Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
     as well as some other functions only used by drivers that haven't
     (yet?) made it upstream.

   - A fix for a bug in our handling of hardware watchpoints (eg. perf
     record -e mem: ...) which could lead to register corruption and
     kernel crashes.

   - Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
     vmalloc when using the Radix MMU.

   - A large but incremental rewrite of our exception handling code to
     use gas macros rather than multiple levels of nested CPP macros.

  And the usual small fixes, cleanups and improvements.

  Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
  Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
  Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
  Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
  Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
  Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
  Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
  Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
  Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
  Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
  Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
  Jitindar Singh, Thiago Jung Bauermann, YueHaibing"

* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
  powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
  powerpc/eeh: Handle hugepages in ioremap space
  ocxl: Update for AFU descriptor template version 1.1
  powerpc/boot: pass CONFIG options in a simpler and more robust way
  powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
  powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
  powerpc/module64: Use symbolic instructions names.
  powerpc/module32: Use symbolic instructions names.
  powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
  powerpc/module64: Fix comment in R_PPC64_ENTRY handling
  powerpc/boot: Add lzo support for uImage
  powerpc/boot: Add lzma support for uImage
  powerpc/boot: don't force gzipped uImage
  powerpc/8xx: Add microcode patch to move SMC parameter RAM.
  powerpc/8xx: Use IO accessors in microcode programming.
  powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
  powerpc/8xx: refactor programming of microcode CPM params.
  powerpc/8xx: refactor printing of microcode patch name.
  powerpc/8xx: Refactor microcode write
  powerpc/8xx: refactor writing of CPM microcode arrays
  ...

1 files changed, 585 insertions, 18 deletions

diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index 73620dfb63a1..09bb878c21e0 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -17,6 +17,10 @@
 #include <linux/jump_label.h>
 #include <linux/delay.h>
 #include <linux/stop_machine.h>
+#include <linux/spinlock.h>
+#include <linux/cpuhotplug.h>
+#include <linux/workqueue.h>
+#include <linux/proc_fs.h>
 #include <asm/processor.h>
 #include <asm/mmu.h>
 #include <asm/page.h>
@@ -52,13 +56,591 @@ EXPORT_SYMBOL(plpar_hcall);
 EXPORT_SYMBOL(plpar_hcall9);
 EXPORT_SYMBOL(plpar_hcall_norets);
 
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+static u8 dtl_mask = DTL_LOG_PREEMPT;
+#else
+static u8 dtl_mask;
+#endif
+
+void alloc_dtl_buffers(unsigned long *time_limit)
+{
+	int cpu;
+	struct paca_struct *pp;
+	struct dtl_entry *dtl;
+
+	for_each_possible_cpu(cpu) {
+		pp = paca_ptrs[cpu];
+		if (pp->dispatch_log)
+			continue;
+		dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL);
+		if (!dtl) {
+			pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
+				cpu);
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+			pr_warn("Stolen time statistics will be unreliable\n");
+#endif
+			break;
+		}
+
+		pp->dtl_ridx = 0;
+		pp->dispatch_log = dtl;
+		pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
+		pp->dtl_curr = dtl;
+
+		if (time_limit && time_after(jiffies, *time_limit)) {
+			cond_resched();
+			*time_limit = jiffies + HZ;
+		}
+	}
+}
+
+void register_dtl_buffer(int cpu)
+{
+	long ret;
+	struct paca_struct *pp;
+	struct dtl_entry *dtl;
+	int hwcpu = get_hard_smp_processor_id(cpu);
+
+	pp = paca_ptrs[cpu];
+	dtl = pp->dispatch_log;
+	if (dtl && dtl_mask) {
+		pp->dtl_ridx = 0;
+		pp->dtl_curr = dtl;
+		lppaca_of(cpu).dtl_idx = 0;
+
+		/* hypervisor reads buffer length from this field */
+		dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
+		ret = register_dtl(hwcpu, __pa(dtl));
+		if (ret)
+			pr_err("WARNING: DTL registration of cpu %d (hw %d) failed with %ld\n",
+			       cpu, hwcpu, ret);
+
+		lppaca_of(cpu).dtl_enable_mask = dtl_mask;
+	}
+}
+
+#ifdef CONFIG_PPC_SPLPAR
+struct dtl_worker {
+	struct delayed_work work;
+	int cpu;
+};
+
+struct vcpu_dispatch_data {
+	int last_disp_cpu;
+
+	int total_disp;
+
+	int same_cpu_disp;
+	int same_chip_disp;
+	int diff_chip_disp;
+	int far_chip_disp;
+
+	int numa_home_disp;
+	int numa_remote_disp;
+	int numa_far_disp;
+};
+
+/*
+ * This represents the number of cpus in the hypervisor. Since there is no
+ * architected way to discover the number of processors in the host, we
+ * provision for dealing with NR_CPUS. This is currently 2048 by default, and
+ * is sufficient for our purposes. This will need to be tweaked if
+ * CONFIG_NR_CPUS is changed.
+ */
+#define NR_CPUS_H	NR_CPUS
+
+DEFINE_RWLOCK(dtl_access_lock);
+static DEFINE_PER_CPU(struct vcpu_dispatch_data, vcpu_disp_data);
+static DEFINE_PER_CPU(u64, dtl_entry_ridx);
+static DEFINE_PER_CPU(struct dtl_worker, dtl_workers);
+static enum cpuhp_state dtl_worker_state;
+static DEFINE_MUTEX(dtl_enable_mutex);
+static int vcpudispatch_stats_on __read_mostly;
+static int vcpudispatch_stats_freq = 50;
+static __be32 *vcpu_associativity, *pcpu_associativity;
+
+
+static void free_dtl_buffers(unsigned long *time_limit)
+{
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+	int cpu;
+	struct paca_struct *pp;
+
+	for_each_possible_cpu(cpu) {
+		pp = paca_ptrs[cpu];
+		if (!pp->dispatch_log)
+			continue;
+		kmem_cache_free(dtl_cache, pp->dispatch_log);
+		pp->dtl_ridx = 0;
+		pp->dispatch_log = 0;
+		pp->dispatch_log_end = 0;
+		pp->dtl_curr = 0;
+
+		if (time_limit && time_after(jiffies, *time_limit)) {
+			cond_resched();
+			*time_limit = jiffies + HZ;
+		}
+	}
+#endif
+}
+
+static int init_cpu_associativity(void)
+{
+	vcpu_associativity = kcalloc(num_possible_cpus() / threads_per_core,
+			VPHN_ASSOC_BUFSIZE * sizeof(__be32), GFP_KERNEL);
+	pcpu_associativity = kcalloc(NR_CPUS_H / threads_per_core,
+			VPHN_ASSOC_BUFSIZE * sizeof(__be32), GFP_KERNEL);
+
+	if (!vcpu_associativity || !pcpu_associativity) {
+		pr_err("error allocating memory for associativity information\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void destroy_cpu_associativity(void)
+{
+	kfree(vcpu_associativity);
+	kfree(pcpu_associativity);
+	vcpu_associativity = pcpu_associativity = 0;
+}
+
+static __be32 *__get_cpu_associativity(int cpu, __be32 *cpu_assoc, int flag)
+{
+	__be32 *assoc;
+	int rc = 0;
+
+	assoc = &cpu_assoc[(int)(cpu / threads_per_core) * VPHN_ASSOC_BUFSIZE];
+	if (!assoc[0]) {
+		rc = hcall_vphn(cpu, flag, &assoc[0]);
+		if (rc)
+			return NULL;
+	}
+
+	return assoc;
+}
+
+static __be32 *get_pcpu_associativity(int cpu)
+{
+	return __get_cpu_associativity(cpu, pcpu_associativity, VPHN_FLAG_PCPU);
+}
+
+static __be32 *get_vcpu_associativity(int cpu)
+{
+	return __get_cpu_associativity(cpu, vcpu_associativity, VPHN_FLAG_VCPU);
+}
+
+static int cpu_relative_dispatch_distance(int last_disp_cpu, int cur_disp_cpu)
+{
+	__be32 *last_disp_cpu_assoc, *cur_disp_cpu_assoc;
+
+	if (last_disp_cpu >= NR_CPUS_H || cur_disp_cpu >= NR_CPUS_H)
+		return -EINVAL;
+
+	last_disp_cpu_assoc = get_pcpu_associativity(last_disp_cpu);
+	cur_disp_cpu_assoc = get_pcpu_associativity(cur_disp_cpu);
+
+	if (!last_disp_cpu_assoc || !cur_disp_cpu_assoc)
+		return -EIO;
+
+	return cpu_distance(last_disp_cpu_assoc, cur_disp_cpu_assoc);
+}
+
+static int cpu_home_node_dispatch_distance(int disp_cpu)
+{
+	__be32 *disp_cpu_assoc, *vcpu_assoc;
+	int vcpu_id = smp_processor_id();
+
+	if (disp_cpu >= NR_CPUS_H) {
+		pr_debug_ratelimited("vcpu dispatch cpu %d > %d\n",
+						disp_cpu, NR_CPUS_H);
+		return -EINVAL;
+	}
+
+	disp_cpu_assoc = get_pcpu_associativity(disp_cpu);
+	vcpu_assoc = get_vcpu_associativity(vcpu_id);
+
+	if (!disp_cpu_assoc || !vcpu_assoc)
+		return -EIO;
+
+	return cpu_distance(disp_cpu_assoc, vcpu_assoc);
+}
+
+static void update_vcpu_disp_stat(int disp_cpu)
+{
+	struct vcpu_dispatch_data *disp;
+	int distance;
+
+	disp = this_cpu_ptr(&vcpu_disp_data);
+	if (disp->last_disp_cpu == -1) {
+		disp->last_disp_cpu = disp_cpu;
+		return;
+	}
+
+	disp->total_disp++;
+
+	if (disp->last_disp_cpu == disp_cpu ||
+		(cpu_first_thread_sibling(disp->last_disp_cpu) ==
+					cpu_first_thread_sibling(disp_cpu)))
+		disp->same_cpu_disp++;
+	else {
+		distance = cpu_relative_dispatch_distance(disp->last_disp_cpu,
+								disp_cpu);
+		if (distance < 0)
+			pr_debug_ratelimited("vcpudispatch_stats: cpu %d: error determining associativity\n",
+					smp_processor_id());
+		else {
+			switch (distance) {
+			case 0:
+				disp->same_chip_disp++;
+				break;
+			case 1:
+				disp->diff_chip_disp++;
+				break;
+			case 2:
+				disp->far_chip_disp++;
+				break;
+			default:
+				pr_debug_ratelimited("vcpudispatch_stats: cpu %d (%d -> %d): unexpected relative dispatch distance %d\n",
+						 smp_processor_id(),
+						 disp->last_disp_cpu,
+						 disp_cpu,
+						 distance);
+			}
+		}
+	}
+
+	distance = cpu_home_node_dispatch_distance(disp_cpu);
+	if (distance < 0)
+		pr_debug_ratelimited("vcpudispatch_stats: cpu %d: error determining associativity\n",
+				smp_processor_id());
+	else {
+		switch (distance) {
+		case 0:
+			disp->numa_home_disp++;
+			break;
+		case 1:
+			disp->numa_remote_disp++;
+			break;
+		case 2:
+			disp->numa_far_disp++;
+			break;
+		default:
+			pr_debug_ratelimited("vcpudispatch_stats: cpu %d on %d: unexpected numa dispatch distance %d\n",
+						 smp_processor_id(),
+						 disp_cpu,
+						 distance);
+		}
+	}
+
+	disp->last_disp_cpu = disp_cpu;
+}
+
+static void process_dtl_buffer(struct work_struct *work)
+{
+	struct dtl_entry dtle;
+	u64 i = __this_cpu_read(dtl_entry_ridx);
+	struct dtl_entry *dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
+	struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
+	struct lppaca *vpa = local_paca->lppaca_ptr;
+	struct dtl_worker *d = container_of(work, struct dtl_worker, work.work);
+
+	if (!local_paca->dispatch_log)
+		return;
+
+	/* if we have been migrated away, we cancel ourself */
+	if (d->cpu != smp_processor_id()) {
+		pr_debug("vcpudispatch_stats: cpu %d worker migrated -- canceling worker\n",
+						smp_processor_id());
+		return;
+	}
+
+	if (i == be64_to_cpu(vpa->dtl_idx))
+		goto out;
+
+	while (i < be64_to_cpu(vpa->dtl_idx)) {
+		dtle = *dtl;
+		barrier();
+		if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
+			/* buffer has overflowed */
+			pr_debug_ratelimited("vcpudispatch_stats: cpu %d lost %lld DTL samples\n",
+				d->cpu,
+				be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG - i);
+			i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
+			dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
+			continue;
+		}
+		update_vcpu_disp_stat(be16_to_cpu(dtle.processor_id));
+		++i;
+		++dtl;
+		if (dtl == dtl_end)
+			dtl = local_paca->dispatch_log;
+	}
+
+	__this_cpu_write(dtl_entry_ridx, i);
+
+out:
+	schedule_delayed_work_on(d->cpu, to_delayed_work(work),
+					HZ / vcpudispatch_stats_freq);
+}
+
+static int dtl_worker_online(unsigned int cpu)
+{
+	struct dtl_worker *d = &per_cpu(dtl_workers, cpu);
+
+	memset(d, 0, sizeof(*d));
+	INIT_DELAYED_WORK(&d->work, process_dtl_buffer);
+	d->cpu = cpu;
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+	per_cpu(dtl_entry_ridx, cpu) = 0;
+	register_dtl_buffer(cpu);
+#else
+	per_cpu(dtl_entry_ridx, cpu) = be64_to_cpu(lppaca_of(cpu).dtl_idx);
+#endif
+
+	schedule_delayed_work_on(cpu, &d->work, HZ / vcpudispatch_stats_freq);
+	return 0;
+}
+
+static int dtl_worker_offline(unsigned int cpu)
+{
+	struct dtl_worker *d = &per_cpu(dtl_workers, cpu);
+
+	cancel_delayed_work_sync(&d->work);
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+	unregister_dtl(get_hard_smp_processor_id(cpu));
+#endif
+
+	return 0;
+}
+
+static void set_global_dtl_mask(u8 mask)
+{
+	int cpu;
+
+	dtl_mask = mask;
+	for_each_present_cpu(cpu)
+		lppaca_of(cpu).dtl_enable_mask = dtl_mask;
+}
+
+static void reset_global_dtl_mask(void)
+{
+	int cpu;
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+	dtl_mask = DTL_LOG_PREEMPT;
+#else
+	dtl_mask = 0;
+#endif
+	for_each_present_cpu(cpu)
+		lppaca_of(cpu).dtl_enable_mask = dtl_mask;
+}
+
+static int dtl_worker_enable(unsigned long *time_limit)
+{
+	int rc = 0, state;
+
+	if (!write_trylock(&dtl_access_lock)) {
+		rc = -EBUSY;
+		goto out;
+	}
+
+	set_global_dtl_mask(DTL_LOG_ALL);
+
+	/* Setup dtl buffers and register those */
+	alloc_dtl_buffers(time_limit);
+
+	state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "powerpc/dtl:online",
+					dtl_worker_online, dtl_worker_offline);
+	if (state < 0) {
+		pr_err("vcpudispatch_stats: unable to setup workqueue for DTL processing\n");
+		free_dtl_buffers(time_limit);
+		reset_global_dtl_mask();
+		write_unlock(&dtl_access_lock);
+		rc = -EINVAL;
+		goto out;
+	}
+	dtl_worker_state = state;
+
+out:
+	return rc;
+}
+
+static void dtl_worker_disable(unsigned long *time_limit)
+{
+	cpuhp_remove_state(dtl_worker_state);
+	free_dtl_buffers(time_limit);
+	reset_global_dtl_mask();
+	write_unlock(&dtl_access_lock);
+}
+
+static ssize_t vcpudispatch_stats_write(struct file *file, const char __user *p,
+		size_t count, loff_t *ppos)
+{
+	unsigned long time_limit = jiffies + HZ;
+	struct vcpu_dispatch_data *disp;
+	int rc, cmd, cpu;
+	char buf[16];
+
+	if (count > 15)
+		return -EINVAL;
+
+	if (copy_from_user(buf, p, count))
+		return -EFAULT;
+
+	buf[count] = 0;
+	rc = kstrtoint(buf, 0, &cmd);
+	if (rc || cmd < 0 || cmd > 1) {
+		pr_err("vcpudispatch_stats: please use 0 to disable or 1 to enable dispatch statistics\n");
+		return rc ? rc : -EINVAL;
+	}
+
+	mutex_lock(&dtl_enable_mutex);
+
+	if ((cmd == 0 && !vcpudispatch_stats_on) ||
+			(cmd == 1 && vcpudispatch_stats_on))
+		goto out;
+
+	if (cmd) {
+		rc = init_cpu_associativity();
+		if (rc)
+			goto out;
+
+		for_each_possible_cpu(cpu) {
+			disp = per_cpu_ptr(&vcpu_disp_data, cpu);
+			memset(disp, 0, sizeof(*disp));
+			disp->last_disp_cpu = -1;
+		}
+
+		rc = dtl_worker_enable(&time_limit);
+		if (rc) {
+			destroy_cpu_associativity();
+			goto out;
+		}
+	} else {
+		dtl_worker_disable(&time_limit);
+		destroy_cpu_associativity();
+	}
+
+	vcpudispatch_stats_on = cmd;
+
+out:
+	mutex_unlock(&dtl_enable_mutex);
+	if (rc)
+		return rc;
+	return count;
+}
+
+static int vcpudispatch_stats_display(struct seq_file *p, void *v)
+{
+	int cpu;
+	struct vcpu_dispatch_data *disp;
+
+	if (!vcpudispatch_stats_on) {
+		seq_puts(p, "off\n");
+		return 0;
+	}
+
+	for_each_online_cpu(cpu) {
+		disp = per_cpu_ptr(&vcpu_disp_data, cpu);
+		seq_printf(p, "cpu%d", cpu);
+		seq_put_decimal_ull(p, " ", disp->total_disp);
+		seq_put_decimal_ull(p, " ", disp->same_cpu_disp);
+		seq_put_decimal_ull(p, " ", disp->same_chip_disp);
+		seq_put_decimal_ull(p, " ", disp->diff_chip_disp);
+		seq_put_decimal_ull(p, " ", disp->far_chip_disp);
+		seq_put_decimal_ull(p, " ", disp->numa_home_disp);
+		seq_put_decimal_ull(p, " ", disp->numa_remote_disp);
+		seq_put_decimal_ull(p, " ", disp->numa_far_disp);
+		seq_puts(p, "\n");
+	}
+
+	return 0;
+}
+
+static int vcpudispatch_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, vcpudispatch_stats_display, NULL);
+}
+
+static const struct file_operations vcpudispatch_stats_proc_ops = {
+	.open		= vcpudispatch_stats_open,
+	.read		= seq_read,
+	.write		= vcpudispatch_stats_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static ssize_t vcpudispatch_stats_freq_write(struct file *file,
+		const char __user *p, size_t count, loff_t *ppos)
+{
+	int rc, freq;
+	char buf[16];
+
+	if (count > 15)
+		return -EINVAL;
+
+	if (copy_from_user(buf, p, count))
+		return -EFAULT;
+
+	buf[count] = 0;
+	rc = kstrtoint(buf, 0, &freq);
+	if (rc || freq < 1 || freq > HZ) {
+		pr_err("vcpudispatch_stats_freq: please specify a frequency between 1 and %d\n",
+				HZ);
+		return rc ? rc : -EINVAL;
+	}
+
+	vcpudispatch_stats_freq = freq;
+
+	return count;
+}
+
+static int vcpudispatch_stats_freq_display(struct seq_file *p, void *v)
+{
+	seq_printf(p, "%d\n", vcpudispatch_stats_freq);
+	return 0;
+}
+
+static int vcpudispatch_stats_freq_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, vcpudispatch_stats_freq_display, NULL);
+}
+
+static const struct file_operations vcpudispatch_stats_freq_proc_ops = {
+	.open		= vcpudispatch_stats_freq_open,
+	.read		= seq_read,
+	.write		= vcpudispatch_stats_freq_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init vcpudispatch_stats_procfs_init(void)
+{
+	if (!lppaca_shared_proc(get_lppaca()))
+		return 0;
+
+	if (!proc_create("powerpc/vcpudispatch_stats", 0600, NULL,
+					&vcpudispatch_stats_proc_ops))
+		pr_err("vcpudispatch_stats: error creating procfs file\n");
+	else if (!proc_create("powerpc/vcpudispatch_stats_freq", 0600, NULL,
+					&vcpudispatch_stats_freq_proc_ops))
+		pr_err("vcpudispatch_stats_freq: error creating procfs file\n");
+
+	return 0;
+}
+
+machine_device_initcall(pseries, vcpudispatch_stats_procfs_init);
+#endif /* CONFIG_PPC_SPLPAR */
+
 void vpa_init(int cpu)
 {
 	int hwcpu = get_hard_smp_processor_id(cpu);
 	unsigned long addr;
 	long ret;
-	struct paca_struct *pp;
-	struct dtl_entry *dtl;
 
 	/*
 	 * The spec says it "may be problematic" if CPU x registers the VPA of
@@ -99,22 +681,7 @@ void vpa_init(int cpu)
 	/*
 	 * Register dispatch trace log, if one has been allocated.
 	 */
-	pp = paca_ptrs[cpu];
-	dtl = pp->dispatch_log;
-	if (dtl) {
-		pp->dtl_ridx = 0;
-		pp->dtl_curr = dtl;
-		lppaca_of(cpu).dtl_idx = 0;
-
-		/* hypervisor reads buffer length from this field */
-		dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
-		ret = register_dtl(hwcpu, __pa(dtl));
-		if (ret)
-			pr_err("WARNING: DTL registration of cpu %d (hw %d) "
-			       "failed with %ld\n", smp_processor_id(),
-			       hwcpu, ret);
-		lppaca_of(cpu).dtl_enable_mask = 2;
-	}
+	register_dtl_buffer(cpu);
 }
 
 #ifdef CONFIG_PPC_BOOK3S_64