diff options
Diffstat (limited to 'include/asm-x86/desc_32.h')
| -rw-r--r-- | include/asm-x86/desc_32.h | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/include/asm-x86/desc_32.h b/include/asm-x86/desc_32.h new file mode 100644 index 0000000..c547403 --- /dev/null +++ b/include/asm-x86/desc_32.h @@ -0,0 +1,244 @@ +#ifndef __ARCH_DESC_H +#define __ARCH_DESC_H + +#include <asm/ldt.h> +#include <asm/segment.h> + +#ifndef __ASSEMBLY__ + +#include <linux/preempt.h> +#include <linux/smp.h> +#include <linux/percpu.h> + +#include <asm/mmu.h> + +struct Xgt_desc_struct { + unsigned short size; + unsigned long address __attribute__((packed)); + unsigned short pad; +} __attribute__ ((packed)); + +struct gdt_page +{ + struct desc_struct gdt[GDT_ENTRIES]; +} __attribute__((aligned(PAGE_SIZE))); +DECLARE_PER_CPU(struct gdt_page, gdt_page); + +static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu) +{ + return per_cpu(gdt_page, cpu).gdt; +} + +extern struct Xgt_desc_struct idt_descr; +extern struct desc_struct idt_table[]; +extern void set_intr_gate(unsigned int irq, void * addr); + +static inline void pack_descriptor(__u32 *a, __u32 *b, + unsigned long base, unsigned long limit, unsigned char type, unsigned char flags) +{ + *a = ((base & 0xffff) << 16) | (limit & 0xffff); + *b = (base & 0xff000000) | ((base & 0xff0000) >> 16) | + (limit & 0x000f0000) | ((type & 0xff) << 8) | ((flags & 0xf) << 20); +} + +static inline void pack_gate(__u32 *a, __u32 *b, + unsigned long base, unsigned short seg, unsigned char type, unsigned char flags) +{ + *a = (seg << 16) | (base & 0xffff); + *b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff); +} + +#define DESCTYPE_LDT 0x82 /* present, system, DPL-0, LDT */ +#define DESCTYPE_TSS 0x89 /* present, system, DPL-0, 32-bit TSS */ +#define DESCTYPE_TASK 0x85 /* present, system, DPL-0, task gate */ +#define DESCTYPE_INT 0x8e /* present, system, DPL-0, interrupt gate */ +#define DESCTYPE_TRAP 0x8f /* present, system, DPL-0, trap gate */ +#define DESCTYPE_DPL3 0x60 /* DPL-3 */ +#define DESCTYPE_S 0x10 /* !system */ + +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else +#define load_TR_desc() native_load_tr_desc() +#define load_gdt(dtr) native_load_gdt(dtr) +#define load_idt(dtr) native_load_idt(dtr) +#define load_tr(tr) __asm__ __volatile("ltr %0"::"m" (tr)) +#define load_ldt(ldt) __asm__ __volatile("lldt %0"::"m" (ldt)) + +#define store_gdt(dtr) native_store_gdt(dtr) +#define store_idt(dtr) native_store_idt(dtr) +#define store_tr(tr) (tr = native_store_tr()) +#define store_ldt(ldt) __asm__ ("sldt %0":"=m" (ldt)) + +#define load_TLS(t, cpu) native_load_tls(t, cpu) +#define set_ldt native_set_ldt + +#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#endif + +static inline void write_dt_entry(struct desc_struct *dt, + int entry, u32 entry_low, u32 entry_high) +{ + dt[entry].a = entry_low; + dt[entry].b = entry_high; +} + +static inline void native_set_ldt(const void *addr, unsigned int entries) +{ + if (likely(entries == 0)) + __asm__ __volatile__("lldt %w0"::"q" (0)); + else { + unsigned cpu = smp_processor_id(); + __u32 a, b; + + pack_descriptor(&a, &b, (unsigned long)addr, + entries * sizeof(struct desc_struct) - 1, + DESCTYPE_LDT, 0); + write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b); + __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8)); + } +} + + +static inline void native_load_tr_desc(void) +{ + asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8)); +} + +static inline void native_load_gdt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lgdt %0"::"m" (*dtr)); +} + +static inline void native_load_idt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lidt %0"::"m" (*dtr)); +} + +static inline void native_store_gdt(struct Xgt_desc_struct *dtr) +{ + asm ("sgdt %0":"=m" (*dtr)); +} + +static inline void native_store_idt(struct Xgt_desc_struct *dtr) +{ + asm ("sidt %0":"=m" (*dtr)); +} + +static inline unsigned long native_store_tr(void) +{ + unsigned long tr; + asm ("str %0":"=r" (tr)); + return tr; +} + +static inline void native_load_tls(struct thread_struct *t, unsigned int cpu) +{ + unsigned int i; + struct desc_struct *gdt = get_cpu_gdt_table(cpu); + + for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++) + gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]; +} + +static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg) +{ + __u32 a, b; + pack_gate(&a, &b, (unsigned long)addr, seg, type, 0); + write_idt_entry(idt_table, gate, a, b); +} + +static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr) +{ + __u32 a, b; + pack_descriptor(&a, &b, (unsigned long)addr, + offsetof(struct tss_struct, __cacheline_filler) - 1, + DESCTYPE_TSS, 0); + write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b); +} + + +#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr) + +#define LDT_entry_a(info) \ + ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff)) + +#define LDT_entry_b(info) \ + (((info)->base_addr & 0xff000000) | \ + (((info)->base_addr & 0x00ff0000) >> 16) | \ + ((info)->limit & 0xf0000) | \ + (((info)->read_exec_only ^ 1) << 9) | \ + ((info)->contents << 10) | \ + (((info)->seg_not_present ^ 1) << 15) | \ + ((info)->seg_32bit << 22) | \ + ((info)->limit_in_pages << 23) | \ + ((info)->useable << 20) | \ + 0x7000) + +#define LDT_empty(info) (\ + (info)->base_addr == 0 && \ + (info)->limit == 0 && \ + (info)->contents == 0 && \ + (info)->read_exec_only == 1 && \ + (info)->seg_32bit == 0 && \ + (info)->limit_in_pages == 0 && \ + (info)->seg_not_present == 1 && \ + (info)->useable == 0 ) + +static inline void clear_LDT(void) +{ + set_ldt(NULL, 0); +} + +/* + * load one particular LDT into the current CPU + */ +static inline void load_LDT_nolock(mm_context_t *pc) +{ + set_ldt(pc->ldt, pc->size); +} + +static inline void load_LDT(mm_context_t *pc) +{ + preempt_disable(); + load_LDT_nolock(pc); + preempt_enable(); +} + +static inline unsigned long get_desc_base(unsigned long *desc) +{ + unsigned long base; + base = ((desc[0] >> 16) & 0x0000ffff) | + ((desc[1] << 16) & 0x00ff0000) | + (desc[1] & 0xff000000); + return base; +} + +#else /* __ASSEMBLY__ */ + +/* + * GET_DESC_BASE reads the descriptor base of the specified segment. + * + * Args: + * idx - descriptor index + * gdt - GDT pointer + * base - 32bit register to which the base will be written + * lo_w - lo word of the "base" register + * lo_b - lo byte of the "base" register + * hi_b - hi byte of the low word of the "base" register + * + * Example: + * GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah) + * Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax. + */ +#define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \ + movb idx*8+4(gdt), lo_b; \ + movb idx*8+7(gdt), hi_b; \ + shll $16, base; \ + movw idx*8+2(gdt), lo_w; + +#endif /* !__ASSEMBLY__ */ + +#endif |
