diff options
Diffstat (limited to 'arch/arm/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 61 |
1 files changed, 53 insertions, 8 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 5ff2e77782b1..5eae53e7a2e1 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]); @@ -49,6 +51,9 @@ 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; @@ -903,6 +908,23 @@ 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(); @@ -930,11 +952,7 @@ static void reset_ctrl_regs(void *unused) if ((val & 0x1) == 0) err = -EPERM; - /* - * Check whether we implement OS save and restore. - */ - ARM_DBG_READ(c1, c1, 4, val); - if ((val & 0x9) == 0) + if (!has_ossr) goto clear_vcr; break; case ARM_DEBUG_ARCH_V7_1: @@ -955,9 +973,9 @@ static void reset_ctrl_regs(void *unused) /* * Unconditionally clear the OS lock by writing a value - * other than 0xC5ACCE55 to the access register. + * other than CS_LAR_KEY to the access register. */ - ARM_DBG_WRITE(c1, c0, 4, 0); + ARM_DBG_WRITE(c1, c0, 4, ~CS_LAR_KEY); isb(); /* @@ -1015,6 +1033,30 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = { .notifier_call = dbg_reset_notify, }; +#ifdef CONFIG_CPU_PM +static int dbg_cpu_pm_notify(struct notifier_block *self, unsigned long action, + void *v) +{ + 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(); @@ -1024,6 +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(); @@ -1062,8 +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); |