[GIT PULL] x86/trampoline changes for v2.6.39

From: Ingo Molnar
Date: Wed Mar 16 2011 - 11:34:08 EST

Linus,

Please pull the latest x86-trampoline-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-trampoline-for-linus


out-of-topic modifications in x86-trampoline-for-linus:
-------------------------------------------------------
drivers/acpi/sleep.c # d1ee433: x86, trampoline: Use the unified

Thanks,

Ingo

------------------>
H. Peter Anvin (6):
x86, trampoline: Common infrastructure for low memory trampolines
x86, trampoline: Use the unified trampoline setup for ACPI wakeup
x86: Make the GDT_ENTRY() macro in <asm/segment.h> safe for assembly
x86, reboot: Move the real-mode reboot code to an assembly file
x86, reboot: Fix the use of passed arguments in 32-bit BIOS reboot
x86-64, trampoline: Remove unused variable

Sedat Dilek (1):
x86: Fix binutils-2.21 symbol related build failures


arch/x86/Kconfig | 4 -
arch/x86/include/asm/acpi.h | 4 +-
arch/x86/include/asm/reboot.h | 5 +-
arch/x86/include/asm/segment.h | 12 ++-
arch/x86/include/asm/trampoline.h | 33 +++++---
arch/x86/kernel/Makefile | 4 +-
arch/x86/kernel/acpi/realmode/wakeup.S | 21 +++--
arch/x86/kernel/acpi/realmode/wakeup.h | 5 +-
arch/x86/kernel/acpi/realmode/wakeup.lds.S | 28 +++---
arch/x86/kernel/acpi/sleep.c | 65 ++------------
arch/x86/kernel/acpi/sleep.h | 3 -
arch/x86/kernel/acpi/wakeup_rm.S | 12 ++-
arch/x86/kernel/apm_32.c | 12 +---
arch/x86/kernel/entry_32.S | 2 +-
arch/x86/kernel/head32.c | 9 --
arch/x86/kernel/head_64.S | 3 +-
arch/x86/kernel/reboot.c | 120 +++++-------------------
arch/x86/kernel/reboot_32.S | 135 ++++++++++++++++++++++++++++
arch/x86/kernel/setup.c | 9 +--
arch/x86/kernel/smpboot.c | 10 ++-
arch/x86/kernel/trampoline.c | 42 +++++----
arch/x86/kernel/trampoline_32.S | 15 +++-
arch/x86/kernel/trampoline_64.S | 28 ++++---
arch/x86/kernel/vmlinux.lds.S | 13 +++
drivers/acpi/sleep.c | 1 +
25 files changed, 315 insertions(+), 280 deletions(-)
create mode 100644 arch/x86/kernel/reboot_32.S

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d5ed94d..1359bc9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -217,10 +217,6 @@ config X86_HT
def_bool y
depends on SMP

-config X86_TRAMPOLINE
- def_bool y
- depends on SMP || (64BIT && ACPI_SLEEP)
-
config X86_32_LAZY_GS
def_bool y
depends on X86_32 && !CC_STACKPROTECTOR
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 211ca3f..4784df5 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -29,6 +29,7 @@
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/mpspec.h>
+#include <asm/trampoline.h>

#define COMPILER_DEPENDENT_INT64 long long
#define COMPILER_DEPENDENT_UINT64 unsigned long long
@@ -116,7 +117,8 @@ static inline void acpi_disable_pci(void)
extern int acpi_save_state_mem(void);
extern void acpi_restore_state_mem(void);

-extern unsigned long acpi_wakeup_address;
+extern const unsigned char acpi_wakeup_code[];
+#define acpi_wakeup_address (__pa(TRAMPOLINE_SYM(acpi_wakeup_code)))

/* early initialization routine */
extern void acpi_reserve_wakeup_memory(void);
diff --git a/arch/x86/include/asm/reboot.h b/arch/x86/include/asm/reboot.h
index 562d4fd..3250e3d 100644
--- a/arch/x86/include/asm/reboot.h
+++ b/arch/x86/include/asm/reboot.h
@@ -18,7 +18,10 @@ extern struct machine_ops machine_ops;

void native_machine_crash_shutdown(struct pt_regs *regs);
void native_machine_shutdown(void);
-void machine_real_restart(const unsigned char *code, int length);
+void machine_real_restart(unsigned int type);
+/* These must match dispatch_table in reboot_32.S */
+#define MRR_BIOS 0
+#define MRR_APM 1

typedef void (*nmi_shootdown_cb)(int, struct die_args*);
void nmi_shootdown_cpus(nmi_shootdown_cb callback);
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 231f1c1..cd84f72 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -1,14 +1,16 @@
#ifndef _ASM_X86_SEGMENT_H
#define _ASM_X86_SEGMENT_H

+#include <linux/const.h>
+
/* Constructor for a conventional segment GDT (or LDT) entry */
/* This is a macro so it can be used in initializers */
#define GDT_ENTRY(flags, base, limit) \
- ((((base) & 0xff000000ULL) << (56-24)) | \
- (((flags) & 0x0000f0ffULL) << 40) | \
- (((limit) & 0x000f0000ULL) << (48-16)) | \
- (((base) & 0x00ffffffULL) << 16) | \
- (((limit) & 0x0000ffffULL)))
+ ((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
+ (((flags) & _AC(0x0000f0ff,ULL)) << 40) | \
+ (((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \
+ (((base) & _AC(0x00ffffff,ULL)) << 16) | \
+ (((limit) & _AC(0x0000ffff,ULL))))

/* Simple and small GDT entries for booting only */

diff --git a/arch/x86/include/asm/trampoline.h b/arch/x86/include/asm/trampoline.h
index f4500fb..feca311 100644
--- a/arch/x86/include/asm/trampoline.h
+++ b/arch/x86/include/asm/trampoline.h
@@ -3,25 +3,36 @@

#ifndef __ASSEMBLY__

-#ifdef CONFIG_X86_TRAMPOLINE
+#include <linux/types.h>
+#include <asm/io.h>
+
/*
- * Trampoline 80x86 program as an array.
+ * Trampoline 80x86 program as an array. These are in the init rodata
+ * segment, but that's okay, because we only care about the relative
+ * addresses of the symbols.
*/
-extern const unsigned char trampoline_data [];
-extern const unsigned char trampoline_end [];
-extern unsigned char *trampoline_base;
+extern const unsigned char x86_trampoline_start [];
+extern const unsigned char x86_trampoline_end [];
+extern unsigned char *x86_trampoline_base;

extern unsigned long init_rsp;
extern unsigned long initial_code;
extern unsigned long initial_gs;

-#define TRAMPOLINE_SIZE roundup(trampoline_end - trampoline_data, PAGE_SIZE)
+extern void __init setup_trampolines(void);
+
+extern const unsigned char trampoline_data[];
+extern const unsigned char trampoline_status[];
+
+#define TRAMPOLINE_SYM(x) \
+ ((void *)(x86_trampoline_base + \
+ ((const unsigned char *)(x) - x86_trampoline_start)))

-extern unsigned long setup_trampoline(void);
-extern void __init reserve_trampoline_memory(void);
-#else
-static inline void reserve_trampoline_memory(void) {}
-#endif /* CONFIG_X86_TRAMPOLINE */
+/* Address of the SMP trampoline */
+static inline unsigned long trampoline_address(void)
+{
+ return virt_to_phys(TRAMPOLINE_SYM(trampoline_data));
+}

#endif /* __ASSEMBLY__ */

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 34244b2..778c5b93 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -47,7 +47,7 @@ obj-y += tsc.o io_delay.o rtc.o
obj-y += pci-iommu_table.o
obj-y += resource.o

-obj-$(CONFIG_X86_TRAMPOLINE) += trampoline.o
+obj-y += trampoline.o trampoline_$(BITS).o
obj-y += process.o
obj-y += i387.o xsave.o
obj-y += ptrace.o
@@ -59,6 +59,7 @@ obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += cpu/
obj-y += acpi/
obj-y += reboot.o
+obj-$(CONFIG_X86_32) += reboot_32.o
obj-$(CONFIG_MCA) += mca_32.o
obj-$(CONFIG_X86_MSR) += msr.o
obj-$(CONFIG_X86_CPUID) += cpuid.o
@@ -69,7 +70,6 @@ obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_SMP) += smpboot.o tsc_sync.o
obj-$(CONFIG_SMP) += setup_percpu.o
obj-$(CONFIG_X86_64_SMP) += tsc_sync.o
-obj-$(CONFIG_X86_TRAMPOLINE) += trampoline_$(BITS).o
obj-$(CONFIG_X86_MPPARSE) += mpparse.o
obj-y += apic/
obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.S b/arch/x86/kernel/acpi/realmode/wakeup.S
index 28595d6..ead21b6 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.S
+++ b/arch/x86/kernel/acpi/realmode/wakeup.S
@@ -6,11 +6,17 @@
#include <asm/page_types.h>
#include <asm/pgtable_types.h>
#include <asm/processor-flags.h>
+#include "wakeup.h"

.code16
- .section ".header", "a"
+ .section ".jump", "ax"
+ .globl _start
+_start:
+ cli
+ jmp wakeup_code

/* This should match the structure in wakeup.h */
+ .section ".header", "a"
.globl wakeup_header
wakeup_header:
video_mode: .short 0 /* Video mode number */
@@ -30,14 +36,11 @@ wakeup_jmp: .byte 0xea /* ljmpw */
wakeup_jmp_off: .word 3f
wakeup_jmp_seg: .word 0
wakeup_gdt: .quad 0, 0, 0
-signature: .long 0x51ee1111
+signature: .long WAKEUP_HEADER_SIGNATURE

.text
- .globl _start
.code16
wakeup_code:
-_start:
- cli
cld

/* Apparently some dimwit BIOS programmers don't know how to
@@ -77,12 +80,12 @@ _start:

/* Check header signature... */
movl signature, %eax
- cmpl $0x51ee1111, %eax
+ cmpl $WAKEUP_HEADER_SIGNATURE, %eax
jne bogus_real_magic

/* Check we really have everything... */
movl end_signature, %eax
- cmpl $0x65a22c82, %eax
+ cmpl $WAKEUP_END_SIGNATURE, %eax
jne bogus_real_magic

/* Call the C code */
@@ -147,3 +150,7 @@ wakeup_heap:
wakeup_stack:
.space 2048
wakeup_stack_end:
+
+ .section ".signature","a"
+end_signature:
+ .long WAKEUP_END_SIGNATURE
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.h b/arch/x86/kernel/acpi/realmode/wakeup.h
index 69d38d0..e1828c0 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.h
+++ b/arch/x86/kernel/acpi/realmode/wakeup.h
@@ -35,7 +35,8 @@ struct wakeup_header {
extern struct wakeup_header wakeup_header;
#endif

-#define HEADER_OFFSET 0x3f00
-#define WAKEUP_SIZE 0x4000
+#define WAKEUP_HEADER_OFFSET 8
+#define WAKEUP_HEADER_SIGNATURE 0x51ee1111
+#define WAKEUP_END_SIGNATURE 0x65a22c82

#endif /* ARCH_X86_KERNEL_ACPI_RM_WAKEUP_H */
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.lds.S b/arch/x86/kernel/acpi/realmode/wakeup.lds.S
index 060fff8..d4f8010 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.lds.S
+++ b/arch/x86/kernel/acpi/realmode/wakeup.lds.S
@@ -13,9 +13,19 @@ ENTRY(_start)
SECTIONS
{
. = 0;
+ .jump : {
+ *(.jump)
+ } = 0x90909090
+
+ . = WAKEUP_HEADER_OFFSET;
+ .header : {
+ *(.header)
+ }
+
+ . = ALIGN(16);
.text : {
*(.text*)
- }
+ } = 0x90909090

. = ALIGN(16);
.rodata : {
@@ -33,11 +43,6 @@ SECTIONS
*(.data*)
}

- .signature : {
- end_signature = .;
- LONG(0x65a22c82)
- }
-
. = ALIGN(16);
.bss : {
__bss_start = .;
@@ -45,20 +50,13 @@ SECTIONS
__bss_end = .;
}

- . = HEADER_OFFSET;
- .header : {
- *(.header)
+ .signature : {
+ *(.signature)
}

- . = ALIGN(16);
_end = .;

/DISCARD/ : {
*(.note*)
}
-
- /*
- * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility:
- */
- . = ASSERT(_end <= WAKEUP_SIZE, "Wakeup too big!");
}
diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c
index 68d1537..4572c58 100644
--- a/arch/x86/kernel/acpi/sleep.c
+++ b/arch/x86/kernel/acpi/sleep.c
@@ -18,12 +18,8 @@
#include "realmode/wakeup.h"
#include "sleep.h"

-unsigned long acpi_wakeup_address;
unsigned long acpi_realmode_flags;

-/* address in low memory of the wakeup routine. */
-static unsigned long acpi_realmode;
-
#if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
static char temp_stack[4096];
#endif
@@ -33,22 +29,17 @@ static char temp_stack[4096];
*
* Create an identity mapped page table and copy the wakeup routine to
* low memory.
- *
- * Note that this is too late to change acpi_wakeup_address.
*/
int acpi_save_state_mem(void)
{
struct wakeup_header *header;
+ /* address in low memory of the wakeup routine. */
+ char *acpi_realmode;

- if (!acpi_realmode) {
- printk(KERN_ERR "Could not allocate memory during boot, "
- "S3 disabled\n");
- return -ENOMEM;
- }
- memcpy((void *)acpi_realmode, &wakeup_code_start, WAKEUP_SIZE);
+ acpi_realmode = TRAMPOLINE_SYM(acpi_wakeup_code);

- header = (struct wakeup_header *)(acpi_realmode + HEADER_OFFSET);
- if (header->signature != 0x51ee1111) {
+ header = (struct wakeup_header *)(acpi_realmode + WAKEUP_HEADER_OFFSET);
+ if (header->signature != WAKEUP_HEADER_SIGNATURE) {
printk(KERN_ERR "wakeup header does not match\n");
return -EINVAL;
}
@@ -68,9 +59,7 @@ int acpi_save_state_mem(void)
/* GDT[0]: GDT self-pointer */
header->wakeup_gdt[0] =
(u64)(sizeof(header->wakeup_gdt) - 1) +
- ((u64)(acpi_wakeup_address +
- ((char *)&header->wakeup_gdt - (char *)acpi_realmode))
- << 16);
+ ((u64)__pa(&header->wakeup_gdt) << 16);
/* GDT[1]: big real mode-like code segment */
header->wakeup_gdt[1] =
GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
@@ -96,7 +85,7 @@ int acpi_save_state_mem(void)
header->pmode_cr3 = (u32)__pa(&initial_page_table);
saved_magic = 0x12345678;
#else /* CONFIG_64BIT */
- header->trampoline_segment = setup_trampoline() >> 4;
+ header->trampoline_segment = trampoline_address() >> 4;
#ifdef CONFIG_SMP
stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
early_gdt_descr.address =
@@ -117,46 +106,6 @@ void acpi_restore_state_mem(void)
{
}

-
-/**
- * acpi_reserve_wakeup_memory - do _very_ early ACPI initialisation
- *
- * We allocate a page from the first 1MB of memory for the wakeup
- * routine for when we come back from a sleep state. The
- * runtime allocator allows specification of <16MB pages, but not
- * <1MB pages.
- */
-void __init acpi_reserve_wakeup_memory(void)
-{
- phys_addr_t mem;
-
- if ((&wakeup_code_end - &wakeup_code_start) > WAKEUP_SIZE) {
- printk(KERN_ERR
- "ACPI: Wakeup code way too big, S3 disabled.\n");
- return;
- }
-
- mem = memblock_find_in_range(0, 1<<20, WAKEUP_SIZE, PAGE_SIZE);
-
- if (mem == MEMBLOCK_ERROR) {
- printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
- return;
- }
- acpi_realmode = (unsigned long) phys_to_virt(mem);
- acpi_wakeup_address = mem;
- memblock_x86_reserve_range(mem, mem + WAKEUP_SIZE, "ACPI WAKEUP");
-}
-
-int __init acpi_configure_wakeup_memory(void)
-{
- if (acpi_realmode)
- set_memory_x(acpi_realmode, WAKEUP_SIZE >> PAGE_SHIFT);
-
- return 0;
-}
-arch_initcall(acpi_configure_wakeup_memory);
-
-
static int __init acpi_sleep_setup(char *str)
{
while ((str != NULL) && (*str != '\0')) {
diff --git a/arch/x86/kernel/acpi/sleep.h b/arch/x86/kernel/acpi/sleep.h
index adbcbaa..86ba1c8 100644
--- a/arch/x86/kernel/acpi/sleep.h
+++ b/arch/x86/kernel/acpi/sleep.h
@@ -4,13 +4,10 @@

#include <asm/trampoline.h>

-extern char wakeup_code_start, wakeup_code_end;
-
extern unsigned long saved_video_mode;
extern long saved_magic;

extern int wakeup_pmode_return;
-extern char swsusp_pg_dir[PAGE_SIZE];

extern unsigned long acpi_copy_wakeup_routine(unsigned long);
extern void wakeup_long64(void);
diff --git a/arch/x86/kernel/acpi/wakeup_rm.S b/arch/x86/kernel/acpi/wakeup_rm.S
index 6ff3b57..63b8ab5 100644
--- a/arch/x86/kernel/acpi/wakeup_rm.S
+++ b/arch/x86/kernel/acpi/wakeup_rm.S
@@ -2,9 +2,11 @@
* Wrapper script for the realmode binary as a transport object
* before copying to low memory.
*/
- .section ".rodata","a"
- .globl wakeup_code_start, wakeup_code_end
-wakeup_code_start:
+#include <asm/page_types.h>
+
+ .section ".x86_trampoline","a"
+ .balign PAGE_SIZE
+ .globl acpi_wakeup_code
+acpi_wakeup_code:
.incbin "arch/x86/kernel/acpi/realmode/wakeup.bin"
-wakeup_code_end:
- .size wakeup_code_start, .-wakeup_code_start
+ .size acpi_wakeup_code, .-acpi_wakeup_code
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index 0e4f24c..b929108 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -975,20 +975,10 @@ recalc:

static void apm_power_off(void)
{
- unsigned char po_bios_call[] = {
- 0xb8, 0x00, 0x10, /* movw $0x1000,ax */
- 0x8e, 0xd0, /* movw ax,ss */
- 0xbc, 0x00, 0xf0, /* movw $0xf000,sp */
- 0xb8, 0x07, 0x53, /* movw $0x5307,ax */
- 0xbb, 0x01, 0x00, /* movw $0x0001,bx */
- 0xb9, 0x03, 0x00, /* movw $0x0003,cx */
- 0xcd, 0x15 /* int $0x15 */
- };
-
/* Some bioses don't like being called from CPU != 0 */
if (apm_info.realmode_power_off) {
set_cpus_allowed_ptr(current, cpumask_of(0));
- machine_real_restart(po_bios_call, sizeof(po_bios_call));
+ machine_real_restart(MRR_APM);
} else {
(void)set_system_power_state(APM_STATE_OFF);
}
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index c8b4efa..9ca3b0e 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1413,7 +1413,7 @@ ENTRY(async_page_fault)
CFI_ADJUST_CFA_OFFSET 4
jmp error_code
CFI_ENDPROC
-END(apf_page_fault)
+END(async_page_fault)
#endif

/*
diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 7f138b3..d6d6bb3 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -34,15 +34,6 @@ void __init i386_start_kernel(void)
{
memblock_init();

-#ifdef CONFIG_X86_TRAMPOLINE
- /*
- * But first pinch a few for the stack/trampoline stuff
- * FIXME: Don't need the extra page at 4K, but need to fix
- * trampoline before removing it. (see the GDT stuff)
- */
- memblock_x86_reserve_range(PAGE_SIZE, PAGE_SIZE + PAGE_SIZE, "EX TRAMPOLINE");
-#endif
-
memblock_x86_reserve_range(__pa_symbol(&_text), __pa_symbol(&__bss_stop), "TEXT DATA BSS");

#ifdef CONFIG_BLK_DEV_INITRD
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 239046b..e11e394 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -136,10 +136,9 @@ ident_complete:
/* Fixup phys_base */
addq %rbp, phys_base(%rip)

-#ifdef CONFIG_X86_TRAMPOLINE
+ /* Fixup trampoline */
addq %rbp, trampoline_level4_pgt + 0(%rip)
addq %rbp, trampoline_level4_pgt + (511*8)(%rip)
-#endif

/* Due to ENTRY(), sometimes the empty space gets filled with
* zeros. Better take a jmp than relying on empty space being
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index fc7aae1..10c6619 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -295,68 +295,16 @@ static int __init reboot_init(void)
}
core_initcall(reboot_init);

-/* The following code and data reboots the machine by switching to real
- mode and jumping to the BIOS reset entry point, as if the CPU has
- really been reset. The previous version asked the keyboard
- controller to pulse the CPU reset line, which is more thorough, but
- doesn't work with at least one type of 486 motherboard. It is easy
- to stop this code working; hence the copious comments. */
-static const unsigned long long
-real_mode_gdt_entries [3] =
-{
- 0x0000000000000000ULL, /* Null descriptor */
- 0x00009b000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
- 0x000093000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
-};
+extern const unsigned char machine_real_restart_asm[];
+extern const u64 machine_real_restart_gdt[3];

-static const struct desc_ptr
-real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
-real_mode_idt = { 0x3ff, 0 };
-
-/* This is 16-bit protected mode code to disable paging and the cache,
- switch to real mode and jump to the BIOS reset code.
-
- The instruction that switches to real mode by writing to CR0 must be
- followed immediately by a far jump instruction, which set CS to a
- valid value for real mode, and flushes the prefetch queue to avoid
- running instructions that have already been decoded in protected
- mode.
-
- Clears all the flags except ET, especially PG (paging), PE
- (protected-mode enable) and TS (task switch for coprocessor state
- save). Flushes the TLB after paging has been disabled. Sets CD and
- NW, to disable the cache on a 486, and invalidates the cache. This
- is more like the state of a 486 after reset. I don't know if
- something else should be done for other chips.
-
- More could be done here to set up the registers as if a CPU reset had
- occurred; hopefully real BIOSs don't assume much. */
-static const unsigned char real_mode_switch [] =
-{
- 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
- 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
- 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
- 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
- 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
- 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
- 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
- 0x74, 0x02, /* jz f */
- 0x0f, 0x09, /* wbinvd */
- 0x24, 0x10, /* f: andb $0x10,al */
- 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
-};
-static const unsigned char jump_to_bios [] =
+void machine_real_restart(unsigned int type)
{
- 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
-};
+ void *restart_va;
+ unsigned long restart_pa;
+ void (*restart_lowmem)(unsigned int);
+ u64 *lowmem_gdt;

-/*
- * Switch to real mode and then execute the code
- * specified by the code and length parameters.
- * We assume that length will aways be less that 100!
- */
-void machine_real_restart(const unsigned char *code, int length)
-{
local_irq_disable();

/* Write zero to CMOS register number 0x0f, which the BIOS POST
@@ -384,41 +332,23 @@ void machine_real_restart(const unsigned char *code, int length)
too. */
*((unsigned short *)0x472) = reboot_mode;

- /* For the switch to real mode, copy some code to low memory. It has
- to be in the first 64k because it is running in 16-bit mode, and it
- has to have the same physical and virtual address, because it turns
- off paging. Copy it near the end of the first page, out of the way
- of BIOS variables. */
- memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
- real_mode_switch, sizeof (real_mode_switch));
- memcpy((void *)(0x1000 - 100), code, length);
-
- /* Set up the IDT for real mode. */
- load_idt(&real_mode_idt);
-
- /* Set up a GDT from which we can load segment descriptors for real
- mode. The GDT is not used in real mode; it is just needed here to
- prepare the descriptors. */
- load_gdt(&real_mode_gdt);
-
- /* Load the data segment registers, and thus the descriptors ready for
- real mode. The base address of each segment is 0x100, 16 times the
- selector value being loaded here. This is so that the segment
- registers don't have to be reloaded after switching to real mode:
- the values are consistent for real mode operation already. */
- __asm__ __volatile__ ("movl $0x0010,%%eax\n"
- "\tmovl %%eax,%%ds\n"
- "\tmovl %%eax,%%es\n"
- "\tmovl %%eax,%%fs\n"
- "\tmovl %%eax,%%gs\n"
- "\tmovl %%eax,%%ss" : : : "eax");
-
- /* Jump to the 16-bit code that we copied earlier. It disables paging
- and the cache, switches to real mode, and jumps to the BIOS reset
- entry point. */
- __asm__ __volatile__ ("ljmp $0x0008,%0"
- :
- : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
+ /* Patch the GDT in the low memory trampoline */
+ lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
+
+ restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
+ restart_pa = virt_to_phys(restart_va);
+ restart_lowmem = (void (*)(unsigned int))restart_pa;
+
+ /* GDT[0]: GDT self-pointer */
+ lowmem_gdt[0] =
+ (u64)(sizeof(machine_real_restart_gdt) - 1) +
+ ((u64)virt_to_phys(lowmem_gdt) << 16);
+ /* GDT[1]: 64K real mode code segment */
+ lowmem_gdt[1] =
+ GDT_ENTRY(0x009b, restart_pa, 0xffff);
+
+ /* Jump to the identity-mapped low memory code */
+ restart_lowmem(type);
}
#ifdef CONFIG_APM_MODULE
EXPORT_SYMBOL(machine_real_restart);
@@ -573,7 +503,7 @@ static void native_machine_emergency_restart(void)

#ifdef CONFIG_X86_32
case BOOT_BIOS:
- machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
+ machine_real_restart(MRR_BIOS);

reboot_type = BOOT_KBD;
break;
diff --git a/arch/x86/kernel/reboot_32.S b/arch/x86/kernel/reboot_32.S
new file mode 100644
index 0000000..29092b3
--- /dev/null
+++ b/arch/x86/kernel/reboot_32.S
@@ -0,0 +1,135 @@
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/segment.h>
+#include <asm/page_types.h>
+
+/*
+ * The following code and data reboots the machine by switching to real
+ * mode and jumping to the BIOS reset entry point, as if the CPU has
+ * really been reset. The previous version asked the keyboard
+ * controller to pulse the CPU reset line, which is more thorough, but
+ * doesn't work with at least one type of 486 motherboard. It is easy
+ * to stop this code working; hence the copious comments.
+ *
+ * This code is called with the restart type (0 = BIOS, 1 = APM) in %eax.
+ */
+ .section ".x86_trampoline","a"
+ .balign 16
+ .code32
+ENTRY(machine_real_restart_asm)
+r_base = .
+ /* Get our own relocated address */
+ call 1f
+1: popl %ebx
+ subl $1b, %ebx
+
+ /* Compute the equivalent real-mode segment */
+ movl %ebx, %ecx
+ shrl $4, %ecx
+
+ /* Patch post-real-mode segment jump */
+ movw dispatch_table(%ebx,%eax,2),%ax
+ movw %ax, 101f(%ebx)
+ movw %cx, 102f(%ebx)
+
+ /* Set up the IDT for real mode. */
+ lidtl machine_real_restart_idt(%ebx)
+
+ /*
+ * Set up a GDT from which we can load segment descriptors for real
+ * mode. The GDT is not used in real mode; it is just needed here to
+ * prepare the descriptors.
+ */
+ lgdtl machine_real_restart_gdt(%ebx)
+
+ /*
+ * Load the data segment registers with 16-bit compatible values
+ */
+ movl $16, %ecx
+ movl %ecx, %ds
+ movl %ecx, %es
+ movl %ecx, %fs
+ movl %ecx, %gs
+ movl %ecx, %ss
+ ljmpl $8, $1f - r_base
+
+/*
+ * This is 16-bit protected mode code to disable paging and the cache,
+ * switch to real mode and jump to the BIOS reset code.
+ *
+ * The instruction that switches to real mode by writing to CR0 must be
+ * followed immediately by a far jump instruction, which set CS to a
+ * valid value for real mode, and flushes the prefetch queue to avoid
+ * running instructions that have already been decoded in protected
+ * mode.
+ *
+ * Clears all the flags except ET, especially PG (paging), PE
+ * (protected-mode enable) and TS (task switch for coprocessor state
+ * save). Flushes the TLB after paging has been disabled. Sets CD and
+ * NW, to disable the cache on a 486, and invalidates the cache. This
+ * is more like the state of a 486 after reset. I don't know if
+ * something else should be done for other chips.
+ *
+ * More could be done here to set up the registers as if a CPU reset had
+ * occurred; hopefully real BIOSs don't assume much. This is not the
+ * actual BIOS entry point, anyway (that is at 0xfffffff0).
+ *
+ * Most of this work is probably excessive, but it is what is tested.
+ */
+ .code16
+1:
+ xorl %ecx, %ecx
+ movl %cr0, %eax
+ andl $0x00000011, %eax
+ orl $0x60000000, %eax
+ movl %eax, %cr0
+ movl %ecx, %cr3
+ movl %cr0, %edx
+ andl $0x60000000, %edx /* If no cache bits -> no wbinvd */
+ jz 2f
+ wbinvd
+2:
+ andb $0x10, %al
+ movl %eax, %cr0
+ .byte 0xea /* ljmpw */
+101: .word 0 /* Offset */
+102: .word 0 /* Segment */
+
+bios:
+ ljmpw $0xf000, $0xfff0
+
+apm:
+ movw $0x1000, %ax
+ movw %ax, %ss
+ movw $0xf000, %sp
+ movw $0x5307, %ax
+ movw $0x0001, %bx
+ movw $0x0003, %cx
+ int $0x15
+
+END(machine_real_restart_asm)
+
+ .balign 16
+ /* These must match <asm/reboot.h */
+dispatch_table:
+ .word bios - r_base
+ .word apm - r_base
+END(dispatch_table)
+
+ .balign 16
+machine_real_restart_idt:
+ .word 0xffff /* Length - real mode default value */
+ .long 0 /* Base - real mode default value */
+END(machine_real_restart_idt)
+
+ .balign 16
+ENTRY(machine_real_restart_gdt)
+ .quad 0 /* Self-pointer, filled in by PM code */
+ .quad 0 /* 16-bit code segment, filled in by PM code */
+ /*
+ * 16-bit data segment with the selector value 16 = 0x10 and
+ * base value 0x100; since this is consistent with real mode
+ * semantics we don't have to reload the segments once CR0.PE = 0.
+ */
+ .quad GDT_ENTRY(0x0093, 0x100, 0xffff)
+END(machine_real_restart_gdt)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index d3cfe26..a089fc1 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -935,15 +935,8 @@ void __init setup_arch(char **cmdline_p)
printk(KERN_DEBUG "initial memory mapped : 0 - %08lx\n",
max_pfn_mapped<<PAGE_SHIFT);

- reserve_trampoline_memory();
+ setup_trampolines();

-#ifdef CONFIG_ACPI_SLEEP
- /*
- * Reserve low memory region for sleep support.
- * even before init_memory_mapping
- */
- acpi_reserve_wakeup_memory();
-#endif
init_gbpages();

/* max_pfn_mapped is updated here */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 08776a9..5452733 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -788,7 +788,7 @@ do_rest:
stack_start = c_idle.idle->thread.sp;

/* start_ip had better be page-aligned! */
- start_ip = setup_trampoline();
+ start_ip = trampoline_address();

/* So we see what's up */
announce_cpu(cpu, apicid);
@@ -798,6 +798,8 @@ do_rest:
* the targeted processor.
*/

+ printk(KERN_DEBUG "smpboot cpu %d: start_ip = %lx\n", cpu, start_ip);
+
atomic_set(&init_deasserted, 0);

if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
@@ -851,8 +853,8 @@ do_rest:
pr_debug("CPU%d: has booted.\n", cpu);
else {
boot_error = 1;
- if (*((volatile unsigned char *)trampoline_base)
- == 0xA5)
+ if (*(volatile u32 *)TRAMPOLINE_SYM(trampoline_status)
+ == 0xA5A5A5A5)
/* trampoline started but...? */
pr_err("CPU%d: Stuck ??\n", cpu);
else
@@ -878,7 +880,7 @@ do_rest:
}

/* mark "stuck" area as not stuck */
- *((volatile unsigned long *)trampoline_base) = 0;
+ *(volatile u32 *)TRAMPOLINE_SYM(trampoline_status) = 0;

if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
/*
diff --git a/arch/x86/kernel/trampoline.c b/arch/x86/kernel/trampoline.c
index a375616..a91ae77 100644
--- a/arch/x86/kernel/trampoline.c
+++ b/arch/x86/kernel/trampoline.c
@@ -2,39 +2,41 @@
#include <linux/memblock.h>

#include <asm/trampoline.h>
+#include <asm/cacheflush.h>
#include <asm/pgtable.h>

-#if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
-#define __trampinit
-#define __trampinitdata
-#else
-#define __trampinit __cpuinit
-#define __trampinitdata __cpuinitdata
-#endif
+unsigned char *x86_trampoline_base;

-/* ready for x86_64 and x86 */
-unsigned char *__trampinitdata trampoline_base;
-
-void __init reserve_trampoline_memory(void)
+void __init setup_trampolines(void)
{
phys_addr_t mem;
+ size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);

/* Has to be in very low memory so we can execute real-mode AP code. */
- mem = memblock_find_in_range(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE);
+ mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
if (mem == MEMBLOCK_ERROR)
panic("Cannot allocate trampoline\n");

- trampoline_base = __va(mem);
- memblock_x86_reserve_range(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE");
+ x86_trampoline_base = __va(mem);
+ memblock_x86_reserve_range(mem, mem + size, "TRAMPOLINE");
+
+ printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
+ x86_trampoline_base, (unsigned long long)mem, size);
+
+ memcpy(x86_trampoline_base, x86_trampoline_start, size);
}

/*
- * Currently trivial. Write the real->protected mode
- * bootstrap into the page concerned. The caller
- * has made sure it's suitably aligned.
+ * setup_trampolines() gets called very early, to guarantee the
+ * availability of low memory. This is before the proper kernel page
+ * tables are set up, so we cannot set page permissions in that
+ * function. Thus, we use an arch_initcall instead.
*/
-unsigned long __trampinit setup_trampoline(void)
+static int __init configure_trampolines(void)
{
- memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
- return virt_to_phys(trampoline_base);
+ size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);
+
+ set_memory_x((unsigned long)x86_trampoline_base, size >> PAGE_SHIFT);
+ return 0;
}
+arch_initcall(configure_trampolines);
diff --git a/arch/x86/kernel/trampoline_32.S b/arch/x86/kernel/trampoline_32.S
index 8508237..451c0a7 100644
--- a/arch/x86/kernel/trampoline_32.S
+++ b/arch/x86/kernel/trampoline_32.S
@@ -32,9 +32,11 @@
#include <asm/segment.h>
#include <asm/page_types.h>

-/* We can free up trampoline after bootup if cpu hotplug is not supported. */
-__CPUINITRODATA
-.code16
+#ifdef CONFIG_SMP
+
+ .section ".x86_trampoline","a"
+ .balign PAGE_SIZE
+ .code16

ENTRY(trampoline_data)
r_base = .
@@ -44,7 +46,7 @@ r_base = .

cli # We should be safe anyway

- movl $0xA5A5A5A5, trampoline_data - r_base
+ movl $0xA5A5A5A5, trampoline_status - r_base
# write marker for master knows we're running

/* GDT tables in non default location kernel can be beyond 16MB and
@@ -72,5 +74,10 @@ boot_idt_descr:
.word 0 # idt limit = 0
.long 0 # idt base = 0L

+ENTRY(trampoline_status)
+ .long 0
+
.globl trampoline_end
trampoline_end:
+
+#endif /* CONFIG_SMP */
diff --git a/arch/x86/kernel/trampoline_64.S b/arch/x86/kernel/trampoline_64.S
index 075d130..09ff517 100644
--- a/arch/x86/kernel/trampoline_64.S
+++ b/arch/x86/kernel/trampoline_64.S
@@ -32,13 +32,9 @@
#include <asm/segment.h>
#include <asm/processor-flags.h>

-#ifdef CONFIG_ACPI_SLEEP
-.section .rodata, "a", @progbits
-#else
-/* We can free up the trampoline after bootup if cpu hotplug is not supported. */
-__CPUINITRODATA
-#endif
-.code16
+ .section ".x86_trampoline","a"
+ .balign PAGE_SIZE
+ .code16

ENTRY(trampoline_data)
r_base = .
@@ -50,7 +46,7 @@ r_base = .
mov %ax, %ss


- movl $0xA5A5A5A5, trampoline_data - r_base
+ movl $0xA5A5A5A5, trampoline_status - r_base
# write marker for master knows we're running

# Setup stack
@@ -64,10 +60,13 @@ r_base = .
movzx %ax, %esi # Find the 32bit trampoline location
shll $4, %esi

- # Fixup the vectors
- addl %esi, startup_32_vector - r_base
- addl %esi, startup_64_vector - r_base
- addl %esi, tgdt + 2 - r_base # Fixup the gdt pointer
+ # Fixup the absolute vectors
+ leal (startup_32 - r_base)(%esi), %eax
+ movl %eax, startup_32_vector - r_base
+ leal (startup_64 - r_base)(%esi), %eax
+ movl %eax, startup_64_vector - r_base
+ leal (tgdt - r_base)(%esi), %eax
+ movl %eax, (tgdt + 2 - r_base)

/*
* GDT tables in non default location kernel can be beyond 16MB and
@@ -129,6 +128,7 @@ no_longmode:
jmp no_longmode
#include "verify_cpu.S"

+ .balign 4
# Careful these need to be in the same 64K segment as the above;
tidt:
.word 0 # idt limit = 0
@@ -156,6 +156,10 @@ startup_64_vector:
.long startup_64 - r_base
.word __KERNEL_CS, 0

+ .balign 4
+ENTRY(trampoline_status)
+ .long 0
+
trampoline_stack:
.org 0x1000
trampoline_stack_end:
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index bf47007..cb2c506 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -240,6 +240,18 @@ SECTIONS

INIT_DATA_SECTION(16)

+ /*
+ * Code and data for a variety of lowlevel trampolines, to be
+ * copied into base memory (< 1 MiB) during initialization.
+ * Since it is copied early, the main copy can be discarded
+ * afterwards.
+ */
+ .x86_trampoline : AT(ADDR(.x86_trampoline) - LOAD_OFFSET) {
+ x86_trampoline_start = .;
+ *(.x86_trampoline)
+ x86_trampoline_end = .;
+ }
+
.x86_cpu_dev.init : AT(ADDR(.x86_cpu_dev.init) - LOAD_OFFSET) {
__x86_cpu_dev_start = .;
*(.x86_cpu_dev.init)
@@ -291,6 +303,7 @@ SECTIONS
*(.iommu_table)
__iommu_table_end = .;
}
+
. = ALIGN(8);
/*
* .exit.text is discard at runtime, not link time, to deal with
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
index d6a8cd1..e9fef94d 100644
--- a/drivers/acpi/sleep.c
+++ b/drivers/acpi/sleep.c
@@ -16,6 +16,7 @@
#include <linux/device.h>
#include <linux/suspend.h>
#include <linux/reboot.h>
+#include <linux/acpi.h>

#include <asm/io.h>

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