[PATCH 11/19] drm/radeon: use common fence implementation for fences, v2
Maarten Lankhorst
maarten.lankhorst at canonical.com
Thu Jul 31 08:33:55 PDT 2014
Changes since v1:
- Kill the sw interrupt dance, add and use
radeon_irq_kms_sw_irq_get_delayed instead.
- Change custom wait function, lockdep complained about it.
Holding exclusive_lock in the wait function might cause deadlocks.
Instead do all the processing in .enable_signaling, and wait
on the global fence_queue to pick up gpu resets.
- Process all fences in radeon_gpu_reset after reset to close a race
with the trylock in enable_signaling.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
---
drivers/gpu/drm/radeon/radeon.h | 18 +-
drivers/gpu/drm/radeon/radeon_device.c | 22 ++-
drivers/gpu/drm/radeon/radeon_fence.c | 263 +++++++++++++++++++++++++++----
drivers/gpu/drm/radeon/radeon_irq_kms.c | 43 +++++
4 files changed, 293 insertions(+), 53 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index b01d88fc10cb..599bb28e4104 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -64,6 +64,7 @@
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/kref.h>
+#include <linux/fence.h>
#include <ttm/ttm_bo_api.h>
#include <ttm/ttm_bo_driver.h>
@@ -116,9 +117,6 @@ extern int radeon_deep_color;
#define RADEONFB_CONN_LIMIT 4
#define RADEON_BIOS_NUM_SCRATCH 8
-/* fence seq are set to this number when signaled */
-#define RADEON_FENCE_SIGNALED_SEQ 0LL
-
/* internal ring indices */
/* r1xx+ has gfx CP ring */
#define RADEON_RING_TYPE_GFX_INDEX 0
@@ -352,12 +350,15 @@ struct radeon_fence_driver {
};
struct radeon_fence {
+ struct fence base;
+
struct radeon_device *rdev;
- struct kref kref;
/* protected by radeon_fence.lock */
uint64_t seq;
/* RB, DMA, etc. */
unsigned ring;
+
+ wait_queue_t fence_wake;
};
int radeon_fence_driver_start_ring(struct radeon_device *rdev, int ring);
@@ -769,6 +770,7 @@ struct radeon_irq {
int radeon_irq_kms_init(struct radeon_device *rdev);
void radeon_irq_kms_fini(struct radeon_device *rdev);
void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring);
+void radeon_irq_kms_sw_irq_get_delayed(struct radeon_device *rdev, int ring);
void radeon_irq_kms_sw_irq_put(struct radeon_device *rdev, int ring);
void radeon_irq_kms_pflip_irq_get(struct radeon_device *rdev, int crtc);
void radeon_irq_kms_pflip_irq_put(struct radeon_device *rdev, int crtc);
@@ -2276,6 +2278,7 @@ struct radeon_device {
struct radeon_mman mman;
struct radeon_fence_driver fence_drv[RADEON_NUM_RINGS];
wait_queue_head_t fence_queue;
+ unsigned fence_context;
struct mutex ring_lock;
struct radeon_ring ring[RADEON_NUM_RINGS];
bool ib_pool_ready;
@@ -2314,6 +2317,8 @@ struct radeon_device {
struct work_struct hotplug_work;
struct work_struct audio_work;
struct work_struct reset_work;
+ struct work_struct delayed_irq_work;
+
int num_crtc; /* number of crtcs */
struct mutex dc_hw_i2c_mutex; /* display controller hw i2c mutex */
bool has_uvd;
@@ -2366,11 +2371,6 @@ u32 cik_mm_rdoorbell(struct radeon_device *rdev, u32 index);
void cik_mm_wdoorbell(struct radeon_device *rdev, u32 index, u32 v);
/*
- * Cast helper
- */
-#define to_radeon_fence(p) ((struct radeon_fence *)(p))
-
-/*
* Registers read & write functions.
*/
#define RREG8(reg) readb((rdev->rmmio) + (reg))
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 21efd32d07ee..dbf3a8bc91d2 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -1213,6 +1213,7 @@ int radeon_device_init(struct radeon_device *rdev,
for (i = 0; i < RADEON_NUM_RINGS; i++) {
rdev->ring[i].idx = i;
}
+ rdev->fence_context = fence_context_alloc(RADEON_NUM_RINGS);
DRM_INFO("initializing kernel modesetting (%s 0x%04X:0x%04X 0x%04X:0x%04X).\n",
radeon_family_name[rdev->family], pdev->vendor, pdev->device,
@@ -1622,15 +1623,13 @@ int radeon_gpu_reset(struct radeon_device *rdev)
bool saved = false;
- int i, r;
+ int i, r = 0;
int resched;
down_write(&rdev->exclusive_lock);
- if (!rdev->needs_reset) {
- up_write(&rdev->exclusive_lock);
- return 0;
- }
+ if (!rdev->needs_reset)
+ goto out;
rdev->needs_reset = false;
@@ -1697,7 +1696,18 @@ retry:
dev_info(rdev->dev, "GPU reset failed\n");
}
- up_write(&rdev->exclusive_lock);
+out:
+ /*
+ * force all waiters to recheck, some may have been
+ * added while the exclusive_lock was unavailable
+ */
+ downgrade_write(&rdev->exclusive_lock);
+ for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+ if (rdev->ring[i].ready)
+ radeon_fence_process(rdev, i);
+ }
+ wake_up_all(&rdev->fence_queue);
+ up_read(&rdev->exclusive_lock);
return r;
}
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c
index f79e0b34582b..8ca56ca70503 100644
--- a/drivers/gpu/drm/radeon/radeon_fence.c
+++ b/drivers/gpu/drm/radeon/radeon_fence.c
@@ -39,6 +39,15 @@
#include "radeon.h"
#include "radeon_trace.h"
+static const struct fence_ops radeon_fence_ops;
+
+#define to_radeon_fence(p) \
+ ({ \
+ struct radeon_fence *__f; \
+ __f = container_of((p), struct radeon_fence, base); \
+ __f->base.ops == &radeon_fence_ops ? __f : NULL; \
+ })
+
/*
* Fences
* Fences mark an event in the GPUs pipeline and are used
@@ -111,20 +120,82 @@ int radeon_fence_emit(struct radeon_device *rdev,
struct radeon_fence **fence,
int ring)
{
+ u64 seq = ++rdev->fence_drv[ring].sync_seq[ring];
+
/* we are protected by the ring emission mutex */
*fence = kmalloc(sizeof(struct radeon_fence), GFP_KERNEL);
if ((*fence) == NULL) {
return -ENOMEM;
}
- kref_init(&((*fence)->kref));
- (*fence)->rdev = rdev;
- (*fence)->seq = ++rdev->fence_drv[ring].sync_seq[ring];
(*fence)->ring = ring;
+ fence_init(&(*fence)->base, &radeon_fence_ops,
+ &rdev->fence_queue.lock, rdev->fence_context + ring, seq);
+ (*fence)->rdev = rdev;
+ (*fence)->seq = seq;
radeon_fence_ring_emit(rdev, ring, *fence);
trace_radeon_fence_emit(rdev->ddev, ring, (*fence)->seq);
return 0;
}
+/**
+ * __radeon_fence_read_seq - Returns the current fence value without updating
+ *
+ * @rdev: radeon_device pointer
+ * @ring: ring index to return the seqno of
+ */
+static uint64_t __radeon_fence_read_seq(struct radeon_device *rdev, int ring)
+{
+ uint64_t last_seq = atomic64_read(&rdev->fence_drv[ring].last_seq);
+ uint64_t last_emitted = rdev->fence_drv[ring].sync_seq[ring];
+ uint64_t seq = radeon_fence_read(rdev, ring);
+
+ seq = radeon_fence_read(rdev, ring);
+ seq |= last_seq & 0xffffffff00000000LL;
+ if (seq < last_seq) {
+ seq &= 0xffffffff;
+ seq |= last_emitted & 0xffffffff00000000LL;
+ }
+ return seq;
+}
+
+/**
+ * radeon_fence_check_signaled - callback from fence_queue
+ *
+ * this function is called with fence_queue lock held, which is also used
+ * for the fence locking itself, so unlocked variants are used for
+ * fence_signal, and remove_wait_queue.
+ */
+static int radeon_fence_check_signaled(wait_queue_t *wait, unsigned mode, int flags, void *key)
+{
+ struct radeon_fence *fence;
+ u64 seq;
+
+ fence = container_of(wait, struct radeon_fence, fence_wake);
+
+ /*
+ * We cannot use radeon_fence_process here because we're already
+ * in the waitqueue, in a call from wake_up_all.
+ *
+ * Because the current ring might not have been updated, call
+ * __radeon_fence_read_seq here to check without updating.
+ */
+ seq = __radeon_fence_read_seq(fence->rdev, fence->ring);
+ if (seq >= fence->seq) {
+ int ret = fence_signal_locked(&fence->base);
+
+ if (!ret)
+ FENCE_TRACE(&fence->base, "signaled from irq context\n");
+ else
+ FENCE_TRACE(&fence->base, "was already signaled\n");
+
+ radeon_irq_kms_sw_irq_put(fence->rdev, fence->ring);
+ __remove_wait_queue(&fence->rdev->fence_queue, &fence->fence_wake);
+ fence_put(&fence->base);
+ } else
+ FENCE_TRACE(&fence->base, "pending\n");
+ return 0;
+}
+
static bool __radeon_fence_process(struct radeon_device *rdev, int ring)
{
uint64_t seq, last_seq, last_emitted;
@@ -230,21 +301,6 @@ void radeon_fence_process(struct radeon_device *rdev, int ring)
}
/**
- * radeon_fence_destroy - destroy a fence
- *
- * @kref: fence kref
- *
- * Frees the fence object (all asics).
- */
-static void radeon_fence_destroy(struct kref *kref)
-{
- struct radeon_fence *fence;
-
- fence = container_of(kref, struct radeon_fence, kref);
- kfree(fence);
-}
-
-/**
* radeon_fence_seq_signaled - check if a fence sequence number has signaled
*
* @rdev: radeon device pointer
@@ -272,6 +328,73 @@ static bool radeon_fence_seq_signaled(struct radeon_device *rdev,
return false;
}
+static bool __radeon_fence_signaled(struct fence *f)
+{
+ struct radeon_fence *fence = to_radeon_fence(f);
+ struct radeon_device *rdev = fence->rdev;
+ unsigned ring = fence->ring;
+ u64 seq = fence->seq;
+
+ if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
+ return true;
+ }
+
+ if (down_read_trylock(&rdev->exclusive_lock)) {
+ radeon_fence_process(rdev, ring);
+ up_read(&rdev->exclusive_lock);
+
+ if (atomic64_read(&rdev->fence_drv[ring].last_seq) >= seq) {
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * radeon_fence_enable_signaling - enable signalling on fence
+ * @fence: fence
+ *
+ * This function is called with fence_queue lock held, and adds a callback
+ * to fence_queue that checks if this fence is signaled, and if so it
+ * signals the fence and removes itself.
+ */
+static bool radeon_fence_enable_signaling(struct fence *f)
+{
+ struct radeon_fence *fence = to_radeon_fence(f);
+ struct radeon_device *rdev = fence->rdev;
+
+ if (atomic64_read(&rdev->fence_drv[fence->ring].last_seq) >= fence->seq ||
+ !rdev->ddev->irq_enabled)
+ return false;
+
+ if (down_read_trylock(&rdev->exclusive_lock)) {
+ radeon_irq_kms_sw_irq_get(rdev, fence->ring);
+
+ if (__radeon_fence_process(rdev, fence->ring))
+ wake_up_all_locked(&rdev->fence_queue);
+
+ /* did fence get signaled after we enabled the sw irq? */
+ if (atomic64_read(&rdev->fence_drv[fence->ring].last_seq) >= fence->seq) {
+ radeon_irq_kms_sw_irq_put(rdev, fence->ring);
+ up_read(&rdev->exclusive_lock);
+ return false;
+ }
+
+ up_read(&rdev->exclusive_lock);
+ } else
+ /* we're probably in a lockup, lets not fiddle too much */
+ radeon_irq_kms_sw_irq_get_delayed(rdev, fence->ring);
+
+ fence->fence_wake.flags = 0;
+ fence->fence_wake.private = NULL;
+ fence->fence_wake.func = radeon_fence_check_signaled;
+ __add_wait_queue(&rdev->fence_queue, &fence->fence_wake);
+ fence_get(f);
+
+ FENCE_TRACE(&fence->base, "armed on ring %i!\n", fence->ring);
+ return true;
+}
+
/**
* radeon_fence_signaled - check if a fence has signaled
*
@@ -285,11 +408,13 @@ bool radeon_fence_signaled(struct radeon_fence *fence)
if (!fence) {
return true;
}
- if (fence->seq == RADEON_FENCE_SIGNALED_SEQ) {
- return true;
- }
+
if (radeon_fence_seq_signaled(fence->rdev, fence->seq, fence->ring)) {
- fence->seq = RADEON_FENCE_SIGNALED_SEQ;
+ int ret;
+
+ ret = fence_signal(&fence->base);
+ if (!ret)
+ FENCE_TRACE(&fence->base, "signaled from radeon_fence_signaled\n");
return true;
}
return false;
@@ -400,21 +525,18 @@ int radeon_fence_wait(struct radeon_fence *fence, bool intr)
uint64_t seq[RADEON_NUM_RINGS] = {};
long r;
- if (fence == NULL) {
- WARN(1, "Querying an invalid fence : %p !\n", fence);
- return -EINVAL;
- }
-
- seq[fence->ring] = fence->seq;
- if (seq[fence->ring] == RADEON_FENCE_SIGNALED_SEQ)
+ if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))
return 0;
+ seq[fence->ring] = fence->seq;
r = radeon_fence_wait_seq_timeout(fence->rdev, seq, intr, MAX_SCHEDULE_TIMEOUT);
if (r < 0) {
return r;
}
- fence->seq = RADEON_FENCE_SIGNALED_SEQ;
+ r = fence_signal(&fence->base);
+ if (!r)
+ FENCE_TRACE(&fence->base, "signaled from fence_wait\n");
return 0;
}
@@ -446,12 +568,13 @@ int radeon_fence_wait_any(struct radeon_device *rdev,
continue;
}
+ if (test_bit(FENCE_FLAG_SIGNALED_BIT, &fences[i]->base.flags)) {
+ /* already signaled */
+ return 0;
+ }
+
seq[i] = fences[i]->seq;
++num_rings;
-
- /* test if something was allready signaled */
- if (seq[i] == RADEON_FENCE_SIGNALED_SEQ)
- return 0;
}
/* nothing to wait for ? */
@@ -532,7 +655,7 @@ int radeon_fence_wait_empty(struct radeon_device *rdev, int ring)
*/
struct radeon_fence *radeon_fence_ref(struct radeon_fence *fence)
{
- kref_get(&fence->kref);
+ fence_get(&fence->base);
return fence;
}
@@ -548,9 +671,8 @@ void radeon_fence_unref(struct radeon_fence **fence)
struct radeon_fence *tmp = *fence;
*fence = NULL;
- if (tmp) {
- kref_put(&tmp->kref, radeon_fence_destroy);
- }
+ if (tmp)
+ fence_put(&tmp->base);
}
/**
@@ -855,6 +977,7 @@ static int radeon_debugfs_gpu_reset(struct seq_file *m, void *data)
down_read(&rdev->exclusive_lock);
seq_printf(m, "%d\n", rdev->needs_reset);
rdev->needs_reset = true;
+ wake_up_all(&rdev->fence_queue);
up_read(&rdev->exclusive_lock);
return 0;
@@ -874,3 +997,67 @@ int radeon_debugfs_fence_init(struct radeon_device *rdev)
return 0;
#endif
}
+
+static const char *radeon_fence_get_driver_name(struct fence *fence)
+{
+ return "radeon";
+}
+
+static const char *radeon_fence_get_timeline_name(struct fence *f)
+{
+ struct radeon_fence *fence = to_radeon_fence(f);
+ switch (fence->ring) {
+ case RADEON_RING_TYPE_GFX_INDEX: return "radeon.gfx";
+ case CAYMAN_RING_TYPE_CP1_INDEX: return "radeon.cp1";
+ case CAYMAN_RING_TYPE_CP2_INDEX: return "radeon.cp2";
+ case R600_RING_TYPE_DMA_INDEX: return "radeon.dma";
+ case CAYMAN_RING_TYPE_DMA1_INDEX: return "radeon.dma1";
+ case R600_RING_TYPE_UVD_INDEX: return "radeon.uvd";
+ case TN_RING_TYPE_VCE1_INDEX: return "radeon.vce1";
+ case TN_RING_TYPE_VCE2_INDEX: return "radeon.vce2";
+ default: WARN_ON_ONCE(1); return "radeon.unk";
+ }
+}
+
+static signed long __radeon_fence_default_wait(struct fence *f, bool intr,
+ signed long timeout)
+{
+ struct radeon_fence *fence = to_radeon_fence(f);
+ struct radeon_device *rdev = fence->rdev;
+ bool signaled;
+
+ fence_enable_sw_signaling(&fence->base);
+
+ /*
+ * This function has to return -EDEADLK, but cannot hold
+ * exclusive_lock during the wait because some callers
+ * may already hold it. This means checking needs_reset without
+ * lock, and not fiddling with any gpu internals.
+ *
+ * The callback installed with fence_enable_sw_signaling will
+ * run before our wait_event_*timeout call, so we will see
+ * both the signaled fence and the changes to needs_reset.
+ */
+
+ if (intr)
+ timeout = wait_event_interruptible_timeout(rdev->fence_queue,
+ ((signaled = (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))) || rdev->needs_reset),
+ timeout);
+ else
+ timeout = wait_event_timeout(rdev->fence_queue,
+ ((signaled = (test_bit(FENCE_FLAG_SIGNALED_BIT, &fence->base.flags))) || rdev->needs_reset),
+ timeout);
+
+ if (timeout > 0 && !signaled)
+ return -EDEADLK;
+ return timeout;
+}
+
+static const struct fence_ops radeon_fence_ops = {
+ .get_driver_name = radeon_fence_get_driver_name,
+ .get_timeline_name = radeon_fence_get_timeline_name,
+ .enable_signaling = radeon_fence_enable_signaling,
+ .signaled = __radeon_fence_signaled,
+ .wait = __radeon_fence_default_wait,
+ .release = NULL,
+};
diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index 16807afab362..41310cec61a6 100644
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -254,6 +254,25 @@ static bool radeon_msi_ok(struct radeon_device *rdev)
return true;
}
+static void radeon_delayed_irq_set(struct work_struct *work)
+{
+ struct radeon_device *rdev;
+ unsigned long irqflags;
+
+ rdev = container_of(work, struct radeon_device, delayed_irq_work);
+
+ down_read(&rdev->exclusive_lock);
+
+ spin_lock_irqsave(&rdev->irq.lock, irqflags);
+ radeon_irq_set(rdev);
+ spin_unlock_irqrestore(&rdev->irq.lock, irqflags);
+
+ /* force all waiters to recheck */
+ wake_up_all(&rdev->fence_queue);
+
+ up_read(&rdev->exclusive_lock);
+}
+
/**
* radeon_irq_kms_init - init driver interrupt info
*
@@ -285,6 +304,7 @@ int radeon_irq_kms_init(struct radeon_device *rdev)
INIT_WORK(&rdev->hotplug_work, radeon_hotplug_work_func);
INIT_WORK(&rdev->audio_work, r600_audio_update_hdmi);
INIT_WORK(&rdev->reset_work, radeon_irq_reset_work_func);
+ INIT_WORK(&rdev->delayed_irq_work, radeon_delayed_irq_set);
rdev->irq.installed = true;
r = drm_irq_install(rdev->ddev, rdev->ddev->pdev->irq);
@@ -313,6 +333,7 @@ void radeon_irq_kms_fini(struct radeon_device *rdev)
rdev->irq.installed = false;
if (rdev->msi_enabled)
pci_disable_msi(rdev->pdev);
+ cancel_work_sync(&rdev->delayed_irq_work);
flush_work(&rdev->hotplug_work);
}
}
@@ -342,6 +363,28 @@ void radeon_irq_kms_sw_irq_get(struct radeon_device *rdev, int ring)
}
/**
+ * radeon_irq_kms_sw_irq_get_delayed - enable software interrupt
+ *
+ * @rdev: radeon device pointer
+ * @ring: ring whose interrupt you want to enable
+ *
+ * Enables the software interrupt for a specific ring (all asics).
+ * The software interrupt is generally used to signal a fence on
+ * a particular ring.
+ *
+ * This function can be used without exclusive_lock grabbed,
+ * and will schedule later work for irqs to be set when needed.
+ */
+void radeon_irq_kms_sw_irq_get_delayed(struct radeon_device *rdev, int ring)
+{
+ if (!rdev->ddev->irq_enabled)
+ return;
+
+ if (atomic_inc_return(&rdev->irq.ring_int[ring]) == 1)
+ schedule_work(&rdev->delayed_irq_work);
+}
+
+/**
* radeon_irq_kms_sw_irq_put - disable software interrupt
*
* @rdev: radeon device pointer
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