x86: move _set_gate and its users to a common location

This patch moves _set_gate and its users to desc.h. We can now
use common code for x86_64 and i386.

[ mingo@elte.hu: set_system_gate() fixes for nasty crashes. ]

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

4 files changed, 93 insertions, 65 deletions

diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h
index e61a5a38caba..d75bc0634313 100644
--- a/include/asm-x86/desc.h
+++ b/include/asm-x86/desc.h
@@ -33,6 +33,22 @@ extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
 extern struct desc_ptr cpu_gdt_descr[];
 /* the cpu gdt accessor */
 #define get_cpu_gdt_table(x) ((struct desc_struct *)cpu_gdt_descr[x].address)
+
+static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func,
+                             unsigned dpl, unsigned ist, unsigned seg)
+{
+        gate->offset_low = PTR_LOW(func);
+        gate->segment = __KERNEL_CS;
+        gate->ist = ist;
+        gate->p = 1;
+        gate->dpl = dpl;
+        gate->zero0 = 0;
+        gate->zero1 = 0;
+        gate->type = type;
+        gate->offset_middle = PTR_MIDDLE(func);
+        gate->offset_high = PTR_HIGH(func);
+}
+
 #else
 struct gdt_page {
         struct desc_struct gdt[GDT_ENTRIES];
@@ -43,6 +59,16 @@ static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
 {
         return per_cpu(gdt_page, cpu).gdt;
 }
+
+static inline void pack_gate(gate_desc *gate, unsigned char type,
+       unsigned long base, unsigned dpl, unsigned flags, unsigned short seg)
+
+{
+        gate->a = (seg << 16) | (base & 0xffff);
+        gate->b = (base & 0xffff0000) |
+                  (((0x80 | type | (dpl << 5)) & 0xff) << 8);
+}
+
 #endif
 
 #ifdef CONFIG_PARAVIRT
@@ -242,6 +268,72 @@ static inline unsigned long get_desc_base(struct desc_struct *desc)
 {
         return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24);
 }
+static inline void _set_gate(int gate, unsigned type, void *addr,
+                              unsigned dpl, unsigned ist, unsigned seg)
+{
+        gate_desc s;
+        pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg);
+        /*
+         * does not need to be atomic because it is only done once at
+         * setup time
+         */
+        write_idt_entry(idt_table, gate, &s);
+}
+
+/*
+ * This needs to use 'idt_table' rather than 'idt', and
+ * thus use the _nonmapped_ version of the IDT, as the
+ * Pentium F0 0F bugfix can have resulted in the mapped
+ * IDT being write-protected.
+ */
+static inline void set_intr_gate(unsigned int n, void *addr)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
+}
+
+/*
+ * This routine sets up an interrupt gate at directory privilege level 3.
+ */
+static inline void set_system_intr_gate(unsigned int n, void *addr)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
+}
+
+static inline void set_trap_gate(unsigned int n, void *addr)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS);
+}
+
+static inline void set_system_gate(unsigned int n, void *addr)
+{
+        BUG_ON((unsigned)n > 0xFF);
+#ifdef CONFIG_X86_32
+        _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS);
+#else
+        _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS);
+#endif
+}
+
+static inline void set_task_gate(unsigned int n, unsigned int gdt_entry)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3));
+}
+
+static inline void set_intr_gate_ist(int n, void *addr, unsigned ist)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS);
+}
+
+static inline void set_system_gate_ist(int n, void *addr, unsigned ist)
+{
+        BUG_ON((unsigned)n > 0xFF);
+        _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS);
+}
 
 #else
 /*
diff --git a/include/asm-x86/desc_32.h b/include/asm-x86/desc_32.h
index 4bf20b7dd741..3b112ec186a0 100644
--- a/include/asm-x86/desc_32.h
+++ b/include/asm-x86/desc_32.h
@@ -10,22 +10,6 @@
 #include <linux/preempt.h>
 #include <linux/percpu.h>
 
-extern void set_intr_gate(unsigned int irq, void * addr);
-
-static inline void pack_gate(gate_desc *gate,
-        unsigned long base, unsigned short seg, unsigned char type, unsigned char flags)
-{
-        gate->a = (seg << 16) | (base & 0xffff);
-        gate->b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff);
-}
-
-static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
-{
-        gate_desc g;
-        pack_gate(&g, (unsigned long)addr, seg, type, 0);
-        write_idt_entry(idt_table, gate, &g);
-}
-
 static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr)
 {
         tss_desc tss;
diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h
index b0290c45319c..6bc92e6e5cc3 100644
--- a/include/asm-x86/desc_64.h
+++ b/include/asm-x86/desc_64.h
@@ -11,51 +11,6 @@
 
 #include <asm/segment.h>
 
-static inline void _set_gate(int gate, unsigned type, unsigned long func,
-                             unsigned dpl, unsigned ist)
-{
-        gate_desc 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
-         */
-        write_idt_entry(idt_table, gate, &s);
-}
-
-static inline void set_intr_gate(int nr, void *func)
-{
-        BUG_ON((unsigned)nr > 0xFF);
-        _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 0, 0);
-}
-
-static inline void set_intr_gate_ist(int nr, void *func, unsigned ist)
-{
-        BUG_ON((unsigned)nr > 0xFF);
-        _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 0, ist);
-}
-
-static inline void set_system_gate(int nr, void *func)
-{
-        BUG_ON((unsigned)nr > 0xFF);
-        _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 3, 0);
-}
-
-static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
-{
-        _set_gate(nr, GATE_INTERRUPT, (unsigned long) func, 3, ist);
-}
-
 static inline void set_tss_desc(unsigned cpu, void *addr)
 {
         struct desc_struct *d = get_cpu_gdt_table(cpu);
diff --git a/include/asm-x86/desc_defs.h b/include/asm-x86/desc_defs.h
index ebb64fe3a450..e33f078b3e54 100644
--- a/include/asm-x86/desc_defs.h
+++ b/include/asm-x86/desc_defs.h
@@ -36,6 +36,7 @@ enum {
         GATE_INTERRUPT = 0xE,
         GATE_TRAP = 0xF,
         GATE_CALL = 0xC,
+        GATE_TASK = 0x5,
 };
 
 // 16byte gate
@@ -55,10 +56,6 @@ struct gate_struct64 {
 enum {
         DESC_TSS = 0x9,
         DESC_LDT = 0x2,
-        DESCTYPE_TASK = 0x85,   /* present, system, DPL-0, task gate */
-        DESCTYPE_INT =  0x8e,   /* present, system, DPL-0, interrupt gate */
-        DESCTYPE_TRAP = 0x8f,   /* present, system, DPL-0, trap gate */
-        DESCTYPE_DPL3 = 0x60,   /* DPL-3 */
         DESCTYPE_S =    0x10,   /* !system */
 };