patch-2.4.20 linux-2.4.20/include/asm-x86_64/desc.h

• Lines: 159
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/desc.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/desc.h linux-2.4.20/include/asm-x86_64/desc.h
@@ -0,0 +1,158 @@
+/* Written 2000 by Andi Kleen */ 
+#ifndef __ARCH_DESC_H
+#define __ARCH_DESC_H
+
+#include <linux/threads.h>
+#include <asm/ldt.h>
+
+#ifndef __ASSEMBLY__
+
+#define __TSS_INDEX(n)  ((n)*64)
+#define __LDT_INDEX(n)  ((n)*64)
+
+extern __u8 gdt_table[];
+extern __u8 gdt_end[];
+
+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));
+
+// 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)); 
+
+// 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 per_cpu_gdt {
+	struct ldttss_desc tss;
+	struct ldttss_desc ldt; 
+} ____cacheline_aligned; 
+
+extern struct per_cpu_gdt gdt_cpu_table[]; 
+
+#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,
+}; 
+
+struct desc_ptr {
+	unsigned short size;
+	unsigned long address;
+} __attribute__((packed)) ;
+
+#define __GDT_HEAD_SIZE 64
+#define __CPU_DESC_INDEX(x,field) \
+	((x) * sizeof(struct per_cpu_gdt) + offsetof(struct per_cpu_gdt, field) + __GDT_HEAD_SIZE)
+
+#define load_TR(cpu) asm volatile("ltr %w0"::"r" (__CPU_DESC_INDEX(cpu, tss)));
+#define __load_LDT(cpu) asm volatile("lldt %w0"::"r" (__CPU_DESC_INDEX(cpu, ldt)));
+#define clear_LDT(n)  asm volatile("lldt %w0"::"r" (0))
+
+extern struct gate_struct idt_table[]; 
+
+#define copy_16byte(dst,src)  memcpy((dst), (src), 16)
+
+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); 
+	copy_16byte(adr, &s);
+} 
+
+static inline void set_intr_gate(int nr, void *func) 
+{ 
+	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0); 
+} 
+
+static inline void set_intr_gate_ist(int nr, void *func, unsigned ist) 
+{ 
+	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 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(struct ldttss_desc *dst, unsigned long ptr, unsigned type, 
+					 unsigned size) 
+{ 
+	memset(dst,0,16); 
+	dst->limit0 = size & 0xFFFF;
+	dst->base0 = PTR_LOW(ptr); 
+	dst->base1 = PTR_MIDDLE(ptr) & 0xFF; 
+	dst->type = type;
+	dst->p = 1; 
+	dst->limit1 = 0xF;
+	dst->base2 = (PTR_MIDDLE(ptr) >> 8) & 0xFF; 
+	dst->base3 = PTR_HIGH(ptr); 
+}
+
+static inline void set_tss_desc(unsigned n, void *addr)
+{ 
+	set_tssldt_descriptor((void *)&gdt_table + __CPU_DESC_INDEX(n,tss), (unsigned long)addr, DESC_TSS, sizeof(struct tss_struct)); 
+} 
+
+static inline void set_ldt_desc(unsigned n, void *addr, int size)
+{ 
+	set_tssldt_descriptor((void *)&gdt_table + __CPU_DESC_INDEX(n,ldt), (unsigned long)addr, DESC_LDT, size); 
+}	
+
+/*
+ * load one particular LDT into the current CPU
+ */
+static inline void load_LDT (struct mm_struct *mm)
+{
+	int cpu = smp_processor_id();
+	void *segments = mm->context.segments;
+
+	if (!segments) {
+		clear_LDT(cpu);
+		return;
+	}
+		
+	set_ldt_desc(cpu, segments, LDT_ENTRIES);
+	__load_LDT(cpu);
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif