[ARM] 4137/1: Add kexec support (c587e4a6) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm/Kconfig

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Original line number	Original line	Diff line number	Diff line
	@@ -738,6 +738,20 @@ config XIP_PHYS_ADDR
	be linked for and stored to. This address is dependent on your		be linked for and stored to. This address is dependent on your
	own flash usage.		own flash usage.

			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.

			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.

	endmenu		endmenu

	if (ARCH_SA1100 \|\| ARCH_INTEGRATOR \|\| ARCH_OMAP \|\| ARCH_IMX )		if (ARCH_SA1100 \|\| ARCH_INTEGRATOR \|\| ARCH_OMAP \|\| ARCH_IMX )

arch/arm/kernel/Makefile

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Original line number	Original line	Diff line number	Diff line
	@@ -19,6 +19,7 @@ obj-$(CONFIG_ARTHUR) += arthur.o
	obj-$(CONFIG_ISA_DMA) += dma-isa.o		obj-$(CONFIG_ISA_DMA) += dma-isa.o
	obj-$(CONFIG_PCI) += bios32.o isa.o		obj-$(CONFIG_PCI) += bios32.o isa.o
	obj-$(CONFIG_SMP) += smp.o		obj-$(CONFIG_SMP) += smp.o
			obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
	obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o		obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o

	obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o		obj-$(CONFIG_CRUNCH) += crunch.o crunch-bits.o

arch/arm/kernel/calls.S

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -356,6 +356,7 @@
	CALL(sys_move_pages)		CALL(sys_move_pages)
	/* 345 */ CALL(sys_getcpu)		/* 345 */ CALL(sys_getcpu)
	CALL(sys_ni_syscall) /* eventually epoll_pwait */		CALL(sys_ni_syscall) /* eventually epoll_pwait */
			CALL(sys_kexec_load)
	#ifndef syscalls_counted		#ifndef syscalls_counted
	.equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls		.equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
	#define syscalls_counted		#define syscalls_counted

arch/arm/kernel/machine_kexec.c

0 → 100644

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			/*
			* machine_kexec.c - handle transition of Linux booting another kernel
			*/

			#include <linux/mm.h>
			#include <linux/kexec.h>
			#include <linux/delay.h>
			#include <linux/reboot.h>
			#include <asm/pgtable.h>
			#include <asm/pgalloc.h>
			#include <asm/mmu_context.h>
			#include <asm/io.h>
			#include <asm/cacheflush.h>
			#include <asm/mach-types.h>

			const extern unsigned char relocate_new_kernel[];
			const extern unsigned int relocate_new_kernel_size;

			extern void setup_mm_for_reboot(char mode);

			extern unsigned long kexec_start_address;
			extern unsigned long kexec_indirection_page;
			extern unsigned long kexec_mach_type;

			/*
			* Provide a dummy crash_notes definition while crash dump arrives to arm.
			* This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
			*/

			int machine_kexec_prepare(struct kimage *image)
			{
			return 0;
			}

			void machine_kexec_cleanup(struct kimage *image)
			{
			}

			void machine_shutdown(void)
			{
			}

			void machine_crash_shutdown(struct pt_regs *regs)
			{
			}

			void machine_kexec(struct kimage *image)
			{
			unsigned long page_list;
			unsigned long reboot_code_buffer_phys;
			void *reboot_code_buffer;


			page_list = image->head & PAGE_MASK;

			/* we need both effective and real address here */
			reboot_code_buffer_phys =
			page_to_pfn(image->control_code_page) << PAGE_SHIFT;
			reboot_code_buffer = page_address(image->control_code_page);

			/* Prepare parameters for reboot_code_buffer*/
			kexec_start_address = image->start;
			kexec_indirection_page = page_list;
			kexec_mach_type = machine_arch_type;

			/* copy our kernel relocation code to the control code page */
			memcpy(reboot_code_buffer,
			relocate_new_kernel, relocate_new_kernel_size);


			flush_icache_range((unsigned long) reboot_code_buffer,
			(unsigned long) reboot_code_buffer + KEXEC_CONTROL_CODE_SIZE);
			printk(KERN_INFO "Bye!\n");

			cpu_proc_fin();
			setup_mm_for_reboot(0); /* mode is not used, so just pass 0*/
			cpu_reset(reboot_code_buffer_phys);
			}

arch/arm/kernel/relocate_kernel.S

0 → 100644

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Original line number	Original line	Diff line number	Diff line
			/*
			* relocate_kernel.S - put the kernel image in place to boot
			*/

			#include <asm/kexec.h>

			.globl relocate_new_kernel
			relocate_new_kernel:

			ldr r0,kexec_indirection_page
			ldr r1,kexec_start_address


			0: /* top, read another word for the indirection page */
			ldr r3, [r0],#4

			/* Is it a destination page. Put destination address to r4 */
			tst r3,#1,0
			beq 1f
			bic r4,r3,#1
			b 0b
			1:
			/* Is it an indirection page */
			tst r3,#2,0
			beq 1f
			bic r0,r3,#2
			b 0b
			1:

			/* are we done ? */
			tst r3,#4,0
			beq 1f
			b 2f

			1:
			/* is it source ? */
			tst r3,#8,0
			beq 0b
			bic r3,r3,#8
			mov r6,#1024
			9:
			ldr r5,[r3],#4
			str r5,[r4],#4
			subs r6,r6,#1
			bne 9b
			b 0b

			2:
			/* Jump to relocated kernel */
			mov lr,r1
			mov r0,#0
			ldr r1,kexec_mach_type
			mov r2,#0
			mov pc,lr

			.globl kexec_start_address
			kexec_start_address:
			.long 0x0

			.globl kexec_indirection_page
			kexec_indirection_page:
			.long 0x0

			.globl kexec_mach_type
			kexec_mach_type:
			.long 0x0

			relocate_new_kernel_end:

			.globl relocate_new_kernel_size
			relocate_new_kernel_size:
			.long relocate_new_kernel_end - relocate_new_kernel