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linux/arch/x86/include/asm/hw_breakpoint.h
Frederic Weisbecker feef47d0cb hw-breakpoints: Get the number of available registers on boot dynamically
The breakpoint generic layer assumes that archs always know in advance
the static number of address registers available to host breakpoints
through the HBP_NUM macro.

However this is not true for every archs. For example Arm needs to get
this information dynamically to handle the compatiblity between
different versions.

To solve this, this patch proposes to drop the static HBP_NUM macro
and let the arch provide the number of available slots through a
new hw_breakpoint_slots() function. For archs that have
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS selected, it will be called once
as the number of registers fits for instruction and data breakpoints
together.
For the others it will be called first to get the number of
instruction breakpoint registers and another time to get the
data breakpoint registers, the targeted type is given as a
parameter of hw_breakpoint_slots().

Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
2010-05-01 04:32:14 +02:00

77 lines
1.9 KiB
C

#ifndef _I386_HW_BREAKPOINT_H
#define _I386_HW_BREAKPOINT_H
#ifdef __KERNEL__
#define __ARCH_HW_BREAKPOINT_H
/*
* The name should probably be something dealt in
* a higher level. While dealing with the user
* (display/resolving)
*/
struct arch_hw_breakpoint {
unsigned long address;
u8 len;
u8 type;
};
#include <linux/kdebug.h>
#include <linux/percpu.h>
#include <linux/list.h>
/* Available HW breakpoint length encodings */
#define X86_BREAKPOINT_LEN_1 0x40
#define X86_BREAKPOINT_LEN_2 0x44
#define X86_BREAKPOINT_LEN_4 0x4c
#define X86_BREAKPOINT_LEN_EXECUTE 0x40
#ifdef CONFIG_X86_64
#define X86_BREAKPOINT_LEN_8 0x48
#endif
/* Available HW breakpoint type encodings */
/* trigger on instruction execute */
#define X86_BREAKPOINT_EXECUTE 0x80
/* trigger on memory write */
#define X86_BREAKPOINT_WRITE 0x81
/* trigger on memory read or write */
#define X86_BREAKPOINT_RW 0x83
/* Total number of available HW breakpoint registers */
#define HBP_NUM 4
static inline int hw_breakpoint_slots(int type)
{
return HBP_NUM;
}
struct perf_event;
struct pmu;
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);
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);
void hw_breakpoint_pmu_unthrottle(struct perf_event *bp);
extern void
arch_fill_perf_breakpoint(struct perf_event *bp);
unsigned long encode_dr7(int drnum, unsigned int len, unsigned int type);
int decode_dr7(unsigned long dr7, int bpnum, unsigned *len, unsigned *type);
extern int arch_bp_generic_fields(int x86_len, int x86_type,
int *gen_len, int *gen_type);
extern struct pmu perf_ops_bp;
#endif /* __KERNEL__ */
#endif /* _I386_HW_BREAKPOINT_H */