alistair23-linux/arch/arm64/include/asm/hw_breakpoint.h
Pratyush Anand b08fb180bb arm64: Allow hw watchpoint at varied offset from base address
ARM64 hardware supports watchpoint at any double word aligned address.
However, it can select any consecutive bytes from offset 0 to 7 from that
base address. For example, if base address is programmed as 0x420030 and
byte select is 0x1C, then access of 0x420032,0x420033 and 0x420034 will
generate a watchpoint exception.

Currently, we do not have such modularity. We can only program byte,
halfword, word and double word access exception from any base address.

This patch adds support to overcome above limitations.

Signed-off-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-11-18 17:23:17 +00:00

165 lines
4.3 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_HW_BREAKPOINT_H
#define __ASM_HW_BREAKPOINT_H
#include <asm/cputype.h>
#include <asm/cpufeature.h>
#include <asm/sysreg.h>
#include <asm/virt.h>
#ifdef __KERNEL__
struct arch_hw_breakpoint_ctrl {
u32 __reserved : 19,
len : 8,
type : 2,
privilege : 2,
enabled : 1;
};
struct arch_hw_breakpoint {
u64 address;
u64 trigger;
struct arch_hw_breakpoint_ctrl ctrl;
};
/* Privilege Levels */
#define AARCH64_BREAKPOINT_EL1 1
#define AARCH64_BREAKPOINT_EL0 2
#define DBG_HMC_HYP (1 << 13)
static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
{
u32 val = (ctrl.len << 5) | (ctrl.type << 3) | (ctrl.privilege << 1) |
ctrl.enabled;
if (is_kernel_in_hyp_mode() && ctrl.privilege == AARCH64_BREAKPOINT_EL1)
val |= DBG_HMC_HYP;
return val;
}
static inline void decode_ctrl_reg(u32 reg,
struct arch_hw_breakpoint_ctrl *ctrl)
{
ctrl->enabled = reg & 0x1;
reg >>= 1;
ctrl->privilege = reg & 0x3;
reg >>= 2;
ctrl->type = reg & 0x3;
reg >>= 2;
ctrl->len = reg & 0xff;
}
/* Breakpoint */
#define ARM_BREAKPOINT_EXECUTE 0
/* Watchpoints */
#define ARM_BREAKPOINT_LOAD 1
#define ARM_BREAKPOINT_STORE 2
#define AARCH64_ESR_ACCESS_MASK (1 << 6)
/* Lengths */
#define ARM_BREAKPOINT_LEN_1 0x1
#define ARM_BREAKPOINT_LEN_2 0x3
#define ARM_BREAKPOINT_LEN_4 0xf
#define ARM_BREAKPOINT_LEN_8 0xff
/* Kernel stepping */
#define ARM_KERNEL_STEP_NONE 0
#define ARM_KERNEL_STEP_ACTIVE 1
#define ARM_KERNEL_STEP_SUSPEND 2
/*
* Limits.
* Changing these will require modifications to the register accessors.
*/
#define ARM_MAX_BRP 16
#define ARM_MAX_WRP 16
/* Virtual debug register bases. */
#define AARCH64_DBG_REG_BVR 0
#define AARCH64_DBG_REG_BCR (AARCH64_DBG_REG_BVR + ARM_MAX_BRP)
#define AARCH64_DBG_REG_WVR (AARCH64_DBG_REG_BCR + ARM_MAX_BRP)
#define AARCH64_DBG_REG_WCR (AARCH64_DBG_REG_WVR + ARM_MAX_WRP)
/* Debug register names. */
#define AARCH64_DBG_REG_NAME_BVR bvr
#define AARCH64_DBG_REG_NAME_BCR bcr
#define AARCH64_DBG_REG_NAME_WVR wvr
#define AARCH64_DBG_REG_NAME_WCR wcr
/* Accessor macros for the debug registers. */
#define AARCH64_DBG_READ(N, REG, VAL) do {\
VAL = read_sysreg(dbg##REG##N##_el1);\
} while (0)
#define AARCH64_DBG_WRITE(N, REG, VAL) do {\
write_sysreg(VAL, dbg##REG##N##_el1);\
} while (0)
struct task_struct;
struct notifier_block;
struct perf_event;
struct pmu;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
int *gen_len, int *gen_type, int *offset);
extern int arch_check_bp_in_kernelspace(struct perf_event *bp);
extern int arch_validate_hwbkpt_settings(struct perf_event *bp);
extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
unsigned long val, void *data);
extern int arch_install_hw_breakpoint(struct perf_event *bp);
extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
extern void hw_breakpoint_pmu_read(struct perf_event *bp);
extern int hw_breakpoint_slots(int type);
#ifdef CONFIG_HAVE_HW_BREAKPOINT
extern void hw_breakpoint_thread_switch(struct task_struct *next);
extern void ptrace_hw_copy_thread(struct task_struct *task);
#else
static inline void hw_breakpoint_thread_switch(struct task_struct *next)
{
}
static inline void ptrace_hw_copy_thread(struct task_struct *task)
{
}
#endif
/* Determine number of BRP registers available. */
static inline int get_num_brps(void)
{
u64 dfr0 = read_system_reg(SYS_ID_AA64DFR0_EL1);
return 1 +
cpuid_feature_extract_unsigned_field(dfr0,
ID_AA64DFR0_BRPS_SHIFT);
}
/* Determine number of WRP registers available. */
static inline int get_num_wrps(void)
{
u64 dfr0 = read_system_reg(SYS_ID_AA64DFR0_EL1);
return 1 +
cpuid_feature_extract_unsigned_field(dfr0,
ID_AA64DFR0_WRPS_SHIFT);
}
#endif /* __KERNEL__ */
#endif /* __ASM_BREAKPOINT_H */