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Diffstat (limited to 'arch/arm/kernel/hw_breakpoint.c')
-rw-r--r--arch/arm/kernel/hw_breakpoint.c98
1 files changed, 75 insertions, 23 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 5ff2e77782b..4d963fb66e3 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;
@@ -162,7 +167,7 @@ static int debug_arch_supported(void)
/* Can we determine the watchpoint access type from the fsr? */
static int debug_exception_updates_fsr(void)
{
- return 0;
+ return get_debug_arch() >= ARM_DEBUG_ARCH_V8;
}
/* Determine number of WRP registers available. */
@@ -252,6 +257,7 @@ static int enable_monitor_mode(void)
break;
case ARM_DEBUG_ARCH_V7_ECP14:
case ARM_DEBUG_ARCH_V7_1:
+ case ARM_DEBUG_ARCH_V8:
ARM_DBG_WRITE(c0, c2, 2, (dscr | ARM_DSCR_MDBGEN));
isb();
break;
@@ -339,13 +345,13 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
/* Breakpoint */
ctrl_base = ARM_BASE_BCR;
val_base = ARM_BASE_BVR;
- slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+ slots = this_cpu_ptr(bp_on_reg);
max_slots = core_num_brps;
} else {
/* Watchpoint */
ctrl_base = ARM_BASE_WCR;
val_base = ARM_BASE_WVR;
- slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+ slots = this_cpu_ptr(wp_on_reg);
max_slots = core_num_wrps;
}
@@ -391,12 +397,12 @@ void arch_uninstall_hw_breakpoint(struct perf_event *bp)
if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
/* Breakpoint */
base = ARM_BASE_BCR;
- slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+ slots = this_cpu_ptr(bp_on_reg);
max_slots = core_num_brps;
} else {
/* Watchpoint */
base = ARM_BASE_WCR;
- slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+ slots = this_cpu_ptr(wp_on_reg);
max_slots = core_num_wrps;
}
@@ -692,7 +698,7 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
struct arch_hw_breakpoint *info;
struct arch_hw_breakpoint_ctrl ctrl;
- slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+ slots = this_cpu_ptr(wp_on_reg);
for (i = 0; i < core_num_wrps; ++i) {
rcu_read_lock();
@@ -763,7 +769,7 @@ static void watchpoint_single_step_handler(unsigned long pc)
struct perf_event *wp, **slots;
struct arch_hw_breakpoint *info;
- slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
+ slots = this_cpu_ptr(wp_on_reg);
for (i = 0; i < core_num_wrps; ++i) {
rcu_read_lock();
@@ -797,7 +803,7 @@ static void breakpoint_handler(unsigned long unknown, struct pt_regs *regs)
struct arch_hw_breakpoint *info;
struct arch_hw_breakpoint_ctrl ctrl;
- slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
+ slots = this_cpu_ptr(bp_on_reg);
/* The exception entry code places the amended lr in the PC. */
addr = regs->ARM_pc;
@@ -903,6 +909,23 @@ 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 +953,7 @@ 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:
@@ -948,16 +967,16 @@ static void reset_ctrl_regs(void *unused)
}
if (err) {
- pr_warning("CPU %d debug is powered down!\n", cpu);
+ pr_warn_once("CPU %d debug is powered down!\n", cpu);
cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu));
return;
}
/*
* 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();
/*
@@ -969,7 +988,7 @@ clear_vcr:
isb();
if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
- pr_warning("CPU %d failed to disable vector catch\n", cpu);
+ pr_warn_once("CPU %d failed to disable vector catch\n", cpu);
return;
}
@@ -989,7 +1008,7 @@ clear_vcr:
}
if (cpumask_intersects(&debug_err_mask, cpumask_of(cpu))) {
- pr_warning("CPU %d failed to clear debug register pairs\n", cpu);
+ pr_warn_once("CPU %d failed to clear debug register pairs\n", cpu);
return;
}
@@ -1002,19 +1021,43 @@ out_mdbgen:
cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu));
}
-static int __cpuinit dbg_reset_notify(struct notifier_block *self,
+static int 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;
}
-static struct notifier_block __cpuinitdata dbg_reset_nb = {
+static struct notifier_block 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 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();
@@ -1024,10 +1067,14 @@ 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();
+ cpu_notifier_register_begin();
+
/*
* We need to tread carefully here because DBGSWENABLE may be
* driven low on this core and there isn't an architected way to
@@ -1044,6 +1091,7 @@ static int __init arch_hw_breakpoint_init(void)
if (!cpumask_empty(&debug_err_mask)) {
core_num_brps = 0;
core_num_wrps = 0;
+ cpu_notifier_register_done();
return 0;
}
@@ -1062,8 +1110,12 @@ 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_cpu_notifier(&dbg_reset_nb);
+ /* Register hotplug and PM notifiers. */
+ __register_cpu_notifier(&dbg_reset_nb);
+
+ cpu_notifier_register_done();
+
+ pm_init();
return 0;
}
arch_initcall(arch_hw_breakpoint_init);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 12:18:31 +0000