summaryrefslogtreecommitdiff
path: root/include/asm-i386/desc.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-i386/desc.h')
-rw-r--r--include/asm-i386/desc.h95
1 files changed, 55 insertions, 40 deletions
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h
index 5874ef119ffd..f398cc456448 100644
--- a/include/asm-i386/desc.h
+++ b/include/asm-i386/desc.h
@@ -4,8 +4,6 @@
#include <asm/ldt.h>
#include <asm/segment.h>
-#define CPU_16BIT_STACK_SIZE 1024
-
#ifndef __ASSEMBLY__
#include <linux/preempt.h>
@@ -16,8 +14,6 @@
extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
-DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);
-
struct Xgt_desc_struct {
unsigned short size;
unsigned long address __attribute__((packed));
@@ -33,11 +29,6 @@ static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
return (struct desc_struct *)per_cpu(cpu_gdt_descr, cpu).address;
}
-/*
- * This is the ldt that every process will get unless we need
- * something other than this.
- */
-extern struct desc_struct default_ldt[];
extern struct desc_struct idt_table[];
extern void set_intr_gate(unsigned int irq, void * addr);
@@ -64,8 +55,10 @@ static inline void pack_gate(__u32 *a, __u32 *b,
#define DESCTYPE_DPL3 0x60 /* DPL-3 */
#define DESCTYPE_S 0x10 /* !system */
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#else
#define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8))
-#define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8))
#define load_gdt(dtr) __asm__ __volatile("lgdt %0"::"m" (*dtr))
#define load_idt(dtr) __asm__ __volatile("lidt %0"::"m" (*dtr))
@@ -88,6 +81,10 @@ static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
#undef C
}
+#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)
+
static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b)
{
__u32 *lp = (__u32 *)((char *)dt + entry*8);
@@ -95,9 +92,25 @@ static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entr
*(lp+1) = entry_b;
}
-#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)
+#define set_ldt native_set_ldt
+#endif /* CONFIG_PARAVIRT */
+
+static inline fastcall 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 _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
{
@@ -115,14 +128,6 @@ static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const vo
write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b);
}
-static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entries)
-{
- __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);
-}
#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
@@ -153,35 +158,22 @@ static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entri
static inline void clear_LDT(void)
{
- int cpu = get_cpu();
-
- set_ldt_desc(cpu, &default_ldt[0], 5);
- load_LDT_desc();
- put_cpu();
+ set_ldt(NULL, 0);
}
/*
* load one particular LDT into the current CPU
*/
-static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
+static inline void load_LDT_nolock(mm_context_t *pc)
{
- void *segments = pc->ldt;
- int count = pc->size;
-
- if (likely(!count)) {
- segments = &default_ldt[0];
- count = 5;
- }
-
- set_ldt_desc(cpu, segments, count);
- load_LDT_desc();
+ set_ldt(pc->ldt, pc->size);
}
static inline void load_LDT(mm_context_t *pc)
{
- int cpu = get_cpu();
- load_LDT_nolock(pc, cpu);
- put_cpu();
+ preempt_disable();
+ load_LDT_nolock(pc);
+ preempt_enable();
}
static inline unsigned long get_desc_base(unsigned long *desc)
@@ -193,6 +185,29 @@ static inline unsigned long get_desc_base(unsigned long *desc)
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