[PATCH] ppc64: Add ptrace data breakpoint support

Add hardware data breakpoint support.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

include/asm-ppc64/hvcall.h

@@ -56,6 +56,11 @@
 #define H_PP1			(1UL<<(63-62))
 #define H_PP2			(1UL<<(63-63))
 
+/* DABRX flags */
+#define H_DABRX_HYPERVISOR	(1UL<<(63-61))
+#define H_DABRX_KERNEL		(1UL<<(63-62))
+#define H_DABRX_USER		(1UL<<(63-63))
+
 /* pSeries hypervisor opcodes */
 #define H_REMOVE		0x04
 #define H_ENTER			0x08
@@ -101,6 +106,7 @@
 #define H_VIO_SIGNAL		0x104
 #define H_SEND_CRQ		0x108
 #define H_COPY_RDMA             0x110
+#define H_SET_XDABR		0x134
 #define H_STUFF_TCE		0x138
 #define H_PUT_TCE_INDIRECT	0x13C
 #define H_VTERM_PARTNER_INFO	0x150

include/asm-ppc64/plpar_wrappers.h

@@ -107,5 +107,14 @@ static inline long plpar_put_term_char(unsigned long termno,
 				  lbuf[1]);
 }
 
+static inline long plpar_set_xdabr(unsigned long address, unsigned long flags)
+{
+	return plpar_hcall_norets(H_SET_XDABR, address, flags);
+}
+
+static inline long plpar_set_dabr(unsigned long val)
+{
+	return plpar_hcall_norets(H_SET_DABR, val);
+}
 
 #endif /* _PPC64_PLPAR_WRAPPERS_H */

include/asm-ppc64/processor.h

@@ -433,6 +433,7 @@ struct thread_struct {
 	unsigned long	start_tb;	/* Start purr when proc switched in */
 	unsigned long	accum_tb;	/* Total accumilated purr for process */
 	unsigned long	vdso_base;	/* base of the vDSO library */
+	unsigned long	dabr;		/* Data address breakpoint register */
 #ifdef CONFIG_ALTIVEC
 	/* Complete AltiVec register set */
 	vector128	vr[32] __attribute((aligned(16)));

include/asm-ppc64/ptrace-common.h

@@ -13,6 +13,7 @@
 #define _PPC64_PTRACE_COMMON_H
 
 #include <linux/config.h>
+#include <asm/system.h>
 
 /*
  * Set of msr bits that gdb can change on behalf of a process.
@@ -141,4 +142,23 @@ static inline int set_vrregs(struct task_struct *task,
 }
 #endif
 
+static inline int ptrace_set_debugreg(struct task_struct *task,
+				      unsigned long addr, unsigned long data)
+{
+	/* We only support one DABR and no IABRS at the moment */
+	if (addr > 0)
+		return -EINVAL;
+
+	/* The bottom 3 bits are flags */
+	if ((data & ~0x7UL) >= TASK_SIZE)
+		return -EIO;
+
+	/* Ensure translation is on */
+	if (data && !(data & DABR_TRANSLATION))
+		return -EIO;
+
+	task->thread.dabr = data;
+	return 0;
+}
+
 #endif /* _PPC64_PTRACE_COMMON_H */

include/asm-ppc64/system.h

@@ -101,6 +101,9 @@ static inline int debugger_dabr_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);
+extern void _exception(int signr, struct pt_regs *regs, int code,
+		       unsigned long addr);
 extern int fix_alignment(struct pt_regs *regs);
 extern void bad_page_fault(struct pt_regs *regs, unsigned long address,
 			   int sig);