/* * kexec for arm64 * * Copyright (C) Linaro. * Copyright (C) Huawei Futurewei Technologies. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/kexec.h>#include <linux/linkage.h> #include <asm/assembler.h>#include <asm/kexec.h>#include <asm/page.h>#include <asm/sysreg.h> /* * arm64_relocate_new_kernel - Put a 2nd stage image in place and boot it. * * The memory that the old kernel occupies may be overwritten when coping the * new image to its final location.  To assure that the * arm64_relocate_new_kernel routine which does that copy is not overwritten, * all code and data needed by arm64_relocate_new_kernel must be between the * symbols arm64_relocate_new_kernel and arm64_relocate_new_kernel_end.  The * machine_kexec() routine will copy arm64_relocate_new_kernel to the kexec * control_code_page, a special page which has been set up to be preserved * during the copy operation. */ENTRY(arm64_relocate_new_kernel) 	/* Setup the list loop variables. */	mov	x17, x1				/* x17 = kimage_start */	mov	x16, x0				/* x16 = kimage_head */	raw_dcache_line_size x15, x0		/* x15 = dcache line size */	mov	x14, xzr			/* x14 = entry ptr */	mov	x13, xzr			/* x13 = copy dest */ 	/* Clear the sctlr_el2 flags. */	mrs	x0, CurrentEL	cmp	x0, #CurrentEL_EL2	b.ne	1f	mrs	x0, sctlr_el2	ldr	x1, =SCTLR_ELx_FLAGS	bic	x0, x0, x1	msr	sctlr_el2, x0	isb1: 	/* Check if the new image needs relocation. */	tbnz	x16, IND_DONE_BIT, .Ldone .Lloop:	and	x12, x16, PAGE_MASK		/* x12 = addr */ 	/* Test the entry flags. */.Ltest_source:	tbz	x16, IND_SOURCE_BIT, .Ltest_indirection 	/* Invalidate dest page to PoC. */	mov     x0, x13	add     x20, x0, #PAGE_SIZE	sub     x1, x15, #1	bic     x0, x0, x12:	dc      ivac, x0	add     x0, x0, x15	cmp     x0, x20	b.lo    2b	dsb     sy 	mov x20, x13	mov x21, x12	copy_page x20, x21, x0, x1, x2, x3, x4, x5, x6, x7 	/* dest += PAGE_SIZE */	add	x13, x13, PAGE_SIZE	b	.Lnext .Ltest_indirection:	tbz	x16, IND_INDIRECTION_BIT, .Ltest_destination 	/* ptr = addr */	mov	x14, x12	b	.Lnext .Ltest_destination:	tbz	x16, IND_DESTINATION_BIT, .Lnext 	/* dest = addr */	mov	x13, x12 .Lnext:	/* entry = *ptr++ */	ldr	x16, [x14], #8 	/* while (!(entry & DONE)) */	tbz	x16, IND_DONE_BIT, .Lloop .Ldone:	/* wait for writes from copy_page to finish */	dsb	nsh	ic	iallu	dsb	nsh	isb 	/* Start new image. */	mov	x0, xzr	mov	x1, xzr	mov	x2, xzr	mov	x3, xzr	br	x17 ENDPROC(arm64_relocate_new_kernel) .ltorg .align 3	/* To keep the 64-bit values below naturally aligned. */ .Lcopy_end:.org	KEXEC_CONTROL_PAGE_SIZE /* * arm64_relocate_new_kernel_size - Number of bytes to copy to the * control_code_page. */.globl arm64_relocate_new_kernel_sizearm64_relocate_new_kernel_size:	.quad	.Lcopy_end - arm64_relocate_new_kernel