From 48927bbb97c7d4cf343c05827ab9ac30c60678cb Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 8 May 2012 21:22:28 +0300 Subject: x86, realmode: Move SMP trampoline to unified realmode code Migrated SMP trampoline code to the real mode blob. SMP trampoline code is not yet removed from .x86_trampoline because it is needed by the wakeup code. [ hpa: always enable compiling startup_32_smp in head_32.S... it is only a few instructions which go into .init on UP builds, and it makes the rest of the code less #ifdef ugly. ] Signed-off-by: Jarkko Sakkinen Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/realmode.h | 18 ++++ arch/x86/kernel/head_32.S | 5 +- arch/x86/kernel/head_64.S | 4 - arch/x86/kernel/realmode.c | 14 +++ arch/x86/kernel/smpboot.c | 18 ++-- arch/x86/realmode/rm/Makefile | 1 + arch/x86/realmode/rm/header.S | 11 +++ arch/x86/realmode/rm/trampoline_32.S | 86 +++++++++++++++++ arch/x86/realmode/rm/trampoline_64.S | 175 +++++++++++++++++++++++++++++++++++ 9 files changed, 316 insertions(+), 16 deletions(-) create mode 100644 arch/x86/realmode/rm/trampoline_32.S create mode 100644 arch/x86/realmode/rm/trampoline_64.S diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index bf26b06..9b4a5da 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -13,6 +13,17 @@ struct real_mode_header { #ifdef CONFIG_X86_32 u32 machine_real_restart_asm; #endif + /* SMP trampoline */ + u32 trampoline_data; + u32 trampoline_status; +#ifdef CONFIG_X86_32 + u32 startup_32_smp; + u32 boot_gdt; +#else + u32 startup_64_smp; + u32 level3_ident_pgt; + u32 level3_kernel_pgt; +#endif } __attribute__((__packed__)); extern struct real_mode_header real_mode_header; @@ -25,6 +36,13 @@ extern unsigned long initial_gs; extern unsigned char real_mode_blob[]; extern unsigned char real_mode_relocs[]; +#ifdef CONFIG_X86_32 +extern unsigned char startup_32_smp[]; +extern unsigned char boot_gdt[]; +#else +extern unsigned char secondary_startup_64[]; +#endif + extern void __init setup_real_mode(void); #endif /* _ARCH_X86_REALMODE_H */ diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index ce0be7c..a3c2b4f 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -273,10 +273,7 @@ num_subarch_entries = (. - subarch_entries) / 4 * If cpu hotplug is not supported then this code can go in init section * which will be freed later */ - __CPUINIT - -#ifdef CONFIG_SMP ENTRY(startup_32_smp) cld movl $(__BOOT_DS),%eax @@ -287,7 +284,7 @@ ENTRY(startup_32_smp) movl pa(stack_start),%ecx movl %eax,%ss leal -__PAGE_OFFSET(%ecx),%esp -#endif /* CONFIG_SMP */ + default_entry: /* diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 40f4eb3..d70bc2e 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -136,10 +136,6 @@ ident_complete: /* Fixup phys_base */ addq %rbp, phys_base(%rip) - /* Fixup trampoline */ - addq %rbp, trampoline_level4_pgt + 0(%rip) - addq %rbp, trampoline_level4_pgt + (511*8)(%rip) - /* Due to ENTRY(), sometimes the empty space gets filled with * zeros. Better take a jmp than relying on empty space being * filled with 0x90 (nop) diff --git a/arch/x86/kernel/realmode.c b/arch/x86/kernel/realmode.c index 7415c42..a465775 100644 --- a/arch/x86/kernel/realmode.c +++ b/arch/x86/kernel/realmode.c @@ -58,6 +58,20 @@ void __init setup_real_mode(void) /* Copied header will contain relocated physical addresses. */ memcpy(&real_mode_header, real_mode_base, sizeof(struct real_mode_header)); + +#ifdef CONFIG_X86_32 + *((u32 *)__va(real_mode_header.startup_32_smp)) = __pa(startup_32_smp); + *((u32 *)__va(real_mode_header.boot_gdt)) = __pa(boot_gdt); +#else + *((u64 *) __va(real_mode_header.startup_64_smp)) = + (u64) __pa(secondary_startup_64); + + *((u64 *) __va(real_mode_header.level3_ident_pgt)) = + __pa(level3_ident_pgt) + _KERNPG_TABLE; + + *((u64 *) __va(real_mode_header.level3_kernel_pgt)) = + __pa(level3_kernel_pgt) + _KERNPG_TABLE; +#endif } /* diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 6e1e406..c7971ea 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -57,7 +57,7 @@ #include #include #include -#include +#include #include #include #include @@ -73,6 +73,8 @@ #include #include +#include + /* State of each CPU */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; @@ -662,8 +664,12 @@ static void __cpuinit announce_cpu(int cpu, int apicid) */ static int __cpuinit do_boot_cpu(int apicid, int cpu) { + volatile u32 *trampoline_status = + (volatile u32 *) __va(real_mode_header.trampoline_status); + /* start_ip had better be page-aligned! */ + unsigned long start_ip = real_mode_header.trampoline_data; + unsigned long boot_error = 0; - unsigned long start_ip; int timeout; struct create_idle c_idle = { .cpu = cpu, @@ -713,9 +719,6 @@ do_rest: initial_code = (unsigned long)start_secondary; stack_start = c_idle.idle->thread.sp; - /* start_ip had better be page-aligned! */ - start_ip = trampoline_address(); - /* So we see what's up */ announce_cpu(cpu, apicid); @@ -778,8 +781,7 @@ do_rest: pr_debug("CPU%d: has booted.\n", cpu); } else { boot_error = 1; - if (*(volatile u32 *)TRAMPOLINE_SYM(trampoline_status) - == 0xA5A5A5A5) + if (*trampoline_status == 0xA5A5A5A5) /* trampoline started but...? */ pr_err("CPU%d: Stuck ??\n", cpu); else @@ -805,7 +807,7 @@ do_rest: } /* mark "stuck" area as not stuck */ - *(volatile u32 *)TRAMPOLINE_SYM(trampoline_status) = 0; + *trampoline_status = 0; if (get_uv_system_type() != UV_NON_UNIQUE_APIC) { /* diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile index 3f851c4..56ec64f 100644 --- a/arch/x86/realmode/rm/Makefile +++ b/arch/x86/realmode/rm/Makefile @@ -13,6 +13,7 @@ always := realmode.bin realmode-y += header.o realmode-$(CONFIG_X86_32) += reboot_32.o +realmode-y += trampoline_$(BITS).o targets += $(realmode-y) diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S index db21401..a979004 100644 --- a/arch/x86/realmode/rm/header.S +++ b/arch/x86/realmode/rm/header.S @@ -16,4 +16,15 @@ ENTRY(real_mode_header) #ifdef CONFIG_X86_32 .long pa_machine_real_restart_asm #endif + /* SMP trampoline */ + .long pa_trampoline_data + .long pa_trampoline_status +#ifdef CONFIG_X86_32 + .long pa_startup_32_smp + .long pa_boot_gdt +#else + .long pa_startup_64_smp + .long pa_level3_ident_pgt + .long pa_level3_kernel_pgt +#endif END(real_mode_header) diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S new file mode 100644 index 0000000..18cb7fc --- /dev/null +++ b/arch/x86/realmode/rm/trampoline_32.S @@ -0,0 +1,86 @@ +/* + * + * Trampoline.S Derived from Setup.S by Linus Torvalds + * + * 4 Jan 1997 Michael Chastain: changed to gnu as. + * + * This is only used for booting secondary CPUs in SMP machine + * + * Entry: CS:IP point to the start of our code, we are + * in real mode with no stack, but the rest of the + * trampoline page to make our stack and everything else + * is a mystery. + * + * We jump into arch/x86/kernel/head_32.S. + * + * On entry to trampoline_data, the processor is in real mode + * with 16-bit addressing and 16-bit data. CS has some value + * and IP is zero. Thus, we load CS to the physical segment + * of the real mode code before doing anything further. + * + * The structure real_mode_header includes entries that need + * to be set up before executing this code: + * + * startup_32_smp + * boot_gdt + */ + +#include +#include +#include +#include + + .text + .code16 + .globl trampoline_data + + .balign PAGE_SIZE +trampoline_data: + wbinvd # Needed for NUMA-Q should be harmless for others + + .byte 0xea # ljmpw + .word 1f # Offset + .word real_mode_seg # Segment +1: + mov %cs, %ax # Code and data in the same place + mov %ax, %ds + + cli # We should be safe anyway + + movl $0xA5A5A5A5, trampoline_status + # write marker for master knows we're running + + /* GDT tables in non default location kernel can be beyond 16MB and + * lgdt will not be able to load the address as in real mode default + * operand size is 16bit. Use lgdtl instead to force operand size + * to 32 bit. + */ + + lidtl boot_idt_descr # load idt with 0, 0 + lgdtl boot_gdt_descr # load gdt with whatever is appropriate + + xor %ax, %ax + inc %ax # protected mode (PE) bit + lmsw %ax # into protected mode + + # flush prefetch and jump to startup_32_smp in arch/i386/kernel/head.S + ljmpl *(startup_32_smp) + + .data + .globl startup_32_smp, boot_gdt, trampoline_status + +boot_gdt_descr: + .word __BOOT_DS + 7 # gdt limit +boot_gdt: + .long 0 # gdt base + +boot_idt_descr: + .word 0 # idt limit = 0 + .long 0 # idt base = 0L + +trampoline_status: + .long 0 + +startup_32_smp: + .long 0x00000000 + .word __BOOT_CS, 0 diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S new file mode 100644 index 0000000..063da00 --- /dev/null +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -0,0 +1,175 @@ +/* + * + * Trampoline.S Derived from Setup.S by Linus Torvalds + * + * 4 Jan 1997 Michael Chastain: changed to gnu as. + * 15 Sept 2005 Eric Biederman: 64bit PIC support + * + * Entry: CS:IP point to the start of our code, we are + * in real mode with no stack, but the rest of the + * trampoline page to make our stack and everything else + * is a mystery. + * + * On entry to trampoline_data, the processor is in real mode + * with 16-bit addressing and 16-bit data. CS has some value + * and IP is zero. Thus, data addresses need to be absolute + * (no relocation) and are taken with regard to r_base. + * + * With the addition of trampoline_level4_pgt this code can + * now enter a 64bit kernel that lives at arbitrary 64bit + * physical addresses. + * + * If you work on this file, check the object module with objdump + * --full-contents --reloc to make sure there are no relocation + * entries. + */ + +#include +#include +#include +#include +#include +#include +#include + + .text + .balign PAGE_SIZE + .code16 + +ENTRY(trampoline_data) + cli # We should be safe anyway + wbinvd + + .byte 0xea # ljmpw + .word 1f # Offset + .word real_mode_seg # Segment +1: + mov %cs, %ax # Code and data in the same place + mov %ax, %ds + mov %ax, %es + mov %ax, %ss + + movl $0xA5A5A5A5, trampoline_status + # write marker for master knows we're running + + # Setup stack + movw $trampoline_stack_end, %sp + + call verify_cpu # Verify the cpu supports long mode + testl %eax, %eax # Check for return code + jnz no_longmode + + /* + * GDT tables in non default location kernel can be beyond 16MB and + * lgdt will not be able to load the address as in real mode default + * operand size is 16bit. Use lgdtl instead to force operand size + * to 32 bit. + */ + + lidtl tidt # load idt with 0, 0 + lgdtl tgdt # load gdt with whatever is appropriate + + mov $X86_CR0_PE, %ax # protected mode (PE) bit + lmsw %ax # into protected mode + + # flush prefetch and jump to startup_32 + ljmpl *(startup_32_vector) + +no_longmode: + hlt + jmp no_longmode +#include "../kernel/verify_cpu.S" + + .code32 + .balign 4 +ENTRY(startup_32) + movl $__KERNEL_DS, %eax # Initialize the %ds segment register + movl %eax, %ds + + movl $X86_CR4_PAE, %eax + movl %eax, %cr4 # Enable PAE mode + + movl pa_startup_64_smp, %esi + movl pa_startup_64_smp_high, %edi + + # Setup trampoline 4 level pagetables + leal pa_trampoline_level4_pgt, %eax + movl %eax, %cr3 + + movl $MSR_EFER, %ecx + movl $(1 << _EFER_LME), %eax # Enable Long Mode + xorl %edx, %edx + wrmsr + + # Enable paging and in turn activate Long Mode + # Enable protected mode + movl $(X86_CR0_PG | X86_CR0_PE), %eax + movl %eax, %cr0 + + /* + * At this point we're in long mode but in 32bit compatibility mode + * with EFER.LME = 1, CS.L = 0, CS.D = 1 (and in turn + * EFER.LMA = 1). Now we want to jump in 64bit mode, to do that we use + * the new gdt/idt that has __KERNEL_CS with CS.L = 1. + */ + ljmpl *(pa_startup_64_vector) + + .code64 + .balign 4 +ENTRY(startup_64) + # Now jump into the kernel using virtual addresses + movl %edi, %eax + shlq $32, %rax + addl %esi, %eax + jmp *%rax + + # Careful these need to be in the same 64K segment as the above; +tidt: + .word 0 # idt limit = 0 + .word 0, 0 # idt base = 0L + + # Duplicate the global descriptor table + # so the kernel can live anywhere + .balign 4 + .globl tgdt +tgdt: + .short tgdt_end - tgdt # gdt limit + .long pa_tgdt + .short 0 + .quad 0x00cf9b000000ffff # __KERNEL32_CS + .quad 0x00af9b000000ffff # __KERNEL_CS + .quad 0x00cf93000000ffff # __KERNEL_DS +tgdt_end: + + .balign 4 +startup_32_vector: + .long pa_startup_32 + .word __KERNEL32_CS, 0 + + .balign 4 + .globl startup_64_vector +startup_64_vector: + .long pa_startup_64 + .word __KERNEL_CS, 0 + + .data + + .balign 4 +ENTRY(trampoline_status) + .long 0 + +trampoline_stack: + .org 0x1000 +trampoline_stack_end: + + .globl level3_ident_pgt + .globl level3_kernel_pgt +ENTRY(trampoline_level4_pgt) + level3_ident_pgt: .quad 0 + .fill 510,8,0 + level3_kernel_pgt: .quad 0 + + .globl startup_64_smp + .globl startup_64_smp_high +startup_64_smp: .long 0 +startup_64_smp_high: .long 0 -- cgit v1.1