linux/arch/arm/include/asm/hw_breakpoint.h
Will Deacon 6f26aa05c9 ARM: hw_breakpoint: add support for multiple watchpoints
ARM debug architecture 7.1 mandates that the DFAR is updated on a
watchpoint debug exception to contain the faulting virtual address
of the memory access. This allows us to determine which watchpoints
have fired and therefore report useful information to userspace.

This patch adds support for using the DFAR in the watchpoint handler,
which allows us to support multiple watchpoints on CPUs implementing
the new debug architecture.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2011-08-31 10:42:48 +01:00

136 lines
3.4 KiB
C

#ifndef _ARM_HW_BREAKPOINT_H
#define _ARM_HW_BREAKPOINT_H
#ifdef __KERNEL__
struct task_struct;
#ifdef CONFIG_HAVE_HW_BREAKPOINT
struct arch_hw_breakpoint_ctrl {
u32 __reserved : 9,
mismatch : 1,
: 9,
len : 8,
type : 2,
privilege : 2,
enabled : 1;
};
struct arch_hw_breakpoint {
u32 address;
u32 trigger;
struct arch_hw_breakpoint_ctrl step_ctrl;
struct arch_hw_breakpoint_ctrl ctrl;
};
static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
{
return (ctrl.mismatch << 22) | (ctrl.len << 5) | (ctrl.type << 3) |
(ctrl.privilege << 1) | ctrl.enabled;
}
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;
reg >>= 17;
ctrl->mismatch = reg & 0x1;
}
/* Debug architecture numbers. */
#define ARM_DEBUG_ARCH_RESERVED 0 /* In case of ptrace ABI updates. */
#define ARM_DEBUG_ARCH_V6 1
#define ARM_DEBUG_ARCH_V6_1 2
#define ARM_DEBUG_ARCH_V7_ECP14 3
#define ARM_DEBUG_ARCH_V7_MM 4
#define ARM_DEBUG_ARCH_V7_1 5
/* Breakpoint */
#define ARM_BREAKPOINT_EXECUTE 0
/* Watchpoints */
#define ARM_BREAKPOINT_LOAD 1
#define ARM_BREAKPOINT_STORE 2
#define ARM_FSR_ACCESS_MASK (1 << 11)
/* Privilege Levels */
#define ARM_BREAKPOINT_PRIV 1
#define ARM_BREAKPOINT_USER 2
/* 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
/* Limits */
#define ARM_MAX_BRP 16
#define ARM_MAX_WRP 16
#define ARM_MAX_HBP_SLOTS (ARM_MAX_BRP + ARM_MAX_WRP)
/* DSCR method of entry bits. */
#define ARM_DSCR_MOE(x) ((x >> 2) & 0xf)
#define ARM_ENTRY_BREAKPOINT 0x1
#define ARM_ENTRY_ASYNC_WATCHPOINT 0x2
#define ARM_ENTRY_SYNC_WATCHPOINT 0xa
/* DSCR monitor/halting bits. */
#define ARM_DSCR_HDBGEN (1 << 14)
#define ARM_DSCR_MDBGEN (1 << 15)
/* opcode2 numbers for the co-processor instructions. */
#define ARM_OP2_BVR 4
#define ARM_OP2_BCR 5
#define ARM_OP2_WVR 6
#define ARM_OP2_WCR 7
/* Base register numbers for the debug registers. */
#define ARM_BASE_BVR 64
#define ARM_BASE_BCR 80
#define ARM_BASE_WVR 96
#define ARM_BASE_WCR 112
/* Accessor macros for the debug registers. */
#define ARM_DBG_READ(M, OP2, VAL) do {\
asm volatile("mrc p14, 0, %0, c0," #M ", " #OP2 : "=r" (VAL));\
} while (0)
#define ARM_DBG_WRITE(M, OP2, VAL) do {\
asm volatile("mcr p14, 0, %0, c0," #M ", " #OP2 : : "r" (VAL));\
} while (0)
struct notifier_block;
struct perf_event;
struct pmu;
extern struct pmu perf_ops_bp;
extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
int *gen_len, int *gen_type);
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 u8 arch_get_debug_arch(void);
extern u8 arch_get_max_wp_len(void);
extern void clear_ptrace_hw_breakpoint(struct task_struct *tsk);
int arch_install_hw_breakpoint(struct perf_event *bp);
void arch_uninstall_hw_breakpoint(struct perf_event *bp);
void hw_breakpoint_pmu_read(struct perf_event *bp);
int hw_breakpoint_slots(int type);
#else
static inline void clear_ptrace_hw_breakpoint(struct task_struct *tsk) {}
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif /* __KERNEL__ */
#endif /* _ARM_HW_BREAKPOINT_H */