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Commit 251e6912 authored by Zachary Amsden's avatar Zachary Amsden Committed by Linus Torvalds
Browse files

[PATCH] x86: add an accessor function for getting the per-CPU gdt 



Add an accessor function for getting the per-CPU gdt.  Callee must already
have the CPU.

Signed-off-by: default avatarZachary Amsden <zach@vmware.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 72e12b76

arch/i386/kernel/apm.c

+22 −18
Original line number Diff line number Diff line
@@ -597,12 +597,14 @@ static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, 
	cpumask_t		cpus;

	int			cpu;

	struct desc_struct	save_desc_40;

	struct desc_struct	*gdt;



	cpus = apm_save_cpus();

	

	cpu = get_cpu();

	save_desc_40 = per_cpu(cpu_gdt_table, cpu)[0x40 / 8];

	per_cpu(cpu_gdt_table, cpu)[0x40 / 8] = bad_bios_desc;

	gdt = get_cpu_gdt_table(cpu);

	save_desc_40 = gdt[0x40 / 8];

	gdt[0x40 / 8] = bad_bios_desc;



	local_save_flags(flags);

	APM_DO_CLI;
@@ -610,7 +612,7 @@ static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in, 
	apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);

	APM_DO_RESTORE_SEGS;

	local_irq_restore(flags);

	per_cpu(cpu_gdt_table, cpu)[0x40 / 8] = save_desc_40;

	gdt[0x40 / 8] = save_desc_40;

	put_cpu();

	apm_restore_cpus(cpus);
@@ -639,13 +641,14 @@ static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) 
	cpumask_t		cpus;

	int			cpu;

	struct desc_struct	save_desc_40;



	struct desc_struct	*gdt;



	cpus = apm_save_cpus();

	

	cpu = get_cpu();

	save_desc_40 = per_cpu(cpu_gdt_table, cpu)[0x40 / 8];

	per_cpu(cpu_gdt_table, cpu)[0x40 / 8] = bad_bios_desc;

	gdt = get_cpu_gdt_table(cpu);

	save_desc_40 = gdt[0x40 / 8];

	gdt[0x40 / 8] = bad_bios_desc;



	local_save_flags(flags);

	APM_DO_CLI;
@@ -653,7 +656,7 @@ static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax) 
	error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);

	APM_DO_RESTORE_SEGS;

	local_irq_restore(flags);

	__get_cpu_var(cpu_gdt_table)[0x40 / 8] = save_desc_40;

	gdt[0x40 / 8] = save_desc_40;

	put_cpu();

	apm_restore_cpus(cpus);

	return error;
@@ -2295,35 +2298,36 @@ static int __init apm_init(void) 
	apm_bios_entry.segment = APM_CS;



	for (i = 0; i < NR_CPUS; i++) {

		set_base(per_cpu(cpu_gdt_table, i)[APM_CS >> 3],

		struct desc_struct *gdt = get_cpu_gdt_table(i);

		set_base(gdt[APM_CS >> 3],

			 __va((unsigned long)apm_info.bios.cseg << 4));

		set_base(per_cpu(cpu_gdt_table, i)[APM_CS_16 >> 3],

		set_base(gdt[APM_CS_16 >> 3],

			 __va((unsigned long)apm_info.bios.cseg_16 << 4));

		set_base(per_cpu(cpu_gdt_table, i)[APM_DS >> 3],

		set_base(gdt[APM_DS >> 3],

			 __va((unsigned long)apm_info.bios.dseg << 4));

#ifndef APM_RELAX_SEGMENTS

		if (apm_info.bios.version == 0x100) {

#endif

			/* For ASUS motherboard, Award BIOS rev 110 (and others?) */

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_CS >> 3], 64 * 1024 - 1);

			_set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 - 1);

			/* For some unknown machine. */

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_CS_16 >> 3], 64 * 1024 - 1);

			_set_limit((char *)&gdt[APM_CS_16 >> 3], 64 * 1024 - 1);

			/* For the DEC Hinote Ultra CT475 (and others?) */

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_DS >> 3], 64 * 1024 - 1);

			_set_limit((char *)&gdt[APM_DS >> 3], 64 * 1024 - 1);

#ifndef APM_RELAX_SEGMENTS

		} else {

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_CS >> 3],

			_set_limit((char *)&gdt[APM_CS >> 3],

				(apm_info.bios.cseg_len - 1) & 0xffff);

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_CS_16 >> 3],

			_set_limit((char *)&gdt[APM_CS_16 >> 3],

				(apm_info.bios.cseg_16_len - 1) & 0xffff);

			_set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_DS >> 3],

			_set_limit((char *)&gdt[APM_DS >> 3],

				(apm_info.bios.dseg_len - 1) & 0xffff);

		      /* workaround for broken BIOSes */

	                if (apm_info.bios.cseg_len <= apm_info.bios.offset)

        	                _set_limit((char *)&per_cpu(cpu_gdt_table, i)[APM_CS >> 3], 64 * 1024 -1);

        	                _set_limit((char *)&gdt[APM_CS >> 3], 64 * 1024 -1);

                       if (apm_info.bios.dseg_len <= 0x40) { /* 0x40 * 4kB == 64kB */

                        	/* for the BIOS that assumes granularity = 1 */

                        	per_cpu(cpu_gdt_table, i)[APM_DS >> 3].b |= 0x800000;

                        	gdt[APM_DS >> 3].b |= 0x800000;

                        	printk(KERN_NOTICE "apm: we set the granularity of dseg.\n");

        	        }

		}

arch/i386/kernel/cpu/common.c

+4 −5
Original line number Diff line number Diff line
@@ -573,6 +573,7 @@ void __devinit cpu_init(void) 
	int cpu = smp_processor_id();

	struct tss_struct * t = &per_cpu(init_tss, cpu);

	struct thread_struct *thread = &current->thread;

	struct desc_struct *gdt = get_cpu_gdt_table(cpu);

	__u32 stk16_off = (__u32)&per_cpu(cpu_16bit_stack, cpu);



	if (cpu_test_and_set(cpu, cpu_initialized)) {
@@ -594,18 +595,16 @@ void __devinit cpu_init(void) 
	 * Initialize the per-CPU GDT with the boot GDT,

	 * and set up the GDT descriptor:

	 */

	memcpy(&per_cpu(cpu_gdt_table, cpu), cpu_gdt_table,

	       GDT_SIZE);

 	memcpy(gdt, cpu_gdt_table, GDT_SIZE);



	/* Set up GDT entry for 16bit stack */

	*(__u64 *)&(per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_ESPFIX_SS]) |=

 	*(__u64 *)(&gdt[GDT_ENTRY_ESPFIX_SS]) |=

		((((__u64)stk16_off) << 16) & 0x000000ffffff0000ULL) |

		((((__u64)stk16_off) << 32) & 0xff00000000000000ULL) |

		(CPU_16BIT_STACK_SIZE - 1);



	cpu_gdt_descr[cpu].size = GDT_SIZE - 1;

	cpu_gdt_descr[cpu].address =

	    (unsigned long)&per_cpu(cpu_gdt_table, cpu);

 	cpu_gdt_descr[cpu].address = (unsigned long)gdt;



	load_gdt(&cpu_gdt_descr[cpu]);

	load_idt(&idt_descr);

arch/i386/mm/fault.c

+1 −1
Original line number Diff line number Diff line
@@ -108,7 +108,7 @@ static inline unsigned long get_segment_eip(struct pt_regs *regs, 
		desc = (void *)desc + (seg & ~7);

	} else {

		/* Must disable preemption while reading the GDT. */

		desc = (u32 *)&per_cpu(cpu_gdt_table, get_cpu());

 		desc = (u32 *)get_cpu_gdt_table(get_cpu());

		desc = (void *)desc + (seg & ~7);

	}

include/asm-i386/desc.h

+5 −3
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];

DECLARE_PER_CPU(struct desc_struct, cpu_gdt_table[GDT_ENTRIES]);



#define get_cpu_gdt_table(_cpu) (per_cpu(cpu_gdt_table,_cpu))



DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);



struct Xgt_desc_struct {
@@ -60,7 +62,7 @@ __asm__ __volatile__ ("movw %w3,0(%2)\n\t" \ 


static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *addr)

{

	_set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[entry], (int)addr,

	_set_tssldt_desc(&get_cpu_gdt_table(cpu)[entry], (int)addr,

		offsetof(struct tss_struct, __cacheline_filler) - 1, 0x89);

}
@@ -68,7 +70,7 @@ static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, void *ad 


static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int size)

{

	_set_tssldt_desc(&per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82);

	_set_tssldt_desc(&get_cpu_gdt_table(cpu)[GDT_ENTRY_LDT], (int)addr, ((size << 3)-1), 0x82);

}



#define LDT_entry_a(info) \
@@ -109,7 +111,7 @@ static inline void write_ldt_entry(void *ldt, int entry, __u32 entry_a, __u32 en 


static inline void load_TLS(struct thread_struct *t, unsigned int cpu)

{

#define C(i) per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]

#define C(i) get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]

	C(0); C(1); C(2);

#undef C

}