powerpc: Hardware breakpoints rewrite to handle non DABR breakpoint registers
This is a rewrite so that we don't assume we are using the DABR throughout the
code. We now use the arch_hw_breakpoint to store the breakpoint in a generic
manner in the thread_struct, rather than storing the raw DABR value.
The ptrace GET/SET_DEBUGREG interface currently passes the raw DABR in from
userspace. We keep this functionality, so that future changes (like the POWER8
DAWR), will still fake the DABR to userspace.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 32de257..8d85ffb 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -4,6 +4,8 @@
#ifndef _ASM_POWERPC_DEBUG_H
#define _ASM_POWERPC_DEBUG_H
+#include <asm/hw_breakpoint.h>
+
struct pt_regs;
extern struct dentry *powerpc_debugfs_root;
@@ -15,7 +17,7 @@
extern int (*__debugger_bpt)(struct pt_regs *regs);
extern int (*__debugger_sstep)(struct pt_regs *regs);
extern int (*__debugger_iabr_match)(struct pt_regs *regs);
-extern int (*__debugger_dabr_match)(struct pt_regs *regs);
+extern int (*__debugger_break_match)(struct pt_regs *regs);
extern int (*__debugger_fault_handler)(struct pt_regs *regs);
#define DEBUGGER_BOILERPLATE(__NAME) \
@@ -31,7 +33,7 @@
DEBUGGER_BOILERPLATE(debugger_bpt)
DEBUGGER_BOILERPLATE(debugger_sstep)
DEBUGGER_BOILERPLATE(debugger_iabr_match)
-DEBUGGER_BOILERPLATE(debugger_dabr_match)
+DEBUGGER_BOILERPLATE(debugger_break_match)
DEBUGGER_BOILERPLATE(debugger_fault_handler)
#else
@@ -40,17 +42,18 @@
static inline int debugger_bpt(struct pt_regs *regs) { return 0; }
static inline int debugger_sstep(struct pt_regs *regs) { return 0; }
static inline int debugger_iabr_match(struct pt_regs *regs) { return 0; }
-static inline int debugger_dabr_match(struct pt_regs *regs) { return 0; }
+static inline int debugger_break_match(struct pt_regs *regs) { return 0; }
static inline int debugger_fault_handler(struct pt_regs *regs) { return 0; }
#endif
-extern int set_dabr(unsigned long dabr, unsigned long dabrx);
+int set_break(struct arch_hw_breakpoint *brk);
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
extern void do_send_trap(struct pt_regs *regs, unsigned long address,
unsigned long error_code, int signal_code, int brkpt);
#else
-extern void do_dabr(struct pt_regs *regs, unsigned long address,
- unsigned long error_code);
+
+extern void do_break(struct pt_regs *regs, unsigned long address,
+ unsigned long error_code);
#endif
#endif /* _ASM_POWERPC_DEBUG_H */
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 4234245..2c91faf 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -24,16 +24,30 @@
#define _PPC_BOOK3S_64_HW_BREAKPOINT_H
#ifdef __KERNEL__
-#ifdef CONFIG_HAVE_HW_BREAKPOINT
-
struct arch_hw_breakpoint {
unsigned long address;
- unsigned long dabrx;
- int type;
- u8 len; /* length of the target data symbol */
- bool extraneous_interrupt;
+ u16 type;
+ u16 len; /* length of the target data symbol */
};
+/* Note: Don't change the the first 6 bits below as they are in the same order
+ * as the dabr and dabrx.
+ */
+#define HW_BRK_TYPE_READ 0x01
+#define HW_BRK_TYPE_WRITE 0x02
+#define HW_BRK_TYPE_TRANSLATE 0x04
+#define HW_BRK_TYPE_USER 0x08
+#define HW_BRK_TYPE_KERNEL 0x10
+#define HW_BRK_TYPE_HYP 0x20
+#define HW_BRK_TYPE_EXTRANEOUS_IRQ 0x80
+
+/* bits that overlap with the bottom 3 bits of the dabr */
+#define HW_BRK_TYPE_RDWR (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)
+#define HW_BRK_TYPE_DABR (HW_BRK_TYPE_RDWR | HW_BRK_TYPE_TRANSLATE)
+#define HW_BRK_TYPE_PRIV_ALL (HW_BRK_TYPE_USER | HW_BRK_TYPE_KERNEL | \
+ HW_BRK_TYPE_HYP)
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
#include <linux/kdebug.h>
#include <asm/reg.h>
#include <asm/debug.h>
@@ -62,7 +76,12 @@
struct perf_sample_data *data, struct pt_regs *regs);
static inline void hw_breakpoint_disable(void)
{
- set_dabr(0, 0);
+ struct arch_hw_breakpoint brk;
+
+ brk.address = 0;
+ brk.type = 0;
+ brk.len = 0;
+ set_break(&brk);
}
extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 37f87f0..7938658 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -33,6 +33,7 @@
#include <linux/cache.h>
#include <asm/ptrace.h>
#include <asm/types.h>
+#include <asm/hw_breakpoint.h>
/* We do _not_ want to define new machine types at all, those must die
* in favor of using the device-tree
@@ -225,8 +226,7 @@
struct perf_event *last_hit_ubp;
#endif /* CONFIG_HAVE_HW_BREAKPOINT */
#endif
- unsigned long dabr; /* Data address breakpoint register */
- unsigned long dabrx; /* ... extension */
+ struct arch_hw_breakpoint hw_brk; /* info on the hardware breakpoint */
unsigned long trap_nr; /* last trap # on this thread */
#ifdef CONFIG_ALTIVEC
/* Complete AltiVec register set */
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index d111beb..1f59fbb 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -206,9 +206,6 @@
#define DAWRX_KERNEL (1UL << 1)
#define DAWRX_HYP (1UL << 2)
#define SPRN_DABR 0x3F5 /* Data Address Breakpoint Register */
-#define DABR_TRANSLATION (1UL << 2)
-#define DABR_DATA_WRITE (1UL << 1)
-#define DABR_DATA_READ (1UL << 0)
#define SPRN_DABR2 0x13D /* e300 */
#define SPRN_DABRX 0x3F7 /* Data Address Breakpoint Register Extension */
#define DABRX_USER (1UL << 0)