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

Pull arm64 updates from Will Deacon:

 - virt_to_page/page_address optimisations

 - support for NUMA systems described using device-tree

 - support for hibernate/suspend-to-disk

 - proper support for maxcpus= command line parameter

 - detection and graceful handling of AArch64-only CPUs

 - miscellaneous cleanups and non-critical fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  arm64: do not enforce strict 16 byte alignment to stack pointer
  arm64: kernel: Fix incorrect brk randomization
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: secondary_start_kernel: Remove unnecessary barrier
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
  arm64: always use STRICT_MM_TYPECHECKS
  arm64: kvm: Fix kvm teardown for systems using the extended idmap
  arm64: kaslr: increase randomization granularity
  arm64: kconfig: drop CONFIG_RTC_LIB dependency
  arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
  arm64: hibernate: Refuse to hibernate if the boot cpu is offline
  arm64: kernel: Add support for hibernate/suspend-to-disk
  PM / Hibernate: Call flush_icache_range() on pages restored in-place
  arm64: Add new asm macro copy_page
  arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
  arm64: kernel: Include _AC definition in page.h
  ...

4 files changed, 86 insertions, 48 deletions

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 3850701..738d5ee 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -265,6 +265,15 @@ static inline void __cpu_init_stage2(void)
 	kvm_call_hyp(__init_stage2_translation);
 }
 
+static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+					phys_addr_t phys_idmap_start)
+{
+	/*
+	 * TODO
+	 * kvm_call_reset(boot_pgd_ptr, phys_idmap_start);
+	 */
+}
+
 static inline int kvm_arch_dev_ioctl_check_extension(long ext)
 {
 	return 0;
@@ -277,7 +286,6 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
 
-static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index da44be9..f17a8d4 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -66,6 +66,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
 phys_addr_t kvm_mmu_get_httbr(void);
 phys_addr_t kvm_mmu_get_boot_httbr(void);
 phys_addr_t kvm_get_idmap_vector(void);
+phys_addr_t kvm_get_idmap_start(void);
 int kvm_mmu_init(void);
 void kvm_clear_hyp_idmap(void);
 
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index dded1b7..9ef013d 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -16,7 +16,6 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
-#include <linux/cpu.h>
 #include <linux/cpu_pm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
@@ -66,6 +65,8 @@ static DEFINE_SPINLOCK(kvm_vmid_lock);
 
 static bool vgic_present;
 
+static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
+
 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
 {
 	BUG_ON(preemptible());
@@ -90,11 +91,6 @@ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
 	return &kvm_arm_running_vcpu;
 }
 
-int kvm_arch_hardware_enable(void)
-{
-	return 0;
-}
-
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
@@ -1033,11 +1029,6 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	}
 }
 
-static void cpu_init_stage2(void *dummy)
-{
-	__cpu_init_stage2();
-}
-
 static void cpu_init_hyp_mode(void *dummy)
 {
 	phys_addr_t boot_pgd_ptr;
@@ -1065,43 +1056,87 @@ static void cpu_hyp_reinit(void)
 {
 	if (is_kernel_in_hyp_mode()) {
 		/*
-		 * cpu_init_stage2() is safe to call even if the PM
+		 * __cpu_init_stage2() is safe to call even if the PM
 		 * event was cancelled before the CPU was reset.
 		 */
-		cpu_init_stage2(NULL);
+		__cpu_init_stage2();
 	} else {
 		if (__hyp_get_vectors() == hyp_default_vectors)
 			cpu_init_hyp_mode(NULL);
 	}
 }
 
-static int hyp_init_cpu_notify(struct notifier_block *self,
-			       unsigned long action, void *cpu)
+static void cpu_hyp_reset(void)
+{
+	phys_addr_t boot_pgd_ptr;
+	phys_addr_t phys_idmap_start;
+
+	if (!is_kernel_in_hyp_mode()) {
+		boot_pgd_ptr = kvm_mmu_get_boot_httbr();
+		phys_idmap_start = kvm_get_idmap_start();
+
+		__cpu_reset_hyp_mode(boot_pgd_ptr, phys_idmap_start);
+	}
+}
+
+static void _kvm_arch_hardware_enable(void *discard)
 {
-	switch (action) {
-	case CPU_STARTING:
-	case CPU_STARTING_FROZEN:
+	if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
 		cpu_hyp_reinit();
+		__this_cpu_write(kvm_arm_hardware_enabled, 1);
 	}
+}
+
+int kvm_arch_hardware_enable(void)
+{
+	_kvm_arch_hardware_enable(NULL);
+	return 0;
+}
 
-	return NOTIFY_OK;
+static void _kvm_arch_hardware_disable(void *discard)
+{
+	if (__this_cpu_read(kvm_arm_hardware_enabled)) {
+		cpu_hyp_reset();
+		__this_cpu_write(kvm_arm_hardware_enabled, 0);
+	}
 }
 
-static struct notifier_block hyp_init_cpu_nb = {
-	.notifier_call = hyp_init_cpu_notify,
-};
+void kvm_arch_hardware_disable(void)
+{
+	_kvm_arch_hardware_disable(NULL);
+}
 
 #ifdef CONFIG_CPU_PM
 static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
 				    unsigned long cmd,
 				    void *v)
 {
-	if (cmd == CPU_PM_EXIT) {
-		cpu_hyp_reinit();
+	/*
+	 * kvm_arm_hardware_enabled is left with its old value over
+	 * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
+	 * re-enable hyp.
+	 */
+	switch (cmd) {
+	case CPU_PM_ENTER:
+		if (__this_cpu_read(kvm_arm_hardware_enabled))
+			/*
+			 * don't update kvm_arm_hardware_enabled here
+			 * so that the hardware will be re-enabled
+			 * when we resume. See below.
+			 */
+			cpu_hyp_reset();
+
+		return NOTIFY_OK;
+	case CPU_PM_EXIT:
+		if (__this_cpu_read(kvm_arm_hardware_enabled))
+			/* The hardware was enabled before suspend. */
+			cpu_hyp_reinit();
+
 		return NOTIFY_OK;
-	}
 
-	return NOTIFY_DONE;
+	default:
+		return NOTIFY_DONE;
+	}
 }
 
 static struct notifier_block hyp_init_cpu_pm_nb = {
@@ -1143,16 +1178,12 @@ static int init_common_resources(void)
 
 static int init_subsystems(void)
 {
-	int err;
+	int err = 0;
 
 	/*
-	 * Register CPU Hotplug notifier
+	 * Enable hardware so that subsystem initialisation can access EL2.
 	 */
-	err = register_cpu_notifier(&hyp_init_cpu_nb);
-	if (err) {
-		kvm_err("Cannot register KVM init CPU notifier (%d)\n", err);
-		return err;
-	}
+	on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);
 
 	/*
 	 * Register CPU lower-power notifier
@@ -1170,9 +1201,10 @@ static int init_subsystems(void)
 	case -ENODEV:
 	case -ENXIO:
 		vgic_present = false;
+		err = 0;
 		break;
 	default:
-		return err;
+		goto out;
 	}
 
 	/*
@@ -1180,12 +1212,15 @@ static int init_subsystems(void)
 	 */
 	err = kvm_timer_hyp_init();
 	if (err)
-		return err;
+		goto out;
 
 	kvm_perf_init();
 	kvm_coproc_table_init();
 
-	return 0;
+out:
+	on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
+
+	return err;
 }
 
 static void teardown_hyp_mode(void)
@@ -1198,17 +1233,11 @@ static void teardown_hyp_mode(void)
 	free_hyp_pgds();
 	for_each_possible_cpu(cpu)
 		free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
-	unregister_cpu_notifier(&hyp_init_cpu_nb);
 	hyp_cpu_pm_exit();
 }
 
 static int init_vhe_mode(void)
 {
-	/*
-	 * Execute the init code on each CPU.
-	 */
-	on_each_cpu(cpu_init_stage2, NULL, 1);
-
 	/* set size of VMID supported by CPU */
 	kvm_vmid_bits = kvm_get_vmid_bits();
 	kvm_info("%d-bit VMID\n", kvm_vmid_bits);
@@ -1295,11 +1324,6 @@ static int init_hyp_mode(void)
 		}
 	}
 
-	/*
-	 * Execute the init code on each CPU.
-	 */
-	on_each_cpu(cpu_init_hyp_mode, NULL, 1);
-
 #ifndef CONFIG_HOTPLUG_CPU
 	free_boot_hyp_pgd();
 #endif
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index d6d4191..be30212 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1666,6 +1666,11 @@ phys_addr_t kvm_get_idmap_vector(void)
 	return hyp_idmap_vector;
 }
 
+phys_addr_t kvm_get_idmap_start(void)
+{
+	return hyp_idmap_start;
+}
+
 int kvm_mmu_init(void)
 {
 	int err;