/arch/x86/include/asm/desc.h

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