1 files changed, 217 insertions, 0 deletions

diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h
new file mode 100644
index 000000000000..6aefb9c0280d
--- /dev/null
+++ b/include/asm-x86_64/desc.h
@@ -0,0 +1,217 @@
+/* Written 2000 by Andi Kleen */ 
+#ifndef __ARCH_DESC_H
+#define __ARCH_DESC_H
+
+#include <linux/threads.h>
+#include <asm/ldt.h>
+
+#ifndef __ASSEMBLY__
+
+#include <linux/string.h>
+#include <asm/segment.h>
+#include <asm/mmu.h>
+
+// 8 byte segment descriptor
+struct desc_struct { 
+        u16 limit0;
+        u16 base0;
+        unsigned base1 : 8, type : 4, s : 1, dpl : 2, p : 1;
+        unsigned limit : 4, avl : 1, l : 1, d : 1, g : 1, base2 : 8;
+} __attribute__((packed)); 
+
+struct n_desc_struct { 
+        unsigned int a,b;
+};      
+
+extern struct desc_struct cpu_gdt_table[NR_CPUS][GDT_ENTRIES];
+
+enum { 
+        GATE_INTERRUPT = 0xE, 
+        GATE_TRAP = 0xF,        
+        GATE_CALL = 0xC,
+};      
+
+// 16byte gate
+struct gate_struct {          
+        u16 offset_low;
+        u16 segment; 
+        unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
+        u16 offset_middle;
+        u32 offset_high;
+        u32 zero1; 
+} __attribute__((packed));
+
+#define PTR_LOW(x) ((unsigned long)(x) & 0xFFFF) 
+#define PTR_MIDDLE(x) (((unsigned long)(x) >> 16) & 0xFFFF)
+#define PTR_HIGH(x) ((unsigned long)(x) >> 32)
+
+enum { 
+        DESC_TSS = 0x9,
+        DESC_LDT = 0x2,
+}; 
+
+// LDT or TSS descriptor in the GDT. 16 bytes.
+struct ldttss_desc { 
+        u16 limit0;
+        u16 base0;
+        unsigned base1 : 8, type : 5, dpl : 2, p : 1;
+        unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
+        u32 base3;
+        u32 zero1; 
+} __attribute__((packed)); 
+
+struct desc_ptr {
+        unsigned short size;
+        unsigned long address;
+} __attribute__((packed)) ;
+
+#define load_TR_desc() asm volatile("ltr %w0"::"r" (GDT_ENTRY_TSS*8))
+#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))
+#define clear_LDT()  asm volatile("lldt %w0"::"r" (0))
+
+/*
+ * This is the ldt that every process will get unless we need
+ * something other than this.
+ */
+extern struct desc_struct default_ldt[];
+extern struct gate_struct idt_table[]; 
+
+static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)  
+{
+        struct gate_struct s;   
+        s.offset_low = PTR_LOW(func); 
+        s.segment = __KERNEL_CS;
+        s.ist = ist; 
+        s.p = 1;
+        s.dpl = dpl; 
+        s.zero0 = 0;
+        s.zero1 = 0; 
+        s.type = type; 
+        s.offset_middle = PTR_MIDDLE(func); 
+        s.offset_high = PTR_HIGH(func); 
+        /* does not need to be atomic because it is only done once at setup time */ 
+        memcpy(adr, &s, 16); 
+} 
+
+static inline void set_intr_gate(int nr, void *func) 
+{ 
+        _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, 0); 
+} 
+
+static inline void set_intr_gate_ist(int nr, void *func, unsigned ist) 
+{ 
+        _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 0, ist); 
+} 
+
+static inline void set_system_gate(int nr, void *func) 
+{ 
+        _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0); 
+} 
+
+static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type, 
+                                         unsigned size) 
+{ 
+        struct ldttss_desc d;
+        memset(&d,0,sizeof(d)); 
+        d.limit0 = size & 0xFFFF;
+        d.base0 = PTR_LOW(tss); 
+        d.base1 = PTR_MIDDLE(tss) & 0xFF; 
+        d.type = type;
+        d.p = 1; 
+        d.limit1 = (size >> 16) & 0xF;
+        d.base2 = (PTR_MIDDLE(tss) >> 8) & 0xFF; 
+        d.base3 = PTR_HIGH(tss); 
+        memcpy(ptr, &d, 16); 
+}
+
+static inline void set_tss_desc(unsigned cpu, void *addr)
+{ 
+        set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_TSS], (unsigned long)addr, 
+                              DESC_TSS,
+                              sizeof(struct tss_struct) - 1);
+} 
+
+static inline void set_ldt_desc(unsigned cpu, void *addr, int size)
+{ 
+        set_tssldt_descriptor(&cpu_gdt_table[cpu][GDT_ENTRY_LDT], (unsigned long)addr, 
+                              DESC_LDT, size * 8 - 1);
+}
+
+static inline void set_seg_base(unsigned cpu, int entry, void *base)
+{ 
+        struct desc_struct *d = &cpu_gdt_table[cpu][entry];
+        u32 addr = (u32)(u64)base;
+        BUG_ON((u64)base >> 32); 
+        d->base0 = addr & 0xffff;
+        d->base1 = (addr >> 16) & 0xff;
+        d->base2 = (addr >> 24) & 0xff;
+} 
+
+#define LDT_entry_a(info) \
+        ((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
+/* Don't allow setting of the lm bit. It is useless anyways because 
+   64bit system calls require __USER_CS. */ 
+#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) | \
+        /* ((info)->lm << 21) | */ \
+        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    && \
+        (info)->lm              == 0)
+
+#if TLS_SIZE != 24
+# error update this code.
+#endif
+
+static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
+{
+        u64 *gdt = (u64 *)(cpu_gdt_table[cpu] + GDT_ENTRY_TLS_MIN);
+        gdt[0] = t->tls_array[0];
+        gdt[1] = t->tls_array[1];
+        gdt[2] = t->tls_array[2];
+} 
+
+/*
+ * load one particular LDT into the current CPU
+ */
+extern inline void load_LDT_nolock (mm_context_t *pc, int cpu)
+{
+        int count = pc->size;
+
+        if (likely(!count)) {
+                clear_LDT();
+                return;
+        }
+                
+        set_ldt_desc(cpu, pc->ldt, count);
+        load_LDT_desc();
+}
+
+static inline void load_LDT(mm_context_t *pc)
+{
+        int cpu = get_cpu();
+        load_LDT_nolock(pc, cpu);
+        put_cpu();
+}
+
+extern struct desc_ptr idt_descr;
+
+#endif /* !__ASSEMBLY__ */
+
+#endif