[patch] [RFC] Kexec on MIPS

[patch] [RFC] Kexec on MIPS

[Nicolas Schichan]

[-- Attachment #1: Type: text/plain, Size: 797 bytes --]


Hello,

I have implemented kexec support for the mips architecture, the code is 
available in the attached patch (for 2.6.18 kernel). This code works fine on 
the mips boards I use at work (one in big endian and one in little endian) and 
on qemu.

However it has not been tested on 64 bit mips and it may not work on
those architectures.

It may also not work on machines with more than 512 megabytes as the kexec 
generic code may fill the page list with adresses over the 512 megabytes 
limit (the mips boards I use only have 16mbytes and 32mbytes ram).

A tiny userland application loading the kernel and invoking kexec_load for 
mips is available here:

http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz

Do not hesitate to comment on this patch,

Regards,

-- 
Nicolas Schichan

[-- Attachment #2: kexec-mips --]
[-- Type: text/x-diff, Size: 11724 bytes --]

diff -Nru linux-orig/arch/mips/Kconfig linux-work/arch/mips/Kconfig
--- linux-orig/arch/mips/Kconfig	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/Kconfig	2006-10-17 16:12:04.000000000 +0200
@@ -820,6 +820,23 @@
 
 endchoice
 
+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.
+
 source "arch/mips/ddb5xxx/Kconfig"
 source "arch/mips/gt64120/ev64120/Kconfig"
 source "arch/mips/jazz/Kconfig"
diff -Nru linux-orig/arch/mips/kernel/machine_kexec.c linux-work/arch/mips/kernel/machine_kexec.c
--- linux-orig/arch/mips/kernel/machine_kexec.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/machine_kexec.c	2006-10-18 14:03:59.000000000 +0200
@@ -0,0 +1,84 @@
+/*
+ * machine_kexec.c for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+
+const extern unsigned char relocate_new_kernel[];
+const extern unsigned int relocate_new_kernel_size;
+
+extern unsigned long kexec_start_address;
+extern unsigned long kexec_indirection_page;
+
+int
+machine_kexec_prepare(struct kimage *kimage)
+{
+	return 0;
+}
+
+void
+machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void
+machine_shutdown(void)
+{
+}
+
+void
+machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+void
+machine_kexec(struct kimage *image)
+{
+	unsigned long reboot_code_buffer;
+	unsigned long entry;
+	unsigned long *ptr;
+
+	reboot_code_buffer =
+	  (unsigned long)page_address(image->control_code_page);
+
+	kexec_start_address = image->start;
+	kexec_indirection_page = phys_to_virt(image->head & PAGE_MASK);
+
+	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
+	       relocate_new_kernel_size);
+
+	/*
+	 * The generic kexec code builds a page list with physical
+	 * addresses. they are directly accessible through KSEG0,
+	 * hence the pys_to_virt() call.
+	 */
+	for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
+	     ptr = (entry & IND_INDIRECTION) ?
+	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
+		    *ptr & IND_DESTINATION)
+			*ptr = phys_to_virt(*ptr);
+	}
+
+	/*
+	 * we do not want to be bothered.
+	 */
+	local_irq_disable();
+
+	flush_icache_range(reboot_code_buffer,
+			   reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
+
+	printk("Will call new kernel at %08x\n", image->start);
+	printk("Bye ...\n");
+	flush_cache_all();
+	((void (*)(void))reboot_code_buffer)();
+}
diff -Nru linux-orig/arch/mips/kernel/Makefile linux-work/arch/mips/kernel/Makefile
--- linux-orig/arch/mips/kernel/Makefile	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/Makefile	2006-10-17 15:55:11.000000000 +0200
@@ -66,6 +66,8 @@
 
 obj-$(CONFIG_I8253)		+= i8253.o
 
+obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -Nru linux-orig/arch/mips/kernel/relocate_kernel.S linux-work/arch/mips/kernel/relocate_kernel.S
--- linux-orig/arch/mips/kernel/relocate_kernel.S	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/relocate_kernel.S	2006-10-17 20:01:06.000000000 +0200
@@ -0,0 +1,80 @@
+/*
+ * relocate_kernel.S for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/page.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+	.globl relocate_new_kernel
+relocate_new_kernel:
+
+	PTR_L	s0, kexec_indirection_page
+	PTR_L	s1, kexec_start_address
+
+process_entry:
+	PTR_L	s2, (s0)
+	PTR_ADD	s0, s0, SZREG
+
+	/* destination page */
+	and	s3, s2, 0x1
+	beq	s3, zero, 1f
+	and	s4, s2, ~0x1	/* store destination addr in s4 */
+	move	a0, s4
+	b	process_entry
+
+1:
+	/* indirection page, update s0  */
+	and	s3, s2, 0x2
+	beq	s3, zero, 1f
+	and	s0, s2, ~0x2
+	b	process_entry
+
+1:
+	/* done page */
+	and	s3, s2, 0x4
+	beq	s3, zero, 1f
+	b	done
+1:
+	/* source page */
+	and	s3, s2, 0x8
+	beq	s3, zero, process_entry
+	and	s2, s2, ~0x8
+	li	s6, (1 << PAGE_SHIFT) / SZREG
+
+copy_word:
+	/* copy page word by word */
+	REG_L	s5, (s2)
+	REG_S	s5, (s4)
+	INT_ADD	s4, s4, SZREG
+	INT_ADD	s2, s2, SZREG
+	INT_SUB	s6, s6, 1
+	beq	s6, zero, process_entry
+	b	copy_word
+	b	process_entry
+
+done:
+	/* jump to kexec_start_address */
+	j	s1
+
+	.globl kexec_start_address
+kexec_start_address:
+	.long	0x0
+
+	.globl kexec_indirection_page
+kexec_indirection_page:
+	.long	0x0
+
+relocate_new_kernel_end:
+
+	.globl relocate_new_kernel_size
+relocate_new_kernel_size:
+	.long relocate_new_kernel_end - relocate_new_kernel
diff -Nru linux-orig/arch/mips/kernel/scall32-o32.S linux-work/arch/mips/kernel/scall32-o32.S
--- linux-orig/arch/mips/kernel/scall32-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall32-o32.S	2006-10-17 16:23:21.000000000 +0200
@@ -662,6 +662,7 @@
 	sys	sys_tee			4
 	sys	sys_vmsplice		4
 	sys	sys_move_pages		6
+	sys	sys_kexec_load		1
 	.endm
 
 	/* We pre-compute the number of _instruction_ bytes needed to
diff -Nru linux-orig/arch/mips/kernel/scall64-64.S linux-work/arch/mips/kernel/scall64-64.S
--- linux-orig/arch/mips/kernel/scall64-64.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-64.S	2006-10-17 15:57:15.000000000 +0200
@@ -466,3 +466,4 @@
 	PTR	sys_tee				/* 5265 */
 	PTR	sys_vmsplice
 	PTR	sys_move_pages
+	PTR	sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-n32.S linux-work/arch/mips/kernel/scall64-n32.S
--- linux-orig/arch/mips/kernel/scall64-n32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-n32.S	2006-10-17 15:58:59.000000000 +0200
@@ -392,3 +392,4 @@
 	PTR	sys_tee
 	PTR	sys_vmsplice			/* 6271 */
 	PTR	sys_move_pages
+	PTR	sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-o32.S linux-work/arch/mips/kernel/scall64-o32.S
--- linux-orig/arch/mips/kernel/scall64-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-o32.S	2006-10-17 15:59:23.000000000 +0200
@@ -514,4 +514,5 @@
 	PTR	sys_tee
 	PTR	sys_vmsplice
 	PTR	compat_sys_move_pages
+	PTR	sys_kexec_load
 	.size	sys_call_table,.-sys_call_table
diff -Nru linux-orig/include/asm-mips/kexec.h linux-work/include/asm-mips/kexec.h
--- linux-orig/include/asm-mips/kexec.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/include/asm-mips/kexec.h	2006-10-18 12:29:12.000000000 +0200
@@ -0,0 +1,32 @@
+/*
+ * kexec.h for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 14:59:34 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#ifndef _MIPS_KEXEC
+# define _MIPS_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000)
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_MIPS
+
+#define MAX_NOTE_BYTES 1024
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+				    struct pt_regs *oldregs)
+{
+	/* Dummy implementation for now */
+}
+
+#endif /* !_MIPS_KEXEC */
diff -Nru linux-orig/include/asm-mips/unistd.h linux-work/include/asm-mips/unistd.h
--- linux-orig/include/asm-mips/unistd.h	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/asm-mips/unistd.h	2006-10-17 16:07:57.000000000 +0200
@@ -329,16 +329,17 @@
 #define __NR_tee			(__NR_Linux + 306)
 #define __NR_vmsplice			(__NR_Linux + 307)
 #define __NR_move_pages			(__NR_Linux + 308)
+#define __NR_kexec_load			(__NR_Linux + 309)
 
 /*
  * Offset of the last Linux o32 flavoured syscall
  */
-#define __NR_Linux_syscalls		308
+#define __NR_Linux_syscalls		309
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
 
 #define __NR_O32_Linux			4000
-#define __NR_O32_Linux_syscalls		308
+#define __NR_O32_Linux_syscalls		309
 
 #if _MIPS_SIM == _MIPS_SIM_ABI64
 
@@ -614,16 +615,17 @@
 #define __NR_tee			(__NR_Linux + 265)
 #define __NR_vmsplice			(__NR_Linux + 266)
 #define __NR_move_pages			(__NR_Linux + 267)
+#define __NR_kexec_load			(__NR_Linux + 268)
 
 /*
  * Offset of the last Linux 64-bit flavoured syscall
  */
-#define __NR_Linux_syscalls		267
+#define __NR_Linux_syscalls		268
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
 
 #define __NR_64_Linux			5000
-#define __NR_64_Linux_syscalls		267
+#define __NR_64_Linux_syscalls		268
 
 #if _MIPS_SIM == _MIPS_SIM_NABI32
 
@@ -903,16 +905,16 @@
 #define __NR_tee			(__NR_Linux + 269)
 #define __NR_vmsplice			(__NR_Linux + 270)
 #define __NR_move_pages			(__NR_Linux + 271)
-
+#define __NR_kexec_load			(__Nr_Linux + 272)
 /*
  * Offset of the last N32 flavoured syscall
  */
-#define __NR_Linux_syscalls		271
+#define __NR_Linux_syscalls		272
 
 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
 
 #define __NR_N32_Linux			6000
-#define __NR_N32_Linux_syscalls		271
+#define __NR_N32_Linux_syscalls		272
 
 #ifdef __KERNEL__
 
diff -Nru linux-orig/include/linux/kexec.h linux-work/include/linux/kexec.h
--- linux-orig/include/linux/kexec.h	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/linux/kexec.h	2006-10-17 16:21:49.000000000 +0200
@@ -122,6 +122,8 @@
 #define KEXEC_ARCH_IA_64   (50 << 16)
 #define KEXEC_ARCH_S390    (22 << 16)
 #define KEXEC_ARCH_SH      (42 << 16)
+#define KEXEC_ARCH_MIPS_LE (10 << 16)
+#define KEXEC_ARCH_MIPS    ( 8 << 16)
 
 #define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */
 
diff -Nru linux-orig/Makefile linux-work/Makefile
--- linux-orig/Makefile	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/Makefile	2006-10-17 16:09:02.000000000 +0200
@@ -149,10 +149,11 @@
 # then ARCH is assigned, getting whatever value it gets normally, and 
 # SUBARCH is subsequently ignored.
 
-SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
-				  -e s/arm.*/arm/ -e s/sa110/arm/ \
-				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
-				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
+SUBARCH := mips
+# $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
+#				  -e s/arm.*/arm/ -e s/sa110/arm/ \
+#				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
+#				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
 
 # Cross compiling and selecting different set of gcc/bin-utils
 # ---------------------------------------------------------------------------

Re: [patch] [RFC] Kexec on MIPS

[Ralf Baechle]

On Wed, Oct 18, 2006 at 03:14:55PM +0200, Nicolas Schichan wrote:

> I have implemented kexec support for the mips architecture, the code is 
> available in the attached patch (for 2.6.18 kernel). This code works fine on 
> the mips boards I use at work (one in big endian and one in little endian) and 
> on qemu.

Cool!

> However it has not been tested on 64 bit mips and it may not work on
> those architectures.

Aside of a nit in a 32-bit specific comment the code is looking good.  See
below.

> It may also not work on machines with more than 512 megabytes as the kexec 
> generic code may fill the page list with adresses over the 512 megabytes 
> limit (the mips boards I use only have 16mbytes and 32mbytes ram).

This is only an issue with 32-bit software anyway.  On these you can solve
the problem by manually setting up TLB mappings.  You may want to take a
look at kmap_coherent in arch/mips/mm/init.c for how to create such
temporary mappings.

> A tiny userland application loading the kernel and invoking kexec_load for 
> mips is available here:
> 
> http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz
> 
> Do not hesitate to comment on this patch,

Without having tested this, this actually looks quite fine for the first
cut.  My nits are these:

+       /*
+        * The generic kexec code builds a page list with physical
+        * addresses. they are directly accessible through KSEG0,
+        * hence the pys_to_virt() call.
+        */

On a 64-bit system this could actually be either an XKPHY or CKSEG address,
depending on PAGE_OFFSET.

+       /*
+        * we do not want to be bothered.
+        */
+       local_irq_disable();
+
+       flush_icache_range(reboot_code_buffer,
+                          reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
+
+       printk("Will call new kernel at %08x\n", image->start);
+       printk("Bye ...\n");
+       flush_cache_all();
+       ((void (*)(void))reboot_code_buffer)();

On SMP systems cache flushes may invoke smp_call_function which will barf
when called with interrupts disabled.  So you may want to move the
local_irq_disable further down to somewhere after the last flush.

Your code does not try to deal with SMP at all.  The strategy used by
Linux to get hold of processors 1 and up on bootup relies on the
firmware.  Generally firmware breaks because Linux tramples over it and
even if it would survive that, it does not regain control over non-boot
processors, so starting of those processors would fail.

The solution I have in mind would be something like:

 * The trampoline that transfers control between the old and new kernel
   needs to be modified to keep all additional processors in some sort of
   spinlock.
 * A kernel needs a way to know if it has been executed via kexec or a
   normal bootup.  It uses this knowledge to release one non-boot
   processor after another during SMP initialization.

  Ralf

PS: If you have to send patches as attachments, then please as text/plain.

Re: [patch] [RFC] Kexec on MIPS

[Nicolas Schichan]

[-- Attachment #1: Type: text/plain, Size: 3289 bytes --]

On Wednesday 18 October 2006 16:31, you wrote:
> > It may also not work on machines with more than 512 megabytes as the
> > kexec generic code may fill the page list with adresses over the 512
> > megabytes limit (the mips boards I use only have 16mbytes and 32mbytes
> > ram).
>
> This is only an issue with 32-bit software anyway.  On these you can solve
> the problem by manually setting up TLB mappings.  You may want to take a
> look at kmap_coherent in arch/mips/mm/init.c for how to create such
> temporary mappings.

I think that defining KEXEC_SOURCE_MEMORY_LIMIT, 
KEXEC_DESTINATION_MEMORY_LIMIT and KEXEC_CONTROL_MEMORY_LIMIT to 
HIGHMEM_START in include/asm-mips/kexec.h should solve this issue without 
involving doing some TLB mappings.

> +       /*
> +        * The generic kexec code builds a page list with physical
> +        * addresses. they are directly accessible through KSEG0,
> +        * hence the pys_to_virt() call.
> +        */
>
> On a 64-bit system this could actually be either an XKPHY or CKSEG address,
> depending on PAGE_OFFSET.

I just reworked the comment on the attached patch.

> +       /*
> +        * we do not want to be bothered.
> +        */
> +       local_irq_disable();
> +
> +       flush_icache_range(reboot_code_buffer,
> +                          reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
> +
> +       printk("Will call new kernel at %08x\n", image->start);
> +       printk("Bye ...\n");
> +       flush_cache_all();
> +       ((void (*)(void))reboot_code_buffer)();
>
> On SMP systems cache flushes may invoke smp_call_function which will barf
> when called with interrupts disabled.  So you may want to move the
> local_irq_disable further down to somewhere after the last flush.

local_irq_disable() is called after flush_cache_all() in the attached patch.

> Your code does not try to deal with SMP at all.  The strategy used by
> Linux to get hold of processors 1 and up on bootup relies on the
> firmware.  Generally firmware breaks because Linux tramples over it and
> even if it would survive that, it does not regain control over non-boot
> processors, so starting of those processors would fail.

I  do not have access to a SMP mips machine, so I won't be able to deal with 
this. How about temporarily making KEXEC depend on !SMP for now ?

> The solution I have in mind would be something like:
>
>  * The trampoline that transfers control between the old and new kernel
>    needs to be modified to keep all additional processors in some sort of
>    spinlock.

Something like calling stop_this_cpu() on each cpu except the one we are 
running on ? However we are may face the risk of leaving the infinite loop in 
stop_this_cpu() as the code in relocate_kernel.S overwrites the code of the 
function.

>  * A kernel needs a way to know if it has been executed via kexec or a
>    normal bootup.  It uses this knowledge to release one non-boot
>    processor after another during SMP initialization.

The code in relocate_kernel.S could setup some magic values in a0, a1, a2 or 
a3 before jumping to the new kernel to indicate that the kernel has been 
kexec'd.

> PS: If you have to send patches as attachments, then please as text/plain.

Sorry for this, attached patch is as text/plain.

-- 
Nicolas Schichan

[-- Attachment #2: kexec-mips --]
[-- Type: text/x-diff, Size: 11667 bytes --]

diff -Nru linux-orig/arch/mips/Kconfig linux-work/arch/mips/Kconfig
--- linux-orig/arch/mips/Kconfig	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/Kconfig	2006-10-17 16:12:04.000000000 +0200
@@ -820,6 +820,23 @@
 
 endchoice
 
+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.
+
 source "arch/mips/ddb5xxx/Kconfig"
 source "arch/mips/gt64120/ev64120/Kconfig"
 source "arch/mips/jazz/Kconfig"
diff -Nru linux-orig/arch/mips/kernel/machine_kexec.c linux-work/arch/mips/kernel/machine_kexec.c
--- linux-orig/arch/mips/kernel/machine_kexec.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/machine_kexec.c	2006-10-18 20:54:16.000000000 +0200
@@ -0,0 +1,79 @@
+/*
+ * machine_kexec.c for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 15:15:06 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+
+const extern unsigned char relocate_new_kernel[];
+const extern unsigned int relocate_new_kernel_size;
+
+extern unsigned long kexec_start_address;
+extern unsigned long kexec_indirection_page;
+
+int
+machine_kexec_prepare(struct kimage *kimage)
+{
+	return 0;
+}
+
+void
+machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void
+machine_shutdown(void)
+{
+}
+
+void
+machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+void
+machine_kexec(struct kimage *image)
+{
+	unsigned long reboot_code_buffer;
+	unsigned long entry;
+	unsigned long *ptr;
+
+	reboot_code_buffer =
+	  (unsigned long)page_address(image->control_code_page);
+
+	kexec_start_address = image->start;
+	kexec_indirection_page =
+	  (unsigned long)phys_to_virt(image->head & PAGE_MASK);
+
+	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
+	       relocate_new_kernel_size);
+
+	/*
+	 * The generic kexec code builds a page list with physical
+	 * addresses. they are directly accessible through KSEG0 (or
+	 * XKSEG0 or XPHYS if on 64bit system), hence the
+	 * pys_to_virt() call.
+	 */
+	for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
+	     ptr = (entry & IND_INDIRECTION) ?
+	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
+		    *ptr & IND_DESTINATION)
+			*ptr = (unsigned long)phys_to_virt(*ptr);
+	}
+
+	printk("Will call new kernel at %08lx\n", image->start);
+	printk("Bye ...\n");
+	flush_cache_all();
+	local_irq_disable();
+	((void (*)(void))reboot_code_buffer)();
+}
diff -Nru linux-orig/arch/mips/kernel/Makefile linux-work/arch/mips/kernel/Makefile
--- linux-orig/arch/mips/kernel/Makefile	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/Makefile	2006-10-17 15:55:11.000000000 +0200
@@ -66,6 +66,8 @@
 
 obj-$(CONFIG_I8253)		+= i8253.o
 
+obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -Nru linux-orig/arch/mips/kernel/relocate_kernel.S linux-work/arch/mips/kernel/relocate_kernel.S
--- linux-orig/arch/mips/kernel/relocate_kernel.S	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/relocate_kernel.S	2006-10-17 20:01:06.000000000 +0200
@@ -0,0 +1,80 @@
+/*
+ * relocate_kernel.S for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/page.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+	.globl relocate_new_kernel
+relocate_new_kernel:
+
+	PTR_L	s0, kexec_indirection_page
+	PTR_L	s1, kexec_start_address
+
+process_entry:
+	PTR_L	s2, (s0)
+	PTR_ADD	s0, s0, SZREG
+
+	/* destination page */
+	and	s3, s2, 0x1
+	beq	s3, zero, 1f
+	and	s4, s2, ~0x1	/* store destination addr in s4 */
+	move	a0, s4
+	b	process_entry
+
+1:
+	/* indirection page, update s0  */
+	and	s3, s2, 0x2
+	beq	s3, zero, 1f
+	and	s0, s2, ~0x2
+	b	process_entry
+
+1:
+	/* done page */
+	and	s3, s2, 0x4
+	beq	s3, zero, 1f
+	b	done
+1:
+	/* source page */
+	and	s3, s2, 0x8
+	beq	s3, zero, process_entry
+	and	s2, s2, ~0x8
+	li	s6, (1 << PAGE_SHIFT) / SZREG
+
+copy_word:
+	/* copy page word by word */
+	REG_L	s5, (s2)
+	REG_S	s5, (s4)
+	INT_ADD	s4, s4, SZREG
+	INT_ADD	s2, s2, SZREG
+	INT_SUB	s6, s6, 1
+	beq	s6, zero, process_entry
+	b	copy_word
+	b	process_entry
+
+done:
+	/* jump to kexec_start_address */
+	j	s1
+
+	.globl kexec_start_address
+kexec_start_address:
+	.long	0x0
+
+	.globl kexec_indirection_page
+kexec_indirection_page:
+	.long	0x0
+
+relocate_new_kernel_end:
+
+	.globl relocate_new_kernel_size
+relocate_new_kernel_size:
+	.long relocate_new_kernel_end - relocate_new_kernel
diff -Nru linux-orig/arch/mips/kernel/scall32-o32.S linux-work/arch/mips/kernel/scall32-o32.S
--- linux-orig/arch/mips/kernel/scall32-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall32-o32.S	2006-10-17 16:23:21.000000000 +0200
@@ -662,6 +662,7 @@
 	sys	sys_tee			4
 	sys	sys_vmsplice		4
 	sys	sys_move_pages		6
+	sys	sys_kexec_load		1
 	.endm
 
 	/* We pre-compute the number of _instruction_ bytes needed to
diff -Nru linux-orig/arch/mips/kernel/scall64-64.S linux-work/arch/mips/kernel/scall64-64.S
--- linux-orig/arch/mips/kernel/scall64-64.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-64.S	2006-10-17 15:57:15.000000000 +0200
@@ -466,3 +466,4 @@
 	PTR	sys_tee				/* 5265 */
 	PTR	sys_vmsplice
 	PTR	sys_move_pages
+	PTR	sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-n32.S linux-work/arch/mips/kernel/scall64-n32.S
--- linux-orig/arch/mips/kernel/scall64-n32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-n32.S	2006-10-17 15:58:59.000000000 +0200
@@ -392,3 +392,4 @@
 	PTR	sys_tee
 	PTR	sys_vmsplice			/* 6271 */
 	PTR	sys_move_pages
+	PTR	sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-o32.S linux-work/arch/mips/kernel/scall64-o32.S
--- linux-orig/arch/mips/kernel/scall64-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-o32.S	2006-10-17 15:59:23.000000000 +0200
@@ -514,4 +514,5 @@
 	PTR	sys_tee
 	PTR	sys_vmsplice
 	PTR	compat_sys_move_pages
+	PTR	sys_kexec_load
 	.size	sys_call_table,.-sys_call_table
diff -Nru linux-orig/include/asm-mips/kexec.h linux-work/include/asm-mips/kexec.h
--- linux-orig/include/asm-mips/kexec.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/include/asm-mips/kexec.h	2006-10-18 22:39:22.000000000 +0200
@@ -0,0 +1,32 @@
+/*
+ * kexec.h for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 14:59:34 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#ifndef _MIPS_KEXEC
+# define _MIPS_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (HIGHMEM_START)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (HIGHMEM_START)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (HIGHMEM_START)
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_MIPS
+
+#define MAX_NOTE_BYTES 1024
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+				    struct pt_regs *oldregs)
+{
+	/* Dummy implementation for now */
+}
+
+#endif /* !_MIPS_KEXEC */
diff -Nru linux-orig/include/asm-mips/unistd.h linux-work/include/asm-mips/unistd.h
--- linux-orig/include/asm-mips/unistd.h	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/asm-mips/unistd.h	2006-10-17 16:07:57.000000000 +0200
@@ -329,16 +329,17 @@
 #define __NR_tee			(__NR_Linux + 306)
 #define __NR_vmsplice			(__NR_Linux + 307)
 #define __NR_move_pages			(__NR_Linux + 308)
+#define __NR_kexec_load			(__NR_Linux + 309)
 
 /*
  * Offset of the last Linux o32 flavoured syscall
  */
-#define __NR_Linux_syscalls		308
+#define __NR_Linux_syscalls		309
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
 
 #define __NR_O32_Linux			4000
-#define __NR_O32_Linux_syscalls		308
+#define __NR_O32_Linux_syscalls		309
 
 #if _MIPS_SIM == _MIPS_SIM_ABI64
 
@@ -614,16 +615,17 @@
 #define __NR_tee			(__NR_Linux + 265)
 #define __NR_vmsplice			(__NR_Linux + 266)
 #define __NR_move_pages			(__NR_Linux + 267)
+#define __NR_kexec_load			(__NR_Linux + 268)
 
 /*
  * Offset of the last Linux 64-bit flavoured syscall
  */
-#define __NR_Linux_syscalls		267
+#define __NR_Linux_syscalls		268
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
 
 #define __NR_64_Linux			5000
-#define __NR_64_Linux_syscalls		267
+#define __NR_64_Linux_syscalls		268
 
 #if _MIPS_SIM == _MIPS_SIM_NABI32
 
@@ -903,16 +905,16 @@
 #define __NR_tee			(__NR_Linux + 269)
 #define __NR_vmsplice			(__NR_Linux + 270)
 #define __NR_move_pages			(__NR_Linux + 271)
-
+#define __NR_kexec_load			(__Nr_Linux + 272)
 /*
  * Offset of the last N32 flavoured syscall
  */
-#define __NR_Linux_syscalls		271
+#define __NR_Linux_syscalls		272
 
 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
 
 #define __NR_N32_Linux			6000
-#define __NR_N32_Linux_syscalls		271
+#define __NR_N32_Linux_syscalls		272
 
 #ifdef __KERNEL__
 
diff -Nru linux-orig/include/linux/kexec.h linux-work/include/linux/kexec.h
--- linux-orig/include/linux/kexec.h	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/linux/kexec.h	2006-10-17 16:21:49.000000000 +0200
@@ -122,6 +122,8 @@
 #define KEXEC_ARCH_IA_64   (50 << 16)
 #define KEXEC_ARCH_S390    (22 << 16)
 #define KEXEC_ARCH_SH      (42 << 16)
+#define KEXEC_ARCH_MIPS_LE (10 << 16)
+#define KEXEC_ARCH_MIPS    ( 8 << 16)
 
 #define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */
 
diff -Nru linux-orig/Makefile linux-work/Makefile
--- linux-orig/Makefile	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/Makefile	2006-10-17 16:09:02.000000000 +0200
@@ -149,10 +149,11 @@
 # then ARCH is assigned, getting whatever value it gets normally, and 
 # SUBARCH is subsequently ignored.
 
-SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
-				  -e s/arm.*/arm/ -e s/sa110/arm/ \
-				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
-				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
+SUBARCH := mips
+# $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
+#				  -e s/arm.*/arm/ -e s/sa110/arm/ \
+#				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
+#				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ )
 
 # Cross compiling and selecting different set of gcc/bin-utils
 # ---------------------------------------------------------------------------

Re: [patch] [RFC] Kexec on MIPS

[Nicolas Schichan]

On Wednesday 18 October 2006 23:21, you wrote:
> Sorry for this, attached patch is as text/plain.

Sorry, this patch was apparently sent as text/diff, I forgot to set the 
correct value in my mailer. I will double check this the next time.

-- 
Nicolas Schichan

Re: [patch] [RFC] Kexec on MIPS

[Ralf Baechle]

On Wed, Oct 18, 2006 at 11:21:21PM +0200, Nicolas Schichan wrote:

One more problem:

+       sys     sys_kexec_load          1

The last column is the number of arguments slots of the syscall as counted
by the MIPS argument passing conventions, so this should actually be 4.
Not this was actually a harmless bug; it does hurt for syscalls that need
more than 4 slots.

Then buglets with O32 / N32 ABIs on 64-bit kernels:

diff -Nru linux-orig/arch/mips/kernel/scall64-n32.S linux-work/arch/mips/kernel/scall64-n32.S
--- linux-orig/arch/mips/kernel/scall64-n32.S   2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-n32.S   2006-10-17 15:58:59.000000000 +0200
@@ -392,3 +392,4 @@
        PTR     sys_tee
        PTR     sys_vmsplice                    /* 6271 */
        PTR     sys_move_pages
+       PTR     sys_kexec_load
diff -Nru linux-orig/arch/mips/kernel/scall64-o32.S linux-work/arch/mips/kernel/scall64-o32.S
--- linux-orig/arch/mips/kernel/scall64-o32.S   2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-o32.S   2006-10-17 15:59:23.000000000 +0200
@@ -514,4 +514,5 @@
        PTR     sys_tee
        PTR     sys_vmsplice
        PTR     compat_sys_move_pages
+       PTR     sys_kexec_load
        .size   sys_call_table,.-sys_call_table

That is these two being 32-bit syscalls on a 64-bit kernel need to use the
compat_sys_kexec_load syscall wrapper to work right.

And finally there are the syscall numbers.  The ones you've picked are
already taken, so I've choosen:

	O32 ABI: 4311
	N64 ABI: 5270
	N32 ABI: 6270

Note I'll allocate these syscalls immediately to give ABI stability - it's
a standard Linux syscall afterall.  So you can drop the unistd.h bits from
your patch.

And finally:

diff -Nru linux-orig/Makefile linux-work/Makefile
--- linux-orig/Makefile 2006-10-14 05:34:03.000000000 +0200
+++ linux-work/Makefile 2006-10-17 16:09:02.000000000 +0200

You may want to drop that part from your patch, too ;-)

  Ralf

Re: [patch] [RFC] Kexec on MIPS

[Nicolas Schichan]

On Thursday 19 October 2006 00:38, you wrote:
> On Wed, Oct 18, 2006 at 11:21:21PM +0200, Nicolas Schichan wrote:
> +       sys     sys_kexec_load          1
> 
> The last column is the number of arguments slots of the syscall as counted
> by the MIPS argument passing conventions, so this should actually be 4.
> Not this was actually a harmless bug; it does hurt for syscalls that need
> more than 4 slots.

This is fixed in the patch following.

> diff -Nru linux-orig/arch/mips/kernel/scall64-n32.S
> linux-work/arch/mips/kernel/scall64-n32.S ---
> linux-orig/arch/mips/kernel/scall64-n32.S   2006-10-14 05:34:03.000000000
> +0200 +++ linux-work/arch/mips/kernel/scall64-n32.S   2006-10-17
> 15:58:59.000000000 +0200 @@ -392,3 +392,4 @@
>         PTR     sys_tee
>         PTR     sys_vmsplice                    /* 6271 */
>         PTR     sys_move_pages
> +       PTR     sys_kexec_load
> diff -Nru linux-orig/arch/mips/kernel/scall64-o32.S
> linux-work/arch/mips/kernel/scall64-o32.S ---
> linux-orig/arch/mips/kernel/scall64-o32.S   2006-10-14 05:34:03.000000000
> +0200 +++ linux-work/arch/mips/kernel/scall64-o32.S   2006-10-17
> 15:59:23.000000000 +0200 @@ -514,4 +514,5 @@
>         PTR     sys_tee
>         PTR     sys_vmsplice
>         PTR     compat_sys_move_pages
> +       PTR     sys_kexec_load
>         .size   sys_call_table,.-sys_call_table
>
> That is these two being 32-bit syscalls on a 64-bit kernel need to use the
> compat_sys_kexec_load syscall wrapper to work right.

This is fixed too in the patch following.

> And finally there are the syscall numbers.  The ones you've picked are
> already taken, so I've choosen:
>
> 	O32 ABI: 4311
> 	N64 ABI: 5270
> 	N32 ABI: 6270

The patch following updates scall*.S files accordingly. however as the patch 
is against 2.6.18 kernel I had to pad the holes in the syscall table with 
sys_ni_syscall.

> Note I'll allocate these syscalls immediately to give ABI stability - it's
> a standard Linux syscall afterall.  So you can drop the unistd.h bits from
> your patch.

ok, the unistd.h changes are dropped in the attached patch.

I also made CONFIG_KEXEC depend on !CONFIG_SMP.

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>

diff -Nrup linux-orig/arch/mips/Kconfig linux-work/arch/mips/Kconfig
--- linux-orig/arch/mips/Kconfig	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/Kconfig	2006-10-19 15:18:18.000000000 +0200
@@ -820,6 +820,23 @@ config TOSHIBA_RBTX4938
 
 endchoice
 
+config KEXEC
+ 	bool "Kexec system call (EXPERIMENTAL)"
+ 	depends on EXPERIMENTAL && !SMP
+ 	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.
+
 source "arch/mips/ddb5xxx/Kconfig"
 source "arch/mips/gt64120/ev64120/Kconfig"
 source "arch/mips/jazz/Kconfig"
diff -Nrup linux-orig/arch/mips/kernel/machine_kexec.c linux-work/arch/mips/kernel/machine_kexec.c
--- linux-orig/arch/mips/kernel/machine_kexec.c	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/machine_kexec.c	2006-10-19 15:38:01.000000000 +0200
@@ -0,0 +1,79 @@
+/*
+ * machine_kexec.c for kexec
+ * Created by <nschichan@freebox.fr> on Thu Oct 12 15:15:06 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <linux/kexec.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+
+const extern unsigned char relocate_new_kernel[];
+const extern unsigned int relocate_new_kernel_size;
+
+extern unsigned long kexec_start_address;
+extern unsigned long kexec_indirection_page;
+
+int
+machine_kexec_prepare(struct kimage *kimage)
+{
+	return 0;
+}
+
+void
+machine_kexec_cleanup(struct kimage *kimage)
+{
+}
+
+void
+machine_shutdown(void)
+{
+}
+
+void
+machine_crash_shutdown(struct pt_regs *regs)
+{
+}
+
+void
+machine_kexec(struct kimage *image)
+{
+	unsigned long reboot_code_buffer;
+	unsigned long entry;
+	unsigned long *ptr;
+
+	reboot_code_buffer =
+	  (unsigned long)page_address(image->control_code_page);
+
+	kexec_start_address = image->start;
+	kexec_indirection_page =
+	  (unsigned long)phys_to_virt(image->head & PAGE_MASK);
+
+	memcpy((void*)reboot_code_buffer, relocate_new_kernel,
+	       relocate_new_kernel_size);
+
+	/*
+	 * The generic kexec code builds a page list with physical
+	 * addresses. they are directly accessible through KSEG0 (or
+	 * XKSEG0 or XPHYS if on 64bit system), hence the
+	 * pys_to_virt() call.
+	 */
+	for (ptr = &image->head; (entry = *ptr) && !(entry &IND_DONE);
+	     ptr = (entry & IND_INDIRECTION) ?
+	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
+		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
+		    *ptr & IND_DESTINATION)
+			*ptr = (unsigned long)phys_to_virt(*ptr);
+	}
+
+	printk("Will call new kernel at %08lx\n", image->start);
+	printk("Bye ...\n");
+	flush_cache_all();
+	local_irq_disable();
+	((void (*)(void))reboot_code_buffer)();
+}
diff -Nrup linux-orig/arch/mips/kernel/Makefile linux-work/arch/mips/kernel/Makefile
--- linux-orig/arch/mips/kernel/Makefile	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/Makefile	2006-10-17 15:55:11.000000000 +0200
@@ -66,6 +66,8 @@ obj-$(CONFIG_64BIT)		+= cpu-bugs64.o
 
 obj-$(CONFIG_I8253)		+= i8253.o
 
+obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o
+
 CFLAGS_cpu-bugs64.o	= $(shell if $(CC) $(CFLAGS) -Wa,-mdaddi -c -o /dev/null -xc /dev/null >/dev/null 2>&1; then echo "-DHAVE_AS_SET_DADDI"; fi)
 
 EXTRA_AFLAGS := $(CFLAGS)
diff -Nrup linux-orig/arch/mips/kernel/relocate_kernel.S linux-work/arch/mips/kernel/relocate_kernel.S
--- linux-orig/arch/mips/kernel/relocate_kernel.S	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/arch/mips/kernel/relocate_kernel.S	2006-10-19 15:37:53.000000000 +0200
@@ -0,0 +1,80 @@
+/*
+ * relocate_kernel.S for kexec
+ * Created by <nschichan@freebox.fr> on Thu Oct 12 17:49:57 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/regdef.h>
+#include <asm/page.h>
+#include <asm/mipsregs.h>
+#include <asm/stackframe.h>
+#include <asm/addrspace.h>
+
+	.globl relocate_new_kernel
+relocate_new_kernel:
+
+	PTR_L	s0, kexec_indirection_page
+	PTR_L	s1, kexec_start_address
+
+process_entry:
+	PTR_L	s2, (s0)
+	PTR_ADD	s0, s0, SZREG
+
+	/* destination page */
+	and	s3, s2, 0x1
+	beq	s3, zero, 1f
+	and	s4, s2, ~0x1	/* store destination addr in s4 */
+	move	a0, s4
+	b	process_entry
+
+1:
+	/* indirection page, update s0  */
+	and	s3, s2, 0x2
+	beq	s3, zero, 1f
+	and	s0, s2, ~0x2
+	b	process_entry
+
+1:
+	/* done page */
+	and	s3, s2, 0x4
+	beq	s3, zero, 1f
+	b	done
+1:
+	/* source page */
+	and	s3, s2, 0x8
+	beq	s3, zero, process_entry
+	and	s2, s2, ~0x8
+	li	s6, (1 << PAGE_SHIFT) / SZREG
+
+copy_word:
+	/* copy page word by word */
+	REG_L	s5, (s2)
+	REG_S	s5, (s4)
+	INT_ADD	s4, s4, SZREG
+	INT_ADD	s2, s2, SZREG
+	INT_SUB	s6, s6, 1
+	beq	s6, zero, process_entry
+	b	copy_word
+	b	process_entry
+
+done:
+	/* jump to kexec_start_address */
+	j	s1
+
+	.globl kexec_start_address
+kexec_start_address:
+	.long	0x0
+
+	.globl kexec_indirection_page
+kexec_indirection_page:
+	.long	0x0
+
+relocate_new_kernel_end:
+
+	.globl relocate_new_kernel_size
+relocate_new_kernel_size:
+	.long relocate_new_kernel_end - relocate_new_kernel
diff -Nrup linux-orig/arch/mips/kernel/scall32-o32.S linux-work/arch/mips/kernel/scall32-o32.S
--- linux-orig/arch/mips/kernel/scall32-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall32-o32.S	2006-10-19 15:10:39.000000000 +0200
@@ -662,6 +662,9 @@ einval:	li	v0, -EINVAL
 	sys	sys_tee			4
 	sys	sys_vmsplice		4
 	sys	sys_move_pages		6
+	sys	sys_ni_syscall		0
+	sys	sys_ni_syscall		0	/* 4310 */
+	sys	sys_kexec_load		4
 	.endm
 
 	/* We pre-compute the number of _instruction_ bytes needed to
diff -Nrup linux-orig/arch/mips/kernel/scall64-64.S linux-work/arch/mips/kernel/scall64-64.S
--- linux-orig/arch/mips/kernel/scall64-64.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-64.S	2006-10-19 15:14:27.000000000 +0200
@@ -466,3 +466,6 @@ sys_call_table:
 	PTR	sys_tee				/* 5265 */
 	PTR	sys_vmsplice
 	PTR	sys_move_pages
+	PTR	sys_ni_syscall
+	PTR	sys_ni_syscall
+	PTR	sys_kexec_load			/* 5270 */
diff -Nrup linux-orig/arch/mips/kernel/scall64-n32.S linux-work/arch/mips/kernel/scall64-n32.S
--- linux-orig/arch/mips/kernel/scall64-n32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-n32.S	2006-10-19 15:17:44.000000000 +0200
@@ -390,5 +390,8 @@ EXPORT(sysn32_call_table)
 	PTR	sys_splice
 	PTR	sys_sync_file_range
 	PTR	sys_tee
-	PTR	sys_vmsplice			/* 6271 */
+	PTR	sys_vmsplice			/* 6270 */
 	PTR	sys_move_pages
+	PTR	sys_ni_syscall
+	PTR	sys_ni_syscall
+	PTR	compat_sys_kexec_load
diff -Nrup linux-orig/arch/mips/kernel/scall64-o32.S linux-work/arch/mips/kernel/scall64-o32.S
--- linux-orig/arch/mips/kernel/scall64-o32.S	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/arch/mips/kernel/scall64-o32.S	2006-10-19 15:17:54.000000000 +0200
@@ -514,4 +514,7 @@ sys_call_table:
 	PTR	sys_tee
 	PTR	sys_vmsplice
 	PTR	compat_sys_move_pages
+	PTR	sys_ni_syscall
+	PTR	sys_ni_syscall			/* 4310 */
+	PTR	compat_sys_kexec_load
 	.size	sys_call_table,.-sys_call_table
diff -Nrup linux-orig/include/asm-mips/kexec.h linux-work/include/asm-mips/kexec.h
--- linux-orig/include/asm-mips/kexec.h	1970-01-01 01:00:00.000000000 +0100
+++ linux-work/include/asm-mips/kexec.h	2006-10-19 15:38:15.000000000 +0200
@@ -0,0 +1,32 @@
+/*
+ * kexec.h for kexec
+ * Created by <nschichan@freebox.fr> on Thu Oct 12 14:59:34 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#ifndef _MIPS_KEXEC
+# define _MIPS_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (HIGHMEM_START)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (HIGHMEM_START)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (HIGHMEM_START)
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_MIPS
+
+#define MAX_NOTE_BYTES 1024
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+				    struct pt_regs *oldregs)
+{
+	/* Dummy implementation for now */
+}
+
+#endif /* !_MIPS_KEXEC */
diff -Nrup linux-orig/include/linux/kexec.h linux-work/include/linux/kexec.h
--- linux-orig/include/linux/kexec.h	2006-10-14 05:34:03.000000000 +0200
+++ linux-work/include/linux/kexec.h	2006-10-17 16:21:49.000000000 +0200
@@ -122,6 +122,8 @@ extern struct kimage *kexec_crash_image;
 #define KEXEC_ARCH_IA_64   (50 << 16)
 #define KEXEC_ARCH_S390    (22 << 16)
 #define KEXEC_ARCH_SH      (42 << 16)
+#define KEXEC_ARCH_MIPS_LE (10 << 16)
+#define KEXEC_ARCH_MIPS    ( 8 << 16)
 
 #define KEXEC_FLAGS    (KEXEC_ON_CRASH)  /* List of defined/legal kexec flags */
 
-- 
Nicolas Schichan