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Commit 9d1c6e7c authored by Glauber de Oliveira Costa's avatar Glauber de Oliveira Costa Committed by Thomas Gleixner
Browse files

x86: use descriptor's functions instead of inline assembly 



This patch provides a new set of functions for managing the descriptor
tables that can be used instead of putting the raw assembly in .c files.

Remodeling of store_tr() suggested by Frederik Deweerdt.

[ tglx: arch/x86 adaptation ]

Signed-off-by: default avatarGlauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9d975ebd

arch/x86/kernel/head64.c

+1 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ void __init x86_64_start_kernel(char * real_mode_data) 


	for (i = 0; i < IDT_ENTRIES; i++)

		set_intr_gate(i, early_idt_handler);

	asm volatile("lidt %0" :: "m" (idt_descr));

	load_idt((const struct desc_ptr *)&idt_descr);



	early_printk("Kernel alive\n");

arch/x86/kernel/reboot_64.c

+2 −1
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/sched.h>

#include <asm/io.h>

#include <asm/delay.h>

#include <asm/desc.h>

#include <asm/hw_irq.h>

#include <asm/system.h>

#include <asm/pgtable.h>
@@ -136,7 +137,7 @@ void machine_emergency_restart(void) 
		}



		case BOOT_TRIPLE: 

			__asm__ __volatile__("lidt (%0)": :"r" (&no_idt));

			load_idt((const struct desc_ptr *)&no_idt);

			__asm__ __volatile__("int3");



			reboot_type = BOOT_KBD;

arch/x86/kernel/setup64.c

+2 −2
Original line number Diff line number Diff line
@@ -230,8 +230,8 @@ void __cpuinit cpu_init (void) 
 		memcpy(cpu_gdt(cpu), cpu_gdt_table, GDT_SIZE);



	cpu_gdt_descr[cpu].size = GDT_SIZE;

	asm volatile("lgdt %0" :: "m" (cpu_gdt_descr[cpu]));

	asm volatile("lidt %0" :: "m" (idt_descr));

	load_gdt((const struct desc_ptr *)&cpu_gdt_descr[cpu]);

	load_idt((const struct desc_ptr *)&idt_descr);



	memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);

	syscall_init();

arch/x86/kernel/suspend_64.c

+6 −5
Original line number Diff line number Diff line
@@ -32,9 +32,9 @@ void __save_processor_state(struct saved_context *ctxt) 
	/*

	 * descriptor tables

	 */

	asm volatile ("sgdt %0" : "=m" (ctxt->gdt_limit));

	asm volatile ("sidt %0" : "=m" (ctxt->idt_limit));

	asm volatile ("str %0"  : "=m" (ctxt->tr));

	store_gdt((struct desc_ptr *)&ctxt->gdt_limit);

	store_idt((struct desc_ptr *)&ctxt->idt_limit);

	store_tr(ctxt->tr);



	/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */

	/*
@@ -91,8 +91,9 @@ void __restore_processor_state(struct saved_context *ctxt) 
	 * now restore the descriptor tables to their proper values

	 * ltr is done i fix_processor_context().

	 */

	asm volatile ("lgdt %0" :: "m" (ctxt->gdt_limit));

	asm volatile ("lidt %0" :: "m" (ctxt->idt_limit));

	load_gdt((const struct desc_ptr *)&ctxt->gdt_limit);

	load_idt((const struct desc_ptr *)&ctxt->idt_limit);





	/*

	 * segment registers

include/asm-x86/desc_64.h

+30 −0
Original line number Diff line number Diff line
@@ -20,6 +20,16 @@ extern struct desc_struct cpu_gdt_table[GDT_ENTRIES]; 
#define load_LDT_desc() asm volatile("lldt %w0"::"r" (GDT_ENTRY_LDT*8))

#define clear_LDT()  asm volatile("lldt %w0"::"r" (0))



static inline unsigned long __store_tr(void)

{

       unsigned long tr;



       asm volatile ("str %w0":"=r" (tr));

       return tr;

}



#define store_tr(tr) (tr) = __store_tr()



/*

 * This is the ldt that every process will get unless we need

 * something other than this.
@@ -31,6 +41,16 @@ extern struct desc_ptr cpu_gdt_descr[]; 
/* the cpu gdt accessor */

#define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)



static inline void load_gdt(const struct desc_ptr *ptr)

{

	asm volatile("lgdt %w0"::"m" (*ptr));

}



static inline void store_gdt(struct desc_ptr *ptr)

{

       asm("sgdt %w0":"=m" (*ptr));

}



static inline void _set_gate(void *adr, unsigned type, unsigned long func, unsigned dpl, unsigned ist)  

{

	struct gate_struct s;
@@ -71,6 +91,16 @@ static inline void set_system_gate_ist(int nr, void *func, unsigned ist) 
	_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);

}



static inline void load_idt(const struct desc_ptr *ptr)

{

	asm volatile("lidt %w0"::"m" (*ptr));

}



static inline void store_idt(struct desc_ptr *dtr)

{

       asm("sidt %w0":"=m" (*dtr));

}



static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type, 

					 unsigned size) 

{