0xFF;
168 	desc->base3		= PTR_HIGH(addr);
169 #else
170 	pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0);
171 #endif
172 }
173 
__set_tss_desc(unsigned cpu,unsigned int entry,void * addr)174 static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr)
175 {
176 	struct desc_struct *d = get_cpu_gdt_table(cpu);
177 	tss_desc tss;
178 
179 	/*
180 	 * sizeof(unsigned long) coming from an extra "long" at the end
181 	 * of the iobitmap. See tss_struct definition in processor.h
182 	 *
183 	 * -1? seg base+limit should be pointing to the address of the
184 	 * last valid byte
185 	 */
186 	set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS,
187 			      IO_BITMAP_OFFSET + IO_BITMAP_BYTES +
188 			      sizeof(unsigned long) - 1);
189 	write_gdt_entry(d, entry, &tss, DESC_TSS);
190 }
191 
192 #define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
193 
native_set_ldt(const void * addr,unsigned int entries)194 static inline void native_set_ldt(const void *addr, unsigned int entries)
195 {
196 	if (likely(entries == 0))
197 		asm volatile("lldt %w0"::"q" (0));
198 	else {
199 		unsigned cpu = smp_processor_id();
200 		ldt_desc ldt;
201 
202 		set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT,
203 				      entries * LDT_ENTRY_SIZE - 1);
204 		write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT,
205 				&ldt, DESC_LDT);
206 		asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8));
207 	}
208 }
209 
native_load_tr_desc(void)210 static inline void native_load_tr_desc(void)
211 {
212 	asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8));
213 }
214 
native_load_gdt(const struct desc_ptr * dtr)215 static inline void native_load_gdt(const struct desc_ptr *dtr)
216 {
217 	asm volatile("lgdt %0"::"m" (*dtr));
218 }
219 
native_load_idt(const struct desc_ptr * dtr)220 static inline void native_load_idt(const struct desc_ptr *dtr)
221 {
222 	asm volatile("lidt %0"::"m" (*dtr));
223 }
224 
native_store_gdt(struct desc_ptr * dtr)225 static inline void native_store_gdt(struct desc_ptr *dtr)
226 {
227 	asm volatile("sgdt %0":"=m" (*dtr));
228 }
229 
native_store_idt(struct desc_ptr * dtr)230 static inline void native_store_idt(struct desc_ptr *dtr)
231 {
232 	asm volatile("sidt %0":"=m" (*dtr));
233 }
234 
native_store_tr(void)235 static inline unsigned long native_store_tr(void)
236 {
237 	unsigned long tr;
238 
239 	asm volatile("str %0":"=r" (tr));
240 
241 	return tr;
242 }
243 
native_load_tls(struct thread_struct * t,unsigned int cpu)244 static inline void native_load_tls(struct thread_struct *t, unsigned int cpu)
245 {
246 	struct desc_struct *gdt = get_cpu_gdt_table(cpu);
247 	unsigned int i;
248 
249 	for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++)
250 		gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i];
251 }
252 
253 #define _LDT_empty(info)				\
254 	((info)->base_addr		== 0	&&	\
255 	 (info)->limit			== 0	&&	\
256 	 (info)->contents		== 0	&&	\
257 	 (info)->read_exec_only		== 1	&&	\
258 	 (info)->seg_32bit		== 0	&&	\
259 	 (info)->limit_in_pages		== 0	&&	\
260 	 (info)->seg_not_present	== 1	&&	\
261 	 (info)->useable		== 0)
262 
263 #ifdef CONFIG_X86_64
264 #define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0))
265 #else
266 #define LDT_empty(info) (_LDT_empty(info))
267 #endif
268 
clear_LDT(void)269 static inline void clear_LDT(void)
270 {
271 	set_ldt(NULL, 0);
272 }
273 
274 /*
275  * load one particular LDT into the current CPU
276  */
load_LDT_nolock(mm_context_t * pc)277 static inline void load_LDT_nolock(mm_context_t *pc)
278 {
279 	set_ldt(pc->ldt, pc->size);
280 }
281 
load_LDT(mm_context_t * pc)282 static inline void load_LDT(mm_context_t *pc)
283 {
284 	preempt_disable();
285 	load_LDT_nolock(pc);
286 	preempt_enable();
287 }
288 
get_desc_base(const struct desc_struct * desc)289 static inline unsigned long get_desc_base(const struct desc_struct *desc)
290 {
291 	return (unsigned)(desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24));
292 }
293 
set_desc_base(struct desc_struct * desc,unsigned long base)294 static inline void set_desc_base(struct desc_struct *desc, unsigned long base)
295 {
296 	desc->base0 = base & 0xffff;
297 	desc->base1 = (base >> 16) & 0xff;
298 	desc->base2 = (base >> 24) & 0xff;
299 }
300 
get_desc_limit(const struct desc_struct * desc)301 static inline unsigned long get_desc_limit(const struct desc_struct *desc)
302 {
303 	return desc->limit0 | (desc->limit << 16);
304 }
305 
set_desc_limit(struct desc_struct * desc,unsigned long limit)306 static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
307 {
308 	desc->limit0 = limit & 0xffff;
309 	desc->limit = (limit >> 16) & 0xf;
310 }
311 
312 #ifdef CONFIG_X86_64
set_nmi_gate(int gate,void * addr)313 static inline void set_nmi_gate(int gate, void *addr)
314 {
315 	gate_desc s;
316 
317 	pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
318 	write_idt_entry(nmi_idt_table, gate, &s);
319 }
320 #endif
321 
_set_gate(int gate,unsigned type,void * addr,unsigned dpl,unsigned ist,unsigned seg)322 static inline void _set_gate(int gate, unsigned type, void *addr,
323 			     unsigned dpl, unsigned ist, unsigned seg)
324 {
325 	gate_desc s;
326 
327 	pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
328 	/*
329 	 * does not need to be atomic because it is only done once at
330 	 * setup time
331 	 */
332 	write_idt_entry(idt_table, gate, &s);
333 }
334 
335 /*
336  * This needs to use 'idt_table' rather than 'idt', and
337  * thus use the _nonmapped_ version of the IDT, as the
338  * Pentium F0 0F bugfix can have resulted in the mapped
339  * IDT being write-protected.
340  */
set_intr_gate(unsigned int n,void * addr)341 static inline void set_intr_gate(unsigned int n, void *addr)
342 {
343 	BUG_ON((unsigned)n > 0xFF);
344 	_set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
345 }
346 
347 extern int first_system_vector;
348 /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
349 extern unsigned long used_vectors[];
350 
alloc_system_vector(int vector)351 static inline void alloc_system_vector(int vector)
352 {
353 	if (!test_bit(vector, used_vectors)) {
354 		set_bit(vector, used_vectors);
355 		if (first_system_vector > vector)
356 			first_system_vector = vector;
357 	} else {
358 		BUG();
359 	}
360 }
361 
alloc_intr_gate(unsigned int n,void * addr)362 static inline void alloc_intr_gate(unsigned int n, void *addr)
363 {
364 	alloc_system_vector(n);
365 	set_intr_gate(n, addr);
366 }
367 
368 /*
369  * This routine sets up an interrupt gate at directory privilege level 3.
370  */
set_system_intr_gate(unsigned int n,void * addr)371 static inline void set_system_intr_gate(unsigned int n, void *addr)
372 {
373 	BUG_ON((unsigned)n > 0xFF);
374 	_set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
375 }
376 
set_system_trap_gate(unsigned int n,void * addr)377 static inline void set_system_trap_gate(unsigned int n, void *addr)
378 {
379 	BUG_ON((unsigned)n > 0xFF);
380 	_set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
381 }
382 
set_trap_gate(unsigned int n,void * addr)383 static inline void set_trap_gate(unsigned int n, void *addr)
384 {
385 	BUG_ON((unsigned)n > 0xFF);
386 	_set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
387 }
388 
set_task_gate(unsigned int n,unsigned int gdt_entry)389 static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
390 {
391 	BUG_ON((unsigned)n > 0xFF);
392 	_set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
393 }
394 
set_intr_gate_ist(int n,void * addr,unsigned ist)395 static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
396 {
397 	BUG_ON((unsigned)n > 0xFF);
398 	_set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
399 }
400 
set_system_intr_gate_ist(int n,void * addr,unsigned ist)401 static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist)
402 {
403 	BUG_ON((unsigned)n > 0xFF);
404 	_set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
405 }
406 
407 #endif /* _ASM_X86_DESC_H */
408