From a939098afcfa5f81d3474782ec15c6d114e57763 Mon Sep 17 00:00:00 2001 From: Glauber Costa Date: Wed, 28 May 2008 16:19:53 -0700 Subject: x86: move x86_64 gdt closer to i386 i386 and x86_64 used two different schemes for maintaining the gdt. With this patch, x86_64 initial gdt table is defined in a .c file, same way as i386 is now. Also, we call it "gdt_page", and the descriptor, "early_gdt_descr". This way we achieve common naming, which can allow for more code integration. Signed-off-by: Glauber Costa Signed-off-by: Ingo Molnar --- arch/x86/kernel/head_64.S | 48 +++++----------------------------------- arch/x86/kernel/setup64.c | 5 +---- arch/x86/kernel/setup_64.c | 19 ++++++++++++++-- arch/x86/kernel/smpboot.c | 12 +++------- arch/x86/kernel/x8664_ksyms_64.c | 5 ----- 5 files changed, 26 insertions(+), 63 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 918a2711aff6..32f5a114d1a2 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -203,7 +203,7 @@ ENTRY(secondary_startup_64) * addresses where we're currently running on. We have to do that here * because in 32bit we couldn't load a 64bit linear address. */ - lgdt cpu_gdt_descr(%rip) + lgdt early_gdt_descr(%rip) /* set up data segments. actually 0 would do too */ movl $__KERNEL_DS,%eax @@ -391,54 +391,16 @@ NEXT_PAGE(level2_spare_pgt) .data .align 16 - .globl cpu_gdt_descr -cpu_gdt_descr: - .word gdt_end-cpu_gdt_table-1 -gdt: - .quad cpu_gdt_table -#ifdef CONFIG_SMP - .rept NR_CPUS-1 - .word 0 - .quad 0 - .endr -#endif + .globl early_gdt_descr +early_gdt_descr: + .word GDT_ENTRIES*8-1 + .quad per_cpu__gdt_page ENTRY(phys_base) /* This must match the first entry in level2_kernel_pgt */ .quad 0x0000000000000000 -/* We need valid kernel segments for data and code in long mode too - * IRET will check the segment types kkeil 2000/10/28 - * Also sysret mandates a special GDT layout - */ - - .section .data.page_aligned, "aw" - .align PAGE_SIZE - -/* The TLS descriptors are currently at a different place compared to i386. - Hopefully nobody expects them at a fixed place (Wine?) */ -ENTRY(cpu_gdt_table) - .quad 0x0000000000000000 /* NULL descriptor */ - .quad 0x00cf9b000000ffff /* __KERNEL32_CS */ - .quad 0x00af9b000000ffff /* __KERNEL_CS */ - .quad 0x00cf93000000ffff /* __KERNEL_DS */ - .quad 0x00cffb000000ffff /* __USER32_CS */ - .quad 0x00cff3000000ffff /* __USER_DS, __USER32_DS */ - .quad 0x00affb000000ffff /* __USER_CS */ - .quad 0x0 /* unused */ - .quad 0,0 /* TSS */ - .quad 0,0 /* LDT */ - .quad 0,0,0 /* three TLS descriptors */ - .quad 0x0000f40000000000 /* node/CPU stored in limit */ -gdt_end: - /* asm/segment.h:GDT_ENTRIES must match this */ - /* This should be a multiple of the cache line size */ - /* GDTs of other CPUs are now dynamically allocated */ - - /* zero the remaining page */ - .fill PAGE_SIZE / 8 - GDT_ENTRIES,8,0 - .section .bss, "aw", @nobits .align L1_CACHE_BYTES ENTRY(idt_table) diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c index fc1a56da8240..70ff07186772 100644 --- a/arch/x86/kernel/setup64.c +++ b/arch/x86/kernel/setup64.c @@ -202,11 +202,8 @@ void __cpuinit cpu_init (void) * Initialize the per-CPU GDT with the boot GDT, * and set up the GDT descriptor: */ - if (cpu) - memcpy(get_cpu_gdt_table(cpu), cpu_gdt_table, GDT_SIZE); - cpu_gdt_descr[cpu].size = GDT_SIZE; - load_gdt((const struct desc_ptr *)&cpu_gdt_descr[cpu]); + switch_to_new_gdt(); load_idt((const struct desc_ptr *)&idt_descr); memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8); diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 504caeaffd58..a93300de4da9 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -81,8 +81,6 @@ #define ARCH_SETUP #endif -#include "cpu/cpu.h" - /* * Machine setup.. */ @@ -228,6 +226,23 @@ static inline void copy_edd(void) } #endif +/* Overridden in paravirt.c if CONFIG_PARAVIRT */ +void __attribute__((weak)) __init memory_setup(void) +{ + machine_specific_memory_setup(); +} + +/* Current gdt points %fs at the "master" per-cpu area: after this, + * it's on the real one. */ +void switch_to_new_gdt(void) +{ + struct desc_ptr gdt_descr; + + gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id()); + gdt_descr.size = GDT_SIZE - 1; + load_gdt(&gdt_descr); +} + /* * setup_arch - architecture-specific boot-time initializations * diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index a71e3cad5470..fe2bd515d6cc 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -849,14 +849,8 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu) .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done), }; INIT_WORK(&c_idle.work, do_fork_idle); -#ifdef CONFIG_X86_64 - /* allocate memory for gdts of secondary cpus. Hotplug is considered */ - if (!cpu_gdt_descr[cpu].address && - !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) { - printk(KERN_ERR "Failed to allocate GDT for CPU %d\n", cpu); - return -1; - } +#ifdef CONFIG_X86_64 /* Allocate node local memory for AP pdas */ if (cpu > 0) { boot_error = get_local_pda(cpu); @@ -898,7 +892,6 @@ do_rest: #ifdef CONFIG_X86_32 per_cpu(current_task, cpu) = c_idle.idle; init_gdt(cpu); - early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); c_idle.idle->thread.ip = (unsigned long) start_secondary; /* Stack for startup_32 can be just as for start_secondary onwards */ irq_ctx_init(cpu); @@ -908,6 +901,7 @@ do_rest: initial_code = (unsigned long)start_secondary; clear_tsk_thread_flag(c_idle.idle, TIF_FORK); #endif + early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); stack_start.sp = (void *) c_idle.idle->thread.sp; /* start_ip had better be page-aligned! */ @@ -1252,8 +1246,8 @@ void __init native_smp_prepare_boot_cpu(void) int me = smp_processor_id(); #ifdef CONFIG_X86_32 init_gdt(me); - switch_to_new_gdt(); #endif + switch_to_new_gdt(); /* already set me in cpu_online_map in boot_cpu_init() */ cpu_set(me, cpu_callout_map); per_cpu(cpu_state, me) = CPU_ONLINE; diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c index f6c05d0410fb..2f306a826897 100644 --- a/arch/x86/kernel/x8664_ksyms_64.c +++ b/arch/x86/kernel/x8664_ksyms_64.c @@ -53,8 +53,3 @@ EXPORT_SYMBOL(init_level4_pgt); EXPORT_SYMBOL(load_gs_index); EXPORT_SYMBOL(_proxy_pda); - -#ifdef CONFIG_PARAVIRT -/* Virtualized guests may want to use it */ -EXPORT_SYMBOL_GPL(cpu_gdt_descr); -#endif -- cgit v1.2.3-55-g7522