Merge tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "We have a few new features this time, including a new SFI-based
  cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new
  devfreq class for providing its governors with raw utilization data
  and a new ACPI driver for AMD SoCs.

  Still, the majority of changes here are reworks of existing code to
  make it more straightforward or to prepare it for implementing new
  features on top of it.  The primary example is the rework of ACPI
  resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with
  support for IOAPIC hotplug implemented on top of it, but there is
  quite a number of changes of this kind in the cpufreq core, ACPICA,
  ACPI EC driver, ACPI processor driver and the generic power domains
  core code too.

  The most active developer is Viresh Kumar with his cpufreq changes.

  Specifics:

   - Rework of the core ACPI resources parsing code to fix issues in it
     and make using resource offsets more convenient and consolidation
     of some resource-handing code in a couple of places that have grown
     analagous data structures and code to cover the the same gap in the
     core (Jiang Liu, Thomas Gleixner, Lv Zheng).

   - ACPI-based IOAPIC hotplug support on top of the resources handling
     rework (Jiang Liu, Yinghai Lu).

   - ACPICA update to upstream release 20150204 including an interrupt
     handling rework that allows drivers to install raw handlers for
     ACPI GPEs which then become entirely responsible for the given GPE
     and the ACPICA core code won't touch it (Lv Zheng, David E Box,
     Octavian Purdila).

   - ACPI EC driver rework to fix several concurrency issues and other
     problems related to events handling on top of the ACPICA's new
     support for raw GPE handlers (Lv Zheng).

   - New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
     Subsystem) driver for Intel chips (Ken Xue).

   - Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko
     Nikula).

   - Two new blacklist entries for machines (Samsung 730U3E/740U3E and
     510R) where the native backlight interface doesn't work correctly
     while the ACPI one does (Hans de Goede).

   - Rework of the ACPI processor driver's handling of idle states to
     make the code more straightforward and less bloated overall (Rafael
     J Wysocki).

   - Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
     Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei
     Bai).

   - PCI core power management modification to avoid resuming (some)
     runtime-suspended devices during system suspend if they are in the
     right states already (Rafael J Wysocki).

   - New SFI-based cpufreq driver for Intel platforms using SFI
     (Srinidhi Kasagar).

   - cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
     Doug Anderson, Wolfram Sang).

   - SkyLake CPU support and other updates for the intel_pstate driver
     (Kristen Carlson Accardi, Srinivas Pandruvada).

   - cpufreq-dt driver cleanup (Markus Elfring).

   - Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).

   - Generic power domains core code fixes and cleanups (Ulf Hansson).

   - Operating Performance Points (OPP) core code cleanups and kernel
     documentation update (Nishanth Menon).

   - New dabugfs interface to make the list of PM QoS constraints
     available to user space (Nishanth Menon).

   - New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).

   - New devfreq class (devfreq_event) to provide raw utilization data
     to devfreq governors (Chanwoo Choi).

   - Assorted minor fixes and cleanups related to power management
     (Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel
     Machek, Todd E Brandt, Wonhong Kwon).

   - turbostat updates (Len Brown) and cpupower Makefile improvement
     (Sriram Raghunathan)"

* tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits)
  tools/power turbostat: relax dependency on APERF_MSR
  tools/power turbostat: relax dependency on invariant TSC
  Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
  tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS
  tools/power turbostat: relax dependency on root permission
  ACPI / video: Add disable_native_backlight quirk for Samsung 510R
  ACPI / PM: Remove unneeded nested #ifdef
  USB / PM: Remove unneeded #ifdef and associated dead code
  intel_pstate: provide option to only use intel_pstate with HWP
  ACPI / EC: Add GPE reference counting debugging messages
  ACPI / EC: Add query flushing support
  ACPI / EC: Refine command storm prevention support
  ACPI / EC: Add command flushing support.
  ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag
  ACPI: add AMD ACPI2Platform device support for x86 system
  ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
  ACPI / EC: Update revision due to raw handler mode.
  ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
  ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
  ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
  ...

kernel/power/qos.c

@@ -41,6 +41,8 @@
 #include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <linux/uaccess.h>
 #include <linux/export.h>
@@ -182,6 +184,81 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
 	c->target_value = value;
 }
 
+static inline int pm_qos_get_value(struct pm_qos_constraints *c);
+static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused)
+{
+	struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
+	struct pm_qos_constraints *c;
+	struct pm_qos_request *req;
+	char *type;
+	unsigned long flags;
+	int tot_reqs = 0;
+	int active_reqs = 0;
+
+	if (IS_ERR_OR_NULL(qos)) {
+		pr_err("%s: bad qos param!\n", __func__);
+		return -EINVAL;
+	}
+	c = qos->constraints;
+	if (IS_ERR_OR_NULL(c)) {
+		pr_err("%s: Bad constraints on qos?\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Lock to ensure we have a snapshot */
+	spin_lock_irqsave(&pm_qos_lock, flags);
+	if (plist_head_empty(&c->list)) {
+		seq_puts(s, "Empty!\n");
+		goto out;
+	}
+
+	switch (c->type) {
+	case PM_QOS_MIN:
+		type = "Minimum";
+		break;
+	case PM_QOS_MAX:
+		type = "Maximum";
+		break;
+	case PM_QOS_SUM:
+		type = "Sum";
+		break;
+	default:
+		type = "Unknown";
+	}
+
+	plist_for_each_entry(req, &c->list, node) {
+		char *state = "Default";
+
+		if ((req->node).prio != c->default_value) {
+			active_reqs++;
+			state = "Active";
+		}
+		tot_reqs++;
+		seq_printf(s, "%d: %d: %s\n", tot_reqs,
+			   (req->node).prio, state);
+	}
+
+	seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
+		   type, pm_qos_get_value(c), active_reqs, tot_reqs);
+
+out:
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+	return 0;
+}
+
+static int pm_qos_dbg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pm_qos_dbg_show_requests,
+			   inode->i_private);
+}
+
+static const struct file_operations pm_qos_debug_fops = {
+	.open           = pm_qos_dbg_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
 /**
  * pm_qos_update_target - manages the constraints list and calls the notifiers
  *  if needed
@@ -509,12 +586,17 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
 
 /* User space interface to PM QoS classes via misc devices */
-static int register_pm_qos_misc(struct pm_qos_object *qos)
+static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
 {
 	qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
 	qos->pm_qos_power_miscdev.name = qos->name;
 	qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
 
+	if (d) {
+		(void)debugfs_create_file(qos->name, S_IRUGO, d,
+					  (void *)qos, &pm_qos_debug_fops);
+	}
+
 	return misc_register(&qos->pm_qos_power_miscdev);
 }
 
@@ -608,11 +690,16 @@ static int __init pm_qos_power_init(void)
 {
 	int ret = 0;
 	int i;
+	struct dentry *d;
 
 	BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
 
+	d = debugfs_create_dir("pm_qos", NULL);
+	if (IS_ERR_OR_NULL(d))
+		d = NULL;
+
 	for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
-		ret = register_pm_qos_misc(pm_qos_array[i]);
+		ret = register_pm_qos_misc(pm_qos_array[i], d);
 		if (ret < 0) {
 			printk(KERN_ERR "pm_qos_param: %s setup failed\n",
 			       pm_qos_array[i]->name);

kernel/power/snapshot.c

@@ -1472,9 +1472,9 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
 /**
  * free_unnecessary_pages - Release preallocated pages not needed for the image
  */
-static void free_unnecessary_pages(void)
+static unsigned long free_unnecessary_pages(void)
 {
-	unsigned long save, to_free_normal, to_free_highmem;
+	unsigned long save, to_free_normal, to_free_highmem, free;
 
 	save = count_data_pages();
 	if (alloc_normal >= save) {
@@ -1495,6 +1495,7 @@ static void free_unnecessary_pages(void)
 		else
 			to_free_normal = 0;
 	}
+	free = to_free_normal + to_free_highmem;
 
 	memory_bm_position_reset(&copy_bm);
 
@@ -1518,6 +1519,8 @@ static void free_unnecessary_pages(void)
 		swsusp_unset_page_free(page);
 		__free_page(page);
 	}
+
+	return free;
 }
 
 /**
@@ -1707,7 +1710,7 @@ int hibernate_preallocate_memory(void)
 	 * pages in memory, but we have allocated more.  Release the excessive
 	 * ones now.
 	 */
-	free_unnecessary_pages();
+	pages -= free_unnecessary_pages();
 
  out:
 	stop = ktime_get();
@@ -2310,8 +2313,6 @@ static inline void free_highmem_data(void)
 		free_image_page(buffer, PG_UNSAFE_CLEAR);
 }
 #else
-static inline int get_safe_write_buffer(void) { return 0; }
-
 static unsigned int
 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }