Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the bit set of char/misc drivers for 4.19-rc1

  There is a lot here, much more than normal, seems like everyone is
  writing new driver subsystems these days... Anyway, major things here
  are:

   - new FSI driver subsystem, yet-another-powerpc low-level hardware
     bus

   - gnss, finally an in-kernel GPS subsystem to try to tame all of the
     crazy out-of-tree drivers that have been floating around for years,
     combined with some really hacky userspace implementations. This is
     only for GNSS receivers, but you have to start somewhere, and this
     is great to see.

  Other than that, there are new slimbus drivers, new coresight drivers,
  new fpga drivers, and loads of DT bindings for all of these and
  existing drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
  android: binder: Rate-limit debug and userspace triggered err msgs
  fsi: sbefifo: Bump max command length
  fsi: scom: Fix NULL dereference
  misc: mic: SCIF Fix scif_get_new_port() error handling
  misc: cxl: changed asterisk position
  genwqe: card_base: Use true and false for boolean values
  misc: eeprom: assignment outside the if statement
  uio: potential double frees if __uio_register_device() fails
  eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency
  misc: ti-st: Fix memory leak in the error path of probe()
  android: binder: Show extra_buffers_size in trace
  firmware: vpd: Fix section enabled flag on vpd_section_destroy
  platform: goldfish: Retire pdev_bus
  goldfish: Use dedicated macros instead of manual bit shifting
  goldfish: Add missing includes to goldfish.h
  mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux
  dt-bindings: mux: add adi,adgs1408
  Drivers: hv: vmbus: Cleanup synic memory free path
  Drivers: hv: vmbus: Remove use of slow_virt_to_phys()
  Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
  ...

1 files changed, 54 insertions, 127 deletions

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index 56c6f79a5c5a..2543ef1ece17 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -1,27 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * VMware Balloon driver.
  *
- * Copyright (C) 2000-2014, VMware, Inc. All Rights Reserved.
+ * Copyright (C) 2000-2018, VMware, Inc. All Rights Reserved.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; version 2 of the License and no later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
- * NON INFRINGEMENT.  See the GNU General Public License for more
- * details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Maintained by:	Xavier Deguillard <xdeguillard@vmware.com>
- *			Philip Moltmann <moltmann@vmware.com>
- */
-
-/*
  * This is VMware physical memory management driver for Linux. The driver
  * acts like a "balloon" that can be inflated to reclaim physical pages by
  * reserving them in the guest and invalidating them in the monitor,
@@ -55,25 +37,6 @@ MODULE_ALIAS("vmware_vmmemctl");
 MODULE_LICENSE("GPL");
 
 /*
- * Various constants controlling rate of inflaint/deflating balloon,
- * measured in pages.
- */
-
-/*
- * Rates of memory allocaton when guest experiences memory pressure
- * (driver performs sleeping allocations).
- */
-#define VMW_BALLOON_RATE_ALLOC_MIN	512U
-#define VMW_BALLOON_RATE_ALLOC_MAX	2048U
-#define VMW_BALLOON_RATE_ALLOC_INC	16U
-
-/*
- * When guest is under memory pressure, use a reduced page allocation
- * rate for next several cycles.
- */
-#define VMW_BALLOON_SLOW_CYCLES		4
-
-/*
  * Use __GFP_HIGHMEM to allow pages from HIGHMEM zone. We don't
  * allow wait (__GFP_RECLAIM) for NOSLEEP page allocations. Use
  * __GFP_NOWARN, to suppress page allocation failure warnings.
@@ -284,12 +247,6 @@ struct vmballoon {
 	/* reset flag */
 	bool reset_required;
 
-	/* adjustment rates (pages per second) */
-	unsigned int rate_alloc;
-
-	/* slowdown page allocations for next few cycles */
-	unsigned int slow_allocation_cycles;
-
 	unsigned long capabilities;
 
 	struct vmballoon_batch_page *batch_page;
@@ -341,7 +298,13 @@ static bool vmballoon_send_start(struct vmballoon *b, unsigned long req_caps)
 		success = false;
 	}
 
-	if (b->capabilities & VMW_BALLOON_BATCHED_2M_CMDS)
+	/*
+	 * 2MB pages are only supported with batching. If batching is for some
+	 * reason disabled, do not use 2MB pages, since otherwise the legacy
+	 * mechanism is used with 2MB pages, causing a failure.
+	 */
+	if ((b->capabilities & VMW_BALLOON_BATCHED_2M_CMDS) &&
+	    (b->capabilities & VMW_BALLOON_BATCHED_CMDS))
 		b->supported_page_sizes = 2;
 	else
 		b->supported_page_sizes = 1;
@@ -450,7 +413,7 @@ static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
 
 	pfn32 = (u32)pfn;
 	if (pfn32 != pfn)
-		return -1;
+		return -EINVAL;
 
 	STATS_INC(b->stats.lock[false]);
 
@@ -460,7 +423,7 @@ static int vmballoon_send_lock_page(struct vmballoon *b, unsigned long pfn,
 
 	pr_debug("%s - ppn %lx, hv returns %ld\n", __func__, pfn, status);
 	STATS_INC(b->stats.lock_fail[false]);
-	return 1;
+	return -EIO;
 }
 
 static int vmballoon_send_batched_lock(struct vmballoon *b,
@@ -597,11 +560,12 @@ static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,
 
 	locked = vmballoon_send_lock_page(b, page_to_pfn(page), &hv_status,
 								target);
-	if (locked > 0) {
+	if (locked) {
 		STATS_INC(b->stats.refused_alloc[false]);
 
-		if (hv_status == VMW_BALLOON_ERROR_RESET ||
-				hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED) {
+		if (locked == -EIO &&
+		    (hv_status == VMW_BALLOON_ERROR_RESET ||
+		     hv_status == VMW_BALLOON_ERROR_PPN_NOTNEEDED)) {
 			vmballoon_free_page(page, false);
 			return -EIO;
 		}
@@ -617,7 +581,7 @@ static int vmballoon_lock_page(struct vmballoon *b, unsigned int num_pages,
 		} else {
 			vmballoon_free_page(page, false);
 		}
-		return -EIO;
+		return locked;
 	}
 
 	/* track allocated page */
@@ -790,8 +754,6 @@ static void vmballoon_add_batched_page(struct vmballoon *b, int idx,
  */
 static void vmballoon_inflate(struct vmballoon *b)
 {
-	unsigned rate;
-	unsigned int allocations = 0;
 	unsigned int num_pages = 0;
 	int error = 0;
 	gfp_t flags = VMW_PAGE_ALLOC_NOSLEEP;
@@ -818,17 +780,9 @@ static void vmballoon_inflate(struct vmballoon *b)
 	 * Start with no sleep allocation rate which may be higher
 	 * than sleeping allocation rate.
 	 */
-	if (b->slow_allocation_cycles) {
-		rate = b->rate_alloc;
-		is_2m_pages = false;
-	} else {
-		rate = UINT_MAX;
-		is_2m_pages =
-			b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES;
-	}
+	is_2m_pages = b->supported_page_sizes == VMW_BALLOON_NUM_PAGE_SIZES;
 
-	pr_debug("%s - goal: %d, no-sleep rate: %u, sleep rate: %d\n",
-		 __func__, b->target - b->size, rate, b->rate_alloc);
+	pr_debug("%s - goal: %d",  __func__, b->target - b->size);
 
 	while (!b->reset_required &&
 		b->size + num_pages * vmballoon_page_size(is_2m_pages)
@@ -861,31 +815,24 @@ static void vmballoon_inflate(struct vmballoon *b)
 			if (flags == VMW_PAGE_ALLOC_CANSLEEP) {
 				/*
 				 * CANSLEEP page allocation failed, so guest
-				 * is under severe memory pressure. Quickly
-				 * decrease allocation rate.
+				 * is under severe memory pressure. We just log
+				 * the event, but do not stop the inflation
+				 * due to its negative impact on performance.
 				 */
-				b->rate_alloc = max(b->rate_alloc / 2,
-						    VMW_BALLOON_RATE_ALLOC_MIN);
 				STATS_INC(b->stats.sleep_alloc_fail);
 				break;
 			}
 
 			/*
 			 * NOSLEEP page allocation failed, so the guest is
-			 * under memory pressure. Let us slow down page
-			 * allocations for next few cycles so that the guest
-			 * gets out of memory pressure. Also, if we already
-			 * allocated b->rate_alloc pages, let's pause,
-			 * otherwise switch to sleeping allocations.
+			 * under memory pressure. Slowing down page alloctions
+			 * seems to be reasonable, but doing so might actually
+			 * cause the hypervisor to throttle us down, resulting
+			 * in degraded performance. We will count on the
+			 * scheduler and standard memory management mechanisms
+			 * for now.
 			 */
-			b->slow_allocation_cycles = VMW_BALLOON_SLOW_CYCLES;
-
-			if (allocations >= b->rate_alloc)
-				break;
-
 			flags = VMW_PAGE_ALLOC_CANSLEEP;
-			/* Lower rate for sleeping allocations. */
-			rate = b->rate_alloc;
 			continue;
 		}
 
@@ -899,28 +846,11 @@ static void vmballoon_inflate(struct vmballoon *b)
 		}
 
 		cond_resched();
-
-		if (allocations >= rate) {
-			/* We allocated enough pages, let's take a break. */
-			break;
-		}
 	}
 
 	if (num_pages > 0)
 		b->ops->lock(b, num_pages, is_2m_pages, &b->target);
 
-	/*
-	 * We reached our goal without failures so try increasing
-	 * allocation rate.
-	 */
-	if (error == 0 && allocations >= b->rate_alloc) {
-		unsigned int mult = allocations / b->rate_alloc;
-
-		b->rate_alloc =
-			min(b->rate_alloc + mult * VMW_BALLOON_RATE_ALLOC_INC,
-			    VMW_BALLOON_RATE_ALLOC_MAX);
-	}
-
 	vmballoon_release_refused_pages(b, true);
 	vmballoon_release_refused_pages(b, false);
 }
@@ -1029,29 +959,30 @@ static void vmballoon_vmci_cleanup(struct vmballoon *b)
  */
 static int vmballoon_vmci_init(struct vmballoon *b)
 {
-	int error = 0;
+	unsigned long error, dummy;
 
-	if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) != 0) {
-		error = vmci_doorbell_create(&b->vmci_doorbell,
-				VMCI_FLAG_DELAYED_CB,
-				VMCI_PRIVILEGE_FLAG_RESTRICTED,
-				vmballoon_doorbell, b);
-
-		if (error == VMCI_SUCCESS) {
-			VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET,
-					b->vmci_doorbell.context,
-					b->vmci_doorbell.resource, error);
-			STATS_INC(b->stats.doorbell_set);
-		}
-	}
+	if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) == 0)
+		return 0;
 
-	if (error != 0) {
-		vmballoon_vmci_cleanup(b);
+	error = vmci_doorbell_create(&b->vmci_doorbell, VMCI_FLAG_DELAYED_CB,
+				     VMCI_PRIVILEGE_FLAG_RESTRICTED,
+				     vmballoon_doorbell, b);
 
-		return -EIO;
-	}
+	if (error != VMCI_SUCCESS)
+		goto fail;
+
+	error = VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, b->vmci_doorbell.context,
+				   b->vmci_doorbell.resource, dummy);
+
+	STATS_INC(b->stats.doorbell_set);
+
+	if (error != VMW_BALLOON_SUCCESS)
+		goto fail;
 
 	return 0;
+fail:
+	vmballoon_vmci_cleanup(b);
+	return -EIO;
 }
 
 /*
@@ -1114,9 +1045,6 @@ static void vmballoon_work(struct work_struct *work)
 	if (b->reset_required)
 		vmballoon_reset(b);
 
-	if (b->slow_allocation_cycles > 0)
-		b->slow_allocation_cycles--;
-
 	if (!b->reset_required && vmballoon_send_get_target(b, &target)) {
 		/* update target, adjust size */
 		b->target = target;
@@ -1160,11 +1088,6 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset)
 		   "current:            %8d pages\n",
 		   b->target, b->size);
 
-	/* format rate info */
-	seq_printf(f,
-		   "rateSleepAlloc:     %8d pages/sec\n",
-		   b->rate_alloc);
-
 	seq_printf(f,
 		   "\n"
 		   "timer:              %8u\n"
@@ -1271,9 +1194,6 @@ static int __init vmballoon_init(void)
 		INIT_LIST_HEAD(&balloon.page_sizes[is_2m_pages].refused_pages);
 	}
 
-	/* initialize rates */
-	balloon.rate_alloc = VMW_BALLOON_RATE_ALLOC_MAX;
-
 	INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work);
 
 	error = vmballoon_debugfs_init(&balloon);
@@ -1289,7 +1209,14 @@ static int __init vmballoon_init(void)
 
 	return 0;
 }
-module_init(vmballoon_init);
+
+/*
+ * Using late_initcall() instead of module_init() allows the balloon to use the
+ * VMCI doorbell even when the balloon is built into the kernel. Otherwise the
+ * VMCI is probed only after the balloon is initialized. If the balloon is used
+ * as a module, late_initcall() is equivalent to module_init().
+ */
+late_initcall(vmballoon_init);
 
 static void __exit vmballoon_exit(void)
 {