/* $NetBSD: intel_runtime_pm.c,v 1.12 2021/12/19 12:32:15 riastradh Exp $ */
/*
* 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: intel_runtime_pm.c,v 1.12 2021/12/19 12:32:15 riastradh Exp $");
#include <linux/pm_runtime.h>
#include <drm/drm_print.h>
#include "i915_drv.h"
#include "i915_trace.h"
#include <linux/nbsd-namespace.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([31mCONFIG_DRM_I915_DEBUG_RUNTIME_PM[0m)
#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 __print_depot_stack(depot_stack_handle_t stack,
char *buf, int sz, int indent)
{
unsigned long *entries;
unsigned int nr_entries;
nr_entries = stack_depot_fetch(stack, &entries);
stack_trace_snprint(buf, sz, entries, nr_entries, indent);
}
static void init_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
{
spin_lock_init(&rpm->debug.lock);
}
static void fini_intel_runtime_pm_wakeref(struct intel_runtime_pm *rpm)
{
spin_lock_fini(&rpm->debug.lock);
}
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->available)
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)
{
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 (WARN(!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;
__print_depot_stack(stack, buf, PAGE_SIZE, 2);
DRM_DEBUG_DRIVER("wakeref %x from\n%s", stack, buf);
stack = READ_ONCE(rpm->debug.last_release);
if (stack) {
__print_depot_stack(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) {
__print_depot_stack(dbg->last_acquire, buf, PAGE_SIZE, 2);
drm_printf(p, "Wakeref last acquired:\n%s", buf);
}
if (dbg->last_release) {
__print_depot_stack(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++;
__print_depot_stack(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 void fini_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)
{
int ret;
ret = pm_runtime_get_sync(rpm->kdev);
WARN_ONCE(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_in_use - grab a runtime pm reference if device in use
* @rpm: the intel_runtime_pm structure
*
* This function grabs a device-level runtime pm reference if the device is
* already in use and ensures that it is powered up. It is illegal to try
* and access the HW should intel_runtime_pm_get_if_in_use() report failure.
*
* 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.
*/
intel_wakeref_t intel_runtime_pm_get_if_in_use(struct intel_runtime_pm *rpm)
{
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_in_use(rpm->kdev) <= 0)
return 0;
}
intel_runtime_pm_acquire(rpm, true);
return track_intel_runtime_pm_wakeref(rpm);
}
/**
* 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([31mCONFIG_DRM_I915_DEBUG_RUNTIME_PM[0m)
/**
* 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 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_NEVER_SKIP);
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);
WARN(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
} else {
pm_runtime_use_autosuspend(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 device *kdev = rpm->kdev;
/* Transfer rpm ownership back to core */
WARN(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)
{
int count = atomic_read(&rpm->wakeref_count);
WARN(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);
fini_intel_runtime_pm_wakeref(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 = i915->drm.pdev;
struct device *kdev = pci_dev_dev(pdev);
rpm->kdev = kdev;
rpm->available = HAS_RUNTIME_PM(i915);
init_intel_runtime_pm_wakeref(rpm);
}