From f37240f16bec91f15ce564515f70a6ca9715ce96 Mon Sep 17 00:00:00 2001 From: Jarkko Sakkinen Date: Tue, 8 May 2012 21:22:43 +0300 Subject: [PATCH] x86, realmode: header for trampoline code Added header for trampoline code that can be used to supply input data to it. This makes interface between real mode code and kernel cleaner and simpler. Replaced two confusing pointers to level4 pgt in trampoline_64.S with a single pointer to the beginning of the page table. Signed-off-by: Jarkko Sakkinen Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/realmode.h | 32 +++++++++++++-------- arch/x86/kernel/realmode.c | 27 ++++++++++-------- arch/x86/kernel/smpboot.c | 2 +- arch/x86/realmode/rm/header.S | 35 +++++++++++------------ arch/x86/realmode/rm/trampoline_32.S | 36 ++++-------------------- arch/x86/realmode/rm/trampoline_64.S | 18 ++++-------- arch/x86/realmode/rm/trampoline_common.S | 23 +++++++++++++++ arch/x86/realmode/rm/wakeup_asm.S | 2 +- 8 files changed, 87 insertions(+), 88 deletions(-) create mode 100644 arch/x86/realmode/rm/trampoline_common.S diff --git a/arch/x86/include/asm/realmode.h b/arch/x86/include/asm/realmode.h index d3ae49f4c3ef..1421eed1c8e8 100644 --- a/arch/x86/include/asm/realmode.h +++ b/arch/x86/include/asm/realmode.h @@ -8,24 +8,32 @@ struct real_mode_header { u32 text_start; u32 ro_end; - /* reboot */ -#ifdef CONFIG_X86_32 - u32 machine_real_restart_asm; -#endif /* SMP trampoline */ - u32 trampoline_data; + u32 trampoline_start; 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; + u32 trampoline_header; +#ifdef CONFIG_X86_64 + u32 trampoline_pgd; #endif + /* ACPI S3 wakeup */ #ifdef CONFIG_ACPI_SLEEP u32 wakeup_start; u32 wakeup_header; +#endif + /* APM/BIOS reboot */ +#ifdef CONFIG_X86_32 + u32 machine_real_restart_asm; +#endif +} __attribute__((__packed__)); + +/* This must match data at trampoline_32/64.S */ +struct trampoline_header { +#ifdef CONFIG_X86_32 + u32 start; + u16 gdt_limit; + u32 gdt_base; +#else + u64 start; #endif } __attribute__((__packed__)); diff --git a/arch/x86/kernel/realmode.c b/arch/x86/kernel/realmode.c index 632c810ec8ea..712fba8fd774 100644 --- a/arch/x86/kernel/realmode.c +++ b/arch/x86/kernel/realmode.c @@ -17,8 +17,11 @@ void __init setup_real_mode(void) u16 *seg; int i; unsigned char *base; - + struct trampoline_header *trampoline_header; size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob); +#ifdef CONFIG_X86_64 + u64 *trampoline_pgd; +#endif /* Has to be in very low memory so we can execute real-mode AP code. */ mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE); @@ -28,7 +31,6 @@ void __init setup_real_mode(void) base = __va(mem); memblock_reserve(mem, size); real_mode_header = (struct real_mode_header *) base; - printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n", base, (unsigned long long)mem, size); @@ -53,18 +55,19 @@ void __init setup_real_mode(void) *ptr += __pa(base); } + /* Must be perfomed *after* relocation. */ + trampoline_header = (struct trampoline_header *) + __va(real_mode_header->trampoline_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); + trampoline_header->start = __pa(startup_32_smp); + trampoline_header->gdt_limit = __BOOT_DS + 7; + trampoline_header->gdt_base = __pa(boot_gdt); #else - *((u64 *) __va(real_mode_header->startup_64_smp)) = - (u64)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; + trampoline_header->start = (u64) secondary_startup_64; + trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd); + trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE; + trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE; #endif } diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index b8c0661e2341..757c4b1d0a02 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -667,7 +667,7 @@ 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 start_ip = real_mode_header->trampoline_start; unsigned long boot_error = 0; int timeout; diff --git a/arch/x86/realmode/rm/header.S b/arch/x86/realmode/rm/header.S index c83005c4d455..b4c32632bf16 100644 --- a/arch/x86/realmode/rm/header.S +++ b/arch/x86/realmode/rm/header.S @@ -7,28 +7,25 @@ #include #include - .section ".header", "a" + .section ".header", "a" GLOBAL(real_mode_header) - .long pa_text_start - .long pa_ro_end -#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 + .long pa_text_start + .long pa_ro_end + /* SMP trampoline */ + .long pa_trampoline_start + .long pa_trampoline_status + .long pa_trampoline_header +#ifdef CONFIG_X86_64 + .long pa_trampoline_pgd; #endif - /* ACPI sleep */ + /* ACPI S3 wakeup */ #ifdef CONFIG_ACPI_SLEEP - .long pa_wakeup_start - .long pa_wakeup_header + .long pa_wakeup_start + .long pa_wakeup_header +#endif + /* APM/BIOS reboot */ +#ifdef CONFIG_X86_32 + .long pa_machine_real_restart_asm #endif END(real_mode_header) diff --git a/arch/x86/realmode/rm/trampoline_32.S b/arch/x86/realmode/rm/trampoline_32.S index 1ecdbb59191b..6fc064b4d2b9 100644 --- a/arch/x86/realmode/rm/trampoline_32.S +++ b/arch/x86/realmode/rm/trampoline_32.S @@ -13,16 +13,10 @@ * * We jump into arch/x86/kernel/head_32.S. * - * On entry to trampoline_data, the processor is in real mode + * On entry to trampoline_start, 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 @@ -35,7 +29,7 @@ .code16 .balign PAGE_SIZE -ENTRY(trampoline_data) +ENTRY(trampoline_start) wbinvd # Needed for NUMA-Q should be harmless for others LJMPW_RM(1f) @@ -45,7 +39,7 @@ ENTRY(trampoline_data) cli # We should be safe anyway - movl startup_32_smp, %eax # where we need to go + movl tr_start, %eax # where we need to go movl $0xA5A5A5A5, trampoline_status # write marker for master knows we're running @@ -56,8 +50,8 @@ ENTRY(trampoline_data) * 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 + lidtl tr_idt # load idt with 0, 0 + lgdtl tr_gdt # load gdt with whatever is appropriate movw $1, %dx # protected mode (PE) bit lmsw %dx # into protected mode @@ -69,22 +63,4 @@ ENTRY(trampoline_data) ENTRY(startup_32) # note: also used from wakeup_asm.S jmp *%eax - .section ".rodata","a" - - .balign 4 -boot_idt_descr: - .word 0 # idt limit = 0 - .long 0 # idt base = 0L - - .data - -boot_gdt_descr: - .word __BOOT_DS + 7 # gdt limit -GLOBAL(boot_gdt) - .long 0 # gdt base - - .bss - - .balign 4 -GLOBAL(trampoline_status) .space 4 -GLOBAL(startup_32_smp) .space 4 +#include "trampoline_common.S" diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S index f71ea0800d3d..3f7293239365 100644 --- a/arch/x86/realmode/rm/trampoline_64.S +++ b/arch/x86/realmode/rm/trampoline_64.S @@ -10,7 +10,7 @@ * trampoline page to make our stack and everything else * is a mystery. * - * On entry to trampoline_data, the processor is in real mode + * On entry to trampoline_start, 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. @@ -37,7 +37,7 @@ .balign PAGE_SIZE .code16 -ENTRY(trampoline_data) +ENTRY(trampoline_start) cli # We should be safe anyway wbinvd @@ -97,7 +97,7 @@ ENTRY(startup_32) movl %eax, %cr4 # Enable PAE mode # Setup trampoline 4 level pagetables - movl $pa_level3_ident_pgt, %eax + movl $pa_trampoline_pgd, %eax movl %eax, %cr3 movl $MSR_EFER, %ecx @@ -122,7 +122,7 @@ ENTRY(startup_32) .balign 4 ENTRY(startup_64) # Now jump into the kernel using virtual addresses - jmpq *startup_64_smp(%rip) + jmpq *tr_start(%rip) .section ".rodata","a" .balign 16 @@ -143,12 +143,4 @@ tgdt: .quad 0x00cf93000000ffff # __KERNEL_DS tgdt_end: - .bss - - .balign PAGE_SIZE -GLOBAL(level3_ident_pgt) .space 511*8 -GLOBAL(level3_kernel_pgt) .space 8 - - .balign 8 -GLOBAL(startup_64_smp) .space 8 -GLOBAL(trampoline_status) .space 4 +#include "trampoline_common.S" diff --git a/arch/x86/realmode/rm/trampoline_common.S b/arch/x86/realmode/rm/trampoline_common.S new file mode 100644 index 000000000000..c3f951c468c5 --- /dev/null +++ b/arch/x86/realmode/rm/trampoline_common.S @@ -0,0 +1,23 @@ + .section ".rodata","a" + + .balign 4 +tr_idt: .fill 1, 6, 0 + + .bss + + .balign 4 +GLOBAL(trampoline_status) .space 4 + +GLOBAL(trampoline_header) +#ifdef CONFIG_X86_32 + tr_start: .space 4 + tr_gdt: .space 6 +#else + tr_start: .space 8 +#endif +END(trampoline_header) + +#ifdef CONFIG_X86_64 + .balign PAGE_SIZE +GLOBAL(trampoline_pgd) .space PAGE_SIZE +#endif diff --git a/arch/x86/realmode/rm/wakeup_asm.S b/arch/x86/realmode/rm/wakeup_asm.S index 8a57c5a05fbc..46108f05e04e 100644 --- a/arch/x86/realmode/rm/wakeup_asm.S +++ b/arch/x86/realmode/rm/wakeup_asm.S @@ -132,7 +132,7 @@ ENTRY(wakeup_start) ljmpl $__KERNEL_CS, $pa_startup_32 /* -> jmp *%eax in trampoline_32.S */ #else - jmp trampoline_data + jmp trampoline_start #endif bogus_real_magic: -- 2.20.1