From: Eric W. Biederman <ebiederm@xmission.com>
Finally the ppc port of kexec. So far it has not been tested on anything
except a gamecube but it should work in general.
Little things like fleshing out machine_shutdown still need to happen though.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/ppc/Kconfig | 20 ++++
25-akpm/arch/ppc/kernel/Makefile | 1
25-akpm/arch/ppc/kernel/machine_kexec.c | 132 ++++++++++++++++++++++++++++++
25-akpm/arch/ppc/kernel/misc.S | 2
25-akpm/arch/ppc/kernel/relocate_kernel.S | 127 ++++++++++++++++++++++++++++
25-akpm/include/asm-ppc/kexec.h | 26 +++++
6 files changed, 307 insertions(+), 1 deletion(-)
diff -puN arch/ppc/Kconfig~kexec-kexecppc arch/ppc/Kconfig
--- 25/arch/ppc/Kconfig~kexec-kexecppc Tue Aug 24 15:38:01 2004
+++ 25-akpm/arch/ppc/Kconfig Tue Aug 24 15:38:01 2004
@@ -1222,6 +1222,26 @@ config SERIAL_SICC_CONSOLE
depends on SERIAL_SICC && UART0_TTYS1
default y
+config KEXEC
+ bool "kexec system call (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ help
+ kexec is a system call that implements the ability to shutdown your
+ current kernel, and to start another kernel. It is like a reboot
+ but it is indepedent of the system firmware. And like a reboot
+ you can start any kernel with it, not just Linux.
+
+ The name comes from the similiarity to the exec system call.
+
+ It is an ongoing process to be certain the hardware in a machine
+ is properly shutdown, so do not be surprised if this code does not
+ initially work for you. It may help to enable device hotplugging
+ support. As of this writing the exact hardware interface is
+ strongly in flux, so no good recommendation can be made.
+
+ In the GAMECUBE implementation, kexec allows you to load and
+ run DOL files, including kernel and homebrew DOLs.
+
endmenu
source "lib/Kconfig"
diff -puN /dev/null arch/ppc/kernel/machine_kexec.c
--- /dev/null Thu Apr 11 07:25:15 2002
+++ 25-akpm/arch/ppc/kernel/machine_kexec.c Tue Aug 24 15:38:01 2004
@@ -0,0 +1,132 @@
+/*
+ * machine_kexec.c - handle transition of Linux booting another kernel
+ * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
+ *
+ * GAMECUBE/PPC32 port Copyright (C) 2004 Albert Herranz
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/delay.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu_context.h>
+#include <asm/io.h>
+#include <asm/hw_irq.h>
+#include <asm/cacheflush.h>
+
+typedef void (*relocate_new_kernel_t)(
+ unsigned long indirection_page, unsigned long reboot_code_buffer,
+ unsigned long start_address);
+
+const extern unsigned char relocate_new_kernel[];
+const extern unsigned int relocate_new_kernel_size;
+extern void use_mm(struct mm_struct *mm);
+
+static int identity_map_pages(struct page *pages, int order)
+{
+ struct mm_struct *mm;
+ struct vm_area_struct *vma;
+ int error;
+
+ mm = &init_mm;
+ vma = NULL;
+
+ down_write(&mm->mmap_sem);
+ error = -ENOMEM;
+ vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+ if (!vma) {
+ goto out;
+ }
+
+ memset(vma, 0, sizeof(*vma));
+ vma->vm_mm = mm;
+ vma->vm_start = page_to_pfn(pages) << PAGE_SHIFT;
+ vma->vm_end = vma->vm_start + (1 << (order + PAGE_SHIFT));
+ vma->vm_ops = NULL;
+ vma->vm_flags = VM_SHARED \
+ | VM_READ | VM_WRITE | VM_EXEC \
+ | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC \
+ | VM_DONTCOPY | VM_RESERVED;
+ vma->vm_page_prot = protection_map[vma->vm_flags & 0xf];
+ vma->vm_file = NULL;
+ vma->vm_private_data = NULL;
+ insert_vm_struct(mm, vma);
+
+ error = remap_page_range(vma, vma->vm_start, vma->vm_start,
+ vma->vm_end - vma->vm_start, vma->vm_page_prot);
+ if (error) {
+ goto out;
+ }
+
+ error = 0;
+ out:
+ if (error && vma) {
+ kmem_cache_free(vm_area_cachep, vma);
+ vma = NULL;
+ }
+ up_write(&mm->mmap_sem);
+
+ return error;
+}
+
+/*
+ * Do what every setup is needed on image and the
+ * reboot code buffer to allow us to avoid allocations
+ * later.
+ */
+int machine_kexec_prepare(struct kimage *image)
+{
+ unsigned int order;
+ order = get_order(KEXEC_CONTROL_CODE_SIZE);
+ return identity_map_pages(image->control_code_page, order);
+}
+
+void machine_kexec_cleanup(struct kimage *image)
+{
+ unsigned int order;
+ order = get_order(KEXEC_CONTROL_CODE_SIZE);
+ do_munmap(&init_mm,
+ page_to_pfn(image->control_code_page) << PAGE_SHIFT,
+ 1 << (order + PAGE_SHIFT));
+}
+
+void machine_shutdown(void)
+{
+}
+
+/*
+ * Do not allocate memory (or fail in any way) in machine_kexec().
+ * We are past the point of no return, committed to rebooting now.
+ */
+void machine_kexec(struct kimage *image)
+{
+ unsigned long indirection_page;
+ unsigned long reboot_code_buffer;
+ relocate_new_kernel_t rnk;
+
+ /* switch to an mm where the reboot_code_buffer is identity mapped */
+ use_mm(&init_mm);
+
+ /* Interrupts aren't acceptable while we reboot */
+ local_irq_disable();
+
+ reboot_code_buffer = page_to_pfn(image->control_code_page) <<PAGE_SHIFT;
+ indirection_page = image->head & PAGE_MASK;
+
+ /* copy it out */
+ memcpy((void *)reboot_code_buffer,
+ relocate_new_kernel, relocate_new_kernel_size);
+
+ flush_icache_range(reboot_code_buffer,
+ reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
+ printk(KERN_INFO "Bye!\n");
+
+ /* now call it */
+ rnk = (relocate_new_kernel_t) reboot_code_buffer;
+ (*rnk)(indirection_page, reboot_code_buffer, image->start);
+}
+
diff -puN arch/ppc/kernel/Makefile~kexec-kexecppc arch/ppc/kernel/Makefile
--- 25/arch/ppc/kernel/Makefile~kexec-kexecppc Tue Aug 24 15:38:01 2004
+++ 25-akpm/arch/ppc/kernel/Makefile Tue Aug 24 15:38:01 2004
@@ -24,6 +24,7 @@ obj-$(CONFIG_KGDB) += ppc-stub.o
obj-$(CONFIG_SMP) += smp.o smp-tbsync.o
obj-$(CONFIG_TAU) += temp.o
obj-$(CONFIG_ALTIVEC) += vecemu.o vector.o
+obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
ifdef CONFIG_MATH_EMULATION
obj-$(CONFIG_8xx) += softemu8xx.o
diff -puN arch/ppc/kernel/misc.S~kexec-kexecppc arch/ppc/kernel/misc.S
--- 25/arch/ppc/kernel/misc.S~kexec-kexecppc Tue Aug 24 15:38:01 2004
+++ 25-akpm/arch/ppc/kernel/misc.S Tue Aug 24 15:38:01 2004
@@ -1446,7 +1446,7 @@ _GLOBAL(sys_call_table)
.long sys_mq_timedreceive /* 265 */
.long sys_mq_notify
.long sys_mq_getsetattr
- .long sys_ni_syscall /* 268 reserved for sys_kexec_load */
+ .long sys_kexec_load
.long sys_perfctr_info
.long sys_vperfctr_open /* 270 */
.long sys_vperfctr_control
diff -puN /dev/null arch/ppc/kernel/relocate_kernel.S
--- /dev/null Thu Apr 11 07:25:15 2002
+++ 25-akpm/arch/ppc/kernel/relocate_kernel.S Tue Aug 24 15:38:01 2004
@@ -0,0 +1,127 @@
+/*
+ * relocate_kernel.S - put the kernel image in place to boot
+ * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
+ *
+ * GAMECUBE/PPC32 port Copyright (C) 2004 Albert Herranz
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <asm/reg.h>
+#include <asm/ppc_asm.h>
+#include <asm/processor.h>
+
+#include <asm/kexec.h>
+
+#define PAGE_SIZE 4096 /* must be same value as in <asm/page.h> */
+
+/* returns r3 = relocated address of sym */
+/* modifies r0 */
+#define RELOC_SYM(sym) \
+ mflr r3; \
+ bl 1f; \
+1: mflr r0; \
+ mtlr r3; \
+ lis r3, 1b@ha; \
+ ori r3, r3, 1b@l; \
+ subf r0, r3, r0; \
+ lis r3, sym@ha; \
+ ori r3, r3, sym@l; \
+ add r3, r3, r0
+
+ /*
+ * Must be relocatable PIC code callable as a C function.
+ */
+ .globl relocate_new_kernel
+relocate_new_kernel:
+ /* r3 = indirection_page */
+ /* r4 = reboot_code_buffer */
+ /* r5 = start_address */
+
+ li r0, 0
+
+ /* Set Machine Status Register to a known status */
+ mr r8, r0
+ ori r8, r8, MSR_RI|MSR_ME
+ mtmsr r8
+ isync
+
+ /* from this point address translation is turned off */
+ /* and interrupts are disabled */
+
+ /* set a new stack at the bottom of our page... */
+ /* (not really needed now) */
+ addi r1, r4, KEXEC_CONTROL_CODE_SIZE - 8 /* for LR Save+Back Chain */
+ stw r0, 0(r1)
+
+ /* Do the copies */
+ li r6, 0 /* checksum */
+ subi r3, r3, 4
+
+0: /* top, read another word for the indirection page */
+ lwzu r0, 4(r3)
+
+ /* is it a destination page? (r8) */
+ rlwinm. r7, r0, 0, 31, 31 /* IND_DESTINATION (1<<0) */
+ beq 1f
+
+ rlwinm r8, r0, 0, 0, 19 /* clear kexec flags, page align */
+ b 0b
+
+1: /* is it an indirection page? (r3) */
+ rlwinm. r7, r0, 0, 30, 30 /* IND_INDIRECTION (1<<1) */
+ beq 1f
+
+ rlwinm r3, r0, 0, 0, 19 /* clear kexec flags, page align */
+ subi r3, r3, 4
+ b 0b
+
+1: /* are we done? */
+ rlwinm. r7, r0, 0, 29, 29 /* IND_DONE (1<<2) */
+ beq 1f
+ b 2f
+
+1: /* is it a source page? (r9) */
+ rlwinm. r7, r0, 0, 28, 28 /* IND_SOURCE (1<<3) */
+ beq 0b
+
+ rlwinm r9, r0, 0, 0, 19 /* clear kexec flags, page align */
+
+ li r7, PAGE_SIZE / 4
+ mtctr r7
+ subi r9, r9, 4
+ subi r8, r8, 4
+9:
+ lwzu r0, 4(r9) /* do the copy */
+ xor r6, r6, r0
+ stwu r0, 4(r8)
+ dcbst 0, r8
+ sync
+ icbi 0, r8
+ bdnz 9b
+
+ addi r9, r9, 4
+ addi r8, r8, 4
+ b 0b
+
+2:
+
+ /* To be certain of avoiding problems with self-modifying code
+ * execute a serializing instruction here.
+ */
+ isync
+ sync
+
+ /* jump to the entry point, usually the setup routine */
+ mtlr r5
+ blrl
+
+1: b 1b
+
+relocate_new_kernel_end:
+
+ .globl relocate_new_kernel_size
+relocate_new_kernel_size:
+ .long relocate_new_kernel_end - relocate_new_kernel
+
diff -puN /dev/null include/asm-ppc/kexec.h
--- /dev/null Thu Apr 11 07:25:15 2002
+++ 25-akpm/include/asm-ppc/kexec.h Tue Aug 24 15:38:01 2004
@@ -0,0 +1,26 @@
+#ifndef _PPC_KEXEC_H
+#define _PPC_KEXEC_H
+
+#ifdef CONFIG_KEXEC
+/*
+ * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
+ * I.e. Maximum page that is mapped directly into kernel memory,
+ * and kmap is not required.
+ *
+ * Someone correct me if FIXADDR_START - PAGEOFFSET is not the correct
+ * calculation for the amount of memory directly mappable into the
+ * kernel memory space.
+ */
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (-1UL)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (-1UL)
+/* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT TASK_SIZE
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+#endif /* CONFIG_KEXEC */
+
+#endif /* _PPC_KEXEC_H */
_