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 000000000000..c547403f341d
--- /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