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 <jarkko.sakkinen@intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-6-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Jarkko Sakkinen 2012-05-08 21:22:28 +03:00 committed by H. Peter Anvin
parent 5a8c9aebe0
commit 48927bbb97
9 changed files with 316 additions and 16 deletions

View File

@ -12,6 +12,17 @@ struct real_mode_header {
/* reboot */
#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__));
@ -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 */

View File

@ -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:
/*

View File

@ -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)

View File

@ -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
}
/*

View File

@ -57,7 +57,7 @@
#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/idle.h>
#include <asm/trampoline.h>
#include <asm/realmode.h>
#include <asm/cpu.h>
#include <asm/numa.h>
#include <asm/pgtable.h>
@ -73,6 +73,8 @@
#include <asm/smpboot_hooks.h>
#include <asm/i8259.h>
#include <asm/realmode.h>
/* 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) {
/*

View File

@ -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)

View File

@ -15,5 +15,16 @@ ENTRY(real_mode_header)
.long pa_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
#endif
END(real_mode_header)

View File

@ -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 <linux/linkage.h>
#include <linux/init.h>
#include <asm/segment.h>
#include <asm/page_types.h>
.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

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@ -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 <linux/linkage.h>
#include <linux/init.h>
#include <asm/pgtable_types.h>
#include <asm/page_types.h>
#include <asm/msr.h>
#include <asm/segment.h>
#include <asm/processor-flags.h>
.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