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drm/i915: Move GEM request routines to i915_gem_request.c 

Migrate the request operations out of the main body of i915_gem.c and
into their own C file for easier expansion.

v2: Move __i915_add_request() across as well

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1469002875-2335-1-git-send-email-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-07-20 09:21:08 +01:00
parent fe993bc958
commit 05235c5354
5 changed files with 905 additions and 856 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/gpu/drm/i915/Makefile
View File

@ -33,6 +33,7 @@ i915-y += i915_cmd_parser.o \
i915_gem_gtt.o \
i915_gem.o \
i915_gem_render_state.o \
i915_gem_request.o \
i915_gem_shrinker.o \
i915_gem_stolen.o \
i915_gem_tiling.o \

209
drivers/gpu/drm/i915/i915_drv.h
View File

@ -61,6 +61,7 @@
#include "i915_gem.h"
#include "i915_gem_gtt.h"
#include "i915_gem_render_state.h"
#include "i915_gem_request.h"
#include "intel_gvt.h"
@ -2365,171 +2366,6 @@ static inline struct scatterlist *__sg_next(struct scatterlist *sg)
(((__iter).curr += PAGE_SIZE) < (__iter).max) || \
((__iter) = __sgt_iter(__sg_next((__iter).sgp), false), 0))
/**
* Request queue structure.
*
* The request queue allows us to note sequence numbers that have been emitted
* and may be associated with active buffers to be retired.
*
* By keeping this list, we can avoid having to do questionable sequence
* number comparisons on buffer last_read|write_seqno. It also allows an
* emission time to be associated with the request for tracking how far ahead
* of the GPU the submission is.
*
* The requests are reference counted, so upon creation they should have an
* initial reference taken using kref_init
*/
struct drm_i915_gem_request {
struct kref ref;
/** On Which ring this request was generated */
struct drm_i915_private *i915;
struct intel_engine_cs *engine;
struct intel_signal_node signaling;
/** GEM sequence number associated with the previous request,
* when the HWS breadcrumb is equal to this the GPU is processing
* this request.
*/
u32 previous_seqno;
/** GEM sequence number associated with this request,
* when the HWS breadcrumb is equal or greater than this the GPU
* has finished processing this request.
*/
u32 seqno;
/** Position in the ringbuffer of the start of the request */
u32 head;
/**
* Position in the ringbuffer of the start of the postfix.
* This is required to calculate the maximum available ringbuffer
* space without overwriting the postfix.
*/
u32 postfix;
/** Position in the ringbuffer of the end of the whole request */
u32 tail;
/** Preallocate space in the ringbuffer for the emitting the request */
u32 reserved_space;
/**
* Context and ring buffer related to this request
* Contexts are refcounted, so when this request is associated with a
* context, we must increment the context's refcount, to guarantee that
* it persists while any request is linked to it. Requests themselves
* are also refcounted, so the request will only be freed when the last
* reference to it is dismissed, and the code in
* i915_gem_request_free() will then decrement the refcount on the
* context.
*/
struct i915_gem_context *ctx;
struct intel_ringbuffer *ringbuf;
/**
* Context related to the previous request.
* As the contexts are accessed by the hardware until the switch is
* completed to a new context, the hardware may still be writing
* to the context object after the breadcrumb is visible. We must
* not unpin/unbind/prune that object whilst still active and so
* we keep the previous context pinned until the following (this)
* request is retired.
*/
struct i915_gem_context *previous_context;
/** Batch buffer related to this request if any (used for
error state dump only) */
struct drm_i915_gem_object *batch_obj;
/** Time at which this request was emitted, in jiffies. */
unsigned long emitted_jiffies;
/** global list entry for this request */
struct list_head list;
struct drm_i915_file_private *file_priv;
/** file_priv list entry for this request */
struct list_head client_list;
/** process identifier submitting this request */
struct pid *pid;
/**
* The ELSP only accepts two elements at a time, so we queue
* context/tail pairs on a given queue (ring->execlist_queue) until the
* hardware is available. The queue serves a double purpose: we also use
* it to keep track of the up to 2 contexts currently in the hardware
* (usually one in execution and the other queued up by the GPU): We
* only remove elements from the head of the queue when the hardware
* informs us that an element has been completed.
*
* All accesses to the queue are mediated by a spinlock
* (ring->execlist_lock).
*/
/** Execlist link in the submission queue.*/
struct list_head execlist_link;
/** Execlists no. of times this request has been sent to the ELSP */
int elsp_submitted;
/** Execlists context hardware id. */
unsigned ctx_hw_id;
};
struct drm_i915_gem_request * __must_check
i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx);
void i915_gem_request_free(struct kref *req_ref);
int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
struct drm_file *file);
static inline uint32_t
i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
{
return req ? req->seqno : 0;
}
static inline struct intel_engine_cs *
i915_gem_request_get_engine(struct drm_i915_gem_request *req)
{
return req ? req->engine : NULL;
}
static inline struct drm_i915_gem_request *
i915_gem_request_reference(struct drm_i915_gem_request *req)
{
if (req)
kref_get(&req->ref);
return req;
}
static inline void
i915_gem_request_unreference(struct drm_i915_gem_request *req)
{
kref_put(&req->ref, i915_gem_request_free);
}
static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
struct drm_i915_gem_request *src)
{
if (src)
i915_gem_request_reference(src);
if (*pdst)
i915_gem_request_unreference(*pdst);
*pdst = src;
}
/*
* XXX: i915_gem_request_completed should be here but currently needs the
* definition of i915_seqno_passed() which is below. It will be moved in
* a later patch when the call to i915_seqno_passed() is obsoleted...
*/
/*
* A command that requires special handling by the command parser.
*/
@ -3297,37 +3133,6 @@ void i915_gem_track_fb(struct drm_i915_gem_object *old,
struct drm_i915_gem_object *new,
unsigned frontbuffer_bits);
/**
* Returns true if seq1 is later than seq2.
*/
static inline bool
i915_seqno_passed(uint32_t seq1, uint32_t seq2)
{
return (int32_t)(seq1 - seq2) >= 0;
}
static inline bool i915_gem_request_started(const struct drm_i915_gem_request *req)
{
return i915_seqno_passed(intel_engine_get_seqno(req->engine),
req->previous_seqno);
}
static inline bool i915_gem_request_completed(const struct drm_i915_gem_request *req)
{
return i915_seqno_passed(intel_engine_get_seqno(req->engine),
req->seqno);
}
bool __i915_spin_request(const struct drm_i915_gem_request *request,
int state, unsigned long timeout_us);
static inline bool i915_spin_request(const struct drm_i915_gem_request *request,
int state, unsigned long timeout_us)
{
return (i915_gem_request_started(request) &&
__i915_spin_request(request, state, timeout_us));
}
int __must_check i915_gem_get_seqno(struct drm_i915_private *dev_priv, u32 *seqno);
int __must_check i915_gem_set_seqno(struct drm_device *dev, u32 seqno);
struct drm_i915_gem_request *
@ -3385,18 +3190,6 @@ void i915_gem_cleanup_engines(struct drm_device *dev);
int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv);
int __must_check i915_gem_suspend(struct drm_device *dev);
void i915_gem_resume(struct drm_device *dev);
void __i915_add_request(struct drm_i915_gem_request *req,
struct drm_i915_gem_object *batch_obj,
bool flush_caches);
#define i915_add_request(req) \
__i915_add_request(req, NULL, true)
#define i915_add_request_no_flush(req) \
__i915_add_request(req, NULL, false)
int __i915_wait_request(struct drm_i915_gem_request *req,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps);
int __must_check i915_wait_request(struct drm_i915_gem_request *req);
int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
int __must_check
i915_gem_object_wait_rendering(struct drm_i915_gem_object *obj,

655
drivers/gpu/drm/i915/i915_gem.c
View File

@ -1325,365 +1325,6 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
return ret;
}
static int
i915_gem_check_wedge(unsigned reset_counter, bool interruptible)
{
if (__i915_terminally_wedged(reset_counter))
return -EIO;
if (__i915_reset_in_progress(reset_counter)) {
/* Non-interruptible callers can't handle -EAGAIN, hence return
* -EIO unconditionally for these. */
if (!interruptible)
return -EIO;
return -EAGAIN;
}
return 0;
}
static unsigned long local_clock_us(unsigned *cpu)
{
unsigned long t;
/* Cheaply and approximately convert from nanoseconds to microseconds.
* The result and subsequent calculations are also defined in the same
* approximate microseconds units. The principal source of timing
* error here is from the simple truncation.
*
* Note that local_clock() is only defined wrt to the current CPU;
* the comparisons are no longer valid if we switch CPUs. Instead of
* blocking preemption for the entire busywait, we can detect the CPU
* switch and use that as indicator of system load and a reason to
* stop busywaiting, see busywait_stop().
*/
*cpu = get_cpu();
t = local_clock() >> 10;
put_cpu();
return t;
}
static bool busywait_stop(unsigned long timeout, unsigned cpu)
{
unsigned this_cpu;
if (time_after(local_clock_us(&this_cpu), timeout))
return true;
return this_cpu != cpu;
}
bool __i915_spin_request(const struct drm_i915_gem_request *req,
int state, unsigned long timeout_us)
{
unsigned cpu;
/* When waiting for high frequency requests, e.g. during synchronous
* rendering split between the CPU and GPU, the finite amount of time
* required to set up the irq and wait upon it limits the response
* rate. By busywaiting on the request completion for a short while we
* can service the high frequency waits as quick as possible. However,
* if it is a slow request, we want to sleep as quickly as possible.
* The tradeoff between waiting and sleeping is roughly the time it
* takes to sleep on a request, on the order of a microsecond.
*/
timeout_us += local_clock_us(&cpu);
do {
if (i915_gem_request_completed(req))
return true;
if (signal_pending_state(state, current))
break;
if (busywait_stop(timeout_us, cpu))
break;
cpu_relax_lowlatency();
} while (!need_resched());
return false;
}
/**
* __i915_wait_request - wait until execution of request has finished
* @req: duh!
* @interruptible: do an interruptible wait (normally yes)
* @timeout: in - how long to wait (NULL forever); out - how much time remaining
* @rps: RPS client
*
* Note: It is of utmost importance that the passed in seqno and reset_counter
* values have been read by the caller in an smp safe manner. Where read-side
* locks are involved, it is sufficient to read the reset_counter before
* unlocking the lock that protects the seqno. For lockless tricks, the
* reset_counter _must_ be read before, and an appropriate smp_rmb must be
* inserted.
*
* Returns 0 if the request was found within the alloted time. Else returns the
* errno with remaining time filled in timeout argument.
*/
int __i915_wait_request(struct drm_i915_gem_request *req,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps)
{
int state = interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
DEFINE_WAIT(reset);
struct intel_wait wait;
unsigned long timeout_remain;
s64 before = 0; /* Only to silence a compiler warning. */
int ret = 0;
might_sleep();
if (list_empty(&req->list))
return 0;
if (i915_gem_request_completed(req))
return 0;
timeout_remain = MAX_SCHEDULE_TIMEOUT;
if (timeout) {
if (WARN_ON(*timeout < 0))
return -EINVAL;
if (*timeout == 0)
return -ETIME;
timeout_remain = nsecs_to_jiffies_timeout(*timeout);
/*
* Record current time in case interrupted by signal, or wedged.
*/
before = ktime_get_raw_ns();
}
trace_i915_gem_request_wait_begin(req);
/* This client is about to stall waiting for the GPU. In many cases
* this is undesirable and limits the throughput of the system, as
* many clients cannot continue processing user input/output whilst
* blocked. RPS autotuning may take tens of milliseconds to respond
* to the GPU load and thus incurs additional latency for the client.
* We can circumvent that by promoting the GPU frequency to maximum
* before we wait. This makes the GPU throttle up much more quickly
* (good for benchmarks and user experience, e.g. window animations),
* but at a cost of spending more power processing the workload
* (bad for battery). Not all clients even want their results
* immediately and for them we should just let the GPU select its own
* frequency to maximise efficiency. To prevent a single client from
* forcing the clocks too high for the whole system, we only allow
* each client to waitboost once in a busy period.
*/
if (INTEL_INFO(req->i915)->gen >= 6)
gen6_rps_boost(req->i915, rps, req->emitted_jiffies);
/* Optimistic spin for the next ~jiffie before touching IRQs */
if (i915_spin_request(req, state, 5))
goto complete;
set_current_state(state);
add_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
intel_wait_init(&wait, req->seqno);
if (intel_engine_add_wait(req->engine, &wait))
/* In order to check that we haven't missed the interrupt
* as we enabled it, we need to kick ourselves to do a
* coherent check on the seqno before we sleep.
*/
goto wakeup;
for (;;) {
if (signal_pending_state(state, current)) {
ret = -ERESTARTSYS;
break;
}
timeout_remain = io_schedule_timeout(timeout_remain);
if (timeout_remain == 0) {
ret = -ETIME;
break;
}
if (intel_wait_complete(&wait))
break;
set_current_state(state);
wakeup:
/* Carefully check if the request is complete, giving time
* for the seqno to be visible following the interrupt.
* We also have to check in case we are kicked by the GPU
* reset in order to drop the struct_mutex.
*/
if (__i915_request_irq_complete(req))
break;
/* Only spin if we know the GPU is processing this request */
if (i915_spin_request(req, state, 2))
break;
}
remove_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
intel_engine_remove_wait(req->engine, &wait);
__set_current_state(TASK_RUNNING);
complete:
trace_i915_gem_request_wait_end(req);
if (timeout) {
s64 tres = *timeout - (ktime_get_raw_ns() - before);
*timeout = tres < 0 ? 0 : tres;
/*
* Apparently ktime isn't accurate enough and occasionally has a
* bit of mismatch in the jiffies<->nsecs<->ktime loop. So patch
* things up to make the test happy. We allow up to 1 jiffy.
*
* This is a regrssion from the timespec->ktime conversion.
*/
if (ret == -ETIME && *timeout < jiffies_to_usecs(1)*1000)
*timeout = 0;
}
if (rps && req->seqno == req->engine->last_submitted_seqno) {
/* The GPU is now idle and this client has stalled.
* Since no other client has submitted a request in the
* meantime, assume that this client is the only one
* supplying work to the GPU but is unable to keep that
* work supplied because it is waiting. Since the GPU is
* then never kept fully busy, RPS autoclocking will
* keep the clocks relatively low, causing further delays.
* Compensate by giving the synchronous client credit for
* a waitboost next time.
*/
spin_lock(&req->i915->rps.client_lock);
list_del_init(&rps->link);
spin_unlock(&req->i915->rps.client_lock);
}
return ret;
}
int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
struct drm_file *file)
{
struct drm_i915_file_private *file_priv;
WARN_ON(!req || !file || req->file_priv);
if (!req || !file)
return -EINVAL;
if (req->file_priv)
return -EINVAL;
file_priv = file->driver_priv;
spin_lock(&file_priv->mm.lock);
req->file_priv = file_priv;
list_add_tail(&req->client_list, &file_priv->mm.request_list);
spin_unlock(&file_priv->mm.lock);
req->pid = get_pid(task_pid(current));
return 0;
}
static inline void
i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
{
struct drm_i915_file_private *file_priv = request->file_priv;
if (!file_priv)
return;
spin_lock(&file_priv->mm.lock);
list_del(&request->client_list);
request->file_priv = NULL;
spin_unlock(&file_priv->mm.lock);
put_pid(request->pid);
request->pid = NULL;
}
static void i915_gem_request_retire(struct drm_i915_gem_request *request)
{
trace_i915_gem_request_retire(request);
/* We know the GPU must have read the request to have
* sent us the seqno + interrupt, so use the position
* of tail of the request to update the last known position
* of the GPU head.
*
* Note this requires that we are always called in request
* completion order.
*/
request->ringbuf->last_retired_head = request->postfix;
list_del_init(&request->list);
i915_gem_request_remove_from_client(request);
if (request->previous_context) {
if (i915.enable_execlists)
intel_lr_context_unpin(request->previous_context,
request->engine);
}
i915_gem_context_unreference(request->ctx);
i915_gem_request_unreference(request);
}
static void
__i915_gem_request_retire__upto(struct drm_i915_gem_request *req)
{
struct intel_engine_cs *engine = req->engine;
struct drm_i915_gem_request *tmp;
lockdep_assert_held(&engine->i915->drm.struct_mutex);
if (list_empty(&req->list))
return;
do {
tmp = list_first_entry(&engine->request_list,
typeof(*tmp), list);
i915_gem_request_retire(tmp);
} while (tmp != req);
WARN_ON(i915_verify_lists(engine->dev));
}
/**
* Waits for a request to be signaled, and cleans up the
* request and object lists appropriately for that event.
* @req: request to wait on
*/
int
i915_wait_request(struct drm_i915_gem_request *req)
{
struct drm_i915_private *dev_priv = req->i915;
bool interruptible;
int ret;
interruptible = dev_priv->mm.interruptible;
BUG_ON(!mutex_is_locked(&dev_priv->drm.struct_mutex));
ret = __i915_wait_request(req, interruptible, NULL, NULL);
if (ret)
return ret;
/* If the GPU hung, we want to keep the requests to find the guilty. */
if (!i915_reset_in_progress(&dev_priv->gpu_error))
__i915_gem_request_retire__upto(req);
return 0;
}
/**
* Ensures that all rendering to the object has completed and the object is
* safe to unbind from the GTT or access from the CPU.
@ -1740,7 +1381,7 @@ i915_gem_object_retire_request(struct drm_i915_gem_object *obj,
i915_gem_object_retire__write(obj);
if (!i915_reset_in_progress(&req->i915->gpu_error))
__i915_gem_request_retire__upto(req);
i915_gem_request_retire_upto(req);
}
/* A nonblocking variant of the above wait. This is a highly dangerous routine
@ -2761,193 +2402,6 @@ i915_gem_object_retire__read(struct drm_i915_gem_object *obj, int ring)
drm_gem_object_unreference(&obj->base);
}
static int
i915_gem_init_seqno(struct drm_i915_private *dev_priv, u32 seqno)
{
struct intel_engine_cs *engine;
int ret;
/* Carefully retire all requests without writing to the rings */
for_each_engine(engine, dev_priv) {
ret = intel_engine_idle(engine);
if (ret)
return ret;
}
i915_gem_retire_requests(dev_priv);
/* If the seqno wraps around, we need to clear the breadcrumb rbtree */
if (!i915_seqno_passed(seqno, dev_priv->next_seqno)) {
while (intel_kick_waiters(dev_priv) ||
intel_kick_signalers(dev_priv))
yield();
}
/* Finally reset hw state */
for_each_engine(engine, dev_priv)
intel_ring_init_seqno(engine, seqno);
return 0;
}
int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
{
struct drm_i915_private *dev_priv = to_i915(dev);
int ret;
if (seqno == 0)
return -EINVAL;
/* HWS page needs to be set less than what we
* will inject to ring
*/
ret = i915_gem_init_seqno(dev_priv, seqno - 1);
if (ret)
return ret;
/* Carefully set the last_seqno value so that wrap
* detection still works
*/
dev_priv->next_seqno = seqno;
dev_priv->last_seqno = seqno - 1;
if (dev_priv->last_seqno == 0)
dev_priv->last_seqno--;
return 0;
}
int
i915_gem_get_seqno(struct drm_i915_private *dev_priv, u32 *seqno)
{
/* reserve 0 for non-seqno */
if (dev_priv->next_seqno == 0) {
int ret = i915_gem_init_seqno(dev_priv, 0);
if (ret)
return ret;
dev_priv->next_seqno = 1;
}
*seqno = dev_priv->last_seqno = dev_priv->next_seqno++;
return 0;
}
static void i915_gem_mark_busy(const struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
dev_priv->gt.active_engines |= intel_engine_flag(engine);
if (dev_priv->gt.awake)
return;
intel_runtime_pm_get_noresume(dev_priv);
dev_priv->gt.awake = true;
intel_enable_gt_powersave(dev_priv);
i915_update_gfx_val(dev_priv);
if (INTEL_GEN(dev_priv) >= 6)
gen6_rps_busy(dev_priv);
queue_delayed_work(dev_priv->wq,
&dev_priv->gt.retire_work,
round_jiffies_up_relative(HZ));
}
/*
* NB: This function is not allowed to fail. Doing so would mean the the
* request is not being tracked for completion but the work itself is
* going to happen on the hardware. This would be a Bad Thing(tm).
*/
void __i915_add_request(struct drm_i915_gem_request *request,
struct drm_i915_gem_object *obj,
bool flush_caches)
{
struct intel_engine_cs *engine;
struct intel_ringbuffer *ringbuf;
u32 request_start;
u32 reserved_tail;
int ret;
if (WARN_ON(request == NULL))
return;
engine = request->engine;
ringbuf = request->ringbuf;
/*
* To ensure that this call will not fail, space for its emissions
* should already have been reserved in the ring buffer. Let the ring
* know that it is time to use that space up.
*/
request_start = intel_ring_get_tail(ringbuf);
reserved_tail = request->reserved_space;
request->reserved_space = 0;
/*
* Emit any outstanding flushes - execbuf can fail to emit the flush
* after having emitted the batchbuffer command. Hence we need to fix
* things up similar to emitting the lazy request. The difference here
* is that the flush _must_ happen before the next request, no matter
* what.
*/
if (flush_caches) {
if (i915.enable_execlists)
ret = logical_ring_flush_all_caches(request);
else
ret = intel_ring_flush_all_caches(request);
/* Not allowed to fail! */
WARN(ret, "*_ring_flush_all_caches failed: %d!\n", ret);
}
trace_i915_gem_request_add(request);
request->head = request_start;
/* Whilst this request exists, batch_obj will be on the
* active_list, and so will hold the active reference. Only when this
* request is retired will the the batch_obj be moved onto the
* inactive_list and lose its active reference. Hence we do not need
* to explicitly hold another reference here.
*/
request->batch_obj = obj;
/* Seal the request and mark it as pending execution. Note that
* we may inspect this state, without holding any locks, during
* hangcheck. Hence we apply the barrier to ensure that we do not
* see a more recent value in the hws than we are tracking.
*/
request->emitted_jiffies = jiffies;
request->previous_seqno = engine->last_submitted_seqno;
smp_store_mb(engine->last_submitted_seqno, request->seqno);
list_add_tail(&request->list, &engine->request_list);
/* Record the position of the start of the request so that
* should we detect the updated seqno part-way through the
* GPU processing the request, we never over-estimate the
* position of the head.
*/
request->postfix = intel_ring_get_tail(ringbuf);
if (i915.enable_execlists)
ret = engine->emit_request(request);
else {
ret = engine->add_request(request);
request->tail = intel_ring_get_tail(ringbuf);
}
/* Not allowed to fail! */
WARN(ret, "emit|add_request failed: %d!\n", ret);
/* Sanity check that the reserved size was large enough. */
ret = intel_ring_get_tail(ringbuf) - request_start;
if (ret < 0)
ret += ringbuf->size;
WARN_ONCE(ret > reserved_tail,
"Not enough space reserved (%d bytes) "
"for adding the request (%d bytes)\n",
reserved_tail, ret);
i915_gem_mark_busy(engine);
}
static bool i915_context_is_banned(const struct i915_gem_context *ctx)
{
unsigned long elapsed;
@ -2979,101 +2433,6 @@ static void i915_set_reset_status(struct i915_gem_context *ctx,
}
}
void i915_gem_request_free(struct kref *req_ref)
{
struct drm_i915_gem_request *req = container_of(req_ref,
typeof(*req), ref);
kmem_cache_free(req->i915->requests, req);
}
static inline int
__i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx,
struct drm_i915_gem_request **req_out)
{
struct drm_i915_private *dev_priv = engine->i915;
unsigned reset_counter = i915_reset_counter(&dev_priv->gpu_error);
struct drm_i915_gem_request *req;
int ret;
if (!req_out)
return -EINVAL;
*req_out = NULL;
/* ABI: Before userspace accesses the GPU (e.g. execbuffer), report
* EIO if the GPU is already wedged, or EAGAIN to drop the struct_mutex
* and restart.
*/
ret = i915_gem_check_wedge(reset_counter, dev_priv->mm.interruptible);
if (ret)
return ret;
req = kmem_cache_zalloc(dev_priv->requests, GFP_KERNEL);
if (req == NULL)
return -ENOMEM;
ret = i915_gem_get_seqno(engine->i915, &req->seqno);
if (ret)
goto err;
kref_init(&req->ref);
req->i915 = dev_priv;
req->engine = engine;
req->ctx = ctx;
i915_gem_context_reference(req->ctx);
/*
* Reserve space in the ring buffer for all the commands required to
* eventually emit this request. This is to guarantee that the
* i915_add_request() call can't fail. Note that the reserve may need
* to be redone if the request is not actually submitted straight
* away, e.g. because a GPU scheduler has deferred it.
*/
req->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
if (i915.enable_execlists)
ret = intel_logical_ring_alloc_request_extras(req);
else
ret = intel_ring_alloc_request_extras(req);
if (ret)
goto err_ctx;
*req_out = req;
return 0;
err_ctx:
i915_gem_context_unreference(ctx);
err:
kmem_cache_free(dev_priv->requests, req);
return ret;
}
/**
* i915_gem_request_alloc - allocate a request structure
*
* @engine: engine that we wish to issue the request on.
* @ctx: context that the request will be associated with.
* This can be NULL if the request is not directly related to
* any specific user context, in which case this function will
* choose an appropriate context to use.
*
* Returns a pointer to the allocated request if successful,
* or an error code if not.
*/
struct drm_i915_gem_request *
i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx)
{
struct drm_i915_gem_request *req;
int err;
if (ctx == NULL)
ctx = engine->i915->kernel_context;
err = __i915_gem_request_alloc(engine, ctx, &req);
return err ? ERR_PTR(err) : req;
}
struct drm_i915_gem_request *
i915_gem_find_active_request(struct intel_engine_cs *engine)
{
@ -3147,14 +2506,14 @@ static void i915_gem_reset_engine_cleanup(struct intel_engine_cs *engine)
* implicit references on things like e.g. ppgtt address spaces through
* the request.
*/
while (!list_empty(&engine->request_list)) {
if (!list_empty(&engine->request_list)) {
struct drm_i915_gem_request *request;
request = list_first_entry(&engine->request_list,
struct drm_i915_gem_request,
list);
request = list_last_entry(&engine->request_list,
struct drm_i915_gem_request,
list);
i915_gem_request_retire(request);
i915_gem_request_retire_upto(request);
}
/* Having flushed all requests from all queues, we know that all
@ -3222,7 +2581,7 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *engine)
if (!i915_gem_request_completed(request))
break;
i915_gem_request_retire(request);
i915_gem_request_retire_upto(request);
}
/* Move any buffers on the active list that are no longer referenced

658
drivers/gpu/drm/i915/i915_gem_request.c Normal file
View File

@ -0,0 +1,658 @@
/*
* Copyright © 2008-2015 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.
*
*/
#include "i915_drv.h"
int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
struct drm_file *file)
{
struct drm_i915_private *dev_private;
struct drm_i915_file_private *file_priv;
WARN_ON(!req || !file || req->file_priv);
if (!req || !file)
return -EINVAL;
if (req->file_priv)
return -EINVAL;
dev_private = req->i915;
file_priv = file->driver_priv;
spin_lock(&file_priv->mm.lock);
req->file_priv = file_priv;
list_add_tail(&req->client_list, &file_priv->mm.request_list);
spin_unlock(&file_priv->mm.lock);
req->pid = get_pid(task_pid(current));
return 0;
}
static inline void
i915_gem_request_remove_from_client(struct drm_i915_gem_request *request)
{
struct drm_i915_file_private *file_priv = request->file_priv;
if (!file_priv)
return;
spin_lock(&file_priv->mm.lock);
list_del(&request->client_list);
request->file_priv = NULL;
spin_unlock(&file_priv->mm.lock);
put_pid(request->pid);
request->pid = NULL;
}
static void i915_gem_request_retire(struct drm_i915_gem_request *request)
{
trace_i915_gem_request_retire(request);
list_del_init(&request->list);
/* We know the GPU must have read the request to have
* sent us the seqno + interrupt, so use the position
* of tail of the request to update the last known position
* of the GPU head.
*
* Note this requires that we are always called in request
* completion order.
*/
request->ringbuf->last_retired_head = request->postfix;
i915_gem_request_remove_from_client(request);
if (request->previous_context) {
if (i915.enable_execlists)
intel_lr_context_unpin(request->previous_context,
request->engine);
}
i915_gem_context_unreference(request->ctx);
i915_gem_request_unreference(request);
}
void i915_gem_request_retire_upto(struct drm_i915_gem_request *req)
{
struct intel_engine_cs *engine = req->engine;
struct drm_i915_gem_request *tmp;
lockdep_assert_held(&req->i915->drm.struct_mutex);
if (list_empty(&req->list))
return;
do {
tmp = list_first_entry(&engine->request_list,
typeof(*tmp), list);
i915_gem_request_retire(tmp);
} while (tmp != req);
WARN_ON(i915_verify_lists(engine->dev));
}
static int i915_gem_check_wedge(unsigned int reset_counter, bool interruptible)
{
if (__i915_terminally_wedged(reset_counter))
return -EIO;
if (__i915_reset_in_progress(reset_counter)) {
/* Non-interruptible callers can't handle -EAGAIN, hence return
* -EIO unconditionally for these.
*/
if (!interruptible)
return -EIO;
return -EAGAIN;
}
return 0;
}
static int i915_gem_init_seqno(struct drm_i915_private *dev_priv, u32 seqno)
{
struct intel_engine_cs *engine;
int ret;
/* Carefully retire all requests without writing to the rings */
for_each_engine(engine, dev_priv) {
ret = intel_engine_idle(engine);
if (ret)
return ret;
}
i915_gem_retire_requests(dev_priv);
/* If the seqno wraps around, we need to clear the breadcrumb rbtree */
if (!i915_seqno_passed(seqno, dev_priv->next_seqno)) {
while (intel_kick_waiters(dev_priv) ||
intel_kick_signalers(dev_priv))
yield();
}
/* Finally reset hw state */
for_each_engine(engine, dev_priv)
intel_ring_init_seqno(engine, seqno);
return 0;
}
int i915_gem_set_seqno(struct drm_device *dev, u32 seqno)
{
struct drm_i915_private *dev_priv = to_i915(dev);
int ret;
if (seqno == 0)
return -EINVAL;
/* HWS page needs to be set less than what we
* will inject to ring
*/
ret = i915_gem_init_seqno(dev_priv, seqno - 1);
if (ret)
return ret;
/* Carefully set the last_seqno value so that wrap
* detection still works
*/
dev_priv->next_seqno = seqno;
dev_priv->last_seqno = seqno - 1;
if (dev_priv->last_seqno == 0)
dev_priv->last_seqno--;
return 0;
}
static int i915_gem_get_seqno(struct drm_i915_private *dev_priv, u32 *seqno)
{
/* reserve 0 for non-seqno */
if (unlikely(dev_priv->next_seqno == 0)) {
int ret;
ret = i915_gem_init_seqno(dev_priv, 0);
if (ret)
return ret;
dev_priv->next_seqno = 1;
}
*seqno = dev_priv->last_seqno = dev_priv->next_seqno++;
return 0;
}
static inline int
__i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx,
struct drm_i915_gem_request **req_out)
{
struct drm_i915_private *dev_priv = engine->i915;
unsigned int reset_counter = i915_reset_counter(&dev_priv->gpu_error);
struct drm_i915_gem_request *req;
int ret;
if (!req_out)
return -EINVAL;
*req_out = NULL;
/* ABI: Before userspace accesses the GPU (e.g. execbuffer), report
* EIO if the GPU is already wedged, or EAGAIN to drop the struct_mutex
* and restart.
*/
ret = i915_gem_check_wedge(reset_counter, dev_priv->mm.interruptible);
if (ret)
return ret;
req = kmem_cache_zalloc(dev_priv->requests, GFP_KERNEL);
if (!req)
return -ENOMEM;
ret = i915_gem_get_seqno(dev_priv, &req->seqno);
if (ret)
goto err;
kref_init(&req->ref);
req->i915 = dev_priv;
req->engine = engine;
req->ctx = ctx;
i915_gem_context_reference(ctx);
/*
* Reserve space in the ring buffer for all the commands required to
* eventually emit this request. This is to guarantee that the
* i915_add_request() call can't fail. Note that the reserve may need
* to be redone if the request is not actually submitted straight
* away, e.g. because a GPU scheduler has deferred it.
*/
req->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
if (i915.enable_execlists)
ret = intel_logical_ring_alloc_request_extras(req);
else
ret = intel_ring_alloc_request_extras(req);
if (ret)
goto err_ctx;
*req_out = req;
return 0;
err_ctx:
i915_gem_context_unreference(ctx);
err:
kmem_cache_free(dev_priv->requests, req);
return ret;
}
/**
* i915_gem_request_alloc - allocate a request structure
*
* @engine: engine that we wish to issue the request on.
* @ctx: context that the request will be associated with.
* This can be NULL if the request is not directly related to
* any specific user context, in which case this function will
* choose an appropriate context to use.
*
* Returns a pointer to the allocated request if successful,
* or an error code if not.
*/
struct drm_i915_gem_request *
i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx)
{
struct drm_i915_gem_request *req;
int err;
if (!ctx)
ctx = engine->i915->kernel_context;
err = __i915_gem_request_alloc(engine, ctx, &req);
return err ? ERR_PTR(err) : req;
}
static void i915_gem_mark_busy(const struct intel_engine_cs *engine)
{
struct drm_i915_private *dev_priv = engine->i915;
dev_priv->gt.active_engines |= intel_engine_flag(engine);
if (dev_priv->gt.awake)
return;
intel_runtime_pm_get_noresume(dev_priv);
dev_priv->gt.awake = true;
intel_enable_gt_powersave(dev_priv);
i915_update_gfx_val(dev_priv);
if (INTEL_GEN(dev_priv) >= 6)
gen6_rps_busy(dev_priv);
queue_delayed_work(dev_priv->wq,
&dev_priv->gt.retire_work,
round_jiffies_up_relative(HZ));
}
/*
* NB: This function is not allowed to fail. Doing so would mean the the
* request is not being tracked for completion but the work itself is
* going to happen on the hardware. This would be a Bad Thing(tm).
*/
void __i915_add_request(struct drm_i915_gem_request *request,
struct drm_i915_gem_object *obj,
bool flush_caches)
{
struct intel_engine_cs *engine;
struct intel_ringbuffer *ringbuf;
u32 request_start;
u32 reserved_tail;
int ret;
if (WARN_ON(!request))
return;
engine = request->engine;
ringbuf = request->ringbuf;
/*
* To ensure that this call will not fail, space for its emissions
* should already have been reserved in the ring buffer. Let the ring
* know that it is time to use that space up.
*/
request_start = intel_ring_get_tail(ringbuf);
reserved_tail = request->reserved_space;
request->reserved_space = 0;
/*
* Emit any outstanding flushes - execbuf can fail to emit the flush
* after having emitted the batchbuffer command. Hence we need to fix
* things up similar to emitting the lazy request. The difference here
* is that the flush _must_ happen before the next request, no matter
* what.
*/
if (flush_caches) {
if (i915.enable_execlists)
ret = logical_ring_flush_all_caches(request);
else
ret = intel_ring_flush_all_caches(request);
/* Not allowed to fail! */
WARN(ret, "*_ring_flush_all_caches failed: %d!\n", ret);
}
trace_i915_gem_request_add(request);
request->head = request_start;
/* Whilst this request exists, batch_obj will be on the
* active_list, and so will hold the active reference. Only when this
* request is retired will the the batch_obj be moved onto the
* inactive_list and lose its active reference. Hence we do not need
* to explicitly hold another reference here.
*/
request->batch_obj = obj;
/* Seal the request and mark it as pending execution. Note that
* we may inspect this state, without holding any locks, during
* hangcheck. Hence we apply the barrier to ensure that we do not
* see a more recent value in the hws than we are tracking.
*/
request->emitted_jiffies = jiffies;
request->previous_seqno = engine->last_submitted_seqno;
smp_store_mb(engine->last_submitted_seqno, request->seqno);
list_add_tail(&request->list, &engine->request_list);
/* Record the position of the start of the request so that
* should we detect the updated seqno part-way through the
* GPU processing the request, we never over-estimate the
* position of the head.
*/
request->postfix = intel_ring_get_tail(ringbuf);
if (i915.enable_execlists) {
ret = engine->emit_request(request);
} else {
ret = engine->add_request(request);
request->tail = intel_ring_get_tail(ringbuf);
}
/* Not allowed to fail! */
WARN(ret, "emit|add_request failed: %d!\n", ret);
/* Sanity check that the reserved size was large enough. */
ret = intel_ring_get_tail(ringbuf) - request_start;
if (ret < 0)
ret += ringbuf->size;
WARN_ONCE(ret > reserved_tail,
"Not enough space reserved (%d bytes) "
"for adding the request (%d bytes)\n",
reserved_tail, ret);
i915_gem_mark_busy(engine);
}
static unsigned long local_clock_us(unsigned int *cpu)
{
unsigned long t;
/* Cheaply and approximately convert from nanoseconds to microseconds.
* The result and subsequent calculations are also defined in the same
* approximate microseconds units. The principal source of timing
* error here is from the simple truncation.
*
* Note that local_clock() is only defined wrt to the current CPU;
* the comparisons are no longer valid if we switch CPUs. Instead of
* blocking preemption for the entire busywait, we can detect the CPU
* switch and use that as indicator of system load and a reason to
* stop busywaiting, see busywait_stop().
*/
*cpu = get_cpu();
t = local_clock() >> 10;
put_cpu();
return t;
}
static bool busywait_stop(unsigned long timeout, unsigned int cpu)
{
unsigned int this_cpu;
if (time_after(local_clock_us(&this_cpu), timeout))
return true;
return this_cpu != cpu;
}
bool __i915_spin_request(const struct drm_i915_gem_request *req,
int state, unsigned long timeout_us)
{
unsigned int cpu;
/* When waiting for high frequency requests, e.g. during synchronous
* rendering split between the CPU and GPU, the finite amount of time
* required to set up the irq and wait upon it limits the response
* rate. By busywaiting on the request completion for a short while we
* can service the high frequency waits as quick as possible. However,
* if it is a slow request, we want to sleep as quickly as possible.
* The tradeoff between waiting and sleeping is roughly the time it
* takes to sleep on a request, on the order of a microsecond.
*/
timeout_us += local_clock_us(&cpu);
do {
if (i915_gem_request_completed(req))
return true;
if (signal_pending_state(state, current))
break;
if (busywait_stop(timeout_us, cpu))
break;
cpu_relax_lowlatency();
} while (!need_resched());
return false;
}
/**
* __i915_wait_request - wait until execution of request has finished
* @req: duh!
* @interruptible: do an interruptible wait (normally yes)
* @timeout: in - how long to wait (NULL forever); out - how much time remaining
* @rps: client to charge for RPS boosting
*
* Note: It is of utmost importance that the passed in seqno and reset_counter
* values have been read by the caller in an smp safe manner. Where read-side
* locks are involved, it is sufficient to read the reset_counter before
* unlocking the lock that protects the seqno. For lockless tricks, the
* reset_counter _must_ be read before, and an appropriate smp_rmb must be
* inserted.
*
* Returns 0 if the request was found within the alloted time. Else returns the
* errno with remaining time filled in timeout argument.
*/
int __i915_wait_request(struct drm_i915_gem_request *req,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps)
{
int state = interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
DEFINE_WAIT(reset);
struct intel_wait wait;
unsigned long timeout_remain;
int ret = 0;
might_sleep();
if (list_empty(&req->list))
return 0;
if (i915_gem_request_completed(req))
return 0;
timeout_remain = MAX_SCHEDULE_TIMEOUT;
if (timeout) {
if (WARN_ON(*timeout < 0))
return -EINVAL;
if (*timeout == 0)
return -ETIME;
/* Record current time in case interrupted, or wedged */
timeout_remain = nsecs_to_jiffies_timeout(*timeout);
*timeout += ktime_get_raw_ns();
}
trace_i915_gem_request_wait_begin(req);
/* This client is about to stall waiting for the GPU. In many cases
* this is undesirable and limits the throughput of the system, as
* many clients cannot continue processing user input/output whilst
* blocked. RPS autotuning may take tens of milliseconds to respond
* to the GPU load and thus incurs additional latency for the client.
* We can circumvent that by promoting the GPU frequency to maximum
* before we wait. This makes the GPU throttle up much more quickly
* (good for benchmarks and user experience, e.g. window animations),
* but at a cost of spending more power processing the workload
* (bad for battery). Not all clients even want their results
* immediately and for them we should just let the GPU select its own
* frequency to maximise efficiency. To prevent a single client from
* forcing the clocks too high for the whole system, we only allow
* each client to waitboost once in a busy period.
*/
if (INTEL_GEN(req->i915) >= 6)
gen6_rps_boost(req->i915, rps, req->emitted_jiffies);
/* Optimistic spin for the next ~jiffie before touching IRQs */
if (i915_spin_request(req, state, 5))
goto complete;
set_current_state(state);
add_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
intel_wait_init(&wait, req->seqno);
if (intel_engine_add_wait(req->engine, &wait))
/* In order to check that we haven't missed the interrupt
* as we enabled it, we need to kick ourselves to do a
* coherent check on the seqno before we sleep.
*/
goto wakeup;
for (;;) {
if (signal_pending_state(state, current)) {
ret = -ERESTARTSYS;
break;
}
timeout_remain = io_schedule_timeout(timeout_remain);
if (timeout_remain == 0) {
ret = -ETIME;
break;
}
if (intel_wait_complete(&wait))
break;
set_current_state(state);
wakeup:
/* Carefully check if the request is complete, giving time
* for the seqno to be visible following the interrupt.
* We also have to check in case we are kicked by the GPU
* reset in order to drop the struct_mutex.
*/
if (__i915_request_irq_complete(req))
break;
/* Only spin if we know the GPU is processing this request */
if (i915_spin_request(req, state, 2))
break;
}
remove_wait_queue(&req->i915->gpu_error.wait_queue, &reset);
intel_engine_remove_wait(req->engine, &wait);
__set_current_state(TASK_RUNNING);
complete:
trace_i915_gem_request_wait_end(req);
if (timeout) {
*timeout -= ktime_get_raw_ns();
if (*timeout < 0)
*timeout = 0;
/*
* Apparently ktime isn't accurate enough and occasionally has a
* bit of mismatch in the jiffies<->nsecs<->ktime loop. So patch
* things up to make the test happy. We allow up to 1 jiffy.
*
* This is a regrssion from the timespec->ktime conversion.
*/
if (ret == -ETIME && *timeout < jiffies_to_usecs(1)*1000)
*timeout = 0;
}
if (rps && req->seqno == req->engine->last_submitted_seqno) {
/* The GPU is now idle and this client has stalled.
* Since no other client has submitted a request in the
* meantime, assume that this client is the only one
* supplying work to the GPU but is unable to keep that
* work supplied because it is waiting. Since the GPU is
* then never kept fully busy, RPS autoclocking will
* keep the clocks relatively low, causing further delays.
* Compensate by giving the synchronous client credit for
* a waitboost next time.
*/
spin_lock(&req->i915->rps.client_lock);
list_del_init(&rps->link);
spin_unlock(&req->i915->rps.client_lock);
}
return ret;
}
/**
* Waits for a request to be signaled, and cleans up the
* request and object lists appropriately for that event.
*/
int i915_wait_request(struct drm_i915_gem_request *req)
{
int ret;
GEM_BUG_ON(!req);
lockdep_assert_held(&req->i915->drm.struct_mutex);
ret = __i915_wait_request(req, req->i915->mm.interruptible, NULL, NULL);
if (ret)
return ret;
/* If the GPU hung, we want to keep the requests to find the guilty. */
if (!i915_reset_in_progress(&req->i915->gpu_error))
i915_gem_request_retire_upto(req);
return 0;
}
void i915_gem_request_free(struct kref *req_ref)
{
struct drm_i915_gem_request *req =
container_of(req_ref, typeof(*req), ref);
kmem_cache_free(req->i915->requests, req);
}

238
drivers/gpu/drm/i915/i915_gem_request.h Normal file
View File

@ -0,0 +1,238 @@
/*
* Copyright © 2008-2015 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.
*
*/
#ifndef I915_GEM_REQUEST_H
#define I915_GEM_REQUEST_H
/**
* Request queue structure.
*
* The request queue allows us to note sequence numbers that have been emitted
* and may be associated with active buffers to be retired.
*
* By keeping this list, we can avoid having to do questionable sequence
* number comparisons on buffer last_read|write_seqno. It also allows an
* emission time to be associated with the request for tracking how far ahead
* of the GPU the submission is.
*
* The requests are reference counted, so upon creation they should have an
* initial reference taken using kref_init
*/
struct drm_i915_gem_request {
struct kref ref;
/** On Which ring this request was generated */
struct drm_i915_private *i915;
/**
* Context and ring buffer related to this request
* Contexts are refcounted, so when this request is associated with a
* context, we must increment the context's refcount, to guarantee that
* it persists while any request is linked to it. Requests themselves
* are also refcounted, so the request will only be freed when the last
* reference to it is dismissed, and the code in
* i915_gem_request_free() will then decrement the refcount on the
* context.
*/
struct i915_gem_context *ctx;
struct intel_engine_cs *engine;
struct intel_ringbuffer *ringbuf;
struct intel_signal_node signaling;
/** GEM sequence number associated with the previous request,
* when the HWS breadcrumb is equal to this the GPU is processing
* this request.
*/
u32 previous_seqno;
/** GEM sequence number associated with this request,
* when the HWS breadcrumb is equal or greater than this the GPU
* has finished processing this request.
*/
u32 seqno;
/** Position in the ringbuffer of the start of the request */
u32 head;
/**
* Position in the ringbuffer of the start of the postfix.
* This is required to calculate the maximum available ringbuffer
* space without overwriting the postfix.
*/
u32 postfix;
/** Position in the ringbuffer of the end of the whole request */
u32 tail;
/** Preallocate space in the ringbuffer for the emitting the request */
u32 reserved_space;
/**
* Context related to the previous request.
* As the contexts are accessed by the hardware until the switch is
* completed to a new context, the hardware may still be writing
* to the context object after the breadcrumb is visible. We must
* not unpin/unbind/prune that object whilst still active and so
* we keep the previous context pinned until the following (this)
* request is retired.
*/
struct i915_gem_context *previous_context;
/** Batch buffer related to this request if any (used for
* error state dump only).
*/
struct drm_i915_gem_object *batch_obj;
/** Time at which this request was emitted, in jiffies. */
unsigned long emitted_jiffies;
/** global list entry for this request */
struct list_head list;
struct drm_i915_file_private *file_priv;
/** file_priv list entry for this request */
struct list_head client_list;
/** process identifier submitting this request */
struct pid *pid;
/**
* The ELSP only accepts two elements at a time, so we queue
* context/tail pairs on a given queue (ring->execlist_queue) until the
* hardware is available. The queue serves a double purpose: we also use
* it to keep track of the up to 2 contexts currently in the hardware
* (usually one in execution and the other queued up by the GPU): We
* only remove elements from the head of the queue when the hardware
* informs us that an element has been completed.
*
* All accesses to the queue are mediated by a spinlock
* (ring->execlist_lock).
*/
/** Execlist link in the submission queue.*/
struct list_head execlist_link;
/** Execlists no. of times this request has been sent to the ELSP */
int elsp_submitted;
/** Execlists context hardware id. */
unsigned int ctx_hw_id;
};
struct drm_i915_gem_request * __must_check
i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx);
void i915_gem_request_free(struct kref *req_ref);
int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
struct drm_file *file);
void i915_gem_request_retire_upto(struct drm_i915_gem_request *req);
static inline u32
i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
{
return req ? req->seqno : 0;
}
static inline struct intel_engine_cs *
i915_gem_request_get_engine(struct drm_i915_gem_request *req)
{
return req ? req->engine : NULL;
}
static inline struct drm_i915_gem_request *
i915_gem_request_reference(struct drm_i915_gem_request *req)
{
if (req)
kref_get(&req->ref);
return req;
}
static inline void
i915_gem_request_unreference(struct drm_i915_gem_request *req)
{
kref_put(&req->ref, i915_gem_request_free);
}
static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
struct drm_i915_gem_request *src)
{
if (src)
i915_gem_request_reference(src);
if (*pdst)
i915_gem_request_unreference(*pdst);
*pdst = src;
}
void __i915_add_request(struct drm_i915_gem_request *req,
struct drm_i915_gem_object *batch_obj,
bool flush_caches);
#define i915_add_request(req) \
__i915_add_request(req, NULL, true)
#define i915_add_request_no_flush(req) \
__i915_add_request(req, NULL, false)
struct intel_rps_client;
int __i915_wait_request(struct drm_i915_gem_request *req,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps);
int __must_check i915_wait_request(struct drm_i915_gem_request *req);
static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine);
/**
* Returns true if seq1 is later than seq2.
*/
static inline bool i915_seqno_passed(u32 seq1, u32 seq2)
{
return (s32)(seq1 - seq2) >= 0;
}
static inline bool
i915_gem_request_started(const struct drm_i915_gem_request *req)
{
return i915_seqno_passed(intel_engine_get_seqno(req->engine),
req->previous_seqno);
}
static inline bool
i915_gem_request_completed(const struct drm_i915_gem_request *req)
{
return i915_seqno_passed(intel_engine_get_seqno(req->engine),
req->seqno);
}
bool __i915_spin_request(const struct drm_i915_gem_request *request,
int state, unsigned long timeout_us);
static inline bool i915_spin_request(const struct drm_i915_gem_request *request,
int state, unsigned long timeout_us)
{
return (i915_gem_request_started(request) &&
__i915_spin_request(request, state, timeout_us));
}
#endif /* I915_GEM_REQUEST_H */