[PATCH 2/9] drm/i915: Move GEM request routines to i915_gem_request.c

Chris Wilson
2016-07-15T10:11:43Z

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>
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_drv.h | 209 +---------
drivers/gpu/drm/i915/i915_gem.c | 655 +------------------------------
drivers/gpu/drm/i915/i915_gem_request.c | 658 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_gem_request.h | 238 ++++++++++++
5 files changed, 905 insertions(+), 856 deletions(-)
create mode 100644 drivers/gpu/drm/i915/i915_gem_request.c
create mode 100644 drivers/gpu/drm/i915/i915_gem_request.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 75318ebb8d25..6092f0ea24df 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -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 \
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e73c0fc84c73..a4767c198413 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -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,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 8b42a5101f11..10e5db3f294e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1325,365 +1325,6 @@ put_rpm:
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
diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c
new file mode 100644
index 000000000000..9e9aa6b725f7
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_request.c
@@ -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);
+}
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
new file mode 100644
index 000000000000..ea700befcc28
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -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 */
--
2.8.1