Merge branch 'next' into for-linus

Prepare first set of updates for 3.10 merge window.

1 files changed, 133 insertions, 72 deletions

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 281bf3301241..96093b75ab90 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -28,6 +28,7 @@
 #include <linux/perf_event.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/smp.h>
+#include <linux/cpu_pm.h>
 
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
@@ -35,6 +36,7 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/kdebug.h>
 #include <asm/traps.h>
+#include <asm/hardware/coresight.h>
 
 /* Breakpoint currently in use for each BRP. */
 static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]);
@@ -49,17 +51,20 @@ static int core_num_wrps;
 /* Debug architecture version. */
 static u8 debug_arch;
 
+/* Does debug architecture support OS Save and Restore? */
+static bool has_ossr;
+
 /* Maximum supported watchpoint length. */
 static u8 max_watchpoint_len;
 
-#define READ_WB_REG_CASE(OP2, M, VAL)		\
-	case ((OP2 << 4) + M):			\
-		ARM_DBG_READ(c ## M, OP2, VAL); \
+#define READ_WB_REG_CASE(OP2, M, VAL)			\
+	case ((OP2 << 4) + M):				\
+		ARM_DBG_READ(c0, c ## M, OP2, VAL);	\
 		break
 
-#define WRITE_WB_REG_CASE(OP2, M, VAL)		\
-	case ((OP2 << 4) + M):			\
-		ARM_DBG_WRITE(c ## M, OP2, VAL);\
+#define WRITE_WB_REG_CASE(OP2, M, VAL)			\
+	case ((OP2 << 4) + M):				\
+		ARM_DBG_WRITE(c0, c ## M, OP2, VAL);	\
 		break
 
 #define GEN_READ_WB_REG_CASES(OP2, VAL)		\
@@ -136,12 +141,12 @@ static u8 get_debug_arch(void)
 
 	/* Do we implement the extended CPUID interface? */
 	if (((read_cpuid_id() >> 16) & 0xf) != 0xf) {
-		pr_warning("CPUID feature registers not supported. "
-			   "Assuming v6 debug is present.\n");
+		pr_warn_once("CPUID feature registers not supported. "
+			     "Assuming v6 debug is present.\n");
 		return ARM_DEBUG_ARCH_V6;
 	}
 
-	ARM_DBG_READ(c0, 0, didr);
+	ARM_DBG_READ(c0, c0, 0, didr);
 	return (didr >> 16) & 0xf;
 }
 
@@ -169,7 +174,7 @@ static int debug_exception_updates_fsr(void)
 static int get_num_wrp_resources(void)
 {
 	u32 didr;
-	ARM_DBG_READ(c0, 0, didr);
+	ARM_DBG_READ(c0, c0, 0, didr);
 	return ((didr >> 28) & 0xf) + 1;
 }
 
@@ -177,7 +182,7 @@ static int get_num_wrp_resources(void)
 static int get_num_brp_resources(void)
 {
 	u32 didr;
-	ARM_DBG_READ(c0, 0, didr);
+	ARM_DBG_READ(c0, c0, 0, didr);
 	return ((didr >> 24) & 0xf) + 1;
 }
 
@@ -228,19 +233,17 @@ static int get_num_brps(void)
  * be put into halting debug mode at any time by an external debugger
  * but there is nothing we can do to prevent that.
  */
-static int enable_monitor_mode(void)
+static int monitor_mode_enabled(void)
 {
 	u32 dscr;
-	int ret = 0;
-
-	ARM_DBG_READ(c1, 0, dscr);
+	ARM_DBG_READ(c0, c1, 0, dscr);
+	return !!(dscr & ARM_DSCR_MDBGEN);
+}
 
-	/* Ensure that halting mode is disabled. */
-	if (WARN_ONCE(dscr & ARM_DSCR_HDBGEN,
-		"halting debug mode enabled. Unable to access hardware resources.\n")) {
-		ret = -EPERM;
-		goto out;
-	}
+static int enable_monitor_mode(void)
+{
+	u32 dscr;
+	ARM_DBG_READ(c0, c1, 0, dscr);
 
 	/* If monitor mode is already enabled, just return. */
 	if (dscr & ARM_DSCR_MDBGEN)
@@ -250,24 +253,27 @@ static int enable_monitor_mode(void)
 	switch (get_debug_arch()) {
 	case ARM_DEBUG_ARCH_V6:
 	case ARM_DEBUG_ARCH_V6_1:
-		ARM_DBG_WRITE(c1, 0, (dscr | ARM_DSCR_MDBGEN));
+		ARM_DBG_WRITE(c0, c1, 0, (dscr | ARM_DSCR_MDBGEN));
 		break;
 	case ARM_DEBUG_ARCH_V7_ECP14:
 	case ARM_DEBUG_ARCH_V7_1:
-		ARM_DBG_WRITE(c2, 2, (dscr | ARM_DSCR_MDBGEN));
+		ARM_DBG_WRITE(c0, c2, 2, (dscr | ARM_DSCR_MDBGEN));
+		isb();
 		break;
 	default:
-		ret = -ENODEV;
-		goto out;
+		return -ENODEV;
 	}
 
 	/* Check that the write made it through. */
-	ARM_DBG_READ(c1, 0, dscr);
-	if (!(dscr & ARM_DSCR_MDBGEN))
-		ret = -EPERM;
+	ARM_DBG_READ(c0, c1, 0, dscr);
+	if (!(dscr & ARM_DSCR_MDBGEN)) {
+		pr_warn_once("Failed to enable monitor mode on CPU %d.\n",
+				smp_processor_id());
+		return -EPERM;
+	}
 
 out:
-	return ret;
+	return 0;
 }
 
 int hw_breakpoint_slots(int type)
@@ -328,14 +334,9 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 {
 	struct arch_hw_breakpoint *info = counter_arch_bp(bp);
 	struct perf_event **slot, **slots;
-	int i, max_slots, ctrl_base, val_base, ret = 0;
+	int i, max_slots, ctrl_base, val_base;
 	u32 addr, ctrl;
 
-	/* Ensure that we are in monitor mode and halting mode is disabled. */
-	ret = enable_monitor_mode();
-	if (ret)
-		goto out;
-
 	addr = info->address;
 	ctrl = encode_ctrl_reg(info->ctrl) | 0x1;
 
@@ -362,9 +363,9 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 		}
 	}
 
-	if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n")) {
-		ret = -EBUSY;
-		goto out;
+	if (i == max_slots) {
+		pr_warning("Can't find any breakpoint slot\n");
+		return -EBUSY;
 	}
 
 	/* Override the breakpoint data with the step data. */
@@ -383,9 +384,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
 
 	/* Setup the control register. */
 	write_wb_reg(ctrl_base + i, ctrl);
-
-out:
-	return ret;
+	return 0;
 }
 
 void arch_uninstall_hw_breakpoint(struct perf_event *bp)
@@ -416,8 +415,10 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
 		}
 	}
 
-	if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n"))
+	if (i == max_slots) {
+		pr_warning("Can't find any breakpoint slot\n");
 		return;
+	}
 
 	/* Ensure that we disable the mismatch breakpoint. */
 	if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE &&
@@ -596,6 +597,10 @@ int arch_validate_hwbkpt_settings(struct perf_event *bp)
 	int ret = 0;
 	u32 offset, alignment_mask = 0x3;
 
+	/* Ensure that we are in monitor debug mode. */
+	if (!monitor_mode_enabled())
+		return -ENODEV;
+
 	/* Build the arch_hw_breakpoint. */
 	ret = arch_build_bp_info(bp);
 	if (ret)
@@ -858,7 +863,7 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr,
 		local_irq_enable();
 
 	/* We only handle watchpoints and hardware breakpoints. */
-	ARM_DBG_READ(c1, 0, dscr);
+	ARM_DBG_READ(c0, c1, 0, dscr);
 
 	/* Perform perf callbacks. */
 	switch (ARM_DSCR_MOE(dscr)) {
@@ -903,10 +908,27 @@ static struct undef_hook debug_reg_hook = {
 	.fn		= debug_reg_trap,
 };
 
+/* Does this core support OS Save and Restore? */
+static bool core_has_os_save_restore(void)
+{
+	u32 oslsr;
+
+	switch (get_debug_arch()) {
+	case ARM_DEBUG_ARCH_V7_1:
+		return true;
+	case ARM_DEBUG_ARCH_V7_ECP14:
+		ARM_DBG_READ(c1, c1, 4, oslsr);
+		if (oslsr & ARM_OSLSR_OSLM0)
+			return true;
+	default:
+		return false;
+	}
+}
+
 static void reset_ctrl_regs(void *unused)
 {
 	int i, raw_num_brps, err = 0, cpu = smp_processor_id();
-	u32 dbg_power;
+	u32 val;
 
 	/*
 	 * v7 debug contains save and restore registers so that debug state
@@ -919,23 +941,26 @@ static void reset_ctrl_regs(void *unused)
 	switch (debug_arch) {
 	case ARM_DEBUG_ARCH_V6:
 	case ARM_DEBUG_ARCH_V6_1:
-		/* ARMv6 cores just need to reset the registers. */
-		goto reset_regs;
+		/* ARMv6 cores clear the registers out of reset. */
+		goto out_mdbgen;
 	case ARM_DEBUG_ARCH_V7_ECP14:
 		/*
 		 * Ensure sticky power-down is clear (i.e. debug logic is
 		 * powered up).
 		 */
-		asm volatile("mrc p14, 0, %0, c1, c5, 4" : "=r" (dbg_power));
-		if ((dbg_power & 0x1) == 0)
+		ARM_DBG_READ(c1, c5, 4, val);
+		if ((val & 0x1) == 0)
 			err = -EPERM;
+
+		if (!has_ossr)
+			goto clear_vcr;
 		break;
 	case ARM_DEBUG_ARCH_V7_1:
 		/*
 		 * Ensure the OS double lock is clear.
 		 */
-		asm volatile("mrc p14, 0, %0, c1, c3, 4" : "=r" (dbg_power));
-		if ((dbg_power & 0x1) == 1)
+		ARM_DBG_READ(c1, c3, 4, val);
+		if ((val & 0x1) == 1)
 			err = -EPERM;
 		break;
 	}
@@ -947,24 +972,29 @@ static void reset_ctrl_regs(void *unused)
 	}
 
 	/*
-	 * Unconditionally clear the lock by writing a value
-	 * other than 0xC5ACCE55 to the access register.
+	 * Unconditionally clear the OS lock by writing a value
+	 * other than CS_LAR_KEY to the access register.
 	 */
-	asm volatile("mcr p14, 0, %0, c1, c0, 4" : : "r" (0));
+	ARM_DBG_WRITE(c1, c0, 4, ~CS_LAR_KEY);
 	isb();
 
 	/*
 	 * Clear any configured vector-catch events before
 	 * enabling monitor mode.
 	 */
-	asm volatile("mcr p14, 0, %0, c0, c7, 0" : : "r" (0));
+clear_vcr:
+	ARM_DBG_WRITE(c0, c7, 0, 0);
 	isb();
 
-reset_regs:
-	if (enable_monitor_mode())
+	if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
+		pr_warning("CPU %d failed to disable vector catch\n", cpu);
 		return;
+	}
 
-	/* We must also reset any reserved registers. */
+	/*
+	 * The control/value register pairs are UNKNOWN out of reset so
+	 * clear them to avoid spurious debug events.
+	 */
 	raw_num_brps = get_num_brp_resources();
 	for (i = 0; i < raw_num_brps; ++i) {
 		write_wb_reg(ARM_BASE_BCR + i, 0UL);
@@ -975,12 +1005,25 @@ reset_regs:
 		write_wb_reg(ARM_BASE_WCR + i, 0UL);
 		write_wb_reg(ARM_BASE_WVR + i, 0UL);
 	}
+
+	if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
+		pr_warning("CPU %d failed to clear debug register pairs\n", cpu);
+		return;
+	}
+
+	/*
+	 * Have a crack at enabling monitor mode. We don't actually need
+	 * it yet, but reporting an error early is useful if it fails.
+	 */
+out_mdbgen:
+	if (enable_monitor_mode())
+		cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu));
 }
 
 static int __cpuinit dbg_reset_notify(struct notifier_block *self,
 				      unsigned long action, void *cpu)
 {
-	if (action == CPU_ONLINE)
+	if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE)
 		smp_call_function_single((int)cpu, reset_ctrl_regs, NULL, 1);
 
 	return NOTIFY_OK;
@@ -990,10 +1033,32 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = {
 	.notifier_call = dbg_reset_notify,
 };
 
-static int __init arch_hw_breakpoint_init(void)
+#ifdef CONFIG_CPU_PM
+static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action,
+			     void *v)
 {
-	u32 dscr;
+	if (action == CPU_PM_EXIT)
+		reset_ctrl_regs(NULL);
 
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata dbg_cpu_pm_nb = {
+	.notifier_call = dbg_cpu_pm_notify,
+};
+
+static void __init pm_init(void)
+{
+	cpu_pm_register_notifier(&dbg_cpu_pm_nb);
+}
+#else
+static inline void pm_init(void)
+{
+}
+#endif
+
+static int __init arch_hw_breakpoint_init(void)
+{
 	debug_arch = get_debug_arch();
 
 	if (!debug_arch_supported()) {
@@ -1001,6 +1066,8 @@ static int __init arch_hw_breakpoint_init(void)
 		return 0;
 	}
 
+	has_ossr = core_has_os_save_restore();
+
 	/* Determine how many BRPs/WRPs are available. */
 	core_num_brps = get_num_brps();
 	core_num_wrps = get_num_wrps();
@@ -1028,17 +1095,10 @@ static int __init arch_hw_breakpoint_init(void)
 		core_num_brps, core_has_mismatch_brps() ? "(+1 reserved) " :
 		"", core_num_wrps);
 
-	ARM_DBG_READ(c1, 0, dscr);
-	if (dscr & ARM_DSCR_HDBGEN) {
-		max_watchpoint_len = 4;
-		pr_warning("halting debug mode enabled. Assuming maximum watchpoint size of %u bytes.\n",
-			   max_watchpoint_len);
-	} else {
-		/* Work out the maximum supported watchpoint length. */
-		max_watchpoint_len = get_max_wp_len();
-		pr_info("maximum watchpoint size is %u bytes.\n",
-				max_watchpoint_len);
-	}
+	/* Work out the maximum supported watchpoint length. */
+	max_watchpoint_len = get_max_wp_len();
+	pr_info("maximum watchpoint size is %u bytes.\n",
+			max_watchpoint_len);
 
 	/* Register debug fault handler. */
 	hook_fault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP,
@@ -1046,8 +1106,9 @@ static int __init arch_hw_breakpoint_init(void)
 	hook_ifault_code(FAULT_CODE_DEBUG, hw_breakpoint_pending, SIGTRAP,
 			TRAP_HWBKPT, "breakpoint debug exception");
 
-	/* Register hotplug notifier. */
+	/* Register hotplug and PM notifiers. */
 	register_cpu_notifier(&dbg_reset_nb);
+	pm_init();
 	return 0;
 }
 arch_initcall(arch_hw_breakpoint_init);