[PATCH 4/5] powerpc: Rework set_dabr so it can take a DABRX value as well

Michael Neuling mikey at neuling.org
Thu Sep 6 15:17:50 EST 2012


Rework set_dabr to take a DABRX value as well. We are not actually
changing any functionality at this stage, just preparing for that.

The SET_XDABR hcall checks to make sure DABRX is non-zero, and if it
is it barfs.  So in this case when we are clearing both DABR and
DABRX, just set 1 bit to make sure the hcall doesn't fail.

Signed-off-by: Michael Neuling <mikey at neuling.org>
---
 arch/powerpc/include/asm/debug.h         |    2 +-
 arch/powerpc/include/asm/hw_breakpoint.h |    2 +-
 arch/powerpc/include/asm/machdep.h       |    3 ++-
 arch/powerpc/include/asm/processor.h     |    1 +
 arch/powerpc/include/asm/reg.h           |    3 +++
 arch/powerpc/kernel/hw_breakpoint.c      |   12 ++++++------
 arch/powerpc/kernel/process.c            |   14 +++++++-------
 arch/powerpc/kernel/ptrace.c             |    3 +++
 arch/powerpc/kernel/signal.c             |    2 +-
 arch/powerpc/platforms/cell/beat.c       |    4 ++--
 arch/powerpc/platforms/cell/beat.h       |    2 +-
 arch/powerpc/platforms/ps3/setup.c       |    6 ++----
 arch/powerpc/platforms/pseries/setup.c   |    9 ++++++---
 arch/powerpc/xmon/xmon.c                 |    4 ++--
 14 files changed, 38 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/include/asm/debug.h b/arch/powerpc/include/asm/debug.h
index 716d2f0..32de257 100644
--- a/arch/powerpc/include/asm/debug.h
+++ b/arch/powerpc/include/asm/debug.h
@@ -44,7 +44,7 @@ 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 int set_dabr(unsigned long dabr, unsigned long dabrx);
 #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);
diff --git a/arch/powerpc/include/asm/hw_breakpoint.h b/arch/powerpc/include/asm/hw_breakpoint.h
index 39b323e..c6f48eb 100644
--- a/arch/powerpc/include/asm/hw_breakpoint.h
+++ b/arch/powerpc/include/asm/hw_breakpoint.h
@@ -61,7 +61,7 @@ extern void ptrace_triggered(struct perf_event *bp,
 			struct perf_sample_data *data, struct pt_regs *regs);
 static inline void hw_breakpoint_disable(void)
 {
-	set_dabr(0);
+	set_dabr(0, 0);
 }
 extern void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs);
 
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 42ce570..236b477 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -180,7 +180,8 @@ struct machdep_calls {
 	void		(*enable_pmcs)(void);
 
 	/* Set DABR for this platform, leave empty for default implemenation */
-	int		(*set_dabr)(unsigned long dabr);
+	int		(*set_dabr)(unsigned long dabr,
+				    unsigned long dabrx);
 
 #ifdef CONFIG_PPC32	/* XXX for now */
 	/* A general init function, called by ppc_init in init/main.c.
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 54b73a2..17b58e5 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -219,6 +219,7 @@ struct thread_struct {
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
 	unsigned long	dabr;		/* Data address breakpoint register */
+	unsigned long	dabrx;		/*      ... extension  */
 #ifdef CONFIG_ALTIVEC
 	/* Complete AltiVec register set */
 	vector128	vr[32] __attribute__((aligned(16)));
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 6386086..334be34 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -208,6 +208,9 @@
 #define SPRN_DABRX	0x3F7	/* Data Address Breakpoint Register Extension */
 #define   DABRX_USER	(1UL << 0)
 #define   DABRX_KERNEL	(1UL << 1)
+#define   DABRX_HYP	(1UL << 2)
+#define   DABRX_BTI	(1UL << 3)
+#define   DABRX_ALL     (DABRX_BTI | DABRX_HYP | DABRX_KERNEL | DABRX_USER)
 #define SPRN_DAR	0x013	/* Data Address Register */
 #define SPRN_DBCR	0x136	/* e300 Data Breakpoint Control Reg */
 #define SPRN_DSISR	0x012	/* Data Storage Interrupt Status Register */
diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index 6767445..6891d79 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -73,7 +73,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 	 * If so, DABR will be populated in single_step_dabr_instruction().
 	 */
 	if (current->thread.last_hit_ubp != bp)
-		set_dabr(info->address | info->type | DABR_TRANSLATION);
+		set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);
 
 	return 0;
 }
@@ -97,7 +97,7 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 	}
 
 	*slot = NULL;
-	set_dabr(0);
+	set_dabr(0, 0);
 }
 
 /*
@@ -197,7 +197,7 @@ void thread_change_pc(struct task_struct *tsk, struct pt_regs *regs)
 
 	info = counter_arch_bp(tsk->thread.last_hit_ubp);
 	regs->msr &= ~MSR_SE;
-	set_dabr(info->address | info->type | DABR_TRANSLATION);
+	set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);
 	tsk->thread.last_hit_ubp = NULL;
 }
 
@@ -215,7 +215,7 @@ int __kprobes hw_breakpoint_handler(struct die_args *args)
 	unsigned long dar = regs->dar;
 
 	/* Disable breakpoints during exception handling */
-	set_dabr(0);
+	set_dabr(0, 0);
 
 	/*
 	 * The counter may be concurrently released but that can only
@@ -281,7 +281,7 @@ int __kprobes hw_breakpoint_handler(struct die_args *args)
 	if (!info->extraneous_interrupt)
 		perf_bp_event(bp, regs);
 
-	set_dabr(info->address | info->type | DABR_TRANSLATION);
+	set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);
 out:
 	rcu_read_unlock();
 	return rc;
@@ -313,7 +313,7 @@ int __kprobes single_step_dabr_instruction(struct die_args *args)
 	if (!info->extraneous_interrupt)
 		perf_bp_event(bp, regs);
 
-	set_dabr(info->address | info->type | DABR_TRANSLATION);
+	set_dabr(info->address | info->type | DABR_TRANSLATION, DABRX_ALL);
 	current->thread.last_hit_ubp = NULL;
 
 	/*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 1a1f2dd..53c32a9 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -283,7 +283,7 @@ void do_dabr(struct pt_regs *regs, unsigned long address,
 		return;
 
 	/* Clear the DABR */
-	set_dabr(0);
+	set_dabr(0, 0);
 
 	/* Deliver the signal to userspace */
 	info.si_signo = SIGTRAP;
@@ -364,18 +364,19 @@ static void set_debug_reg_defaults(struct thread_struct *thread)
 {
 	if (thread->dabr) {
 		thread->dabr = 0;
-		set_dabr(0);
+		thread->dabrx = 0;
+		set_dabr(0, 0);
 	}
 }
 #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
 #endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
 
-int set_dabr(unsigned long dabr)
+int set_dabr(unsigned long dabr, unsigned long dabrx)
 {
 	__get_cpu_var(current_dabr) = dabr;
 
 	if (ppc_md.set_dabr)
-		return ppc_md.set_dabr(dabr);
+		return ppc_md.set_dabr(dabr, dabrx);
 
 	/* XXX should we have a CPU_FTR_HAS_DABR ? */
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
@@ -385,9 +386,8 @@ int set_dabr(unsigned long dabr)
 #endif
 #elif defined(CONFIG_PPC_BOOK3S)
 	mtspr(SPRN_DABR, dabr);
+	mtspr(SPRN_DABRX, dabrx);
 #endif
-
-
 	return 0;
 }
 
@@ -480,7 +480,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
  */
 #ifndef CONFIG_HAVE_HW_BREAKPOINT
 	if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
-		set_dabr(new->thread.dabr);
+		set_dabr(new->thread.dabr, new->thread.dabrx);
 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
 
diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index c10fc28..79d8e56 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -960,6 +960,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 		thread->ptrace_bps[0] = bp;
 		ptrace_put_breakpoints(task);
 		thread->dabr = data;
+		thread->dabrx = DABRX_ALL;
 		return 0;
 	}
 
@@ -983,6 +984,7 @@ int ptrace_set_debugreg(struct task_struct *task, unsigned long addr,
 
 	/* Move contents to the DABR register */
 	task->thread.dabr = data;
+	task->thread.dabrx = DABRX_ALL;
 #else /* CONFIG_PPC_ADV_DEBUG_REGS */
 	/* As described above, it was assumed 3 bits were passed with the data
 	 *  address, but we will assume only the mode bits will be passed
@@ -1397,6 +1399,7 @@ static long ppc_set_hwdebug(struct task_struct *child,
 		dabr |= DABR_DATA_WRITE;
 
 	child->thread.dabr = dabr;
+	child->thread.dabrx = DABRX_ALL;
 
 	return 1;
 #endif /* !CONFIG_PPC_ADV_DEBUG_DVCS */
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 5c023c9..b936b45 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -130,7 +130,7 @@ static int do_signal(struct pt_regs *regs)
 	 * triggered inside the kernel.
 	 */
 	if (current->thread.dabr)
-		set_dabr(current->thread.dabr);
+		set_dabr(current->thread.dabr, current->thread.dabrx);
 #endif
 	/* Re-enable the breakpoints for the signal stack */
 	thread_change_pc(current, regs);
diff --git a/arch/powerpc/platforms/cell/beat.c b/arch/powerpc/platforms/cell/beat.c
index 852592b..affcf56 100644
--- a/arch/powerpc/platforms/cell/beat.c
+++ b/arch/powerpc/platforms/cell/beat.c
@@ -136,9 +136,9 @@ ssize_t beat_nvram_get_size(void)
 	return BEAT_NVRAM_SIZE;
 }
 
-int beat_set_xdabr(unsigned long dabr)
+int beat_set_xdabr(unsigned long dabr, unsigned long dabrx)
 {
-	if (beat_set_dabr(dabr, DABRX_KERNEL | DABRX_USER))
+	if (beat_set_dabr(dabr, dabrx))
 		return -1;
 	return 0;
 }
diff --git a/arch/powerpc/platforms/cell/beat.h b/arch/powerpc/platforms/cell/beat.h
index 32c8efc..bfcb8e3 100644
--- a/arch/powerpc/platforms/cell/beat.h
+++ b/arch/powerpc/platforms/cell/beat.h
@@ -32,7 +32,7 @@ void beat_get_rtc_time(struct rtc_time *);
 ssize_t beat_nvram_get_size(void);
 ssize_t beat_nvram_read(char *, size_t, loff_t *);
 ssize_t beat_nvram_write(char *, size_t, loff_t *);
-int beat_set_xdabr(unsigned long);
+int beat_set_xdabr(unsigned long, unsigned long);
 void beat_power_save(void);
 void beat_kexec_cpu_down(int, int);
 
diff --git a/arch/powerpc/platforms/ps3/setup.c b/arch/powerpc/platforms/ps3/setup.c
index 2d664c5..ef7de10 100644
--- a/arch/powerpc/platforms/ps3/setup.c
+++ b/arch/powerpc/platforms/ps3/setup.c
@@ -184,11 +184,9 @@ early_param("ps3flash", early_parse_ps3flash);
 #define prealloc_ps3flash_bounce_buffer()	do { } while (0)
 #endif
 
-static int ps3_set_dabr(unsigned long dabr)
+static int ps3_set_dabr(unsigned long dabr, unsigned long dabrx)
 {
-	enum {DABR_USER = 1, DABR_KERNEL = 2,};
-
-	return lv1_set_dabr(dabr, DABR_KERNEL | DABR_USER) ? -1 : 0;
+	return lv1_set_dabr(dabr, dabrx) ? -1 : 0;
 }
 
 static void __init ps3_setup_arch(void)
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 36b7744..5ea8e4f 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -416,16 +416,19 @@ static int __init pSeries_init_panel(void)
 }
 machine_arch_initcall(pseries, pSeries_init_panel);
 
-static int pseries_set_dabr(unsigned long dabr)
+static int pseries_set_dabr(unsigned long dabr, unsigned long dabrx)
 {
 	return plpar_hcall_norets(H_SET_DABR, dabr);
 }
 
-static int pseries_set_xdabr(unsigned long dabr)
+static int pseries_set_xdabr(unsigned long dabr, unsigned long dabrx)
 {
+	/* Have to set at least one bit in the DABRX according to PAPR */
+	if (dabrx == 0 && dabr == 0)
+		dabrx = H_DABRX_USER;
 	/* We want to catch accesses from kernel and userspace */
 	return plpar_hcall_norets(H_SET_XDABR, dabr,
-			H_DABRX_KERNEL | H_DABRX_USER);
+				  dabrx & (H_DABRX_KERNEL | H_DABRX_USER));
 }
 
 #define CMO_CHARACTERISTICS_TOKEN 44
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 9b49c65..987f441 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -740,7 +740,7 @@ static void insert_bpts(void)
 static void insert_cpu_bpts(void)
 {
 	if (dabr.enabled)
-		set_dabr(dabr.address | (dabr.enabled & 7));
+		set_dabr(dabr.address | (dabr.enabled & 7), DABRX_ALL);
 	if (iabr && cpu_has_feature(CPU_FTR_IABR))
 		mtspr(SPRN_IABR, iabr->address
 			 | (iabr->enabled & (BP_IABR|BP_IABR_TE)));
@@ -768,7 +768,7 @@ static void remove_bpts(void)
 
 static void remove_cpu_bpts(void)
 {
-	set_dabr(0);
+	set_dabr(0, 0);
 	if (cpu_has_feature(CPU_FTR_IABR))
 		mtspr(SPRN_IABR, 0);
 }
-- 
1.7.9.5



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