164 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
		
		
			
		
	
	
			164 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
|   | /* | ||
|  |  * linux/arch/unicore32/lib/backtrace.S | ||
|  |  * | ||
|  |  * Code specific to PKUnity SoC and UniCore ISA | ||
|  |  * | ||
|  |  * Copyright (C) 2001-2010 GUAN Xue-tao | ||
|  |  * | ||
|  |  * 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/linkage.h> | ||
|  | #include <asm/assembler.h> | ||
|  | 		.text | ||
|  | 
 | ||
|  | @ fp is 0 or stack frame
 | ||
|  | 
 | ||
|  | #define frame	v4 | ||
|  | #define sv_fp	v5 | ||
|  | #define sv_pc	v6 | ||
|  | #define offset	v8 | ||
|  | 
 | ||
|  | ENTRY(__backtrace) | ||
|  | 		mov	r0, fp | ||
|  | 
 | ||
|  | ENTRY(c_backtrace) | ||
|  | 
 | ||
|  | #if !defined(CONFIG_FRAME_POINTER) || !defined(CONFIG_PRINTK) | ||
|  | 		mov	pc, lr | ||
|  | ENDPROC(__backtrace) | ||
|  | ENDPROC(c_backtrace) | ||
|  | #else | ||
|  | 		stm.w	(v4 - v8, lr), [sp-]	@ Save an extra register
 | ||
|  | 						@ so we have a location...
 | ||
|  | 		mov.a	frame, r0		@ if frame pointer is zero
 | ||
|  | 		beq	no_frame		@ we have no stack frames
 | ||
|  | 
 | ||
|  | 1:		stm.w	(pc), [sp-]		@ calculate offset of PC stored
 | ||
|  | 		ldw.w	r0, [sp]+, #4		@ by stmfd for this CPU
 | ||
|  | 		adr	r1, 1b | ||
|  | 		sub	offset, r0, r1 | ||
|  | 
 | ||
|  | /* | ||
|  |  * Stack frame layout: | ||
|  |  *             optionally saved caller registers (r4 - r10) | ||
|  |  *             saved fp | ||
|  |  *             saved sp | ||
|  |  *             saved lr | ||
|  |  *    frame => saved pc | ||
|  |  *             optionally saved arguments (r0 - r3) | ||
|  |  * saved sp => <next word> | ||
|  |  * | ||
|  |  * Functions start with the following code sequence: | ||
|  |  *                  mov   ip, sp | ||
|  |  *                  stm.w (r0 - r3), [sp-] (optional) | ||
|  |  * corrected pc =>  stm.w sp, (..., fp, ip, lr, pc) | ||
|  |  */ | ||
|  | for_each_frame: | ||
|  | 
 | ||
|  | 1001:		ldw	sv_pc, [frame+], #0	@ get saved pc
 | ||
|  | 1002:		ldw	sv_fp, [frame+], #-12	@ get saved fp
 | ||
|  | 
 | ||
|  | 		sub	sv_pc, sv_pc, offset	@ Correct PC for prefetching
 | ||
|  | 
 | ||
|  | 1003:		ldw	r2, [sv_pc+], #-4	@ if stmfd sp, {args} exists,
 | ||
|  | 		ldw	r3, .Ldsi+4		@ adjust saved 'pc' back one
 | ||
|  | 		cxor.a	r3, r2 >> #14		@ instruction
 | ||
|  | 		beq	201f | ||
|  | 		sub	r0, sv_pc, #4		@ allow for mov
 | ||
|  | 		b	202f | ||
|  | 201: | ||
|  | 		sub	r0, sv_pc, #8		@ allow for mov + stmia
 | ||
|  | 202: | ||
|  | 		ldw	r1, [frame+], #-4	@ get saved lr
 | ||
|  | 		mov	r2, frame | ||
|  | 		b.l	dump_backtrace_entry | ||
|  | 
 | ||
|  | 		ldw	r1, [sv_pc+], #-4	@ if stmfd sp, {args} exists,
 | ||
|  | 		ldw	r3, .Ldsi+4 | ||
|  | 		cxor.a	r3, r1 >> #14 | ||
|  | 		bne	1004f | ||
|  | 		ldw	r0, [frame+], #-8	@ get sp
 | ||
|  | 		sub	r0, r0, #4		@ point at the last arg
 | ||
|  | 		b.l	.Ldumpstm		@ dump saved registers
 | ||
|  | 
 | ||
|  | 1004:		ldw	r1, [sv_pc+], #0	@ if stmfd {, fp, ip, lr, pc}
 | ||
|  | 		ldw	r3, .Ldsi		@ instruction exists,
 | ||
|  | 		cxor.a	r3, r1 >> #14 | ||
|  | 		bne	201f | ||
|  | 		sub	r0, frame, #16 | ||
|  | 		b.l	.Ldumpstm		@ dump saved registers
 | ||
|  | 201: | ||
|  | 		cxor.a	sv_fp, #0		@ zero saved fp means
 | ||
|  | 		beq	no_frame		@ no further frames
 | ||
|  | 
 | ||
|  | 		csub.a	sv_fp, frame		@ next frame must be
 | ||
|  | 		mov	frame, sv_fp		@ above the current frame
 | ||
|  | 		bua	for_each_frame | ||
|  | 
 | ||
|  | 1006:		adr	r0, .Lbad | ||
|  | 		mov	r1, frame | ||
|  | 		b.l	printk | ||
|  | no_frame:	ldm.w	(v4 - v8, pc), [sp]+ | ||
|  | ENDPROC(__backtrace) | ||
|  | ENDPROC(c_backtrace) | ||
|  | 
 | ||
|  | 		.pushsection __ex_table,"a" | ||
|  | 		.align	3
 | ||
|  | 		.long	1001b, 1006b | ||
|  | 		.long	1002b, 1006b | ||
|  | 		.long	1003b, 1006b | ||
|  | 		.long	1004b, 1006b | ||
|  | 		.popsection | ||
|  | 
 | ||
|  | #define instr v4 | ||
|  | #define reg   v5 | ||
|  | #define stack v6 | ||
|  | 
 | ||
|  | .Ldumpstm:	stm.w	(instr, reg, stack, v7, lr), [sp-] | ||
|  | 		mov	stack, r0 | ||
|  | 		mov	instr, r1 | ||
|  | 		mov	reg, #14 | ||
|  | 		mov	v7, #0 | ||
|  | 1:		mov	r3, #1 | ||
|  | 		csub.a	reg, #8 | ||
|  | 		bne	201f | ||
|  | 		sub	reg, reg, #3 | ||
|  | 201: | ||
|  | 		cand.a	instr, r3 << reg | ||
|  | 		beq	2f | ||
|  | 		add	v7, v7, #1 | ||
|  | 		cxor.a	v7, #6 | ||
|  | 		cmoveq	v7, #1 | ||
|  | 		cmoveq	r1, #'\n' | ||
|  | 		cmovne	r1, #' ' | ||
|  | 		ldw.w	r3, [stack]+, #-4 | ||
|  | 		mov	r2, reg | ||
|  | 		csub.a	r2, #8 | ||
|  | 		bsl	201f | ||
|  | 		sub	r2, r2, #3 | ||
|  | 201: | ||
|  | 		cand.a	instr, #0x40		@ if H is 1, high 16 regs
 | ||
|  | 		beq	201f | ||
|  | 		add	r2, r2, #0x10		@ so r2 need add 16
 | ||
|  | 201: | ||
|  | 		adr	r0, .Lfp | ||
|  | 		b.l	printk | ||
|  | 2:		sub.a	reg, reg, #1 | ||
|  | 		bns	1b | ||
|  | 		cxor.a	v7, #0 | ||
|  | 		beq	201f | ||
|  | 		adr	r0, .Lcr | ||
|  | 		b.l	printk | ||
|  | 201:		ldm.w	(instr, reg, stack, v7, pc), [sp]+ | ||
|  | 
 | ||
|  | .Lfp:		.asciz	"%cr%d:%08x" | ||
|  | .Lcr:		.asciz	"\n" | ||
|  | .Lbad:		.asciz	"Backtrace aborted due to bad frame pointer <%p>\n" | ||
|  | 		.align | ||
|  | .Ldsi:		.word	0x92eec000 >> 14	@ stm.w sp, (... fp, ip, lr, pc)
 | ||
|  | 		.word	0x92e10000 >> 14	@ stm.w sp, ()
 | ||
|  | 
 | ||
|  | #endif |