Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The bulk is in-kernel pointer authentication, activity monitors and
  lots of asm symbol annotations. I also queued the sys_mremap() patch
  commenting the asymmetry in the address untagging.

  Summary:

   - In-kernel Pointer Authentication support (previously only offered
     to user space).

   - ARM Activity Monitors (AMU) extension support allowing better CPU
     utilisation numbers for the scheduler (frequency invariance).

   - Memory hot-remove support for arm64.

   - Lots of asm annotations (SYM_*) in preparation for the in-kernel
     Branch Target Identification (BTI) support.

   - arm64 perf updates: ARMv8.5-PMU 64-bit counters, refactoring the
     PMU init callbacks, support for new DT compatibles.

   - IPv6 header checksum optimisation.

   - Fixes: SDEI (software delegated exception interface) double-lock on
     hibernate with shared events.

   - Minor clean-ups and refactoring: cpu_ops accessor,
     cpu_do_switch_mm() converted to C, cpufeature finalisation helper.

   - sys_mremap() comment explaining the asymmetric address untagging
     behaviour"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (81 commits)
  mm/mremap: Add comment explaining the untagging behaviour of mremap()
  arm64: head: Convert install_el2_stub to SYM_INNER_LABEL
  arm64: Introduce get_cpu_ops() helper function
  arm64: Rename cpu_read_ops() to init_cpu_ops()
  arm64: Declare ACPI parking protocol CPU operation if needed
  arm64: move kimage_vaddr to .rodata
  arm64: use mov_q instead of literal ldr
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  ...

drivers/firmware/arm_sdei.c

@@ -267,26 +267,19 @@ static struct sdei_event *sdei_event_create(u32 event_num,
 		event->private_registered = regs;
 	}
 
-	if (sdei_event_find(event_num)) {
-		kfree(event->registered);
-		kfree(event);
-		event = ERR_PTR(-EBUSY);
-	} else {
-		spin_lock(&sdei_list_lock);
-		list_add(&event->list, &sdei_list);
-		spin_unlock(&sdei_list_lock);
-	}
+	spin_lock(&sdei_list_lock);
+	list_add(&event->list, &sdei_list);
+	spin_unlock(&sdei_list_lock);
 
 	return event;
 }
 
-static void sdei_event_destroy(struct sdei_event *event)
+static void sdei_event_destroy_llocked(struct sdei_event *event)
 {
 	lockdep_assert_held(&sdei_events_lock);
+	lockdep_assert_held(&sdei_list_lock);
 
-	spin_lock(&sdei_list_lock);
 	list_del(&event->list);
-	spin_unlock(&sdei_list_lock);
 
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		kfree(event->registered);
@@ -296,6 +289,13 @@ static void sdei_event_destroy(struct sdei_event *event)
 	kfree(event);
 }
 
+static void sdei_event_destroy(struct sdei_event *event)
+{
+	spin_lock(&sdei_list_lock);
+	sdei_event_destroy_llocked(event);
+	spin_unlock(&sdei_list_lock);
+}
+
 static int sdei_api_get_version(u64 *version)
 {
 	return invoke_sdei_fn(SDEI_1_0_FN_SDEI_VERSION, 0, 0, 0, 0, 0, version);
@@ -412,14 +412,19 @@ int sdei_event_enable(u32 event_num)
 		return -ENOENT;
 	}
 
-	spin_lock(&sdei_list_lock);
-	event->reenable = true;
-	spin_unlock(&sdei_list_lock);
 
+	cpus_read_lock();
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		err = sdei_api_event_enable(event->event_num);
 	else
 		err = sdei_do_cross_call(_local_event_enable, event);
+
+	if (!err) {
+		spin_lock(&sdei_list_lock);
+		event->reenable = true;
+		spin_unlock(&sdei_list_lock);
+	}
+	cpus_read_unlock();
 	mutex_unlock(&sdei_events_lock);
 
 	return err;
@@ -491,11 +496,6 @@ static int _sdei_event_unregister(struct sdei_event *event)
 {
 	lockdep_assert_held(&sdei_events_lock);
 
-	spin_lock(&sdei_list_lock);
-	event->reregister = false;
-	event->reenable = false;
-	spin_unlock(&sdei_list_lock);
-
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		return sdei_api_event_unregister(event->event_num);
 
@@ -518,6 +518,11 @@ int sdei_event_unregister(u32 event_num)
 			break;
 		}
 
+		spin_lock(&sdei_list_lock);
+		event->reregister = false;
+		event->reenable = false;
+		spin_unlock(&sdei_list_lock);
+
 		err = _sdei_event_unregister(event);
 		if (err)
 			break;
@@ -585,26 +590,15 @@ static int _sdei_event_register(struct sdei_event *event)
 
 	lockdep_assert_held(&sdei_events_lock);
 
-	spin_lock(&sdei_list_lock);
-	event->reregister = true;
-	spin_unlock(&sdei_list_lock);
-
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		return sdei_api_event_register(event->event_num,
 					       sdei_entry_point,
 					       event->registered,
 					       SDEI_EVENT_REGISTER_RM_ANY, 0);
 
-
 	err = sdei_do_cross_call(_local_event_register, event);
-	if (err) {
-		spin_lock(&sdei_list_lock);
-		event->reregister = false;
-		event->reenable = false;
-		spin_unlock(&sdei_list_lock);
-
+	if (err)
 		sdei_do_cross_call(_local_event_unregister, event);
-	}
 
 	return err;
 }
@@ -632,12 +626,18 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 			break;
 		}
 
+		cpus_read_lock();
 		err = _sdei_event_register(event);
 		if (err) {
 			sdei_event_destroy(event);
 			pr_warn("Failed to register event %u: %d\n", event_num,
 				err);
+		} else {
+			spin_lock(&sdei_list_lock);
+			event->reregister = true;
+			spin_unlock(&sdei_list_lock);
 		}
+		cpus_read_unlock();
 	} while (0);
 	mutex_unlock(&sdei_events_lock);
 
@@ -645,16 +645,17 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 }
 EXPORT_SYMBOL(sdei_event_register);
 
-static int sdei_reregister_event(struct sdei_event *event)
+static int sdei_reregister_event_llocked(struct sdei_event *event)
 {
 	int err;
 
 	lockdep_assert_held(&sdei_events_lock);
+	lockdep_assert_held(&sdei_list_lock);
 
 	err = _sdei_event_register(event);
 	if (err) {
 		pr_err("Failed to re-register event %u\n", event->event_num);
-		sdei_event_destroy(event);
+		sdei_event_destroy_llocked(event);
 		return err;
 	}
 
@@ -683,7 +684,7 @@ static int sdei_reregister_shared(void)
 			continue;
 
 		if (event->reregister) {
-			err = sdei_reregister_event(event);
+			err = sdei_reregister_event_llocked(event);
 			if (err)
 				break;
 		}