1 files changed, 21 insertions, 18 deletions

diff --git a/kernel/arch/arm64/kernel/debug-monitors.c b/kernel/arch/arm64/kernel/debug-monitors.c
index 70654d843..c1492ba1f 100644
--- a/kernel/arch/arm64/kernel/debug-monitors.c
+++ b/kernel/arch/arm64/kernel/debug-monitors.c
@@ -26,14 +26,16 @@
 #include <linux/stat.h>
 #include <linux/uaccess.h>
 
-#include <asm/debug-monitors.h>
+#include <asm/cpufeature.h>
 #include <asm/cputype.h>
+#include <asm/debug-monitors.h>
 #include <asm/system_misc.h>
 
 /* Determine debug architecture. */
 u8 debug_monitors_arch(void)
 {
-	return read_cpuid(ID_AA64DFR0_EL1) & 0xf;
+	return cpuid_feature_extract_field(read_system_reg(SYS_ID_AA64DFR0_EL1),
+						ID_AA64DFR0_DEBUGVER_SHIFT);
 }
 
 /*
@@ -58,7 +60,7 @@ static u32 mdscr_read(void)
  * Allow root to disable self-hosted debug from userspace.
  * This is useful if you want to connect an external JTAG debugger.
  */
-static u32 debug_enabled = 1;
+static bool debug_enabled = true;
 
 static int create_debug_debugfs_entry(void)
 {
@@ -69,7 +71,7 @@ fs_initcall(create_debug_debugfs_entry);
 
 static int __init early_debug_disable(char *buf)
 {
-	debug_enabled = 0;
+	debug_enabled = false;
 	return 0;
 }
 
@@ -82,7 +84,7 @@ early_param("nodebugmon", early_debug_disable);
 static DEFINE_PER_CPU(int, mde_ref_count);
 static DEFINE_PER_CPU(int, kde_ref_count);
 
-void enable_debug_monitors(enum debug_el el)
+void enable_debug_monitors(enum dbg_active_el el)
 {
 	u32 mdscr, enable = 0;
 
@@ -102,7 +104,7 @@ void enable_debug_monitors(enum debug_el el)
 	}
 }
 
-void disable_debug_monitors(enum debug_el el)
+void disable_debug_monitors(enum dbg_active_el el)
 {
 	u32 mdscr, disable = 0;
 
@@ -134,7 +136,7 @@ static int os_lock_notify(struct notifier_block *self,
 				    unsigned long action, void *data)
 {
 	int cpu = (unsigned long)data;
-	if (action == CPU_ONLINE)
+	if ((action & ~CPU_TASKS_FROZEN) == CPU_ONLINE)
 		smp_call_function_single(cpu, clear_os_lock, NULL, 1);
 	return NOTIFY_OK;
 }
@@ -184,24 +186,25 @@ static void clear_regs_spsr_ss(struct pt_regs *regs)
 
 /* EL1 Single Step Handler hooks */
 static LIST_HEAD(step_hook);
-static DEFINE_RWLOCK(step_hook_lock);
+static DEFINE_SPINLOCK(step_hook_lock);
 
 void register_step_hook(struct step_hook *hook)
 {
-	write_lock(&step_hook_lock);
-	list_add(&hook->node, &step_hook);
-	write_unlock(&step_hook_lock);
+	spin_lock(&step_hook_lock);
+	list_add_rcu(&hook->node, &step_hook);
+	spin_unlock(&step_hook_lock);
 }
 
 void unregister_step_hook(struct step_hook *hook)
 {
-	write_lock(&step_hook_lock);
-	list_del(&hook->node);
-	write_unlock(&step_hook_lock);
+	spin_lock(&step_hook_lock);
+	list_del_rcu(&hook->node);
+	spin_unlock(&step_hook_lock);
+	synchronize_rcu();
 }
 
 /*
- * Call registered single step handers
+ * Call registered single step handlers
  * There is no Syndrome info to check for determining the handler.
  * So we call all the registered handlers, until the right handler is
  * found which returns zero.
@@ -211,15 +214,15 @@ static int call_step_hook(struct pt_regs *regs, unsigned int esr)
 	struct step_hook *hook;
 	int retval = DBG_HOOK_ERROR;
 
-	read_lock(&step_hook_lock);
+	rcu_read_lock();
 
-	list_for_each_entry(hook, &step_hook, node)	{
+	list_for_each_entry_rcu(hook, &step_hook, node)	{
 		retval = hook->fn(regs, esr);
 		if (retval == DBG_HOOK_HANDLED)
 			break;
 	}
 
-	read_unlock(&step_hook_lock);
+	rcu_read_unlock();
 
 	return retval;
 }