xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

drm/i915: Mark up the calling context for intel_wakeref_put()

Browse Source 
Previously, we assumed we could use mutex_trylock() within an atomic
context, falling back to a worker if contended. However, such trickery
is illegal inside interrupt context, and so we need to always use a
worker under such circumstances. As we normally are in process context,
we can typically use a plain mutex, and only defer to a work when we
know we are being called from an interrupt path.

Fixes: 51fbd8de87 ("drm/i915/pmu: Atomically acquire the gt_pm wakeref")
References: a0855d24fc ("locking/mutex: Complain upon mutex API misuse in IRQ contexts")
References: https://bugs.freedesktop.org/show_bug.cgi?id=111626
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191120125433.3767149-1-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson
2019-11-20 12:54:33 +00:00
parent 8a126392b7
commit 07779a76ee
11 changed files with 54 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

30
drivers/gpu/drm/i915/intel_wakeref.h
View File

@@ -9,6 +9,7 @@
#include <linux/atomic.h>
#include <linux/bits.h>
#include <linux/lockdep.h>
#include <linux/mutex.h>
#include <linux/refcount.h>
#include <linux/stackdepot.h>
@@ -29,9 +30,6 @@ typedef depot_stack_handle_t intel_wakeref_t;
struct intel_wakeref_ops {
int (*get)(struct intel_wakeref *wf);
int (*put)(struct intel_wakeref *wf);
unsigned long flags;
#define INTEL_WAKEREF_PUT_ASYNC BIT(0)
};
struct intel_wakeref {
@@ -57,7 +55,7 @@ void __intel_wakeref_init(struct intel_wakeref *wf,
} while (0)
int __intel_wakeref_get_first(struct intel_wakeref *wf);
void __intel_wakeref_put_last(struct intel_wakeref *wf);
void __intel_wakeref_put_last(struct intel_wakeref *wf, unsigned long flags);
/**
* intel_wakeref_get: Acquire the wakeref
@@ -100,10 +98,9 @@ intel_wakeref_get_if_active(struct intel_wakeref *wf)
}
/**
* intel_wakeref_put: Release the wakeref
* @i915: the drm_i915_private device
* intel_wakeref_put_flags: Release the wakeref
* @wf: the wakeref
* @fn: callback for releasing the wakeref, called only on final release.
* @flags: control flags
*
* Release our hold on the wakeref. When there are no more users,
* the runtime pm wakeref will be released after the @fn callback is called
@@ -116,11 +113,25 @@ intel_wakeref_get_if_active(struct intel_wakeref *wf)
* code otherwise.
*/
static inline void
intel_wakeref_put(struct intel_wakeref *wf)
__intel_wakeref_put(struct intel_wakeref *wf, unsigned long flags)
#define INTEL_WAKEREF_PUT_ASYNC BIT(0)
{
INTEL_WAKEREF_BUG_ON(atomic_read(&wf->count) <= 0);
if (unlikely(!atomic_add_unless(&wf->count, -1, 1)))
__intel_wakeref_put_last(wf);
__intel_wakeref_put_last(wf, flags);
}
static inline void
intel_wakeref_put(struct intel_wakeref *wf)
{
might_sleep();
__intel_wakeref_put(wf, 0);
}
static inline void
intel_wakeref_put_async(struct intel_wakeref *wf)
{
__intel_wakeref_put(wf, INTEL_WAKEREF_PUT_ASYNC);
}
/**
@@ -185,6 +196,7 @@ intel_wakeref_is_active(const struct intel_wakeref *wf)
static inline void
__intel_wakeref_defer_park(struct intel_wakeref *wf)
{
lockdep_assert_held(&wf->mutex);
INTEL_WAKEREF_BUG_ON(atomic_read(&wf->count));
atomic_set_release(&wf->count, 1);
}