linux/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
Monk Liu 48c60c03bc drm/amdgpu: fix bug in fence driver fini
Using wrong counter for walking fences.  Fixes
a crash when unloading the driver.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-05-25 09:42:53 -04:00

660 lines
17 KiB
C

/*
* Copyright 2009 Jerome Glisse.
* All Rights Reserved.
*
* 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, sub license, 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 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 NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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.
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
*/
/*
* Authors:
* Jerome Glisse <glisse@freedesktop.org>
* Dave Airlie
*/
#include <linux/seq_file.h>
#include <linux/atomic.h>
#include <linux/wait.h>
#include <linux/kref.h>
#include <linux/slab.h>
#include <linux/firmware.h>
#include <drm/drmP.h>
#include "amdgpu.h"
#include "amdgpu_trace.h"
/*
* Fences
* Fences mark an event in the GPUs pipeline and are used
* for GPU/CPU synchronization. When the fence is written,
* it is expected that all buffers associated with that fence
* are no longer in use by the associated ring on the GPU and
* that the the relevant GPU caches have been flushed.
*/
struct amdgpu_fence {
struct fence base;
/* RB, DMA, etc. */
struct amdgpu_ring *ring;
};
static struct kmem_cache *amdgpu_fence_slab;
int amdgpu_fence_slab_init(void)
{
amdgpu_fence_slab = kmem_cache_create(
"amdgpu_fence", sizeof(struct amdgpu_fence), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!amdgpu_fence_slab)
return -ENOMEM;
return 0;
}
void amdgpu_fence_slab_fini(void)
{
kmem_cache_destroy(amdgpu_fence_slab);
}
/*
* Cast helper
*/
static const struct fence_ops amdgpu_fence_ops;
static inline struct amdgpu_fence *to_amdgpu_fence(struct fence *f)
{
struct amdgpu_fence *__f = container_of(f, struct amdgpu_fence, base);
if (__f->base.ops == &amdgpu_fence_ops)
return __f;
return NULL;
}
/**
* amdgpu_fence_write - write a fence value
*
* @ring: ring the fence is associated with
* @seq: sequence number to write
*
* Writes a fence value to memory (all asics).
*/
static void amdgpu_fence_write(struct amdgpu_ring *ring, u32 seq)
{
struct amdgpu_fence_driver *drv = &ring->fence_drv;
if (drv->cpu_addr)
*drv->cpu_addr = cpu_to_le32(seq);
}
/**
* amdgpu_fence_read - read a fence value
*
* @ring: ring the fence is associated with
*
* Reads a fence value from memory (all asics).
* Returns the value of the fence read from memory.
*/
static u32 amdgpu_fence_read(struct amdgpu_ring *ring)
{
struct amdgpu_fence_driver *drv = &ring->fence_drv;
u32 seq = 0;
if (drv->cpu_addr)
seq = le32_to_cpu(*drv->cpu_addr);
else
seq = atomic_read(&drv->last_seq);
return seq;
}
/**
* amdgpu_fence_emit - emit a fence on the requested ring
*
* @ring: ring the fence is associated with
* @f: resulting fence object
*
* Emits a fence command on the requested ring (all asics).
* Returns 0 on success, -ENOMEM on failure.
*/
int amdgpu_fence_emit(struct amdgpu_ring *ring, struct fence **f)
{
struct amdgpu_device *adev = ring->adev;
struct amdgpu_fence *fence;
struct fence *old, **ptr;
uint32_t seq;
fence = kmem_cache_alloc(amdgpu_fence_slab, GFP_KERNEL);
if (fence == NULL)
return -ENOMEM;
seq = ++ring->fence_drv.sync_seq;
fence->ring = ring;
fence_init(&fence->base, &amdgpu_fence_ops,
&ring->fence_drv.lock,
adev->fence_context + ring->idx,
seq);
amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
seq, AMDGPU_FENCE_FLAG_INT);
ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
/* This function can't be called concurrently anyway, otherwise
* emitting the fence would mess up the hardware ring buffer.
*/
old = rcu_dereference_protected(*ptr, 1);
if (old && !fence_is_signaled(old)) {
DRM_INFO("rcu slot is busy\n");
fence_wait(old, false);
}
rcu_assign_pointer(*ptr, fence_get(&fence->base));
*f = &fence->base;
return 0;
}
/**
* amdgpu_fence_schedule_fallback - schedule fallback check
*
* @ring: pointer to struct amdgpu_ring
*
* Start a timer as fallback to our interrupts.
*/
static void amdgpu_fence_schedule_fallback(struct amdgpu_ring *ring)
{
mod_timer(&ring->fence_drv.fallback_timer,
jiffies + AMDGPU_FENCE_JIFFIES_TIMEOUT);
}
/**
* amdgpu_fence_process - check for fence activity
*
* @ring: pointer to struct amdgpu_ring
*
* Checks the current fence value and calculates the last
* signalled fence value. Wakes the fence queue if the
* sequence number has increased.
*/
void amdgpu_fence_process(struct amdgpu_ring *ring)
{
struct amdgpu_fence_driver *drv = &ring->fence_drv;
uint32_t seq, last_seq;
int r;
do {
last_seq = atomic_read(&ring->fence_drv.last_seq);
seq = amdgpu_fence_read(ring);
} while (atomic_cmpxchg(&drv->last_seq, last_seq, seq) != last_seq);
if (seq != ring->fence_drv.sync_seq)
amdgpu_fence_schedule_fallback(ring);
while (last_seq != seq) {
struct fence *fence, **ptr;
ptr = &drv->fences[++last_seq & drv->num_fences_mask];
/* There is always exactly one thread signaling this fence slot */
fence = rcu_dereference_protected(*ptr, 1);
RCU_INIT_POINTER(*ptr, NULL);
BUG_ON(!fence);
r = fence_signal(fence);
if (!r)
FENCE_TRACE(fence, "signaled from irq context\n");
else
BUG();
fence_put(fence);
}
}
/**
* amdgpu_fence_fallback - fallback for hardware interrupts
*
* @work: delayed work item
*
* Checks for fence activity.
*/
static void amdgpu_fence_fallback(unsigned long arg)
{
struct amdgpu_ring *ring = (void *)arg;
amdgpu_fence_process(ring);
}
/**
* amdgpu_fence_wait_empty - wait for all fences to signal
*
* @adev: amdgpu device pointer
* @ring: ring index the fence is associated with
*
* Wait for all fences on the requested ring to signal (all asics).
* Returns 0 if the fences have passed, error for all other cases.
*/
int amdgpu_fence_wait_empty(struct amdgpu_ring *ring)
{
uint64_t seq = ACCESS_ONCE(ring->fence_drv.sync_seq);
struct fence *fence, **ptr;
int r;
if (!seq)
return 0;
ptr = &ring->fence_drv.fences[seq & ring->fence_drv.num_fences_mask];
rcu_read_lock();
fence = rcu_dereference(*ptr);
if (!fence || !fence_get_rcu(fence)) {
rcu_read_unlock();
return 0;
}
rcu_read_unlock();
r = fence_wait(fence, false);
fence_put(fence);
return r;
}
/**
* amdgpu_fence_count_emitted - get the count of emitted fences
*
* @ring: ring the fence is associated with
*
* Get the number of fences emitted on the requested ring (all asics).
* Returns the number of emitted fences on the ring. Used by the
* dynpm code to ring track activity.
*/
unsigned amdgpu_fence_count_emitted(struct amdgpu_ring *ring)
{
uint64_t emitted;
/* We are not protected by ring lock when reading the last sequence
* but it's ok to report slightly wrong fence count here.
*/
amdgpu_fence_process(ring);
emitted = 0x100000000ull;
emitted -= atomic_read(&ring->fence_drv.last_seq);
emitted += ACCESS_ONCE(ring->fence_drv.sync_seq);
return lower_32_bits(emitted);
}
/**
* amdgpu_fence_driver_start_ring - make the fence driver
* ready for use on the requested ring.
*
* @ring: ring to start the fence driver on
* @irq_src: interrupt source to use for this ring
* @irq_type: interrupt type to use for this ring
*
* Make the fence driver ready for processing (all asics).
* Not all asics have all rings, so each asic will only
* start the fence driver on the rings it has.
* Returns 0 for success, errors for failure.
*/
int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
struct amdgpu_irq_src *irq_src,
unsigned irq_type)
{
struct amdgpu_device *adev = ring->adev;
uint64_t index;
if (ring != &adev->uvd.ring) {
ring->fence_drv.cpu_addr = &adev->wb.wb[ring->fence_offs];
ring->fence_drv.gpu_addr = adev->wb.gpu_addr + (ring->fence_offs * 4);
} else {
/* put fence directly behind firmware */
index = ALIGN(adev->uvd.fw->size, 8);
ring->fence_drv.cpu_addr = adev->uvd.cpu_addr + index;
ring->fence_drv.gpu_addr = adev->uvd.gpu_addr + index;
}
amdgpu_fence_write(ring, atomic_read(&ring->fence_drv.last_seq));
amdgpu_irq_get(adev, irq_src, irq_type);
ring->fence_drv.irq_src = irq_src;
ring->fence_drv.irq_type = irq_type;
ring->fence_drv.initialized = true;
dev_info(adev->dev, "fence driver on ring %d use gpu addr 0x%016llx, "
"cpu addr 0x%p\n", ring->idx,
ring->fence_drv.gpu_addr, ring->fence_drv.cpu_addr);
return 0;
}
/**
* amdgpu_fence_driver_init_ring - init the fence driver
* for the requested ring.
*
* @ring: ring to init the fence driver on
* @num_hw_submission: number of entries on the hardware queue
*
* Init the fence driver for the requested ring (all asics).
* Helper function for amdgpu_fence_driver_init().
*/
int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
unsigned num_hw_submission)
{
long timeout;
int r;
/* Check that num_hw_submission is a power of two */
if ((num_hw_submission & (num_hw_submission - 1)) != 0)
return -EINVAL;
ring->fence_drv.cpu_addr = NULL;
ring->fence_drv.gpu_addr = 0;
ring->fence_drv.sync_seq = 0;
atomic_set(&ring->fence_drv.last_seq, 0);
ring->fence_drv.initialized = false;
setup_timer(&ring->fence_drv.fallback_timer, amdgpu_fence_fallback,
(unsigned long)ring);
ring->fence_drv.num_fences_mask = num_hw_submission * 2 - 1;
spin_lock_init(&ring->fence_drv.lock);
ring->fence_drv.fences = kcalloc(num_hw_submission * 2, sizeof(void *),
GFP_KERNEL);
if (!ring->fence_drv.fences)
return -ENOMEM;
timeout = msecs_to_jiffies(amdgpu_lockup_timeout);
if (timeout == 0) {
/*
* FIXME:
* Delayed workqueue cannot use it directly,
* so the scheduler will not use delayed workqueue if
* MAX_SCHEDULE_TIMEOUT is set.
* Currently keep it simple and silly.
*/
timeout = MAX_SCHEDULE_TIMEOUT;
}
r = amd_sched_init(&ring->sched, &amdgpu_sched_ops,
num_hw_submission,
timeout, ring->name);
if (r) {
DRM_ERROR("Failed to create scheduler on ring %s.\n",
ring->name);
return r;
}
return 0;
}
/**
* amdgpu_fence_driver_init - init the fence driver
* for all possible rings.
*
* @adev: amdgpu device pointer
*
* Init the fence driver for all possible rings (all asics).
* Not all asics have all rings, so each asic will only
* start the fence driver on the rings it has using
* amdgpu_fence_driver_start_ring().
* Returns 0 for success.
*/
int amdgpu_fence_driver_init(struct amdgpu_device *adev)
{
if (amdgpu_debugfs_fence_init(adev))
dev_err(adev->dev, "fence debugfs file creation failed\n");
return 0;
}
/**
* amdgpu_fence_driver_fini - tear down the fence driver
* for all possible rings.
*
* @adev: amdgpu device pointer
*
* Tear down the fence driver for all possible rings (all asics).
*/
void amdgpu_fence_driver_fini(struct amdgpu_device *adev)
{
unsigned i, j;
int r;
for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
struct amdgpu_ring *ring = adev->rings[i];
if (!ring || !ring->fence_drv.initialized)
continue;
r = amdgpu_fence_wait_empty(ring);
if (r) {
/* no need to trigger GPU reset as we are unloading */
amdgpu_fence_driver_force_completion(adev);
}
amdgpu_irq_put(adev, ring->fence_drv.irq_src,
ring->fence_drv.irq_type);
amd_sched_fini(&ring->sched);
del_timer_sync(&ring->fence_drv.fallback_timer);
for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
fence_put(ring->fence_drv.fences[j]);
kfree(ring->fence_drv.fences);
ring->fence_drv.initialized = false;
}
}
/**
* amdgpu_fence_driver_suspend - suspend the fence driver
* for all possible rings.
*
* @adev: amdgpu device pointer
*
* Suspend the fence driver for all possible rings (all asics).
*/
void amdgpu_fence_driver_suspend(struct amdgpu_device *adev)
{
int i, r;
for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
struct amdgpu_ring *ring = adev->rings[i];
if (!ring || !ring->fence_drv.initialized)
continue;
/* wait for gpu to finish processing current batch */
r = amdgpu_fence_wait_empty(ring);
if (r) {
/* delay GPU reset to resume */
amdgpu_fence_driver_force_completion(adev);
}
/* disable the interrupt */
amdgpu_irq_put(adev, ring->fence_drv.irq_src,
ring->fence_drv.irq_type);
}
}
/**
* amdgpu_fence_driver_resume - resume the fence driver
* for all possible rings.
*
* @adev: amdgpu device pointer
*
* Resume the fence driver for all possible rings (all asics).
* Not all asics have all rings, so each asic will only
* start the fence driver on the rings it has using
* amdgpu_fence_driver_start_ring().
* Returns 0 for success.
*/
void amdgpu_fence_driver_resume(struct amdgpu_device *adev)
{
int i;
for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
struct amdgpu_ring *ring = adev->rings[i];
if (!ring || !ring->fence_drv.initialized)
continue;
/* enable the interrupt */
amdgpu_irq_get(adev, ring->fence_drv.irq_src,
ring->fence_drv.irq_type);
}
}
/**
* amdgpu_fence_driver_force_completion - force all fence waiter to complete
*
* @adev: amdgpu device pointer
*
* In case of GPU reset failure make sure no process keep waiting on fence
* that will never complete.
*/
void amdgpu_fence_driver_force_completion(struct amdgpu_device *adev)
{
int i;
for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
struct amdgpu_ring *ring = adev->rings[i];
if (!ring || !ring->fence_drv.initialized)
continue;
amdgpu_fence_write(ring, ring->fence_drv.sync_seq);
}
}
/*
* Common fence implementation
*/
static const char *amdgpu_fence_get_driver_name(struct fence *fence)
{
return "amdgpu";
}
static const char *amdgpu_fence_get_timeline_name(struct fence *f)
{
struct amdgpu_fence *fence = to_amdgpu_fence(f);
return (const char *)fence->ring->name;
}
/**
* amdgpu_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 amdgpu_fence_enable_signaling(struct fence *f)
{
struct amdgpu_fence *fence = to_amdgpu_fence(f);
struct amdgpu_ring *ring = fence->ring;
if (!timer_pending(&ring->fence_drv.fallback_timer))
amdgpu_fence_schedule_fallback(ring);
FENCE_TRACE(&fence->base, "armed on ring %i!\n", ring->idx);
return true;
}
/**
* amdgpu_fence_free - free up the fence memory
*
* @rcu: RCU callback head
*
* Free up the fence memory after the RCU grace period.
*/
static void amdgpu_fence_free(struct rcu_head *rcu)
{
struct fence *f = container_of(rcu, struct fence, rcu);
struct amdgpu_fence *fence = to_amdgpu_fence(f);
kmem_cache_free(amdgpu_fence_slab, fence);
}
/**
* amdgpu_fence_release - callback that fence can be freed
*
* @fence: fence
*
* This function is called when the reference count becomes zero.
* It just RCU schedules freeing up the fence.
*/
static void amdgpu_fence_release(struct fence *f)
{
call_rcu(&f->rcu, amdgpu_fence_free);
}
static const struct fence_ops amdgpu_fence_ops = {
.get_driver_name = amdgpu_fence_get_driver_name,
.get_timeline_name = amdgpu_fence_get_timeline_name,
.enable_signaling = amdgpu_fence_enable_signaling,
.wait = fence_default_wait,
.release = amdgpu_fence_release,
};
/*
* Fence debugfs
*/
#if defined(CONFIG_DEBUG_FS)
static int amdgpu_debugfs_fence_info(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *)m->private;
struct drm_device *dev = node->minor->dev;
struct amdgpu_device *adev = dev->dev_private;
int i;
for (i = 0; i < AMDGPU_MAX_RINGS; ++i) {
struct amdgpu_ring *ring = adev->rings[i];
if (!ring || !ring->fence_drv.initialized)
continue;
amdgpu_fence_process(ring);
seq_printf(m, "--- ring %d (%s) ---\n", i, ring->name);
seq_printf(m, "Last signaled fence 0x%08x\n",
atomic_read(&ring->fence_drv.last_seq));
seq_printf(m, "Last emitted 0x%08x\n",
ring->fence_drv.sync_seq);
}
return 0;
}
/**
* amdgpu_debugfs_gpu_reset - manually trigger a gpu reset
*
* Manually trigger a gpu reset at the next fence wait.
*/
static int amdgpu_debugfs_gpu_reset(struct seq_file *m, void *data)
{
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct amdgpu_device *adev = dev->dev_private;
seq_printf(m, "gpu reset\n");
amdgpu_gpu_reset(adev);
return 0;
}
static const struct drm_info_list amdgpu_debugfs_fence_list[] = {
{"amdgpu_fence_info", &amdgpu_debugfs_fence_info, 0, NULL},
{"amdgpu_gpu_reset", &amdgpu_debugfs_gpu_reset, 0, NULL}
};
#endif
int amdgpu_debugfs_fence_init(struct amdgpu_device *adev)
{
#if defined(CONFIG_DEBUG_FS)
return amdgpu_debugfs_add_files(adev, amdgpu_debugfs_fence_list, 2);
#else
return 0;
#endif
}