[PATCH 2/2] Kexec jump: Kexec jump
From: Huang, Ying
Date: Wed Jul 11 2007 - 03:32:02 EST
This patch provide the kexec based implementation of hibernation image
operation. Now, only jumping between original kernel and kexeced
kernel is supported, real image write/read/check will be provided in
next patches.
Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
arch/i386/kernel/Makefile | 1
arch/i386/kernel/kexec_jump.S | 73 ++++++++++++++++++++++++++
arch/i386/kernel/machine_kexec.c | 58 +++++++++++++++++++++
include/asm-i386/kexec.h | 4 +
include/linux/kexec.h | 8 ++
kernel/kexec.c | 25 +++++++++
kernel/ksysfs.c | 12 ++++
kernel/power/Kconfig | 8 ++
kernel/power/Makefile | 1
kernel/power/kexec.c | 106 +++++++++++++++++++++++++++++++++++++++
10 files changed, 296 insertions(+)
Index: linux-2.6/arch/i386/kernel/Makefile
===================================================================
--- linux-2.6.orig/arch/i386/kernel/Makefile 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/arch/i386/kernel/Makefile 2007-07-09 21:53:46.000000000 +0000
@@ -27,6 +27,7 @@
obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump.o
+obj-$(CONFIG_KEXEC_HIBERNATION) += kexec_jump.o
obj-$(CONFIG_X86_NUMAQ) += numaq.o
obj-$(CONFIG_X86_SUMMIT_NUMA) += summit.o
obj-$(CONFIG_KPROBES) += kprobes.o
Index: linux-2.6/arch/i386/kernel/machine_kexec.c
===================================================================
--- linux-2.6.orig/arch/i386/kernel/machine_kexec.c 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/arch/i386/kernel/machine_kexec.c 2007-07-10 09:17:23.000000000 +0000
@@ -10,6 +10,7 @@
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/highmem.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
@@ -169,3 +170,60 @@
return 0;
}
early_param("crashkernel", parse_crashkernel);
+
+#ifdef CONFIG_KEXEC_HIBERNATION
+int kexec_jump(int jump_type)
+{
+ asmlinkage int (*real_jump)(int jmp, void *buf);
+ unsigned long jump_buf_pfn;
+ void *jump_buf;
+
+ if (jump_type == KEXEC_JUMP_TYPE_EXEC && !kexec_crash_image)
+ return -EINVAL;
+ jump_buf_pfn = kexec_get_jump_buf_pfn(0);
+ if (!jump_buf_pfn)
+ return -EINVAL;
+ jump_buf = kmap_atomic_pfn(jump_buf_pfn, KM_PTE0);
+ memcpy(jump_buf + PAGE_SIZE/2, kexec_real_jump, PAGE_SIZE/2);
+ real_jump = jump_buf + PAGE_SIZE/2;
+
+ if (!real_jump(jump_type == KEXEC_JUMP_TYPE_EXEC, jump_buf))
+ machine_kexec(kexec_crash_image);
+ kunmap_atomic(jump_buf, KM_PTE0);
+ return 0;
+}
+
+static unsigned long kexec_backup_addr = ~0UL;
+
+/* kexec_backup= specifies the location of backuped 0~640k memory of
+ * crashed kernel.
+ */
+static int __init parse_kexec_backup(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ kexec_backup_addr = memparse(arg, &arg);
+ return 0;
+}
+early_param("kexec_backup", parse_kexec_backup);
+
+void kexec_restore_backup(void)
+{
+ void *vaddr;
+ void *vaddr_backup;
+ unsigned long paddr;
+
+ if (kexec_backup_addr == ~0UL)
+ return;
+
+ for (paddr = 0; paddr < 640 * 1024; paddr += PAGE_SIZE) {
+ vaddr = kmap_atomic_pfn(paddr >> PAGE_SHIFT, KM_PTE0);
+ vaddr_backup = kmap_atomic_pfn((paddr+kexec_backup_addr) >> PAGE_SHIFT,
+ KM_PTE1);
+ memcpy(vaddr, vaddr_backup, PAGE_SIZE);
+ kunmap_atomic(vaddr, KM_PTE0);
+ kunmap_atomic(vaddr_backup, KM_PTE1);
+ }
+}
+#endif /* CONFIG_KEXEC_HIBERNATION */
Index: linux-2.6/include/asm-i386/kexec.h
===================================================================
--- linux-2.6.orig/include/asm-i386/kexec.h 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/include/asm-i386/kexec.h 2007-07-09 21:53:46.000000000 +0000
@@ -94,6 +94,10 @@
unsigned long start_address,
unsigned int has_pae) ATTRIB_NORET;
+#ifdef CONFIG_KEXEC_HIBERNATION
+extern asmlinkage int kexec_real_jump(int save_only, void *buf);
+#endif
+
#endif /* __ASSEMBLY__ */
#endif /* _I386_KEXEC_H */
Index: linux-2.6/include/linux/kexec.h
===================================================================
--- linux-2.6.orig/include/linux/kexec.h 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/include/linux/kexec.h 2007-07-09 21:53:46.000000000 +0000
@@ -161,4 +161,12 @@
static inline void crash_kexec(struct pt_regs *regs) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
#endif /* CONFIG_KEXEC */
+
+#ifdef CONFIG_KEXEC_HIBERNATION
+#define KEXEC_JUMP_TYPE_EXEC 0
+#define KEXEC_JUMP_TYPE_JUMP 1
+extern int kexec_jump(int jump_type);
+extern unsigned long kexec_get_jump_buf_pfn(int alloc);
+extern void kexec_restore_backup(void);
+#endif
#endif /* LINUX_KEXEC_H */
Index: linux-2.6/kernel/kexec.c
===================================================================
--- linux-2.6.orig/kernel/kexec.c 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/kernel/kexec.c 2007-07-09 21:53:46.000000000 +0000
@@ -1135,3 +1135,28 @@
return 0;
}
module_init(crash_notes_memory_init)
+
+#ifdef CONFIG_KEXEC_HIBERNATION
+static unsigned long kexec_jump_buf_pfn;
+
+static int __init parse_kexec_jump_buf_pfn(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ kexec_jump_buf_pfn = memparse(arg, &arg);
+ return 0;
+}
+early_param("kexec_jump_buf_pfn", parse_kexec_jump_buf_pfn);
+
+unsigned long kexec_get_jump_buf_pfn(int alloc)
+{
+ struct page *jump_buf_page;
+
+ if (!kexec_jump_buf_pfn && alloc) {
+ jump_buf_page = alloc_page(GFP_KERNEL);
+ kexec_jump_buf_pfn = page_to_pfn(jump_buf_page);
+ }
+ return kexec_jump_buf_pfn;
+}
+#endif /* CONFIG_KEXEC_HIBERNATION */
Index: linux-2.6/kernel/ksysfs.c
===================================================================
--- linux-2.6.orig/kernel/ksysfs.c 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/kernel/ksysfs.c 2007-07-09 21:53:46.000000000 +0000
@@ -60,6 +60,15 @@
return sprintf(page, "%d\n", !!kexec_crash_image);
}
KERNEL_ATTR_RO(kexec_crash_loaded);
+
+#ifdef CONFIG_KEXEC_HIBERNATION
+static ssize_t kexec_jump_buf_pfn_show(struct kset *kset, char *page)
+{
+ return sprintf(page, "0x%lx\n", kexec_get_jump_buf_pfn(1));
+}
+
+KERNEL_ATTR_RO(kexec_jump_buf_pfn);
+#endif
#endif /* CONFIG_KEXEC */
decl_subsys(kernel, NULL, NULL);
@@ -73,6 +82,9 @@
#ifdef CONFIG_KEXEC
&kexec_loaded_attr.attr,
&kexec_crash_loaded_attr.attr,
+#ifdef CONFIG_KEXEC_HIBERNATION
+ &kexec_jump_buf_pfn_attr.attr,
+#endif
#endif
NULL
};
Index: linux-2.6/kernel/power/Kconfig
===================================================================
--- linux-2.6.orig/kernel/power/Kconfig 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/kernel/power/Kconfig 2007-07-09 21:53:46.000000000 +0000
@@ -115,6 +115,14 @@
For more information take a look at <file:Documentation/power/swsusp.txt>.
+config KEXEC_HIBERNATION
+ bool "Kexec based software suspend (hibernation) (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ depends on SOFTWARE_SUSPEND && X86_32 && KEXEC
+ ---help---
+ Writing the hibernation image through booting another kernel with
+ kexec.
+
config PM_STD_PARTITION
string "Default resume partition"
depends on SOFTWARE_SUSPEND
Index: linux-2.6/kernel/power/Makefile
===================================================================
--- linux-2.6.orig/kernel/power/Makefile 2007-07-09 21:51:45.000000000 +0000
+++ linux-2.6/kernel/power/Makefile 2007-07-09 21:53:46.000000000 +0000
@@ -6,5 +6,6 @@
obj-y := main.o process.o console.o
obj-$(CONFIG_PM_LEGACY) += pm.o
obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o user.o
+obj-$(CONFIG_KEXEC_HIBERNATION) += kexec.o
obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
Index: linux-2.6/arch/i386/kernel/kexec_jump.S
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/arch/i386/kernel/kexec_jump.S 2007-07-09 22:13:35.000000000 +0000
@@ -0,0 +1,73 @@
+/*
+ * kexec_jump.S - Jump between normal kernel and hibernation kernel
+ * Copyright (C) 2007 Huang Ying <ying.huang@xxxxxxxxx>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/page.h>
+#include <asm/kexec.h>
+
+/*
+ * Must be relocatable PIC code callable as a C function
+ */
+#define HALF_PAGE_ALIGNED (1 << (PAGE_SHIFT-1))
+
+#define EBX 0x0
+#define ESI 0x4
+#define EDI 0x8
+#define EBP 0xc
+#define ESP 0x10
+#define CR0 0x14
+#define CR3 0x18
+#define CR4 0x1c
+#define FLAG 0x20
+#define RET 0x24
+
+ .text
+ .align HALF_PAGE_ALIGNED
+ .globl kexec_real_jump
+kexec_real_jump:
+ movl 4(%esp), %ecx
+ movl 8(%esp), %edx
+ cmpl $1, %ecx
+ jnz 1f
+ movl %ebx, EBX(%edx)
+ movl %esi, ESI(%edx)
+ movl %edi, EDI(%edx)
+ movl %ebp, EBP(%edx)
+ movl %esp, ESP(%edx)
+ movl %cr0, %eax
+ movl %eax, CR0(%edx)
+ movl %cr3, %eax
+ movl %eax, CR3(%edx)
+ movl %cr4, %eax
+ movl %eax, CR4(%edx)
+ pushf
+ popl %eax
+ movl %eax, FLAG(%edx)
+ movl (%esp), %eax
+ movl %eax, RET(%edx)
+ mov $0, %eax
+ ret
+1:
+ movl EBX(%edx), %ebx
+ movl ESI(%edx), %esi
+ movl EDI(%edx), %edi
+ movl EBP(%edx), %ebp
+ movl FLAG(%edx), %eax
+ pushl %eax
+ popf
+ movl ESP(%edx), %esp
+ movl CR4(%edx), %eax
+ movl %eax, %cr4
+ movl CR3(%edx), %eax
+ movl %eax, %cr3
+ movl CR0(%edx), %eax
+ movl %eax, %cr0
+ movl RET(%edx), %eax
+ movl %eax, (%esp)
+ mov $1, %eax
+ ret
Index: linux-2.6/kernel/power/kexec.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6/kernel/power/kexec.c 2007-07-10 09:16:47.000000000 +0000
@@ -0,0 +1,106 @@
+/*
+ * kernel/power/kexec.c - Kexec based Suspend-to-disk support.
+ *
+ * Copyright (C) 2007 Huang Ying <ying.huang@xxxxxxxxx>
+ *
+ * This file is released under the GPLv2.
+ *
+ */
+
+#include <linux/suspend.h>
+#include <linux/pm.h>
+#include <linux/kexec.h>
+
+#include "power.h"
+
+
+static int kexec_suspend(void)
+{
+ int error;
+
+ local_irq_disable();
+ /* At this point, device_suspend() has been called, but *not*
+ * device_power_down(). We *must* device_power_down() now.
+ * Otherwise, drivers for some devices (e.g. interrupt controllers)
+ * become desynchronized with the actual state of the hardware
+ * at resume time, and evil weirdness ensues.
+ */
+ error = device_power_down(PMSG_FREEZE);
+ if (error) {
+ printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
+ goto Enable_irqs;
+ }
+
+ save_processor_state();
+ error = kexec_jump(KEXEC_JUMP_TYPE_EXEC);
+ restore_processor_state();
+
+ /* NOTE: device_power_up() is just a resume() for devices
+ * that suspended with irqs off ... no overall powerup.
+ */
+ device_power_up();
+ Enable_irqs:
+ in_suspend = 0;
+ local_irq_enable();
+ return error;
+}
+
+static int kexec_write(void)
+{
+ return 0;
+}
+
+static int kexec_check(void)
+{
+ return 0;
+}
+
+static int kexec_read(void)
+{
+ return 0;
+}
+
+static void kexec_close(void)
+{
+}
+
+static int kexec_resume(void)
+{
+ int error = 0;
+
+ local_irq_disable();
+ /* NOTE: device_power_down() is just a suspend() with irqs off;
+ * it has no special "power things down" semantics
+ */
+ if (device_power_down(PMSG_PRETHAW))
+ printk(KERN_ERR "Some devices failed to power down, very bad\n");
+ /* We'll ignore saved state, but this gets preempt count (etc) right */
+ save_processor_state();
+ kexec_restore_backup();
+ error = kexec_jump(KEXEC_JUMP_TYPE_JUMP);
+ swsusp_free();
+ restore_processor_state();
+ touch_softlockup_watchdog();
+ device_power_up();
+ local_irq_enable();
+ return error;
+}
+
+static struct hibernation_image_ops kexec_hibernation_image_ops =
+{
+ .name = "kexec",
+ .suspend = kexec_suspend,
+ .resume = kexec_resume,
+ .write = kexec_write,
+ .check = kexec_check,
+ .read = kexec_read,
+ .close = kexec_close,
+};
+
+static int __init kexec_hibernation_init(void)
+{
+ hibernation_add_image_ops(&kexec_hibernation_image_ops);
+ return 0;
+}
+
+subsys_initcall(kexec_hibernation_init);
-
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