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      1 /* SPDX-License-Identifier: GPL-2.0+ */
      2 /*
      3  * Copyright (C) 2001 - 2007 Tensilica Inc.
      4  */
      5 
      6 #ifndef _XTENSA_PTRACE_H
      7 #define _XTENSA_PTRACE_H
      8 
      9 #include <compiler.h>
     10 
     11 /*
     12  * Kernel stack
     13  *
     14  *		+-----------------------+  -------- STACK_SIZE
     15  *		|     register file     |  |
     16  *		+-----------------------+  |
     17  *		|    struct pt_regs     |  |
     18  *		+-----------------------+  | ------ PT_REGS_OFFSET
     19  * double	:  16 bytes spill area  :  |  ^
     20  * exception	:- - - - - - - - - - - -:  |  |
     21  * frame	:    struct pt_regs     :  |  |
     22  *		:- - - - - - - - - - - -:  |  |
     23  *		|                       |  |  |
     24  *		|     memory stack      |  |  |
     25  *		|                       |  |  |
     26  *		~                       ~  ~  ~
     27  *		~                       ~  ~  ~
     28  *		|                       |  |  |
     29  *		|                       |  |  |
     30  *		+-----------------------+  |  | --- STACK_BIAS
     31  *		|  struct task_struct   |  |  |  ^
     32  *  current --> +-----------------------+  |  |  |
     33  *		|  struct thread_info   |  |  |  |
     34  *		+-----------------------+ --------
     35  */
     36 
     37 #define KERNEL_STACK_SIZE (2 * PAGE_SIZE)
     38 
     39 /*  Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables) */
     40 
     41 #define EXC_TABLE_KSTK		0x004	/* Kernel Stack */
     42 #define EXC_TABLE_DOUBLE_SAVE	0x008	/* Double exception save area for a0 */
     43 #define EXC_TABLE_FIXUP		0x00c	/* Fixup handler */
     44 #define EXC_TABLE_PARAM		0x010	/* For passing a parameter to fixup */
     45 #define EXC_TABLE_SYSCALL_SAVE	0x014	/* For fast syscall handler */
     46 #define EXC_TABLE_FAST_USER	0x100	/* Fast user exception handler */
     47 #define EXC_TABLE_FAST_KERNEL	0x200	/* Fast kernel exception handler */
     48 #define EXC_TABLE_DEFAULT	0x300	/* Default C-Handler */
     49 #define EXC_TABLE_SIZE		0x400
     50 
     51 /* Registers used by strace */
     52 
     53 #define REG_A_BASE	0xfc000000
     54 #define REG_AR_BASE	0x04000000
     55 #define REG_PC		0x14000000
     56 #define REG_PS		0x080000e6
     57 #define REG_WB		0x08000048
     58 #define REG_WS		0x08000049
     59 #define REG_LBEG	0x08000000
     60 #define REG_LEND	0x08000001
     61 #define REG_LCOUNT	0x08000002
     62 #define REG_SAR		0x08000003
     63 #define REG_DEPC	0x080000c0
     64 #define REG_EXCCAUSE	0x080000e8
     65 #define REG_EXCVADDR	0x080000ee
     66 #define SYSCALL_NR	0x1
     67 
     68 #define AR_REGNO_TO_A_REGNO(ar, wb) (ar - wb*4) & ~(XCHAL_NUM_AREGS - 1)
     69 
     70 /* Other PTRACE_ values defined in <linux/ptrace.h> using values 0-9,16,17,24 */
     71 
     72 #define PTRACE_GETREGS            12
     73 #define PTRACE_SETREGS            13
     74 #define PTRACE_GETFPREGS          14
     75 #define PTRACE_SETFPREGS          15
     76 #define PTRACE_GETFPREGSIZE       18
     77 
     78 #ifndef __ASSEMBLY__
     79 
     80 /*
     81  * This struct defines the way the registers are stored on the
     82  * kernel stack during a system call or other kernel entry.
     83  */
     84 struct pt_regs {
     85 	unsigned long pc;		/*   4 */
     86 	unsigned long ps;		/*   8 */
     87 	unsigned long depc;		/*  12 */
     88 	unsigned long exccause;		/*  16 */
     89 	unsigned long excvaddr;		/*  20 */
     90 	unsigned long debugcause;	/*  24 */
     91 	unsigned long wmask;		/*  28 */
     92 	unsigned long lbeg;		/*  32 */
     93 	unsigned long lend;		/*  36 */
     94 	unsigned long lcount;		/*  40 */
     95 	unsigned long sar;		/*  44 */
     96 	unsigned long windowbase;	/*  48 */
     97 	unsigned long windowstart;	/*  52 */
     98 	unsigned long syscall;		/*  56 */
     99 	unsigned long icountlevel;	/*  60 */
    100 	int reserved[1];		/*  64 */
    101 
    102 	/* Make sure the areg field is 16 bytes aligned */
    103 	int align[0] __aligned(16);
    104 
    105 	/* current register frame.
    106 	 * Note: The ESF for kernel exceptions ends after 16 registers!
    107 	 */
    108 	unsigned long areg[16];		/* 128 (64) */
    109 };
    110 
    111 #ifdef __KERNEL__
    112 
    113 # define task_pt_regs(tsk) ((struct pt_regs *) \
    114 	(task_stack_page(tsk) + KERNEL_STACK_SIZE - (XCHAL_NUM_AREGS-16)*4) - 1)
    115 # define user_mode(regs) (((regs)->ps & 0x00000020) != 0)
    116 # define instruction_pointer(regs) ((regs)->pc)
    117 void show_regs(struct pt_regs *);
    118 
    119 # ifndef CONFIG_SMP
    120 #  define profile_pc(regs) instruction_pointer(regs)
    121 # endif
    122 #endif /* __KERNEL__ */
    123 
    124 #else	/* __ASSEMBLY__ */
    125 
    126 #ifdef __KERNEL__
    127 # include <asm/asm-offsets.h>
    128 #define PT_REGS_OFFSET	  (KERNEL_STACK_SIZE - PT_USER_SIZE)
    129 #endif
    130 
    131 #endif	/* !__ASSEMBLY__ */
    132 #endif	/* _XTENSA_PTRACE_H */
    133