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-rw-r--r--drivers/gpu/drm/i915/intel_runtime_pm.c660
1 files changed, 660 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c
new file mode 100644
index 000000000..129746713
--- /dev/null
+++ b/drivers/gpu/drm/i915/intel_runtime_pm.c
@@ -0,0 +1,660 @@
+/*
+ * Copyright © 2012-2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ * Eugeni Dodonov <eugeni.dodonov@intel.com>
+ * Daniel Vetter <daniel.vetter@ffwll.ch>
+ *
+ */
+
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_print.h>
+
+#include "i915_drv.h"
+#include "i915_trace.h"
+
+/**
+ * DOC: runtime pm
+ *
+ * The i915 driver supports dynamic enabling and disabling of entire hardware
+ * blocks at runtime. This is especially important on the display side where
+ * software is supposed to control many power gates manually on recent hardware,
+ * since on the GT side a lot of the power management is done by the hardware.
+ * But even there some manual control at the device level is required.
+ *
+ * Since i915 supports a diverse set of platforms with a unified codebase and
+ * hardware engineers just love to shuffle functionality around between power
+ * domains there's a sizeable amount of indirection required. This file provides
+ * generic functions to the driver for grabbing and releasing references for
+ * abstract power domains. It then maps those to the actual power wells
+ * present for a given platform.
+ */
+
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+
+#include <linux/sort.h>
+
+#define STACKDEPTH 8
+
+static noinline depot_stack_handle_t __save_depot_stack(void)
+{
+ unsigned long entries[STACKDEPTH];
+ unsigned int n;
+
+ n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
+ return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN);
+}
+
+static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
+{
+ spin_lock_init(&rpm->debug.lock);
+ stack_depot_init();
+}
+
+static noinline depot_stack_handle_t
+track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
+{
+ depot_stack_handle_t stack, *stacks;
+ unsigned long flags;
+
+ if (rpm->no_wakeref_tracking)
+ return -1;
+
+ stack = __save_depot_stack();
+ if (!stack)
+ return -1;
+
+ spin_lock_irqsave(&rpm->debug.lock, flags);
+
+ if (!rpm->debug.count)
+ rpm->debug.last_acquire = stack;
+
+ stacks = krealloc(rpm->debug.owners,
+ (rpm->debug.count + 1) * sizeof(*stacks),
+ GFP_NOWAIT | __GFP_NOWARN);
+ if (stacks) {
+ stacks[rpm->debug.count++] = stack;
+ rpm->debug.owners = stacks;
+ } else {
+ stack = -1;
+ }
+
+ spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+ return stack;
+}
+
+static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
+ depot_stack_handle_t stack)
+{
+ struct drm_i915_private *i915 = container_of(rpm,
+ struct drm_i915_private,
+ runtime_pm);
+ unsigned long flags, n;
+ bool found = false;
+
+ if (unlikely(stack == -1))
+ return;
+
+ spin_lock_irqsave(&rpm->debug.lock, flags);
+ for (n = rpm->debug.count; n--; ) {
+ if (rpm->debug.owners[n] == stack) {
+ memmove(rpm->debug.owners + n,
+ rpm->debug.owners + n + 1,
+ (--rpm->debug.count - n) * sizeof(stack));
+ found = true;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+ if (drm_WARN(&i915->drm, !found,
+ "Unmatched wakeref (tracking %lu), count %u\n",
+ rpm->debug.count, atomic_read(&rpm->wakeref_count))) {
+ char *buf;
+
+ buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
+ if (!buf)
+ return;
+
+ stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
+ DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
+
+ stack = READ_ONCE(rpm->debug.last_release);
+ if (stack) {
+ stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
+ DRM_DEBUG_DRIVER("wakeref last released at\n%s", buf);
+ }
+
+ kfree(buf);
+ }
+}
+
+static int cmphandle(const void *_a, const void *_b)
+{
+ const depot_stack_handle_t * const a = _a, * const b = _b;
+
+ if (*a < *b)
+ return -1;
+ else if (*a > *b)
+ return 1;
+ else
+ return 0;
+}
+
+static void
+__print_intel_runtime_pm_wakeref(struct drm_printer *p,
+ const struct intel_runtime_pm_debug *dbg)
+{
+ unsigned long i;
+ char *buf;
+
+ buf = kmalloc(PAGE_SIZE, GFP_NOWAIT | __GFP_NOWARN);
+ if (!buf)
+ return;
+
+ if (dbg->last_acquire) {
+ stack_depot_snprint(dbg->last_acquire, buf, PAGE_SIZE, 2);
+ drm_printf(p, "Wakeref last acquired:\n%s", buf);
+ }
+
+ if (dbg->last_release) {
+ stack_depot_snprint(dbg->last_release, buf, PAGE_SIZE, 2);
+ drm_printf(p, "Wakeref last released:\n%s", buf);
+ }
+
+ drm_printf(p, "Wakeref count: %lu\n", dbg->count);
+
+ sort(dbg->owners, dbg->count, sizeof(*dbg->owners), cmphandle, NULL);
+
+ for (i = 0; i < dbg->count; i++) {
+ depot_stack_handle_t stack = dbg->owners[i];
+ unsigned long rep;
+
+ rep = 1;
+ while (i + 1 < dbg->count && dbg->owners[i + 1] == stack)
+ rep++, i++;
+ stack_depot_snprint(stack, buf, PAGE_SIZE, 2);
+ drm_printf(p, "Wakeref x%lu taken at:\n%s", rep, buf);
+ }
+
+ kfree(buf);
+}
+
+static noinline void
+__untrack_all_wakerefs(struct intel_runtime_pm_debug *debug,
+ struct intel_runtime_pm_debug *saved)
+{
+ *saved = *debug;
+
+ debug->owners = NULL;
+ debug->count = 0;
+ debug->last_release = __save_depot_stack();
+}
+
+static void
+dump_and_free_wakeref_tracking(struct intel_runtime_pm_debug *debug)
+{
+ if (debug->count) {
+ struct drm_printer p = drm_debug_printer("i915");
+
+ __print_intel_runtime_pm_wakeref(&p, debug);
+ }
+
+ kfree(debug->owners);
+}
+
+static noinline void
+__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
+{
+ struct intel_runtime_pm_debug dbg = {};
+ unsigned long flags;
+
+ if (!atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
+ &rpm->debug.lock,
+ flags))
+ return;
+
+ __untrack_all_wakerefs(&rpm->debug, &dbg);
+ spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+ dump_and_free_wakeref_tracking(&dbg);
+}
+
+static noinline void
+untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
+{
+ struct intel_runtime_pm_debug dbg = {};
+ unsigned long flags;
+
+ spin_lock_irqsave(&rpm->debug.lock, flags);
+ __untrack_all_wakerefs(&rpm->debug, &dbg);
+ spin_unlock_irqrestore(&rpm->debug.lock, flags);
+
+ dump_and_free_wakeref_tracking(&dbg);
+}
+
+void print_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
+ struct drm_printer *p)
+{
+ struct intel_runtime_pm_debug dbg = {};
+
+ do {
+ unsigned long alloc = dbg.count;
+ depot_stack_handle_t *s;
+
+ spin_lock_irq(&rpm->debug.lock);
+ dbg.count = rpm->debug.count;
+ if (dbg.count <= alloc) {
+ memcpy(dbg.owners,
+ rpm->debug.owners,
+ dbg.count * sizeof(*s));
+ }
+ dbg.last_acquire = rpm->debug.last_acquire;
+ dbg.last_release = rpm->debug.last_release;
+ spin_unlock_irq(&rpm->debug.lock);
+ if (dbg.count <= alloc)
+ break;
+
+ s = krealloc(dbg.owners,
+ dbg.count * sizeof(*s),
+ GFP_NOWAIT | __GFP_NOWARN);
+ if (!s)
+ goto out;
+
+ dbg.owners = s;
+ } while (1);
+
+ __print_intel_runtime_pm_wakeref(p, &dbg);
+
+out:
+ kfree(dbg.owners);
+}
+
+#else
+
+static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
+{
+}
+
+static depot_stack_handle_t
+track_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
+{
+ return -1;
+}
+
+static void untrack_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm,
+ intel_wakeref_t wref)
+{
+}
+
+static void
+__intel_wakeref_dec_and_check_tracking(struct intel_runtime_pm *rpm)
+{
+ atomic_dec(&rpm->wakeref_count);
+}
+
+static void
+untrack_all_intel_runtime_pm_wakerefs(struct intel_runtime_pm *rpm)
+{
+}
+
+#endif
+
+static void
+intel_runtime_pm_acquire(struct intel_runtime_pm *rpm, bool wakelock)
+{
+ if (wakelock) {
+ atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
+ assert_rpm_wakelock_held(rpm);
+ } else {
+ atomic_inc(&rpm->wakeref_count);
+ assert_rpm_raw_wakeref_held(rpm);
+ }
+}
+
+static void
+intel_runtime_pm_release(struct intel_runtime_pm *rpm, int wakelock)
+{
+ if (wakelock) {
+ assert_rpm_wakelock_held(rpm);
+ atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
+ } else {
+ assert_rpm_raw_wakeref_held(rpm);
+ }
+
+ __intel_wakeref_dec_and_check_tracking(rpm);
+}
+
+static intel_wakeref_t __intel_runtime_pm_get(struct intel_runtime_pm *rpm,
+ bool wakelock)
+{
+ struct drm_i915_private *i915 = container_of(rpm,
+ struct drm_i915_private,
+ runtime_pm);
+ int ret;
+
+ ret = pm_runtime_get_sync(rpm->kdev);
+ drm_WARN_ONCE(&i915->drm, ret < 0,
+ "pm_runtime_get_sync() failed: %d\n", ret);
+
+ intel_runtime_pm_acquire(rpm, wakelock);
+
+ return track_intel_runtime_pm_wakeref(rpm);
+}
+
+/**
+ * intel_runtime_pm_get_raw - grab a raw runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This is the unlocked version of intel_display_power_is_enabled() and should
+ * only be used from error capture and recovery code where deadlocks are
+ * possible.
+ * This function grabs a device-level runtime pm reference (mostly used for
+ * asynchronous PM management from display code) and ensures that it is powered
+ * up. Raw references are not considered during wakelock assert checks.
+ *
+ * Any runtime pm reference obtained by this function must have a symmetric
+ * call to intel_runtime_pm_put_raw() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put_raw(), evaluates
+ * as True if the wakeref was acquired, or False otherwise.
+ */
+intel_wakeref_t intel_runtime_pm_get_raw(struct intel_runtime_pm *rpm)
+{
+ return __intel_runtime_pm_get(rpm, false);
+}
+
+/**
+ * intel_runtime_pm_get - grab a runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function grabs a device-level runtime pm reference (mostly used for GEM
+ * code to ensure the GTT or GT is on) and ensures that it is powered up.
+ *
+ * Any runtime pm reference obtained by this function must have a symmetric
+ * call to intel_runtime_pm_put() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
+ */
+intel_wakeref_t intel_runtime_pm_get(struct intel_runtime_pm *rpm)
+{
+ return __intel_runtime_pm_get(rpm, true);
+}
+
+/**
+ * __intel_runtime_pm_get_if_active - grab a runtime pm reference if device is active
+ * @rpm: the intel_runtime_pm structure
+ * @ignore_usecount: get a ref even if dev->power.usage_count is 0
+ *
+ * This function grabs a device-level runtime pm reference if the device is
+ * already active and ensures that it is powered up. It is illegal to try
+ * and access the HW should intel_runtime_pm_get_if_active() report failure.
+ *
+ * If @ignore_usecount is true, a reference will be acquired even if there is no
+ * user requiring the device to be powered up (dev->power.usage_count == 0).
+ * If the function returns false in this case then it's guaranteed that the
+ * device's runtime suspend hook has been called already or that it will be
+ * called (and hence it's also guaranteed that the device's runtime resume
+ * hook will be called eventually).
+ *
+ * Any runtime pm reference obtained by this function must have a symmetric
+ * call to intel_runtime_pm_put() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put(), evaluates
+ * as True if the wakeref was acquired, or False otherwise.
+ */
+static intel_wakeref_t __intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm,
+ bool ignore_usecount)
+{
+ if (IS_ENABLED(CONFIG_PM)) {
+ /*
+ * In cases runtime PM is disabled by the RPM core and we get
+ * an -EINVAL return value we are not supposed to call this
+ * function, since the power state is undefined. This applies
+ * atm to the late/early system suspend/resume handlers.
+ */
+ if (pm_runtime_get_if_active(rpm->kdev, ignore_usecount) <= 0)
+ return 0;
+ }
+
+ intel_runtime_pm_acquire(rpm, true);
+
+ return track_intel_runtime_pm_wakeref(rpm);
+}
+
+intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
+{
+ return __intel_runtime_pm_get_if_active(rpm, false);
+}
+
+intel_wakeref_t intel_runtime_pm_get_if_active(struct intel_runtime_pm *rpm)
+{
+ return __intel_runtime_pm_get_if_active(rpm, true);
+}
+
+/**
+ * intel_runtime_pm_get_noresume - grab a runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function grabs a device-level runtime pm reference (mostly used for GEM
+ * code to ensure the GTT or GT is on).
+ *
+ * It will _not_ power up the device but instead only check that it's powered
+ * on. Therefore it is only valid to call this functions from contexts where
+ * the device is known to be powered up and where trying to power it up would
+ * result in hilarity and deadlocks. That pretty much means only the system
+ * suspend/resume code where this is used to grab runtime pm references for
+ * delayed setup down in work items.
+ *
+ * Any runtime pm reference obtained by this function must have a symmetric
+ * call to intel_runtime_pm_put() to release the reference again.
+ *
+ * Returns: the wakeref cookie to pass to intel_runtime_pm_put()
+ */
+intel_wakeref_t intel_runtime_pm_get_noresume(struct intel_runtime_pm *rpm)
+{
+ assert_rpm_wakelock_held(rpm);
+ pm_runtime_get_noresume(rpm->kdev);
+
+ intel_runtime_pm_acquire(rpm, true);
+
+ return track_intel_runtime_pm_wakeref(rpm);
+}
+
+static void __intel_runtime_pm_put(struct intel_runtime_pm *rpm,
+ intel_wakeref_t wref,
+ bool wakelock)
+{
+ struct device *kdev = rpm->kdev;
+
+ untrack_intel_runtime_pm_wakeref(rpm, wref);
+
+ intel_runtime_pm_release(rpm, wakelock);
+
+ pm_runtime_mark_last_busy(kdev);
+ pm_runtime_put_autosuspend(kdev);
+}
+
+/**
+ * intel_runtime_pm_put_raw - release a raw runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ * @wref: wakeref acquired for the reference that is being released
+ *
+ * This function drops the device-level runtime pm reference obtained by
+ * intel_runtime_pm_get_raw() and might power down the corresponding
+ * hardware block right away if this is the last reference.
+ */
+void
+intel_runtime_pm_put_raw(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
+{
+ __intel_runtime_pm_put(rpm, wref, false);
+}
+
+/**
+ * intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function drops the device-level runtime pm reference obtained by
+ * intel_runtime_pm_get() and might power down the corresponding
+ * hardware block right away if this is the last reference.
+ *
+ * This function exists only for historical reasons and should be avoided in
+ * new code, as the correctness of its use cannot be checked. Always use
+ * intel_runtime_pm_put() instead.
+ */
+void intel_runtime_pm_put_unchecked(struct intel_runtime_pm *rpm)
+{
+ __intel_runtime_pm_put(rpm, -1, true);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
+/**
+ * intel_runtime_pm_put - release a runtime pm reference
+ * @rpm: the intel_runtime_pm structure
+ * @wref: wakeref acquired for the reference that is being released
+ *
+ * This function drops the device-level runtime pm reference obtained by
+ * intel_runtime_pm_get() and might power down the corresponding
+ * hardware block right away if this is the last reference.
+ */
+void intel_runtime_pm_put(struct intel_runtime_pm *rpm, intel_wakeref_t wref)
+{
+ __intel_runtime_pm_put(rpm, wref, true);
+}
+#endif
+
+/**
+ * intel_runtime_pm_enable - enable runtime pm
+ * @rpm: the intel_runtime_pm structure
+ *
+ * This function enables runtime pm at the end of the driver load sequence.
+ *
+ * Note that this function does currently not enable runtime pm for the
+ * subordinate display power domains. That is done by
+ * intel_power_domains_enable().
+ */
+void intel_runtime_pm_enable(struct intel_runtime_pm *rpm)
+{
+ struct drm_i915_private *i915 = container_of(rpm,
+ struct drm_i915_private,
+ runtime_pm);
+ struct device *kdev = rpm->kdev;
+
+ /*
+ * Disable the system suspend direct complete optimization, which can
+ * leave the device suspended skipping the driver's suspend handlers
+ * if the device was already runtime suspended. This is needed due to
+ * the difference in our runtime and system suspend sequence and
+ * becaue the HDA driver may require us to enable the audio power
+ * domain during system suspend.
+ */
+ dev_pm_set_driver_flags(kdev, DPM_FLAG_NO_DIRECT_COMPLETE);
+
+ pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */
+ pm_runtime_mark_last_busy(kdev);
+
+ /*
+ * Take a permanent reference to disable the RPM functionality and drop
+ * it only when unloading the driver. Use the low level get/put helpers,
+ * so the driver's own RPM reference tracking asserts also work on
+ * platforms without RPM support.
+ */
+ if (!rpm->available) {
+ int ret;
+
+ pm_runtime_dont_use_autosuspend(kdev);
+ ret = pm_runtime_get_sync(kdev);
+ drm_WARN(&i915->drm, ret < 0,
+ "pm_runtime_get_sync() failed: %d\n", ret);
+ } else {
+ pm_runtime_use_autosuspend(kdev);
+ }
+
+ /*
+ * FIXME: Temp hammer to keep autosupend disable on lmem supported platforms.
+ * As per PCIe specs 5.3.1.4.1, all iomem read write request over a PCIe
+ * function will be unsupported in case PCIe endpoint function is in D3.
+ * Let's keep i915 autosuspend control 'on' till we fix all known issue
+ * with lmem access in D3.
+ */
+ if (!IS_DGFX(i915))
+ pm_runtime_allow(kdev);
+
+ /*
+ * The core calls the driver load handler with an RPM reference held.
+ * We drop that here and will reacquire it during unloading in
+ * intel_power_domains_fini().
+ */
+ pm_runtime_put_autosuspend(kdev);
+}
+
+void intel_runtime_pm_disable(struct intel_runtime_pm *rpm)
+{
+ struct drm_i915_private *i915 = container_of(rpm,
+ struct drm_i915_private,
+ runtime_pm);
+ struct device *kdev = rpm->kdev;
+
+ /* Transfer rpm ownership back to core */
+ drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0,
+ "Failed to pass rpm ownership back to core\n");
+
+ pm_runtime_dont_use_autosuspend(kdev);
+
+ if (!rpm->available)
+ pm_runtime_put(kdev);
+}
+
+void intel_runtime_pm_driver_release(struct intel_runtime_pm *rpm)
+{
+ struct drm_i915_private *i915 = container_of(rpm,
+ struct drm_i915_private,
+ runtime_pm);
+ int count = atomic_read(&rpm->wakeref_count);
+
+ intel_wakeref_auto_fini(&rpm->userfault_wakeref);
+
+ drm_WARN(&i915->drm, count,
+ "i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
+ intel_rpm_raw_wakeref_count(count),
+ intel_rpm_wakelock_count(count));
+
+ untrack_all_intel_runtime_pm_wakerefs(rpm);
+}
+
+void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
+{
+ struct drm_i915_private *i915 =
+ container_of(rpm, struct drm_i915_private, runtime_pm);
+ struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+ struct device *kdev = &pdev->dev;
+
+ rpm->kdev = kdev;
+ rpm->available = HAS_RUNTIME_PM(i915);
+
+ init_intel_runtime_pm_wakeref(rpm);
+ INIT_LIST_HEAD(&rpm->lmem_userfault_list);
+ spin_lock_init(&rpm->lmem_userfault_lock);
+ intel_wakeref_auto_init(&rpm->userfault_wakeref, rpm);
+}