Commit 4547c255 authored by Imre Deak's avatar Imre Deak

drm/i915: Add support for tracking wakerefs w/o power-on guarantee

It's useful to track runtime PM refs that don't guarantee a device
power-on state to the rest of the driver. One such case is holding a
reference that will be put asynchronously, during which normal users
without their own reference shouldn't access the HW. A follow-up patch
will add support for disabling display power domains asynchronously
which needs this.

For this we can split wakeref_count into a low half-word tracking
all references (raw-wakerefs) and a high half-word tracking
references guaranteeing a power-on state (wakelocks).

Follow-up patches will make use of the API added here.

While at it add the missing docbook header for the unchecked
display-power and runtime_pm put functions.

No functional changes, except for printing leaked raw-wakerefs
and wakelocks separately in intel_runtime_pm_cleanup().

v2:
- Track raw wakerefs/wakelocks in the low/high half-word of
  wakeref_count, instead of adding a new counter. (Chris)
v3:
- Add a struct_member(T, m) helper instead of open-coding it. (Chris)
- Checkpatch indentation formatting fix.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190509173446.31095-2-imre.deak@intel.com
parent 1aa37508
......@@ -102,6 +102,8 @@
#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
#define struct_member(T, member) (((T *)0)->member)
#define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
#define fetch_and_zero(ptr) ({ \
......@@ -118,7 +120,7 @@
*/
#define container_of_user(ptr, type, member) ({ \
void __user *__mptr = (void __user *)(ptr); \
BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \
BUILD_BUG_ON_MSG(!__same_type(*(ptr), struct_member(type, member)) && \
!__same_type(*(ptr), void), \
"pointer type mismatch in container_of()"); \
((type __user *)(__mptr - offsetof(type, member))); })
......
......@@ -1620,6 +1620,24 @@ unsigned int i9xx_plane_max_stride(struct intel_plane *plane,
int bdw_get_pipemisc_bpp(struct intel_crtc *crtc);
/* intel_runtime_pm.c */
#define BITS_PER_WAKEREF \
BITS_PER_TYPE(struct_member(struct i915_runtime_pm, wakeref_count))
#define INTEL_RPM_WAKELOCK_SHIFT (BITS_PER_WAKEREF / 2)
#define INTEL_RPM_WAKELOCK_BIAS (1 << INTEL_RPM_WAKELOCK_SHIFT)
#define INTEL_RPM_RAW_WAKEREF_MASK (INTEL_RPM_WAKELOCK_BIAS - 1)
static inline int
intel_rpm_raw_wakeref_count(int wakeref_count)
{
return wakeref_count & INTEL_RPM_RAW_WAKEREF_MASK;
}
static inline int
intel_rpm_wakelock_count(int wakeref_count)
{
return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
}
static inline void
assert_rpm_device_not_suspended(struct i915_runtime_pm *rpm)
{
......@@ -1628,11 +1646,33 @@ assert_rpm_device_not_suspended(struct i915_runtime_pm *rpm)
}
static inline void
__assert_rpm_wakelock_held(struct i915_runtime_pm *rpm)
____assert_rpm_raw_wakeref_held(struct i915_runtime_pm *rpm, int wakeref_count)
{
assert_rpm_device_not_suspended(rpm);
WARN_ONCE(!atomic_read(&rpm->wakeref_count),
"RPM wakelock ref not held during HW access");
WARN_ONCE(!intel_rpm_raw_wakeref_count(wakeref_count),
"RPM raw-wakeref not held\n");
}
static inline void
____assert_rpm_wakelock_held(struct i915_runtime_pm *rpm, int wakeref_count)
{
____assert_rpm_raw_wakeref_held(rpm, wakeref_count);
WARN_ONCE(!intel_rpm_wakelock_count(wakeref_count),
"RPM wakelock ref not held during HW access\n");
}
static inline void
assert_rpm_raw_wakeref_held(struct drm_i915_private *i915)
{
struct i915_runtime_pm *rpm = &i915->runtime_pm;
____assert_rpm_raw_wakeref_held(rpm, atomic_read(&rpm->wakeref_count));
}
static inline void
__assert_rpm_wakelock_held(struct i915_runtime_pm *rpm)
{
____assert_rpm_wakelock_held(rpm, atomic_read(&rpm->wakeref_count));
}
static inline void
......@@ -1662,7 +1702,8 @@ assert_rpm_wakelock_held(struct drm_i915_private *i915)
static inline void
disable_rpm_wakeref_asserts(struct drm_i915_private *i915)
{
atomic_inc(&i915->runtime_pm.wakeref_count);
atomic_add(INTEL_RPM_WAKELOCK_BIAS + 1,
&i915->runtime_pm.wakeref_count);
}
/**
......@@ -1679,7 +1720,8 @@ disable_rpm_wakeref_asserts(struct drm_i915_private *i915)
static inline void
enable_rpm_wakeref_asserts(struct drm_i915_private *i915)
{
atomic_dec(&i915->runtime_pm.wakeref_count);
atomic_sub(INTEL_RPM_WAKELOCK_BIAS + 1,
&i915->runtime_pm.wakeref_count);
}
#endif /* __INTEL_DRV_H__ */
......@@ -110,9 +110,6 @@ track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
depot_stack_handle_t stack, *stacks;
unsigned long flags;
atomic_inc(&rpm->wakeref_count);
assert_rpm_wakelock_held(i915);
if (!HAS_RUNTIME_PM(i915))
return -1;
......@@ -140,7 +137,7 @@ track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
return stack;
}
static void cancel_intel_runtime_pm_wakeref(struct drm_i915_private *i915,
static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915,
depot_stack_handle_t stack)
{
struct i915_runtime_pm *rpm = &i915->runtime_pm;
......@@ -236,14 +233,13 @@ __print_intel_runtime_pm_wakeref(struct drm_printer *p,
}
static noinline void
untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
__intel_wakeref_dec_and_check_tracking(struct drm_i915_private *i915)
{
struct i915_runtime_pm *rpm = &i915->runtime_pm;
struct intel_runtime_pm_debug dbg = {};
struct drm_printer p;
unsigned long flags;
assert_rpm_wakelock_held(i915);
if (atomic_dec_and_lock_irqsave(&rpm->wakeref_count,
&rpm->debug.lock,
flags)) {
......@@ -311,19 +307,51 @@ static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
static depot_stack_handle_t
track_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
{
atomic_inc(&i915->runtime_pm.wakeref_count);
assert_rpm_wakelock_held(i915);
return -1;
}
static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915)
static void untrack_intel_runtime_pm_wakeref(struct drm_i915_private *i915,
intel_wakeref_t wref)
{
}
static void
__intel_wakeref_dec_and_check_tracking(struct drm_i915_private *i915)
{
assert_rpm_wakelock_held(i915);
atomic_dec(&i915->runtime_pm.wakeref_count);
}
#endif
static void
intel_runtime_pm_acquire(struct drm_i915_private *i915, bool wakelock)
{
struct i915_runtime_pm *rpm = &i915->runtime_pm;
if (wakelock) {
atomic_add(1 + INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
assert_rpm_wakelock_held(i915);
} else {
atomic_inc(&rpm->wakeref_count);
assert_rpm_raw_wakeref_held(i915);
}
}
static void
intel_runtime_pm_release(struct drm_i915_private *i915, int wakelock)
{
struct i915_runtime_pm *rpm = &i915->runtime_pm;
if (wakelock) {
assert_rpm_wakelock_held(i915);
atomic_sub(INTEL_RPM_WAKELOCK_BIAS, &rpm->wakeref_count);
} else {
assert_rpm_raw_wakeref_held(i915);
}
__intel_wakeref_dec_and_check_tracking(i915);
}
bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
enum i915_power_well_id power_well_id);
......@@ -1946,13 +1974,17 @@ static void __intel_display_power_put(struct drm_i915_private *dev_priv,
}
/**
* intel_display_power_put - release a power domain reference
* intel_display_power_put_unchecked - release an unchecked power domain reference
* @dev_priv: i915 device instance
* @domain: power domain to reference
*
* This function drops the power domain reference obtained by
* intel_display_power_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_display_power_put() instead.
*/
void intel_display_power_put_unchecked(struct drm_i915_private *dev_priv,
enum intel_display_power_domain domain)
......@@ -1962,6 +1994,16 @@ void intel_display_power_put_unchecked(struct drm_i915_private *dev_priv,
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
/**
* intel_display_power_put - release a power domain reference
* @dev_priv: i915 device instance
* @domain: power domain to reference
* @wakeref: wakeref acquired for the reference that is being released
*
* This function drops the power domain reference obtained by
* intel_display_power_get() and might power down the corresponding hardware
* block right away if this is the last reference.
*/
void intel_display_power_put(struct drm_i915_private *dev_priv,
enum intel_display_power_domain domain,
intel_wakeref_t wakeref)
......@@ -4579,6 +4621,21 @@ static void intel_power_domains_verify_state(struct drm_i915_private *i915)
#endif
static intel_wakeref_t __intel_runtime_pm_get(struct drm_i915_private *i915,
bool wakelock)
{
struct pci_dev *pdev = i915->drm.pdev;
struct device *kdev = &pdev->dev;
int ret;
ret = pm_runtime_get_sync(kdev);
WARN_ONCE(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
intel_runtime_pm_acquire(i915, wakelock);
return track_intel_runtime_pm_wakeref(i915);
}
/**
* intel_runtime_pm_get - grab a runtime pm reference
* @i915: i915 device instance
......@@ -4593,14 +4650,7 @@ static void intel_power_domains_verify_state(struct drm_i915_private *i915)
*/
intel_wakeref_t intel_runtime_pm_get(struct drm_i915_private *i915)
{
struct pci_dev *pdev = i915->drm.pdev;
struct device *kdev = &pdev->dev;
int ret;
ret = pm_runtime_get_sync(kdev);
WARN_ONCE(ret < 0, "pm_runtime_get_sync() failed: %d\n", ret);
return track_intel_runtime_pm_wakeref(i915);
return __intel_runtime_pm_get(i915, true);
}
/**
......@@ -4633,6 +4683,8 @@ intel_wakeref_t intel_runtime_pm_get_if_in_use(struct drm_i915_private *i915)
return 0;
}
intel_runtime_pm_acquire(i915, true);
return track_intel_runtime_pm_wakeref(i915);
}
......@@ -4663,33 +4715,56 @@ intel_wakeref_t intel_runtime_pm_get_noresume(struct drm_i915_private *i915)
assert_rpm_wakelock_held(i915);
pm_runtime_get_noresume(kdev);
intel_runtime_pm_acquire(i915, true);
return track_intel_runtime_pm_wakeref(i915);
}
static void __intel_runtime_pm_put(struct drm_i915_private *i915,
intel_wakeref_t wref,
bool wakelock)
{
struct pci_dev *pdev = i915->drm.pdev;
struct device *kdev = &pdev->dev;
untrack_intel_runtime_pm_wakeref(i915, wref);
intel_runtime_pm_release(i915, wakelock);
pm_runtime_mark_last_busy(kdev);
pm_runtime_put_autosuspend(kdev);
}
/**
* intel_runtime_pm_put - release a runtime pm reference
* intel_runtime_pm_put_unchecked - release an unchecked runtime pm reference
* @i915: i915 device instance
*
* 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 drm_i915_private *i915)
{
struct pci_dev *pdev = i915->drm.pdev;
struct device *kdev = &pdev->dev;
untrack_intel_runtime_pm_wakeref(i915);
pm_runtime_mark_last_busy(kdev);
pm_runtime_put_autosuspend(kdev);
__intel_runtime_pm_put(i915, -1, true);
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
/**
* intel_runtime_pm_put - release a runtime pm reference
* @i915: i915 device instance
* @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 drm_i915_private *i915, intel_wakeref_t wref)
{
cancel_intel_runtime_pm_wakeref(i915, wref);
intel_runtime_pm_put_unchecked(i915);
__intel_runtime_pm_put(i915, wref, true);
}
#endif
......@@ -4767,10 +4842,11 @@ void intel_runtime_pm_cleanup(struct drm_i915_private *i915)
count = atomic_fetch_inc(&rpm->wakeref_count); /* balance untrack */
WARN(count,
"i915->runtime_pm.wakeref_count=%d on cleanup\n",
count);
"i915 raw-wakerefs=%d wakelocks=%d on cleanup\n",
intel_rpm_raw_wakeref_count(count),
intel_rpm_wakelock_count(count));
untrack_intel_runtime_pm_wakeref(i915);
intel_runtime_pm_release(i915, false);
}
void intel_runtime_pm_init_early(struct drm_i915_private *i915)
......
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