Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...

3 files changed, 142 insertions, 84 deletions

diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index 7709fcc707f4..5414c4a87bea 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -73,7 +73,7 @@ static LIST_HEAD(hvc_structs);
  * Protect the list of hvc_struct instances from inserts and removals during
  * list traversal.
  */
-static DEFINE_SPINLOCK(hvc_structs_lock);
+static DEFINE_MUTEX(hvc_structs_mutex);
 
 /*
  * This value is used to assign a tty->index value to a hvc_struct based
@@ -83,7 +83,7 @@ static DEFINE_SPINLOCK(hvc_structs_lock);
 static int last_hvc = -1;
 
 /*
- * Do not call this function with either the hvc_structs_lock or the hvc_struct
+ * Do not call this function with either the hvc_structs_mutex or the hvc_struct
  * lock held.  If successful, this function increments the kref reference
  * count against the target hvc_struct so it should be released when finished.
  */
@@ -92,24 +92,46 @@ static struct hvc_struct *hvc_get_by_index(int index)
 	struct hvc_struct *hp;
 	unsigned long flags;
 
-	spin_lock(&hvc_structs_lock);
+	mutex_lock(&hvc_structs_mutex);
 
 	list_for_each_entry(hp, &hvc_structs, next) {
 		spin_lock_irqsave(&hp->lock, flags);
 		if (hp->index == index) {
 			tty_port_get(&hp->port);
 			spin_unlock_irqrestore(&hp->lock, flags);
-			spin_unlock(&hvc_structs_lock);
+			mutex_unlock(&hvc_structs_mutex);
 			return hp;
 		}
 		spin_unlock_irqrestore(&hp->lock, flags);
 	}
 	hp = NULL;
+	mutex_unlock(&hvc_structs_mutex);
 
-	spin_unlock(&hvc_structs_lock);
 	return hp;
 }
 
+static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait)
+{
+	if (wait)
+		might_sleep();
+
+	if (ops->flush)
+		return ops->flush(vtermno, wait);
+	return 0;
+}
+
+static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno)
+{
+	return __hvc_flush(ops, vtermno, false);
+}
+
+/*
+ * Wait for the console to flush before writing more to it. This sleeps.
+ */
+static int hvc_flush(struct hvc_struct *hp)
+{
+	return __hvc_flush(hp->ops, hp->vtermno, true);
+}
 
 /*
  * Initial console vtermnos for console API usage prior to full console
@@ -156,8 +178,12 @@ static void hvc_console_print(struct console *co, const char *b,
 			if (r <= 0) {
 				/* throw away characters on error
 				 * but spin in case of -EAGAIN */
-				if (r != -EAGAIN)
+				if (r != -EAGAIN) {
 					i = 0;
+				} else {
+					hvc_console_flush(cons_ops[index],
+						      vtermnos[index]);
+				}
 			} else if (r > 0) {
 				i -= r;
 				if (i > 0)
@@ -165,6 +191,7 @@ static void hvc_console_print(struct console *co, const char *b,
 			}
 		}
 	}
+	hvc_console_flush(cons_ops[index], vtermnos[index]);
 }
 
 static struct tty_driver *hvc_console_device(struct console *c, int *index)
@@ -224,13 +251,13 @@ static void hvc_port_destruct(struct tty_port *port)
 	struct hvc_struct *hp = container_of(port, struct hvc_struct, port);
 	unsigned long flags;
 
-	spin_lock(&hvc_structs_lock);
+	mutex_lock(&hvc_structs_mutex);
 
 	spin_lock_irqsave(&hp->lock, flags);
 	list_del(&(hp->next));
 	spin_unlock_irqrestore(&hp->lock, flags);
 
-	spin_unlock(&hvc_structs_lock);
+	mutex_unlock(&hvc_structs_mutex);
 
 	kfree(hp);
 }
@@ -494,23 +521,32 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count
 	if (hp->port.count <= 0)
 		return -EIO;
 
-	spin_lock_irqsave(&hp->lock, flags);
+	while (count > 0) {
+		spin_lock_irqsave(&hp->lock, flags);
 
-	/* Push pending writes */
-	if (hp->n_outbuf > 0)
-		hvc_push(hp);
-
-	while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) {
-		if (rsize > count)
-			rsize = count;
-		memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
-		count -= rsize;
-		buf += rsize;
-		hp->n_outbuf += rsize;
-		written += rsize;
-		hvc_push(hp);
+		rsize = hp->outbuf_size - hp->n_outbuf;
+
+		if (rsize) {
+			if (rsize > count)
+				rsize = count;
+			memcpy(hp->outbuf + hp->n_outbuf, buf, rsize);
+			count -= rsize;
+			buf += rsize;
+			hp->n_outbuf += rsize;
+			written += rsize;
+		}
+
+		if (hp->n_outbuf > 0)
+			hvc_push(hp);
+
+		spin_unlock_irqrestore(&hp->lock, flags);
+
+		if (count) {
+			if (hp->n_outbuf > 0)
+				hvc_flush(hp);
+			cond_resched();
+		}
 	}
-	spin_unlock_irqrestore(&hp->lock, flags);
 
 	/*
 	 * Racy, but harmless, kick thread if there is still pending data.
@@ -590,10 +626,10 @@ static u32 timeout = MIN_TIMEOUT;
 #define HVC_POLL_READ	0x00000001
 #define HVC_POLL_WRITE	0x00000002
 
-int hvc_poll(struct hvc_struct *hp)
+static int __hvc_poll(struct hvc_struct *hp, bool may_sleep)
 {
 	struct tty_struct *tty;
-	int i, n, poll_mask = 0;
+	int i, n, count, poll_mask = 0;
 	char buf[N_INBUF] __ALIGNED__;
 	unsigned long flags;
 	int read_total = 0;
@@ -612,6 +648,12 @@ int hvc_poll(struct hvc_struct *hp)
 		timeout = (written_total) ? 0 : MIN_TIMEOUT;
 	}
 
+	if (may_sleep) {
+		spin_unlock_irqrestore(&hp->lock, flags);
+		cond_resched();
+		spin_lock_irqsave(&hp->lock, flags);
+	}
+
 	/* No tty attached, just skip */
 	tty = tty_port_tty_get(&hp->port);
 	if (tty == NULL)
@@ -619,7 +661,7 @@ int hvc_poll(struct hvc_struct *hp)
 
 	/* Now check if we can get data (are we throttled ?) */
 	if (tty_throttled(tty))
-		goto throttled;
+		goto out;
 
 	/* If we aren't notifier driven and aren't throttled, we always
 	 * request a reschedule
@@ -628,56 +670,58 @@ int hvc_poll(struct hvc_struct *hp)
 		poll_mask |= HVC_POLL_READ;
 
 	/* Read data if any */
-	for (;;) {
-		int count = tty_buffer_request_room(&hp->port, N_INBUF);
 
-		/* If flip is full, just reschedule a later read */
-		if (count == 0) {
+	count = tty_buffer_request_room(&hp->port, N_INBUF);
+
+	/* If flip is full, just reschedule a later read */
+	if (count == 0) {
+		poll_mask |= HVC_POLL_READ;
+		goto out;
+	}
+
+	n = hp->ops->get_chars(hp->vtermno, buf, count);
+	if (n <= 0) {
+		/* Hangup the tty when disconnected from host */
+		if (n == -EPIPE) {
+			spin_unlock_irqrestore(&hp->lock, flags);
+			tty_hangup(tty);
+			spin_lock_irqsave(&hp->lock, flags);
+		} else if ( n == -EAGAIN ) {
+			/*
+			 * Some back-ends can only ensure a certain min
+			 * num of bytes read, which may be > 'count'.
+			 * Let the tty clear the flip buff to make room.
+			 */
 			poll_mask |= HVC_POLL_READ;
-			break;
 		}
+		goto out;
+	}
 
-		n = hp->ops->get_chars(hp->vtermno, buf, count);
-		if (n <= 0) {
-			/* Hangup the tty when disconnected from host */
-			if (n == -EPIPE) {
-				spin_unlock_irqrestore(&hp->lock, flags);
-				tty_hangup(tty);
-				spin_lock_irqsave(&hp->lock, flags);
-			} else if ( n == -EAGAIN ) {
-				/*
-				 * Some back-ends can only ensure a certain min
-				 * num of bytes read, which may be > 'count'.
-				 * Let the tty clear the flip buff to make room.
-				 */
-				poll_mask |= HVC_POLL_READ;
-			}
-			break;
-		}
-		for (i = 0; i < n; ++i) {
+	for (i = 0; i < n; ++i) {
 #ifdef CONFIG_MAGIC_SYSRQ
-			if (hp->index == hvc_console.index) {
-				/* Handle the SysRq Hack */
-				/* XXX should support a sequence */
-				if (buf[i] == '\x0f') {	/* ^O */
-					/* if ^O is pressed again, reset
-					 * sysrq_pressed and flip ^O char */
-					sysrq_pressed = !sysrq_pressed;
-					if (sysrq_pressed)
-						continue;
-				} else if (sysrq_pressed) {
-					handle_sysrq(buf[i]);
-					sysrq_pressed = 0;
+		if (hp->index == hvc_console.index) {
+			/* Handle the SysRq Hack */
+			/* XXX should support a sequence */
+			if (buf[i] == '\x0f') {	/* ^O */
+				/* if ^O is pressed again, reset
+				 * sysrq_pressed and flip ^O char */
+				sysrq_pressed = !sysrq_pressed;
+				if (sysrq_pressed)
 					continue;
-				}
+			} else if (sysrq_pressed) {
+				handle_sysrq(buf[i]);
+				sysrq_pressed = 0;
+				continue;
 			}
-#endif /* CONFIG_MAGIC_SYSRQ */
-			tty_insert_flip_char(&hp->port, buf[i], 0);
 		}
-
-		read_total += n;
+#endif /* CONFIG_MAGIC_SYSRQ */
+		tty_insert_flip_char(&hp->port, buf[i], 0);
 	}
- throttled:
+	if (n == count)
+		poll_mask |= HVC_POLL_READ;
+	read_total = n;
+
+ out:
 	/* Wakeup write queue if necessary */
 	if (hp->do_wakeup) {
 		hp->do_wakeup = 0;
@@ -697,6 +741,11 @@ int hvc_poll(struct hvc_struct *hp)
 
 	return poll_mask;
 }
+
+int hvc_poll(struct hvc_struct *hp)
+{
+	return __hvc_poll(hp, false);
+}
 EXPORT_SYMBOL_GPL(hvc_poll);
 
 /**
@@ -733,11 +782,12 @@ static int khvcd(void *unused)
 		try_to_freeze();
 		wmb();
 		if (!cpus_are_in_xmon()) {
-			spin_lock(&hvc_structs_lock);
+			mutex_lock(&hvc_structs_mutex);
 			list_for_each_entry(hp, &hvc_structs, next) {
-				poll_mask |= hvc_poll(hp);
+				poll_mask |= __hvc_poll(hp, true);
+				cond_resched();
 			}
-			spin_unlock(&hvc_structs_lock);
+			mutex_unlock(&hvc_structs_mutex);
 		} else
 			poll_mask |= HVC_POLL_READ;
 		if (hvc_kicked)
@@ -871,7 +921,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
 
 	INIT_WORK(&hp->tty_resize, hvc_set_winsz);
 	spin_lock_init(&hp->lock);
-	spin_lock(&hvc_structs_lock);
+	mutex_lock(&hvc_structs_mutex);
 
 	/*
 	 * find index to use:
@@ -891,7 +941,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
 	vtermnos[i] = vtermno;
 
 	list_add_tail(&(hp->next), &hvc_structs);
-	spin_unlock(&hvc_structs_lock);
+	mutex_unlock(&hvc_structs_mutex);
 
 	/* check if we need to re-register the kernel console */
 	hvc_check_console(i);
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
index ea63090e013f..e9319954c832 100644
--- a/drivers/tty/hvc/hvc_console.h
+++ b/drivers/tty/hvc/hvc_console.h
@@ -54,6 +54,7 @@ struct hvc_struct {
 struct hv_ops {
 	int (*get_chars)(uint32_t vtermno, char *buf, int count);
 	int (*put_chars)(uint32_t vtermno, const char *buf, int count);
+	int (*flush)(uint32_t vtermno, bool wait);
 
 	/* Callbacks for notification. Called in open, close and hangup */
 	int (*notifier_add)(struct hvc_struct *hp, int irq);
diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c
index 9645c0062a90..f631f8bee308 100644
--- a/drivers/tty/hvc/hvc_opal.c
+++ b/drivers/tty/hvc/hvc_opal.c
@@ -183,9 +183,15 @@ static int hvc_opal_probe(struct platform_device *dev)
 			return -ENOMEM;
 		pv->proto = proto;
 		hvc_opal_privs[termno] = pv;
-		if (proto == HV_PROTOCOL_HVSI)
-			hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
+		if (proto == HV_PROTOCOL_HVSI) {
+			/*
+			 * We want put_chars to be atomic to avoid mangling of
+			 * hvsi packets.
+			 */
+			hvsilib_init(&pv->hvsi,
+				     opal_get_chars, opal_put_chars_atomic,
 				     termno, 0);
+		}
 
 		/* Instanciate now to establish a mapping index==vtermno */
 		hvc_instantiate(termno, termno, ops);
@@ -275,6 +281,11 @@ static void udbg_opal_putc(char c)
 			count = hvc_opal_hvsi_put_chars(termno, &c, 1);
 			break;
 		}
+
+		/* This is needed for the cosole to flush
+		 * when there aren't any interrupts.
+		 */
+		opal_flush_console(termno);
 	} while(count == 0 || count == -EAGAIN);
 }
 
@@ -302,14 +313,8 @@ static int udbg_opal_getc(void)
 	int ch;
 	for (;;) {
 		ch = udbg_opal_getc_poll();
-		if (ch == -1) {
-			/* This shouldn't be needed...but... */
-			volatile unsigned long delay;
-			for (delay=0; delay < 2000000; delay++)
-				;
-		} else {
+		if (ch != -1)
 			return ch;
-		}
 	}
 }
 
@@ -370,8 +375,9 @@ void __init hvc_opal_init_early(void)
 	else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
 		hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
 		ops = &hvc_opal_hvsi_ops;
-		hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
-			     opal_put_chars, index, 1);
+		hvsilib_init(&hvc_opal_boot_priv.hvsi,
+			     opal_get_chars, opal_put_chars_atomic,
+			     index, 1);
 		/* HVSI, perform the handshake now */
 		hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 		pr_devel("hvc_opal: Found HVSI console\n");
@@ -403,7 +409,8 @@ void __init udbg_init_debug_opal_hvsi(void)
 	hvc_opal_privs[index] = &hvc_opal_boot_priv;
 	hvc_opal_boot_termno = index;
 	udbg_init_opal_common();
-	hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
+	hvsilib_init(&hvc_opal_boot_priv.hvsi,
+		     opal_get_chars, opal_put_chars_atomic,
 		     index, 1);
 	hvsilib_establish(&hvc_opal_boot_priv.hvsi);
 }