alistair23-linux/arch/xtensa/include/asm/regs.h
Max Filippov c91e02bd97 xtensa: support hardware breakpoints/watchpoints
Use perf framework to manage hardware instruction and data breakpoints.
Add two new ptrace calls: PTRACE_GETHBPREGS and PTRACE_SETHBPREGS to
query and set instruction and data breakpoints.
Address bit 0 choose instruction (0) or data (1) break register, bits
31..1 are the register number.
Both calls transfer two 32-bit words: address (0) and control (1).
Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set.
Data breakpoint control word bit 31 is 'trigger on store', bit 30 is
'trigger on load, bits 29..0 are length. Length 0 is used to clear a
breakpoint. To set a breakpoint length must be a power of 2 in the range
1..64 and the address must be length-aligned.

Introduce new thread_info flag: TIF_DB_DISABLED. Set it if debug
exception is raised by the kernel code accessing watched userspace
address and disable corresponding data breakpoint. On exit to userspace
check that flag and, if set, restore all data breakpoints.

Handle debug exceptions raised with PS.EXCM set. This may happen when
window overflow/underflow handler or fast exception handler hits data
breakpoint, in which case save and disable all data breakpoints,
single-step faulting instruction and restore data breakpoints.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2016-03-11 08:53:32 +00:00

117 lines
3.9 KiB
C

/*
* Copyright (c) 2006 Tensilica, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2.1 of the GNU Lesser General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Further, this software is distributed without any warranty that it is
* free of the rightful claim of any third person regarding infringement
* or the like. Any license provided herein, whether implied or
* otherwise, applies only to this software file. Patent licenses, if
* any, provided herein do not apply to combinations of this program with
* other software, or any other product whatsoever.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307,
* USA.
*/
#ifndef _XTENSA_REGS_H
#define _XTENSA_REGS_H
/* Special registers. */
#define SREG_MR 32
#define SREG_IBREAKENABLE 96
#define SREG_IBREAKA 128
#define SREG_DBREAKA 144
#define SREG_DBREAKC 160
#define SREG_EPC 176
#define SREG_EPS 192
#define SREG_EXCSAVE 208
#define SREG_CCOMPARE 240
#define SREG_MISC 244
/* EXCCAUSE register fields */
#define EXCCAUSE_EXCCAUSE_SHIFT 0
#define EXCCAUSE_EXCCAUSE_MASK 0x3F
#define EXCCAUSE_ILLEGAL_INSTRUCTION 0
#define EXCCAUSE_SYSTEM_CALL 1
#define EXCCAUSE_INSTRUCTION_FETCH_ERROR 2
#define EXCCAUSE_LOAD_STORE_ERROR 3
#define EXCCAUSE_LEVEL1_INTERRUPT 4
#define EXCCAUSE_ALLOCA 5
#define EXCCAUSE_INTEGER_DIVIDE_BY_ZERO 6
#define EXCCAUSE_SPECULATION 7
#define EXCCAUSE_PRIVILEGED 8
#define EXCCAUSE_UNALIGNED 9
#define EXCCAUSE_INSTR_DATA_ERROR 12
#define EXCCAUSE_LOAD_STORE_DATA_ERROR 13
#define EXCCAUSE_INSTR_ADDR_ERROR 14
#define EXCCAUSE_LOAD_STORE_ADDR_ERROR 15
#define EXCCAUSE_ITLB_MISS 16
#define EXCCAUSE_ITLB_MULTIHIT 17
#define EXCCAUSE_ITLB_PRIVILEGE 18
#define EXCCAUSE_ITLB_SIZE_RESTRICTION 19
#define EXCCAUSE_FETCH_CACHE_ATTRIBUTE 20
#define EXCCAUSE_DTLB_MISS 24
#define EXCCAUSE_DTLB_MULTIHIT 25
#define EXCCAUSE_DTLB_PRIVILEGE 26
#define EXCCAUSE_DTLB_SIZE_RESTRICTION 27
#define EXCCAUSE_LOAD_CACHE_ATTRIBUTE 28
#define EXCCAUSE_STORE_CACHE_ATTRIBUTE 29
#define EXCCAUSE_COPROCESSOR0_DISABLED 32
#define EXCCAUSE_COPROCESSOR1_DISABLED 33
#define EXCCAUSE_COPROCESSOR2_DISABLED 34
#define EXCCAUSE_COPROCESSOR3_DISABLED 35
#define EXCCAUSE_COPROCESSOR4_DISABLED 36
#define EXCCAUSE_COPROCESSOR5_DISABLED 37
#define EXCCAUSE_COPROCESSOR6_DISABLED 38
#define EXCCAUSE_COPROCESSOR7_DISABLED 39
/* PS register fields. */
#define PS_WOE_BIT 18
#define PS_CALLINC_SHIFT 16
#define PS_CALLINC_MASK 0x00030000
#define PS_OWB_SHIFT 8
#define PS_OWB_WIDTH 4
#define PS_OWB_MASK 0x00000F00
#define PS_RING_SHIFT 6
#define PS_RING_MASK 0x000000C0
#define PS_UM_BIT 5
#define PS_EXCM_BIT 4
#define PS_INTLEVEL_SHIFT 0
#define PS_INTLEVEL_WIDTH 4
#define PS_INTLEVEL_MASK 0x0000000F
/* DBREAKCn register fields. */
#define DBREAKC_MASK_BIT 0
#define DBREAKC_MASK_MASK 0x0000003F
#define DBREAKC_LOAD_BIT 30
#define DBREAKC_LOAD_MASK 0x40000000
#define DBREAKC_STOR_BIT 31
#define DBREAKC_STOR_MASK 0x80000000
/* DEBUGCAUSE register fields. */
#define DEBUGCAUSE_DBNUM_MASK 0xf00
#define DEBUGCAUSE_DBNUM_SHIFT 8 /* First bit of DBNUM field */
#define DEBUGCAUSE_DEBUGINT_BIT 5 /* External debug interrupt */
#define DEBUGCAUSE_BREAKN_BIT 4 /* BREAK.N instruction */
#define DEBUGCAUSE_BREAK_BIT 3 /* BREAK instruction */
#define DEBUGCAUSE_DBREAK_BIT 2 /* DBREAK match */
#define DEBUGCAUSE_IBREAK_BIT 1 /* IBREAK match */
#define DEBUGCAUSE_ICOUNT_BIT 0 /* ICOUNT would incr. to zero */
#endif /* _XTENSA_SPECREG_H */