blob: 06a506c29463d67b3b1c23d4834ccc2598fac273 [file] [log] [blame]
/*
* Copyright © 2014 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.
*
* Authors:
* Ben Widawsky <ben@bwidawsk.net>
* Michel Thierry <michel.thierry@intel.com>
* Thomas Daniel <thomas.daniel@intel.com>
* Oscar Mateo <oscar.mateo@intel.com>
*
*/
/**
* DOC: Logical Rings, Logical Ring Contexts and Execlists
*
* Motivation:
* GEN8 brings an expansion of the HW contexts: "Logical Ring Contexts".
* These expanded contexts enable a number of new abilities, especially
* "Execlists" (also implemented in this file).
*
* One of the main differences with the legacy HW contexts is that logical
* ring contexts incorporate many more things to the context's state, like
* PDPs or ringbuffer control registers:
*
* The reason why PDPs are included in the context is straightforward: as
* PPGTTs (per-process GTTs) are actually per-context, having the PDPs
* contained there mean you don't need to do a ppgtt->switch_mm yourself,
* instead, the GPU will do it for you on the context switch.
*
* But, what about the ringbuffer control registers (head, tail, etc..)?
* shouldn't we just need a set of those per engine command streamer? This is
* where the name "Logical Rings" starts to make sense: by virtualizing the
* rings, the engine cs shifts to a new "ring buffer" with every context
* switch. When you want to submit a workload to the GPU you: A) choose your
* context, B) find its appropriate virtualized ring, C) write commands to it
* and then, finally, D) tell the GPU to switch to that context.
*
* Instead of the legacy MI_SET_CONTEXT, the way you tell the GPU to switch
* to a contexts is via a context execution list, ergo "Execlists".
*
* LRC implementation:
* Regarding the creation of contexts, we have:
*
* - One global default context.
* - One local default context for each opened fd.
* - One local extra context for each context create ioctl call.
*
* Now that ringbuffers belong per-context (and not per-engine, like before)
* and that contexts are uniquely tied to a given engine (and not reusable,
* like before) we need:
*
* - One ringbuffer per-engine inside each context.
* - One backing object per-engine inside each context.
*
* The global default context starts its life with these new objects fully
* allocated and populated. The local default context for each opened fd is
* more complex, because we don't know at creation time which engine is going
* to use them. To handle this, we have implemented a deferred creation of LR
* contexts:
*
* The local context starts its life as a hollow or blank holder, that only
* gets populated for a given engine once we receive an execbuffer. If later
* on we receive another execbuffer ioctl for the same context but a different
* engine, we allocate/populate a new ringbuffer and context backing object and
* so on.
*
* Finally, regarding local contexts created using the ioctl call: as they are
* only allowed with the render ring, we can allocate & populate them right
* away (no need to defer anything, at least for now).
*
* Execlists implementation:
* Execlists are the new method by which, on gen8+ hardware, workloads are
* submitted for execution (as opposed to the legacy, ringbuffer-based, method).
* This method works as follows:
*
* When a request is committed, its commands (the BB start and any leading or
* trailing commands, like the seqno breadcrumbs) are placed in the ringbuffer
* for the appropriate context. The tail pointer in the hardware context is not
* updated at this time, but instead, kept by the driver in the ringbuffer
* structure. A structure representing this request is added to a request queue
* for the appropriate engine: this structure contains a copy of the context's
* tail after the request was written to the ring buffer and a pointer to the
* context itself.
*
* If the engine's request queue was empty before the request was added, the
* queue is processed immediately. Otherwise the queue will be processed during
* a context switch interrupt. In any case, elements on the queue will get sent
* (in pairs) to the GPU's ExecLists Submit Port (ELSP, for short) with a
* globally unique 20-bits submission ID.
*
* When execution of a request completes, the GPU updates the context status
* buffer with a context complete event and generates a context switch interrupt.
* During the interrupt handling, the driver examines the events in the buffer:
* for each context complete event, if the announced ID matches that on the head
* of the request queue, then that request is retired and removed from the queue.
*
* After processing, if any requests were retired and the queue is not empty
* then a new execution list can be submitted. The two requests at the front of
* the queue are next to be submitted but since a context may not occur twice in
* an execution list, if subsequent requests have the same ID as the first then
* the two requests must be combined. This is done simply by discarding requests
* at the head of the queue until either only one requests is left (in which case
* we use a NULL second context) or the first two requests have unique IDs.
*
* By always executing the first two requests in the queue the driver ensures
* that the GPU is kept as busy as possible. In the case where a single context
* completes but a second context is still executing, the request for this second
* context will be at the head of the queue when we remove the first one. This
* request will then be resubmitted along with a new request for a different context,
* which will cause the hardware to continue executing the second request and queue
* the new request (the GPU detects the condition of a context getting preempted
* with the same context and optimizes the context switch flow by not doing
* preemption, but just sampling the new tail pointer).
*
*/
#include <linux/interrupt.h>
#include "gem/i915_gem_context.h"
#include "i915_drv.h"
#include "i915_perf.h"
#include "i915_trace.h"
#include "i915_vgpu.h"
#include "intel_engine_pm.h"
#include "intel_gt.h"
#include "intel_gt_pm.h"
#include "intel_lrc_reg.h"
#include "intel_mocs.h"
#include "intel_reset.h"
#include "intel_workarounds.h"
#define RING_EXECLIST_QFULL (1 << 0x2)
#define RING_EXECLIST1_VALID (1 << 0x3)
#define RING_EXECLIST0_VALID (1 << 0x4)
#define RING_EXECLIST_ACTIVE_STATUS (3 << 0xE)
#define RING_EXECLIST1_ACTIVE (1 << 0x11)
#define RING_EXECLIST0_ACTIVE (1 << 0x12)
#define GEN8_CTX_STATUS_IDLE_ACTIVE (1 << 0)
#define GEN8_CTX_STATUS_PREEMPTED (1 << 1)
#define GEN8_CTX_STATUS_ELEMENT_SWITCH (1 << 2)
#define GEN8_CTX_STATUS_ACTIVE_IDLE (1 << 3)
#define GEN8_CTX_STATUS_COMPLETE (1 << 4)
#define GEN8_CTX_STATUS_LITE_RESTORE (1 << 15)
#define GEN8_CTX_STATUS_COMPLETED_MASK \
(GEN8_CTX_STATUS_COMPLETE | GEN8_CTX_STATUS_PREEMPTED)
#define CTX_DESC_FORCE_RESTORE BIT_ULL(2)
#define GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE (0x1) /* lower csb dword */
#define GEN12_CTX_SWITCH_DETAIL(csb_dw) ((csb_dw) & 0xF) /* upper csb dword */
#define GEN12_CSB_SW_CTX_ID_MASK GENMASK(25, 15)
#define GEN12_IDLE_CTX_ID 0x7FF
#define GEN12_CSB_CTX_VALID(csb_dw) \
(FIELD_GET(GEN12_CSB_SW_CTX_ID_MASK, csb_dw) != GEN12_IDLE_CTX_ID)
/* Typical size of the average request (2 pipecontrols and a MI_BB) */
#define EXECLISTS_REQUEST_SIZE 64 /* bytes */
#define WA_TAIL_DWORDS 2
#define WA_TAIL_BYTES (sizeof(u32) * WA_TAIL_DWORDS)
struct virtual_engine {
struct intel_engine_cs base;
struct intel_context context;
/*
* We allow only a single request through the virtual engine at a time
* (each request in the timeline waits for the completion fence of
* the previous before being submitted). By restricting ourselves to
* only submitting a single request, each request is placed on to a
* physical to maximise load spreading (by virtue of the late greedy
* scheduling -- each real engine takes the next available request
* upon idling).
*/
struct i915_request *request;
/*
* We keep a rbtree of available virtual engines inside each physical
* engine, sorted by priority. Here we preallocate the nodes we need
* for the virtual engine, indexed by physical_engine->id.
*/
struct ve_node {
struct rb_node rb;
int prio;
} nodes[I915_NUM_ENGINES];
/*
* Keep track of bonded pairs -- restrictions upon on our selection
* of physical engines any particular request may be submitted to.
* If we receive a submit-fence from a master engine, we will only
* use one of sibling_mask physical engines.
*/
struct ve_bond {
const struct intel_engine_cs *master;
intel_engine_mask_t sibling_mask;
} *bonds;
unsigned int num_bonds;
/* And finally, which physical engines this virtual engine maps onto. */
unsigned int num_siblings;
struct intel_engine_cs *siblings[0];
};
static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
{
GEM_BUG_ON(!intel_engine_is_virtual(engine));
return container_of(engine, struct virtual_engine, base);
}
static int __execlists_context_alloc(struct intel_context *ce,
struct intel_engine_cs *engine);
static void execlists_init_reg_state(u32 *reg_state,
struct intel_context *ce,
struct intel_engine_cs *engine,
struct intel_ring *ring);
static void mark_eio(struct i915_request *rq)
{
if (!i915_request_signaled(rq))
dma_fence_set_error(&rq->fence, -EIO);
i915_request_mark_complete(rq);
}
static inline u32 intel_hws_preempt_address(struct intel_engine_cs *engine)
{
return (i915_ggtt_offset(engine->status_page.vma) +
I915_GEM_HWS_PREEMPT_ADDR);
}
static inline void
ring_set_paused(const struct intel_engine_cs *engine, int state)
{
/*
* We inspect HWS_PREEMPT with a semaphore inside
* engine->emit_fini_breadcrumb. If the dword is true,
* the ring is paused as the semaphore will busywait
* until the dword is false.
*/
engine->status_page.addr[I915_GEM_HWS_PREEMPT] = state;
if (state)
wmb();
}
static inline struct i915_priolist *to_priolist(struct rb_node *rb)
{
return rb_entry(rb, struct i915_priolist, node);
}
static inline int rq_prio(const struct i915_request *rq)
{
return rq->sched.attr.priority;
}
static int effective_prio(const struct i915_request *rq)
{
int prio = rq_prio(rq);
/*
* If this request is special and must not be interrupted at any
* cost, so be it. Note we are only checking the most recent request
* in the context and so may be masking an earlier vip request. It
* is hoped that under the conditions where nopreempt is used, this
* will not matter (i.e. all requests to that context will be
* nopreempt for as long as desired).
*/
if (i915_request_has_nopreempt(rq))
prio = I915_PRIORITY_UNPREEMPTABLE;
/*
* On unwinding the active request, we give it a priority bump
* if it has completed waiting on any semaphore. If we know that
* the request has already started, we can prevent an unwanted
* preempt-to-idle cycle by taking that into account now.
*/
if (__i915_request_has_started(rq))
prio |= I915_PRIORITY_NOSEMAPHORE;
/* Restrict mere WAIT boosts from triggering preemption */
BUILD_BUG_ON(__NO_PREEMPTION & ~I915_PRIORITY_MASK); /* only internal */
return prio | __NO_PREEMPTION;
}
static int queue_prio(const struct intel_engine_execlists *execlists)
{
struct i915_priolist *p;
struct rb_node *rb;
rb = rb_first_cached(&execlists->queue);
if (!rb)
return INT_MIN;
/*
* As the priolist[] are inverted, with the highest priority in [0],
* we have to flip the index value to become priority.
*/
p = to_priolist(rb);
return ((p->priority + 1) << I915_USER_PRIORITY_SHIFT) - ffs(p->used);
}
static inline bool need_preempt(const struct intel_engine_cs *engine,
const struct i915_request *rq,
struct rb_node *rb)
{
int last_prio;
if (!intel_engine_has_semaphores(engine))
return false;
/*
* Check if the current priority hint merits a preemption attempt.
*
* We record the highest value priority we saw during rescheduling
* prior to this dequeue, therefore we know that if it is strictly
* less than the current tail of ESLP[0], we do not need to force
* a preempt-to-idle cycle.
*
* However, the priority hint is a mere hint that we may need to
* preempt. If that hint is stale or we may be trying to preempt
* ourselves, ignore the request.
*/
last_prio = effective_prio(rq);
if (!i915_scheduler_need_preempt(engine->execlists.queue_priority_hint,
last_prio))
return false;
/*
* Check against the first request in ELSP[1], it will, thanks to the
* power of PI, be the highest priority of that context.
*/
if (!list_is_last(&rq->sched.link, &engine->active.requests) &&
rq_prio(list_next_entry(rq, sched.link)) > last_prio)
return true;
if (rb) {
struct virtual_engine *ve =
rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
bool preempt = false;
if (engine == ve->siblings[0]) { /* only preempt one sibling */
struct i915_request *next;
rcu_read_lock();
next = READ_ONCE(ve->request);
if (next)
preempt = rq_prio(next) > last_prio;
rcu_read_unlock();
}
if (preempt)
return preempt;
}
/*
* If the inflight context did not trigger the preemption, then maybe
* it was the set of queued requests? Pick the highest priority in
* the queue (the first active priolist) and see if it deserves to be
* running instead of ELSP[0].
*
* The highest priority request in the queue can not be either
* ELSP[0] or ELSP[1] as, thanks again to PI, if it was the same
* context, it's priority would not exceed ELSP[0] aka last_prio.
*/
return queue_prio(&engine->execlists) > last_prio;
}
__maybe_unused static inline bool
assert_priority_queue(const struct i915_request *prev,
const struct i915_request *next)
{
/*
* Without preemption, the prev may refer to the still active element
* which we refuse to let go.
*
* Even with preemption, there are times when we think it is better not
* to preempt and leave an ostensibly lower priority request in flight.
*/
if (i915_request_is_active(prev))
return true;
return rq_prio(prev) >= rq_prio(next);
}
/*
* The context descriptor encodes various attributes of a context,
* including its GTT address and some flags. Because it's fairly
* expensive to calculate, we'll just do it once and cache the result,
* which remains valid until the context is unpinned.
*
* This is what a descriptor looks like, from LSB to MSB::
*
* bits 0-11: flags, GEN8_CTX_* (cached in ctx->desc_template)
* bits 12-31: LRCA, GTT address of (the HWSP of) this context
* bits 32-52: ctx ID, a globally unique tag (highest bit used by GuC)
* bits 53-54: mbz, reserved for use by hardware
* bits 55-63: group ID, currently unused and set to 0
*
* Starting from Gen11, the upper dword of the descriptor has a new format:
*
* bits 32-36: reserved
* bits 37-47: SW context ID
* bits 48:53: engine instance
* bit 54: mbz, reserved for use by hardware
* bits 55-60: SW counter
* bits 61-63: engine class
*
* engine info, SW context ID and SW counter need to form a unique number
* (Context ID) per lrc.
*/
static u64
lrc_descriptor(struct intel_context *ce, struct intel_engine_cs *engine)
{
struct i915_gem_context *ctx = ce->gem_context;
u64 desc;
BUILD_BUG_ON(MAX_CONTEXT_HW_ID > (BIT(GEN8_CTX_ID_WIDTH)));
BUILD_BUG_ON(GEN11_MAX_CONTEXT_HW_ID > (BIT(GEN11_SW_CTX_ID_WIDTH)));
desc = INTEL_LEGACY_32B_CONTEXT;
if (i915_vm_is_4lvl(ce->vm))
desc = INTEL_LEGACY_64B_CONTEXT;
desc <<= GEN8_CTX_ADDRESSING_MODE_SHIFT;
desc |= GEN8_CTX_VALID | GEN8_CTX_PRIVILEGE;
if (IS_GEN(engine->i915, 8))
desc |= GEN8_CTX_L3LLC_COHERENT;
desc |= i915_ggtt_offset(ce->state) + LRC_HEADER_PAGES * PAGE_SIZE;
/* bits 12-31 */
/*
* The following 32bits are copied into the OA reports (dword 2).
* Consider updating oa_get_render_ctx_id in i915_perf.c when changing
* anything below.
*/
if (INTEL_GEN(engine->i915) >= 11) {
GEM_BUG_ON(ctx->hw_id >= BIT(GEN11_SW_CTX_ID_WIDTH));
desc |= (u64)ctx->hw_id << GEN11_SW_CTX_ID_SHIFT;
/* bits 37-47 */
desc |= (u64)engine->instance << GEN11_ENGINE_INSTANCE_SHIFT;
/* bits 48-53 */
/* TODO: decide what to do with SW counter (bits 55-60) */
desc |= (u64)engine->class << GEN11_ENGINE_CLASS_SHIFT;
/* bits 61-63 */
} else {
GEM_BUG_ON(ctx->hw_id >= BIT(GEN8_CTX_ID_WIDTH));
desc |= (u64)ctx->hw_id << GEN8_CTX_ID_SHIFT; /* bits 32-52 */
}
return desc;
}
static void unwind_wa_tail(struct i915_request *rq)
{
rq->tail = intel_ring_wrap(rq->ring, rq->wa_tail - WA_TAIL_BYTES);
assert_ring_tail_valid(rq->ring, rq->tail);
}
static struct i915_request *
__unwind_incomplete_requests(struct intel_engine_cs *engine)
{
struct i915_request *rq, *rn, *active = NULL;
struct list_head *uninitialized_var(pl);
int prio = I915_PRIORITY_INVALID;
lockdep_assert_held(&engine->active.lock);
list_for_each_entry_safe_reverse(rq, rn,
&engine->active.requests,
sched.link) {
struct intel_engine_cs *owner;
if (i915_request_completed(rq))
continue; /* XXX */
__i915_request_unsubmit(rq);
unwind_wa_tail(rq);
/*
* Push the request back into the queue for later resubmission.
* If this request is not native to this physical engine (i.e.
* it came from a virtual source), push it back onto the virtual
* engine so that it can be moved across onto another physical
* engine as load dictates.
*/
owner = rq->hw_context->engine;
if (likely(owner == engine)) {
GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID);
if (rq_prio(rq) != prio) {
prio = rq_prio(rq);
pl = i915_sched_lookup_priolist(engine, prio);
}
GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
list_move(&rq->sched.link, pl);
active = rq;
} else {
/*
* Decouple the virtual breadcrumb before moving it
* back to the virtual engine -- we don't want the
* request to complete in the background and try
* and cancel the breadcrumb on the virtual engine
* (instead of the old engine where it is linked)!
*/
if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
&rq->fence.flags)) {
spin_lock(&rq->lock);
i915_request_cancel_breadcrumb(rq);
spin_unlock(&rq->lock);
}
rq->engine = owner;
owner->submit_request(rq);
active = NULL;
}
}
return active;
}
struct i915_request *
execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists)
{
struct intel_engine_cs *engine =
container_of(execlists, typeof(*engine), execlists);
return __unwind_incomplete_requests(engine);
}
static inline void
execlists_context_status_change(struct i915_request *rq, unsigned long status)
{
/*
* Only used when GVT-g is enabled now. When GVT-g is disabled,
* The compiler should eliminate this function as dead-code.
*/
if (!IS_ENABLED(CONFIG_DRM_I915_GVT))
return;
atomic_notifier_call_chain(&rq->engine->context_status_notifier,
status, rq);
}
static inline struct intel_engine_cs *
__execlists_schedule_in(struct i915_request *rq)
{
struct intel_engine_cs * const engine = rq->engine;
struct intel_context * const ce = rq->hw_context;
intel_context_get(ce);
intel_gt_pm_get(engine->gt);
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN);
intel_engine_context_in(engine);
return engine;
}
static inline struct i915_request *
execlists_schedule_in(struct i915_request *rq, int idx)
{
struct intel_context * const ce = rq->hw_context;
struct intel_engine_cs *old;
GEM_BUG_ON(!intel_engine_pm_is_awake(rq->engine));
trace_i915_request_in(rq, idx);
old = READ_ONCE(ce->inflight);
do {
if (!old) {
WRITE_ONCE(ce->inflight, __execlists_schedule_in(rq));
break;
}
} while (!try_cmpxchg(&ce->inflight, &old, ptr_inc(old)));
GEM_BUG_ON(intel_context_inflight(ce) != rq->engine);
return i915_request_get(rq);
}
static void kick_siblings(struct i915_request *rq, struct intel_context *ce)
{
struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
struct i915_request *next = READ_ONCE(ve->request);
if (next && next->execution_mask & ~rq->execution_mask)
tasklet_schedule(&ve->base.execlists.tasklet);
}
static inline void
__execlists_schedule_out(struct i915_request *rq,
struct intel_engine_cs * const engine)
{
struct intel_context * const ce = rq->hw_context;
intel_engine_context_out(engine);
execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_OUT);
intel_gt_pm_put(engine->gt);
/*
* If this is part of a virtual engine, its next request may
* have been blocked waiting for access to the active context.
* We have to kick all the siblings again in case we need to
* switch (e.g. the next request is not runnable on this
* engine). Hopefully, we will already have submitted the next
* request before the tasklet runs and do not need to rebuild
* each virtual tree and kick everyone again.
*/
if (ce->engine != engine)
kick_siblings(rq, ce);
intel_context_put(ce);
}
static inline void
execlists_schedule_out(struct i915_request *rq)
{
struct intel_context * const ce = rq->hw_context;
struct intel_engine_cs *cur, *old;
trace_i915_request_out(rq);
old = READ_ONCE(ce->inflight);
do
cur = ptr_unmask_bits(old, 2) ? ptr_dec(old) : NULL;
while (!try_cmpxchg(&ce->inflight, &old, cur));
if (!cur)
__execlists_schedule_out(rq, old);
i915_request_put(rq);
}
static u64 execlists_update_context(const struct i915_request *rq)
{
struct intel_context *ce = rq->hw_context;
u64 desc;
ce->lrc_reg_state[CTX_RING_TAIL + 1] =
intel_ring_set_tail(rq->ring, rq->tail);
/*
* Make sure the context image is complete before we submit it to HW.
*
* Ostensibly, writes (including the WCB) should be flushed prior to
* an uncached write such as our mmio register access, the empirical
* evidence (esp. on Braswell) suggests that the WC write into memory
* may not be visible to the HW prior to the completion of the UC
* register write and that we may begin execution from the context
* before its image is complete leading to invalid PD chasing.
*
* Furthermore, Braswell, at least, wants a full mb to be sure that
* the writes are coherent in memory (visible to the GPU) prior to
* execution, and not just visible to other CPUs (as is the result of
* wmb).
*/
mb();
desc = ce->lrc_desc;
ce->lrc_desc &= ~CTX_DESC_FORCE_RESTORE;
return desc;
}
static inline void write_desc(struct intel_engine_execlists *execlists, u64 desc, u32 port)
{
if (execlists->ctrl_reg) {
writel(lower_32_bits(desc), execlists->submit_reg + port * 2);
writel(upper_32_bits(desc), execlists->submit_reg + port * 2 + 1);
} else {
writel(upper_32_bits(desc), execlists->submit_reg);
writel(lower_32_bits(desc), execlists->submit_reg);
}
}
static __maybe_unused void
trace_ports(const struct intel_engine_execlists *execlists,
const char *msg,
struct i915_request * const *ports)
{
const struct intel_engine_cs *engine =
container_of(execlists, typeof(*engine), execlists);
GEM_TRACE("%s: %s { %llx:%lld%s, %llx:%lld }\n",
engine->name, msg,
ports[0]->fence.context,
ports[0]->fence.seqno,
i915_request_completed(ports[0]) ? "!" :
i915_request_started(ports[0]) ? "*" :
"",
ports[1] ? ports[1]->fence.context : 0,
ports[1] ? ports[1]->fence.seqno : 0);
}
static __maybe_unused bool
assert_pending_valid(const struct intel_engine_execlists *execlists,
const char *msg)
{
struct i915_request * const *port, *rq;
struct intel_context *ce = NULL;
trace_ports(execlists, msg, execlists->pending);
if (!execlists->pending[0])
return false;
if (execlists->pending[execlists_num_ports(execlists)])
return false;
for (port = execlists->pending; (rq = *port); port++) {
if (ce == rq->hw_context)
return false;
ce = rq->hw_context;
if (i915_request_completed(rq))
continue;
if (i915_active_is_idle(&ce->active))
return false;
if (!i915_vma_is_pinned(ce->state))
return false;
}
return ce;
}
static void execlists_submit_ports(struct intel_engine_cs *engine)
{
struct intel_engine_execlists *execlists = &engine->execlists;
unsigned int n;
GEM_BUG_ON(!assert_pending_valid(execlists, "submit"));
/*
* We can skip acquiring intel_runtime_pm_get() here as it was taken
* on our behalf by the request (see i915_gem_mark_busy()) and it will
* not be relinquished until the device is idle (see
* i915_gem_idle_work_handler()). As a precaution, we make sure
* that all ELSP are drained i.e. we have processed the CSB,
* before allowing ourselves to idle and calling intel_runtime_pm_put().
*/
GEM_BUG_ON(!intel_engine_pm_is_awake(engine));
/*
* ELSQ note: the submit queue is not cleared after being submitted
* to the HW so we need to make sure we always clean it up. This is
* currently ensured by the fact that we always write the same number
* of elsq entries, keep this in mind before changing the loop below.
*/
for (n = execlists_num_ports(execlists); n--; ) {
struct i915_request *rq = execlists->pending[n];
write_desc(execlists,
rq ? execlists_update_context(rq) : 0,
n);
}
/* we need to manually load the submit queue */
if (execlists->ctrl_reg)
writel(EL_CTRL_LOAD, execlists->ctrl_reg);
}
static bool ctx_single_port_submission(const struct intel_context *ce)
{
return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
i915_gem_context_force_single_submission(ce->gem_context));
}
static bool can_merge_ctx(const struct intel_context *prev,
const struct intel_context *next)
{
if (prev != next)
return false;
if (ctx_single_port_submission(prev))
return false;
return true;
}
static bool can_merge_rq(const struct i915_request *prev,
const struct i915_request *next)
{
GEM_BUG_ON(prev == next);
GEM_BUG_ON(!assert_priority_queue(prev, next));
/*
* We do not submit known completed requests. Therefore if the next
* request is already completed, we can pretend to merge it in
* with the previous context (and we will skip updating the ELSP
* and tracking). Thus hopefully keeping the ELSP full with active
* contexts, despite the best efforts of preempt-to-busy to confuse
* us.
*/
if (i915_request_completed(next))
return true;
if (!can_merge_ctx(prev->hw_context, next->hw_context))
return false;
return true;
}
static void virtual_update_register_offsets(u32 *regs,
struct intel_engine_cs *engine)
{
u32 base = engine->mmio_base;
/* Must match execlists_init_reg_state()! */
regs[CTX_CONTEXT_CONTROL] =
i915_mmio_reg_offset(RING_CONTEXT_CONTROL(base));
regs[CTX_RING_HEAD] = i915_mmio_reg_offset(RING_HEAD(base));
regs[CTX_RING_TAIL] = i915_mmio_reg_offset(RING_TAIL(base));
regs[CTX_RING_BUFFER_START] = i915_mmio_reg_offset(RING_START(base));
regs[CTX_RING_BUFFER_CONTROL] = i915_mmio_reg_offset(RING_CTL(base));
regs[CTX_BB_HEAD_U] = i915_mmio_reg_offset(RING_BBADDR_UDW(base));
regs[CTX_BB_HEAD_L] = i915_mmio_reg_offset(RING_BBADDR(base));
regs[CTX_BB_STATE] = i915_mmio_reg_offset(RING_BBSTATE(base));
regs[CTX_SECOND_BB_HEAD_U] =
i915_mmio_reg_offset(RING_SBBADDR_UDW(base));
regs[CTX_SECOND_BB_HEAD_L] = i915_mmio_reg_offset(RING_SBBADDR(base));
regs[CTX_SECOND_BB_STATE] = i915_mmio_reg_offset(RING_SBBSTATE(base));
regs[CTX_CTX_TIMESTAMP] =
i915_mmio_reg_offset(RING_CTX_TIMESTAMP(base));
regs[CTX_PDP3_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 3));
regs[CTX_PDP3_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 3));
regs[CTX_PDP2_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 2));
regs[CTX_PDP2_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 2));
regs[CTX_PDP1_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 1));
regs[CTX_PDP1_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 1));
regs[CTX_PDP0_UDW] = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, 0));
regs[CTX_PDP0_LDW] = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, 0));
if (engine->class == RENDER_CLASS) {
regs[CTX_RCS_INDIRECT_CTX] =
i915_mmio_reg_offset(RING_INDIRECT_CTX(base));
regs[CTX_RCS_INDIRECT_CTX_OFFSET] =
i915_mmio_reg_offset(RING_INDIRECT_CTX_OFFSET(base));
regs[CTX_BB_PER_CTX_PTR] =
i915_mmio_reg_offset(RING_BB_PER_CTX_PTR(base));
regs[CTX_R_PWR_CLK_STATE] =
i915_mmio_reg_offset(GEN8_R_PWR_CLK_STATE);
}
}
static bool virtual_matches(const struct virtual_engine *ve,
const struct i915_request *rq,
const struct intel_engine_cs *engine)
{
const struct intel_engine_cs *inflight;
if (!(rq->execution_mask & engine->mask)) /* We peeked too soon! */
return false;
/*
* We track when the HW has completed saving the context image
* (i.e. when we have seen the final CS event switching out of
* the context) and must not overwrite the context image before
* then. This restricts us to only using the active engine
* while the previous virtualized request is inflight (so
* we reuse the register offsets). This is a very small
* hystersis on the greedy seelction algorithm.
*/
inflight = intel_context_inflight(&ve->context);
if (inflight && inflight != engine)
return false;
return true;
}
static void virtual_xfer_breadcrumbs(struct virtual_engine *ve,
struct intel_engine_cs *engine)
{
struct intel_engine_cs *old = ve->siblings[0];
/* All unattached (rq->engine == old) must already be completed */
spin_lock(&old->breadcrumbs.irq_lock);
if (!list_empty(&ve->context.signal_link)) {
list_move_tail(&ve->context.signal_link,
&engine->breadcrumbs.signalers);
intel_engine_queue_breadcrumbs(engine);
}
spin_unlock(&old->breadcrumbs.irq_lock);
}
static struct i915_request *
last_active(const struct intel_engine_execlists *execlists)
{
struct i915_request * const *last = READ_ONCE(execlists->active);
while (*last && i915_request_completed(*last))
last++;
return *last;
}
static void defer_request(struct i915_request *rq, struct list_head * const pl)
{
LIST_HEAD(list);
/*
* We want to move the interrupted request to the back of
* the round-robin list (i.e. its priority level), but
* in doing so, we must then move all requests that were in
* flight and were waiting for the interrupted request to
* be run after it again.
*/
do {
struct i915_dependency *p;
GEM_BUG_ON(i915_request_is_active(rq));
list_move_tail(&rq->sched.link, pl);
list_for_each_entry(p, &rq->sched.waiters_list, wait_link) {
struct i915_request *w =
container_of(p->waiter, typeof(*w), sched);
/* Leave semaphores spinning on the other engines */
if (w->engine != rq->engine)
continue;
/* No waiter should start before its signaler */
GEM_BUG_ON(i915_request_started(w) &&
!i915_request_completed(rq));
GEM_BUG_ON(i915_request_is_active(w));
if (list_empty(&w->sched.link))
continue; /* Not yet submitted; unready */
if (rq_prio(w) < rq_prio(rq))
continue;
GEM_BUG_ON(rq_prio(w) > rq_prio(rq));
list_move_tail(&w->sched.link, &list);
}
rq = list_first_entry_or_null(&list, typeof(*rq), sched.link);
} while (rq);
}
static void defer_active(struct intel_engine_cs *engine)
{
struct i915_request *rq;
rq = __unwind_incomplete_requests(engine);
if (!rq)
return;
defer_request(rq, i915_sched_lookup_priolist(engine, rq_prio(rq)));
}
static bool
need_timeslice(struct intel_engine_cs *engine, const struct i915_request *rq)
{
int hint;
if (!intel_engine_has_semaphores(engine))
return false;
if (list_is_last(&rq->sched.link, &engine->active.requests))
return false;
hint = max(rq_prio(list_next_entry(rq, sched.link)),
engine->execlists.queue_priority_hint);
return hint >= effective_prio(rq);
}
static int
switch_prio(struct intel_engine_cs *engine, const struct i915_request *rq)
{
if (list_is_last(&rq->sched.link, &engine->active.requests))
return INT_MIN;
return rq_prio(list_next_entry(rq, sched.link));
}
static bool
enable_timeslice(const struct intel_engine_execlists *execlists)
{
const struct i915_request *rq = *execlists->active;
if (i915_request_completed(rq))
return false;
return execlists->switch_priority_hint >= effective_prio(rq);
}
static void record_preemption(struct intel_engine_execlists *execlists)
{
(void)I915_SELFTEST_ONLY(execlists->preempt_hang.count++);
}
static void execlists_dequeue(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
struct i915_request **port = execlists->pending;
struct i915_request ** const last_port = port + execlists->port_mask;
struct i915_request *last;
struct rb_node *rb;
bool submit = false;
/*
* Hardware submission is through 2 ports. Conceptually each port
* has a (RING_START, RING_HEAD, RING_TAIL) tuple. RING_START is
* static for a context, and unique to each, so we only execute
* requests belonging to a single context from each ring. RING_HEAD
* is maintained by the CS in the context image, it marks the place
* where it got up to last time, and through RING_TAIL we tell the CS
* where we want to execute up to this time.
*
* In this list the requests are in order of execution. Consecutive
* requests from the same context are adjacent in the ringbuffer. We
* can combine these requests into a single RING_TAIL update:
*
* RING_HEAD...req1...req2
* ^- RING_TAIL
* since to execute req2 the CS must first execute req1.
*
* Our goal then is to point each port to the end of a consecutive
* sequence of requests as being the most optimal (fewest wake ups
* and context switches) submission.
*/
for (rb = rb_first_cached(&execlists->virtual); rb; ) {
struct virtual_engine *ve =
rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
struct i915_request *rq = READ_ONCE(ve->request);
if (!rq) { /* lazily cleanup after another engine handled rq */
rb_erase_cached(rb, &execlists->virtual);
RB_CLEAR_NODE(rb);
rb = rb_first_cached(&execlists->virtual);
continue;
}
if (!virtual_matches(ve, rq, engine)) {
rb = rb_next(rb);
continue;
}
break;
}
/*
* If the queue is higher priority than the last
* request in the currently active context, submit afresh.
* We will resubmit again afterwards in case we need to split
* the active context to interject the preemption request,
* i.e. we will retrigger preemption following the ack in case
* of trouble.
*/
last = last_active(execlists);
if (last) {
if (need_preempt(engine, last, rb)) {
GEM_TRACE("%s: preempting last=%llx:%lld, prio=%d, hint=%d\n",
engine->name,
last->fence.context,
last->fence.seqno,
last->sched.attr.priority,
execlists->queue_priority_hint);
record_preemption(execlists);
/*
* Don't let the RING_HEAD advance past the breadcrumb
* as we unwind (and until we resubmit) so that we do
* not accidentally tell it to go backwards.
*/
ring_set_paused(engine, 1);
/*
* Note that we have not stopped the GPU at this point,
* so we are unwinding the incomplete requests as they
* remain inflight and so by the time we do complete
* the preemption, some of the unwound requests may
* complete!
*/
__unwind_incomplete_requests(engine);
/*
* If we need to return to the preempted context, we
* need to skip the lite-restore and force it to
* reload the RING_TAIL. Otherwise, the HW has a
* tendency to ignore us rewinding the TAIL to the
* end of an earlier request.
*/
last->hw_context->lrc_desc |= CTX_DESC_FORCE_RESTORE;
last = NULL;
} else if (need_timeslice(engine, last) &&
!timer_pending(&engine->execlists.timer)) {
GEM_TRACE("%s: expired last=%llx:%lld, prio=%d, hint=%d\n",
engine->name,
last->fence.context,
last->fence.seqno,
last->sched.attr.priority,
execlists->queue_priority_hint);
ring_set_paused(engine, 1);
defer_active(engine);
/*
* Unlike for preemption, if we rewind and continue
* executing the same context as previously active,
* the order of execution will remain the same and
* the tail will only advance. We do not need to
* force a full context restore, as a lite-restore
* is sufficient to resample the monotonic TAIL.
*
* If we switch to any other context, similarly we
* will not rewind TAIL of current context, and
* normal save/restore will preserve state and allow
* us to later continue executing the same request.
*/
last = NULL;
} else {
/*
* Otherwise if we already have a request pending
* for execution after the current one, we can
* just wait until the next CS event before
* queuing more. In either case we will force a
* lite-restore preemption event, but if we wait
* we hopefully coalesce several updates into a single
* submission.
*/
if (!list_is_last(&last->sched.link,
&engine->active.requests))
return;
/*
* WaIdleLiteRestore:bdw,skl
* Apply the wa NOOPs to prevent
* ring:HEAD == rq:TAIL as we resubmit the
* request. See gen8_emit_fini_breadcrumb() for
* where we prepare the padding after the
* end of the request.
*/
last->tail = last->wa_tail;
}
}
while (rb) { /* XXX virtual is always taking precedence */
struct virtual_engine *ve =
rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
struct i915_request *rq;
spin_lock(&ve->base.active.lock);
rq = ve->request;
if (unlikely(!rq)) { /* lost the race to a sibling */
spin_unlock(&ve->base.active.lock);
rb_erase_cached(rb, &execlists->virtual);
RB_CLEAR_NODE(rb);
rb = rb_first_cached(&execlists->virtual);
continue;
}
GEM_BUG_ON(rq != ve->request);
GEM_BUG_ON(rq->engine != &ve->base);
GEM_BUG_ON(rq->hw_context != &ve->context);
if (rq_prio(rq) >= queue_prio(execlists)) {
if (!virtual_matches(ve, rq, engine)) {
spin_unlock(&ve->base.active.lock);
rb = rb_next(rb);
continue;
}
if (last && !can_merge_rq(last, rq)) {
spin_unlock(&ve->base.active.lock);
return; /* leave this for another */
}
GEM_TRACE("%s: virtual rq=%llx:%lld%s, new engine? %s\n",
engine->name,
rq->fence.context,
rq->fence.seqno,
i915_request_completed(rq) ? "!" :
i915_request_started(rq) ? "*" :
"",
yesno(engine != ve->siblings[0]));
ve->request = NULL;
ve->base.execlists.queue_priority_hint = INT_MIN;
rb_erase_cached(rb, &execlists->virtual);
RB_CLEAR_NODE(rb);
GEM_BUG_ON(!(rq->execution_mask & engine->mask));
rq->engine = engine;
if (engine != ve->siblings[0]) {
u32 *regs = ve->context.lrc_reg_state;
unsigned int n;
GEM_BUG_ON(READ_ONCE(ve->context.inflight));
virtual_update_register_offsets(regs, engine);
if (!list_empty(&ve->context.signals))
virtual_xfer_breadcrumbs(ve, engine);
/*
* Move the bound engine to the top of the list
* for future execution. We then kick this
* tasklet first before checking others, so that
* we preferentially reuse this set of bound
* registers.
*/
for (n = 1; n < ve->num_siblings; n++) {
if (ve->siblings[n] == engine) {
swap(ve->siblings[n],
ve->siblings[0]);
break;
}
}
GEM_BUG_ON(ve->siblings[0] != engine);
}
if (__i915_request_submit(rq)) {
submit = true;
last = rq;
}
i915_request_put(rq);
/*
* Hmm, we have a bunch of virtual engine requests,
* but the first one was already completed (thanks
* preempt-to-busy!). Keep looking at the veng queue
* until we have no more relevant requests (i.e.
* the normal submit queue has higher priority).
*/
if (!submit) {
spin_unlock(&ve->base.active.lock);
rb = rb_first_cached(&execlists->virtual);
continue;
}
}
spin_unlock(&ve->base.active.lock);
break;
}
while ((rb = rb_first_cached(&execlists->queue))) {
struct i915_priolist *p = to_priolist(rb);
struct i915_request *rq, *rn;
int i;
priolist_for_each_request_consume(rq, rn, p, i) {
bool merge = true;
/*
* Can we combine this request with the current port?
* It has to be the same context/ringbuffer and not
* have any exceptions (e.g. GVT saying never to
* combine contexts).
*
* If we can combine the requests, we can execute both
* by updating the RING_TAIL to point to the end of the
* second request, and so we never need to tell the
* hardware about the first.
*/
if (last && !can_merge_rq(last, rq)) {
/*
* If we are on the second port and cannot
* combine this request with the last, then we
* are done.
*/
if (port == last_port)
goto done;
/*
* We must not populate both ELSP[] with the
* same LRCA, i.e. we must submit 2 different
* contexts if we submit 2 ELSP.
*/
if (last->hw_context == rq->hw_context)
goto done;
/*
* If GVT overrides us we only ever submit
* port[0], leaving port[1] empty. Note that we
* also have to be careful that we don't queue
* the same context (even though a different
* request) to the second port.
*/
if (ctx_single_port_submission(last->hw_context) ||
ctx_single_port_submission(rq->hw_context))
goto done;
merge = false;
}
if (__i915_request_submit(rq)) {
if (!merge) {
*port = execlists_schedule_in(last, port - execlists->pending);
port++;
last = NULL;
}
GEM_BUG_ON(last &&
!can_merge_ctx(last->hw_context,
rq->hw_context));
submit = true;
last = rq;
}
}
rb_erase_cached(&p->node, &execlists->queue);
i915_priolist_free(p);
}
done:
/*
* Here be a bit of magic! Or sleight-of-hand, whichever you prefer.
*
* We choose the priority hint such that if we add a request of greater
* priority than this, we kick the submission tasklet to decide on
* the right order of submitting the requests to hardware. We must
* also be prepared to reorder requests as they are in-flight on the
* HW. We derive the priority hint then as the first "hole" in
* the HW submission ports and if there are no available slots,
* the priority of the lowest executing request, i.e. last.
*
* When we do receive a higher priority request ready to run from the
* user, see queue_request(), the priority hint is bumped to that
* request triggering preemption on the next dequeue (or subsequent
* interrupt for secondary ports).
*/
execlists->queue_priority_hint = queue_prio(execlists);
GEM_TRACE("%s: queue_priority_hint:%d, submit:%s\n",
engine->name, execlists->queue_priority_hint,
yesno(submit));
if (submit) {
*port = execlists_schedule_in(last, port - execlists->pending);
memset(port + 1, 0, (last_port - port) * sizeof(*port));
execlists->switch_priority_hint =
switch_prio(engine, *execlists->pending);
execlists_submit_ports(engine);
} else {
ring_set_paused(engine, 0);
}
}
static void
cancel_port_requests(struct intel_engine_execlists * const execlists)
{
struct i915_request * const *port, *rq;
for (port = execlists->pending; (rq = *port); port++)
execlists_schedule_out(rq);
memset(execlists->pending, 0, sizeof(execlists->pending));
for (port = execlists->active; (rq = *port); port++)
execlists_schedule_out(rq);
execlists->active =
memset(execlists->inflight, 0, sizeof(execlists->inflight));
}
static inline void
invalidate_csb_entries(const u32 *first, const u32 *last)
{
clflush((void *)first);
clflush((void *)last);
}
static inline bool
reset_in_progress(const struct intel_engine_execlists *execlists)
{
return unlikely(!__tasklet_is_enabled(&execlists->tasklet));
}
enum csb_step {
CSB_NOP,
CSB_PROMOTE,
CSB_PREEMPT,
CSB_COMPLETE,
};
/*
* Starting with Gen12, the status has a new format:
*
* bit 0: switched to new queue
* bit 1: reserved
* bit 2: semaphore wait mode (poll or signal), only valid when
* switch detail is set to "wait on semaphore"
* bits 3-5: engine class
* bits 6-11: engine instance
* bits 12-14: reserved
* bits 15-25: sw context id of the lrc the GT switched to
* bits 26-31: sw counter of the lrc the GT switched to
* bits 32-35: context switch detail
* - 0: ctx complete
* - 1: wait on sync flip
* - 2: wait on vblank
* - 3: wait on scanline
* - 4: wait on semaphore
* - 5: context preempted (not on SEMAPHORE_WAIT or
* WAIT_FOR_EVENT)
* bit 36: reserved
* bits 37-43: wait detail (for switch detail 1 to 4)
* bits 44-46: reserved
* bits 47-57: sw context id of the lrc the GT switched away from
* bits 58-63: sw counter of the lrc the GT switched away from
*/
static inline enum csb_step
gen12_csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb)
{
u32 lower_dw = csb[0];
u32 upper_dw = csb[1];
bool ctx_to_valid = GEN12_CSB_CTX_VALID(lower_dw);
bool ctx_away_valid = GEN12_CSB_CTX_VALID(upper_dw);
bool new_queue = lower_dw & GEN12_CTX_STATUS_SWITCHED_TO_NEW_QUEUE;
if (!ctx_away_valid && ctx_to_valid)
return CSB_PROMOTE;
/*
* The context switch detail is not guaranteed to be 5 when a preemption
* occurs, so we can't just check for that. The check below works for
* all the cases we care about, including preemptions of WAIT
* instructions and lite-restore. Preempt-to-idle via the CTRL register
* would require some extra handling, but we don't support that.
*/
if (new_queue && ctx_away_valid)
return CSB_PREEMPT;
/*
* switch detail = 5 is covered by the case above and we do not expect a
* context switch on an unsuccessful wait instruction since we always
* use polling mode.
*/
GEM_BUG_ON(GEN12_CTX_SWITCH_DETAIL(upper_dw));
if (*execlists->active) {
GEM_BUG_ON(!ctx_away_valid);
return CSB_COMPLETE;
}
return CSB_NOP;
}
static inline enum csb_step
gen8_csb_parse(const struct intel_engine_execlists *execlists, const u32 *csb)
{
unsigned int status = *csb;
if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
return CSB_PROMOTE;
if (status & GEN8_CTX_STATUS_PREEMPTED)
return CSB_PREEMPT;
if (*execlists->active)
return CSB_COMPLETE;
return CSB_NOP;
}
static void process_csb(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
const u32 * const buf = execlists->csb_status;
const u8 num_entries = execlists->csb_size;
u8 head, tail;
GEM_BUG_ON(USES_GUC_SUBMISSION(engine->i915));
/*
* Note that csb_write, csb_status may be either in HWSP or mmio.
* When reading from the csb_write mmio register, we have to be
* careful to only use the GEN8_CSB_WRITE_PTR portion, which is
* the low 4bits. As it happens we know the next 4bits are always
* zero and so we can simply masked off the low u8 of the register
* and treat it identically to reading from the HWSP (without having
* to use explicit shifting and masking, and probably bifurcating
* the code to handle the legacy mmio read).
*/
head = execlists->csb_head;
tail = READ_ONCE(*execlists->csb_write);
GEM_TRACE("%s cs-irq head=%d, tail=%d\n", engine->name, head, tail);
if (unlikely(head == tail))
return;
/*
* Hopefully paired with a wmb() in HW!
*
* We must complete the read of the write pointer before any reads
* from the CSB, so that we do not see stale values. Without an rmb
* (lfence) the HW may speculatively perform the CSB[] reads *before*
* we perform the READ_ONCE(*csb_write).
*/
rmb();
do {
enum csb_step csb_step;
if (++head == num_entries)
head = 0;
/*
* We are flying near dragons again.
*
* We hold a reference to the request in execlist_port[]
* but no more than that. We are operating in softirq
* context and so cannot hold any mutex or sleep. That
* prevents us stopping the requests we are processing
* in port[] from being retired simultaneously (the
* breadcrumb will be complete before we see the
* context-switch). As we only hold the reference to the
* request, any pointer chasing underneath the request
* is subject to a potential use-after-free. Thus we
* store all of the bookkeeping within port[] as
* required, and avoid using unguarded pointers beneath
* request itself. The same applies to the atomic
* status notifier.
*/
GEM_TRACE("%s csb[%d]: status=0x%08x:0x%08x\n",
engine->name, head,
buf[2 * head + 0], buf[2 * head + 1]);
if (INTEL_GEN(engine->i915) >= 12)
csb_step = gen12_csb_parse(execlists, buf + 2 * head);
else
csb_step = gen8_csb_parse(execlists, buf + 2 * head);
switch (csb_step) {
case CSB_PREEMPT: /* cancel old inflight, prepare for switch */
trace_ports(execlists, "preempted", execlists->active);
while (*execlists->active)
execlists_schedule_out(*execlists->active++);
/* fallthrough */
case CSB_PROMOTE: /* switch pending to inflight */
GEM_BUG_ON(*execlists->active);
GEM_BUG_ON(!assert_pending_valid(execlists, "promote"));
execlists->active =
memcpy(execlists->inflight,
execlists->pending,
execlists_num_ports(execlists) *
sizeof(*execlists->pending));
if (enable_timeslice(execlists))
mod_timer(&execlists->timer, jiffies + 1);
if (!inject_preempt_hang(execlists))
ring_set_paused(engine, 0);
WRITE_ONCE(execlists->pending[0], NULL);
break;
case CSB_COMPLETE: /* port0 completed, advanced to port1 */
trace_ports(execlists, "completed", execlists->active);
/*
* We rely on the hardware being strongly
* ordered, that the breadcrumb write is
* coherent (visible from the CPU) before the
* user interrupt and CSB is processed.
*/
GEM_BUG_ON(!i915_request_completed(*execlists->active) &&
!reset_in_progress(execlists));
execlists_schedule_out(*execlists->active++);
GEM_BUG_ON(execlists->active - execlists->inflight >
execlists_num_ports(execlists));
break;
case CSB_NOP:
break;
}
} while (head != tail);
execlists->csb_head = head;
/*
* Gen11 has proven to fail wrt global observation point between
* entry and tail update, failing on the ordering and thus
* we see an old entry in the context status buffer.
*
* Forcibly evict out entries for the next gpu csb update,
* to increase the odds that we get a fresh entries with non
* working hardware. The cost for doing so comes out mostly with
* the wash as hardware, working or not, will need to do the
* invalidation before.
*/
invalidate_csb_entries(&buf[0], &buf[num_entries - 1]);
}
static void __execlists_submission_tasklet(struct intel_engine_cs *const engine)
{
lockdep_assert_held(&engine->active.lock);
if (!engine->execlists.pending[0]) {
rcu_read_lock(); /* protect peeking at execlists->active */
execlists_dequeue(engine);
rcu_read_unlock();
}
}
/*
* Check the unread Context Status Buffers and manage the submission of new
* contexts to the ELSP accordingly.
*/
static void execlists_submission_tasklet(unsigned long data)
{
struct intel_engine_cs * const engine = (struct intel_engine_cs *)data;
unsigned long flags;
process_csb(engine);
if (!READ_ONCE(engine->execlists.pending[0])) {
spin_lock_irqsave(&engine->active.lock, flags);
__execlists_submission_tasklet(engine);
spin_unlock_irqrestore(&engine->active.lock, flags);
}
}
static void execlists_submission_timer(struct timer_list *timer)
{
struct intel_engine_cs *engine =
from_timer(engine, timer, execlists.timer);
/* Kick the tasklet for some interrupt coalescing and reset handling */
tasklet_hi_schedule(&engine->execlists.tasklet);
}
static void queue_request(struct intel_engine_cs *engine,
struct i915_sched_node *node,
int prio)
{
GEM_BUG_ON(!list_empty(&node->link));
list_add_tail(&node->link, i915_sched_lookup_priolist(engine, prio));
}
static void __submit_queue_imm(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
if (reset_in_progress(execlists))
return; /* defer until we restart the engine following reset */
if (execlists->tasklet.func == execlists_submission_tasklet)
__execlists_submission_tasklet(engine);
else
tasklet_hi_schedule(&execlists->tasklet);
}
static void submit_queue(struct intel_engine_cs *engine,
const struct i915_request *rq)
{
struct intel_engine_execlists *execlists = &engine->execlists;
if (rq_prio(rq) <= execlists->queue_priority_hint)
return;
execlists->queue_priority_hint = rq_prio(rq);
__submit_queue_imm(engine);
}
static void execlists_submit_request(struct i915_request *request)
{
struct intel_engine_cs *engine = request->engine;
unsigned long flags;
/* Will be called from irq-context when using foreign fences. */
spin_lock_irqsave(&engine->active.lock, flags);
queue_request(engine, &request->sched, rq_prio(request));
GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
GEM_BUG_ON(list_empty(&request->sched.link));
submit_queue(engine, request);
spin_unlock_irqrestore(&engine->active.lock, flags);
}
static void __execlists_context_fini(struct intel_context *ce)
{
intel_ring_put(ce->ring);
i915_vma_put(ce->state);
}
static void execlists_context_destroy(struct kref *kref)
{
struct intel_context *ce = container_of(kref, typeof(*ce), ref);
GEM_BUG_ON(!i915_active_is_idle(&ce->active));
GEM_BUG_ON(intel_context_is_pinned(ce));
if (ce->state)
__execlists_context_fini(ce);
intel_context_fini(ce);
intel_context_free(ce);
}
static void
set_redzone(void *vaddr, const struct intel_engine_cs *engine)
{
if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
return;
vaddr += LRC_HEADER_PAGES * PAGE_SIZE;
vaddr += engine->context_size;
memset(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE);
}
static void
check_redzone(const void *vaddr, const struct intel_engine_cs *engine)
{
if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
return;
vaddr += LRC_HEADER_PAGES * PAGE_SIZE;
vaddr += engine->context_size;
if (memchr_inv(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE))
dev_err_once(engine->i915->drm.dev,
"%s context redzone overwritten!\n",
engine->name);
}
static void execlists_context_unpin(struct intel_context *ce)
{
check_redzone((void *)ce->lrc_reg_state - LRC_STATE_PN * PAGE_SIZE,
ce->engine);
i915_gem_context_unpin_hw_id(ce->gem_context);
i915_gem_object_unpin_map(ce->state->obj);
intel_ring_reset(ce->ring, ce->ring->tail);
}
static void
__execlists_update_reg_state(struct intel_context *ce,
struct intel_engine_cs *engine)
{
struct intel_ring *ring = ce->ring;
u32 *regs = ce->lrc_reg_state;
GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->head));
GEM_BUG_ON(!intel_ring_offset_valid(ring, ring->tail));
regs[CTX_RING_BUFFER_START + 1] = i915_ggtt_offset(ring->vma);
regs[CTX_RING_HEAD + 1] = ring->head;
regs[CTX_RING_TAIL + 1] = ring->tail;
/* RPCS */
if (engine->class == RENDER_CLASS) {
regs[CTX_R_PWR_CLK_STATE + 1] =
intel_sseu_make_rpcs(engine->i915, &ce->sseu);
i915_oa_init_reg_state(engine, ce, regs);
}
}
static int
__execlists_context_pin(struct intel_context *ce,
struct intel_engine_cs *engine)
{
void *vaddr;
int ret;
GEM_BUG_ON(!ce->state);
ret = intel_context_active_acquire(ce);
if (ret)
goto err;
GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
vaddr = i915_gem_object_pin_map(ce->state->obj,
i915_coherent_map_type(engine->i915) |
I915_MAP_OVERRIDE);
if (IS_ERR(vaddr)) {
ret = PTR_ERR(vaddr);
goto unpin_active;
}
ret = i915_gem_context_pin_hw_id(ce->gem_context);
if (ret)
goto unpin_map;
ce->lrc_desc = lrc_descriptor(ce, engine);
ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE;
__execlists_update_reg_state(ce, engine);
return 0;
unpin_map:
i915_gem_object_unpin_map(ce->state->obj);
unpin_active:
intel_context_active_release(ce);
err:
return ret;
}
static int execlists_context_pin(struct intel_context *ce)
{
return __execlists_context_pin(ce, ce->engine);
}
static int execlists_context_alloc(struct intel_context *ce)
{
return __execlists_context_alloc(ce, ce->engine);
}
static void execlists_context_reset(struct intel_context *ce)
{
/*
* Because we emit WA_TAIL_DWORDS there may be a disparity
* between our bookkeeping in ce->ring->head and ce->ring->tail and
* that stored in context. As we only write new commands from
* ce->ring->tail onwards, everything before that is junk. If the GPU
* starts reading from its RING_HEAD from the context, it may try to
* execute that junk and die.
*
* The contexts that are stilled pinned on resume belong to the
* kernel, and are local to each engine. All other contexts will
* have their head/tail sanitized upon pinning before use, so they
* will never see garbage,
*
* So to avoid that we reset the context images upon resume. For
* simplicity, we just zero everything out.
*/
intel_ring_reset(ce->ring, 0);
__execlists_update_reg_state(ce, ce->engine);
}
static const struct intel_context_ops execlists_context_ops = {
.alloc = execlists_context_alloc,
.pin = execlists_context_pin,
.unpin = execlists_context_unpin,
.enter = intel_context_enter_engine,
.exit = intel_context_exit_engine,
.reset = execlists_context_reset,
.destroy = execlists_context_destroy,
};
static int gen8_emit_init_breadcrumb(struct i915_request *rq)
{
u32 *cs;
GEM_BUG_ON(!rq->timeline->has_initial_breadcrumb);
cs = intel_ring_begin(rq, 6);
if (IS_ERR(cs))
return PTR_ERR(cs);
/*
* Check if we have been preempted before we even get started.
*
* After this point i915_request_started() reports true, even if
* we get preempted and so are no longer running.
*/
*cs++ = MI_ARB_CHECK;
*cs++ = MI_NOOP;
*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
*cs++ = rq->timeline->hwsp_offset;
*cs++ = 0;
*cs++ = rq->fence.seqno - 1;
intel_ring_advance(rq, cs);
/* Record the updated position of the request's payload */
rq->infix = intel_ring_offset(rq, cs);
return 0;
}
static int emit_pdps(struct i915_request *rq)
{
const struct intel_engine_cs * const engine = rq->engine;
struct i915_ppgtt * const ppgtt = i915_vm_to_ppgtt(rq->hw_context->vm);
int err, i;
u32 *cs;
GEM_BUG_ON(intel_vgpu_active(rq->i915));
/*
* Beware ye of the dragons, this sequence is magic!
*
* Small changes to this sequence can cause anything from
* GPU hangs to forcewake errors and machine lockups!
*/
/* Flush any residual operations from the context load */
err = engine->emit_flush(rq, EMIT_FLUSH);
if (err)
return err;
/* Magic required to prevent forcewake errors! */
err = engine->emit_flush(rq, EMIT_INVALIDATE);
if (err)
return err;
cs = intel_ring_begin(rq, 4 * GEN8_3LVL_PDPES + 2);
if (IS_ERR(cs))
return PTR_ERR(cs);
/* Ensure the LRI have landed before we invalidate & continue */
*cs++ = MI_LOAD_REGISTER_IMM(2 * GEN8_3LVL_PDPES) | MI_LRI_FORCE_POSTED;
for (i = GEN8_3LVL_PDPES; i--; ) {
const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i);
u32 base = engine->mmio_base;
*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(base, i));
*cs++ = upper_32_bits(pd_daddr);
*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(base, i));
*cs++ = lower_32_bits(pd_daddr);
}
*cs++ = MI_NOOP;
intel_ring_advance(rq, cs);
/* Be doubly sure the LRI have landed before proceeding */
err = engine->emit_flush(rq, EMIT_FLUSH);
if (err)
return err;
/* Re-invalidate the TLB for luck */
return engine->emit_flush(rq, EMIT_INVALIDATE);
}
static int execlists_request_alloc(struct i915_request *request)
{
int ret;
GEM_BUG_ON(!intel_context_is_pinned(request->hw_context));
/*
* Flush enough space to reduce the likelihood of waiting after
* we start building the request - in which case we will just
* have to repeat work.
*/
request->reserved_space += EXECLISTS_REQUEST_SIZE;
/*
* Note that after this point, we have committed to using
* this request as it is being used to both track the
* state of engine initialisation and liveness of the
* golden renderstate above. Think twice before you try
* to cancel/unwind this request now.
*/
/* Unconditionally invalidate GPU caches and TLBs. */
if (i915_vm_is_4lvl(request->hw_context->vm))
ret = request->engine->emit_flush(request, EMIT_INVALIDATE);
else
ret = emit_pdps(request);
if (ret)
return ret;
request->reserved_space -= EXECLISTS_REQUEST_SIZE;
return 0;
}
/*
* In this WA we need to set GEN8_L3SQCREG4[21:21] and reset it after
* PIPE_CONTROL instruction. This is required for the flush to happen correctly
* but there is a slight complication as this is applied in WA batch where the
* values are only initialized once so we cannot take register value at the
* beginning and reuse it further; hence we save its value to memory, upload a
* constant value with bit21 set and then we restore it back with the saved value.
* To simplify the WA, a constant value is formed by using the default value
* of this register. This shouldn't be a problem because we are only modifying
* it for a short period and this batch in non-premptible. We can ofcourse
* use additional instructions that read the actual value of the register
* at that time and set our bit of interest but it makes the WA complicated.
*
* This WA is also required for Gen9 so extracting as a function avoids
* code duplication.
*/
static u32 *
gen8_emit_flush_coherentl3_wa(struct intel_engine_cs *engine, u32 *batch)
{
/* NB no one else is allowed to scribble over scratch + 256! */
*batch++ = MI_STORE_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT;
*batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
*batch++ = intel_gt_scratch_offset(engine->gt,
INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA);
*batch++ = 0;
*batch++ = MI_LOAD_REGISTER_IMM(1);
*batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
*batch++ = 0x40400000 | GEN8_LQSC_FLUSH_COHERENT_LINES;
batch = gen8_emit_pipe_control(batch,
PIPE_CONTROL_CS_STALL |
PIPE_CONTROL_DC_FLUSH_ENABLE,
0);
*batch++ = MI_LOAD_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT;
*batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
*batch++ = intel_gt_scratch_offset(engine->gt,
INTEL_GT_SCRATCH_FIELD_COHERENTL3_WA);
*batch++ = 0;
return batch;
}
static u32 slm_offset(struct intel_engine_cs *engine)
{
return intel_gt_scratch_offset(engine->gt,
INTEL_GT_SCRATCH_FIELD_CLEAR_SLM_WA);
}
/*
* Typically we only have one indirect_ctx and per_ctx batch buffer which are
* initialized at the beginning and shared across all contexts but this field
* helps us to have multiple batches at different offsets and select them based
* on a criteria. At the moment this batch always start at the beginning of the page
* and at this point we don't have multiple wa_ctx batch buffers.
*
* The number of WA applied are not known at the beginning; we use this field
* to return the no of DWORDS written.
*
* It is to be noted that this batch does not contain MI_BATCH_BUFFER_END
* so it adds NOOPs as padding to make it cacheline aligned.
* MI_BATCH_BUFFER_END will be added to perctx batch and both of them together
* makes a complete batch buffer.
*/
static u32 *gen8_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
{
/* WaDisableCtxRestoreArbitration:bdw,chv */
*batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
/* WaFlushCoherentL3CacheLinesAtContextSwitch:bdw */
if (IS_BROADWELL(engine->i915))
batch = gen8_emit_flush_coherentl3_wa(engine, batch);
/* WaClearSlmSpaceAtContextSwitch:bdw,chv */
/* Actual scratch location is at 128 bytes offset */
batch = gen8_emit_pipe_control(batch,
PIPE_CONTROL_FLUSH_L3 |
PIPE_CONTROL_GLOBAL_GTT_IVB |
PIPE_CONTROL_CS_STALL |
PIPE_CONTROL_QW_WRITE,
slm_offset(engine));
*batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
/* Pad to end of cacheline */
while ((unsigned long)batch % CACHELINE_BYTES)
*batch++ = MI_NOOP;
/*
* MI_BATCH_BUFFER_END is not required in Indirect ctx BB because
* execution depends on the length specified in terms of cache lines
* in the register CTX_RCS_INDIRECT_CTX
*/
return batch;
}
struct lri {
i915_reg_t reg;
u32 value;
};
static u32 *emit_lri(u32 *batch, const struct lri *lri, unsigned int count)
{
GEM_BUG_ON(!count || count > 63);
*batch++ = MI_LOAD_REGISTER_IMM(count);
do {
*batch++ = i915_mmio_reg_offset(lri->reg);
*batch++ = lri->value;
} while (lri++, --count);
*batch++ = MI_NOOP;
return batch;
}
static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
{
static const struct lri lri[] = {
/* WaDisableGatherAtSetShaderCommonSlice:skl,bxt,kbl,glk */
{
COMMON_SLICE_CHICKEN2,
__MASKED_FIELD(GEN9_DISABLE_GATHER_AT_SET_SHADER_COMMON_SLICE,
0),
},
/* BSpec: 11391 */
{
FF_SLICE_CHICKEN,
__MASKED_FIELD(FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX,
FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX),
},
/* BSpec: 11299 */
{
_3D_CHICKEN3,
__MASKED_FIELD(_3D_CHICKEN_SF_PROVOKING_VERTEX_FIX,
_3D_CHICKEN_SF_PROVOKING_VERTEX_FIX),
}
};
*batch++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
batch = gen8_emit_flush_coherentl3_wa(engine, batch);
batch = emit_lri(batch, lri, ARRAY_SIZE(lri));
/* WaMediaPoolStateCmdInWABB:bxt,glk */
if (HAS_POOLED_EU(engine->i915)) {
/*
* EU pool configuration is setup along with golden context
* during context initialization. This value depends on
* device type (2x6 or 3x6) and needs to be updated based
* on which subslice is disabled especially for 2x6
* devices, however it is safe to load default
* configuration of 3x6 device instead of masking off
* corresponding bits because HW ignores bits of a disabled
* subslice and drops down to appropriate config. Please
* see render_state_setup() in i915_gem_render_state.c for
* possible configurations, to avoid duplication they are
* not shown here again.
*/
*batch++ = GEN9_MEDIA_POOL_STATE;
*batch++ = GEN9_MEDIA_POOL_ENABLE;
*batch++ = 0x00777000;
*batch++ = 0;
*batch++ = 0;
*batch++ = 0;
}
*batch++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
/* Pad to end of cacheline */
while ((unsigned long)batch % CACHELINE_BYTES)
*batch++ = MI_NOOP;
return batch;
}
static u32 *
gen10_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
{
int i;
/*
* WaPipeControlBefore3DStateSamplePattern: cnl
*
* Ensure the engine is idle prior to programming a
* 3DSTATE_SAMPLE_PATTERN during a context restore.
*/
batch = gen8_emit_pipe_control(batch,
PIPE_CONTROL_CS_STALL,
0);
/*
* WaPipeControlBefore3DStateSamplePattern says we need 4 dwords for
* the PIPE_CONTROL followed by 12 dwords of 0x0, so 16 dwords in
* total. However, a PIPE_CONTROL is 6 dwords long, not 4, which is
* confusing. Since gen8_emit_pipe_control() already advances the
* batch by 6 dwords, we advance the other 10 here, completing a
* cacheline. It's not clear if the workaround requires this padding
* before other commands, or if it's just the regular padding we would
* already have for the workaround bb, so leave it here for now.
*/
for (i = 0; i < 10; i++)
*batch++ = MI_NOOP;
/* Pad to end of cacheline */
while ((unsigned long)batch % CACHELINE_BYTES)
*batch++ = MI_NOOP;
return batch;
}
#define CTX_WA_BB_OBJ_SIZE (PAGE_SIZE)
static int lrc_setup_wa_ctx(struct intel_engine_cs *engine)
{
struct drm_i915_gem_object *obj;
struct i915_vma *vma;
int err;
obj = i915_gem_object_create_shmem(engine->i915, CTX_WA_BB_OBJ_SIZE);
if (IS_ERR(obj))
return PTR_ERR(obj);
vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
if (IS_ERR(vma)) {
err = PTR_ERR(vma);
goto err;
}
err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
if (err)
goto err;
engine->wa_ctx.vma = vma;
return 0;
err:
i915_gem_object_put(obj);
return err;
}
static void lrc_destroy_wa_ctx(struct intel_engine_cs *engine)
{
i915_vma_unpin_and_release(&engine->wa_ctx.vma, 0);
}
typedef u32 *(*wa_bb_func_t)(struct intel_engine_cs *engine, u32 *batch);
static int intel_init_workaround_bb(struct intel_engine_cs *engine)
{
struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx;
struct i915_wa_ctx_bb *wa_bb[2] = { &wa_ctx->indirect_ctx,
&wa_ctx->per_ctx };
wa_bb_func_t wa_bb_fn[2];
struct page *page;
void *batch, *batch_ptr;
unsigned int i;
int ret;
if (engine->class != RENDER_CLASS)
return 0;
switch (INTEL_GEN(engine->i915)) {
case 12:
case 11:
return 0;
case 10:
wa_bb_fn[0] = gen10_init_indirectctx_bb;
wa_bb_fn[1] = NULL;
break;
case 9:
wa_bb_fn[0] = gen9_init_indirectctx_bb;
wa_bb_fn[1] = NULL;
break;
case 8:
wa_bb_fn[0] = gen8_init_indirectctx_bb;
wa_bb_fn[1] = NULL;
break;
default:
MISSING_CASE(INTEL_GEN(engine->i915));
return 0;
}
ret = lrc_setup_wa_ctx(engine);
if (ret) {
DRM_DEBUG_DRIVER("Failed to setup context WA page: %d\n", ret);
return ret;
}
page = i915_gem_object_get_dirty_page(wa_ctx->vma->obj, 0);
batch = batch_ptr = kmap_atomic(page);
/*
* Emit the two workaround batch buffers, recording the offset from the
* start of the workaround batch buffer object for each and their
* respective sizes.
*/
for (i = 0; i < ARRAY_SIZE(wa_bb_fn); i++) {
wa_bb[i]->offset = batch_ptr - batch;
if (GEM_DEBUG_WARN_ON(!IS_ALIGNED(wa_bb[i]->offset,
CACHELINE_BYTES))) {
ret = -EINVAL;
break;
}
if (wa_bb_fn[i])
batch_ptr = wa_bb_fn[i](engine, batch_ptr);
wa_bb[i]->size = batch_ptr - (batch + wa_bb[i]->offset);
}
BUG_ON(batch_ptr - batch > CTX_WA_BB_OBJ_SIZE);
kunmap_atomic(batch);
if (ret)
lrc_destroy_wa_ctx(engine);
return ret;
}
static void enable_execlists(struct intel_engine_cs *engine)
{
u32 mode;
assert_forcewakes_active(engine->uncore, FORCEWAKE_ALL);
intel_engine_set_hwsp_writemask(engine, ~0u); /* HWSTAM */
if (INTEL_GEN(engine->i915) >= 11)
mode = _MASKED_BIT_ENABLE(GEN11_GFX_DISABLE_LEGACY_MODE);
else
mode = _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE);
ENGINE_WRITE_FW(engine, RING_MODE_GEN7, mode);
ENGINE_WRITE_FW(engine, RING_MI_MODE, _MASKED_BIT_DISABLE(STOP_RING));
ENGINE_WRITE_FW(engine,
RING_HWS_PGA,
i915_ggtt_offset(engine->status_page.vma));
ENGINE_POSTING_READ(engine, RING_HWS_PGA);
}
static bool unexpected_starting_state(struct intel_engine_cs *engine)
{
bool unexpected = false;
if (ENGINE_READ_FW(engine, RING_MI_MODE) & STOP_RING) {
DRM_DEBUG_DRIVER("STOP_RING still set in RING_MI_MODE\n");
unexpected = true;
}
return unexpected;
}
static int execlists_resume(struct intel_engine_cs *engine)
{
intel_engine_apply_workarounds(engine);
intel_engine_apply_whitelist(engine);
intel_mocs_init_engine(engine);
intel_engine_reset_breadcrumbs(engine);
if (GEM_SHOW_DEBUG() && unexpected_starting_state(engine)) {
struct drm_printer p = drm_debug_printer(__func__);
intel_engine_dump(engine, &p, NULL);
}
enable_execlists(engine);
return 0;
}
static void execlists_reset_prepare(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
unsigned long flags;
GEM_TRACE("%s: depth<-%d\n", engine->name,
atomic_read(&execlists->tasklet.count));
/*
* Prevent request submission to the hardware until we have
* completed the reset in i915_gem_reset_finish(). If a request
* is completed by one engine, it may then queue a request
* to a second via its execlists->tasklet *just* as we are
* calling engine->resume() and also writing the ELSP.
* Turning off the execlists->tasklet until the reset is over
* prevents the race.
*/
__tasklet_disable_sync_once(&execlists->tasklet);
GEM_BUG_ON(!reset_in_progress(execlists));
/* And flush any current direct submission. */
spin_lock_irqsave(&engine->active.lock, flags);
spin_unlock_irqrestore(&engine->active.lock, flags);
/*
* We stop engines, otherwise we might get failed reset and a
* dead gpu (on elk). Also as modern gpu as kbl can suffer
* from system hang if batchbuffer is progressing when
* the reset is issued, regardless of READY_TO_RESET ack.
* Thus assume it is best to stop engines on all gens
* where we have a gpu reset.
*
* WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
*
* FIXME: Wa for more modern gens needs to be validated
*/
intel_engine_stop_cs(engine);
}
static void reset_csb_pointers(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
const unsigned int reset_value = execlists->csb_size - 1;
ring_set_paused(engine, 0);
/*
* After a reset, the HW starts writing into CSB entry [0]. We
* therefore have to set our HEAD pointer back one entry so that
* the *first* entry we check is entry 0. To complicate this further,
* as we don't wait for the first interrupt after reset, we have to
* fake the HW write to point back to the last entry so that our
* inline comparison of our cached head position against the last HW
* write works even before the first interrupt.
*/
execlists->csb_head = reset_value;
WRITE_ONCE(*execlists->csb_write, reset_value);
wmb(); /* Make sure this is visible to HW (paranoia?) */
invalidate_csb_entries(&execlists->csb_status[0],
&execlists->csb_status[reset_value]);
}
static struct i915_request *active_request(struct i915_request *rq)
{
const struct intel_context * const ce = rq->hw_context;
struct i915_request *active = NULL;
struct list_head *list;
if (!i915_request_is_active(rq)) /* unwound, but incomplete! */
return rq;
list = &rq->timeline->requests;
list_for_each_entry_from_reverse(rq, list, link) {
if (i915_request_completed(rq))
break;
if (rq->hw_context != ce)
break;
active = rq;
}
return active;
}
static void __execlists_reset(struct intel_engine_cs *engine, bool stalled)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
struct intel_context *ce;
struct i915_request *rq;
u32 *regs;
process_csb(engine); /* drain preemption events */
/* Following the reset, we need to reload the CSB read/write pointers */
reset_csb_pointers(engine);
/*
* Save the currently executing context, even if we completed
* its request, it was still running at the time of the
* reset and will have been clobbered.
*/
rq = execlists_active(execlists);
if (!rq)
goto unwind;
ce = rq->hw_context;
GEM_BUG_ON(i915_active_is_idle(&ce->active));
GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
rq = active_request(rq);
if (!rq) {
ce->ring->head = ce->ring->tail;
goto out_replay;
}
ce->ring->head = intel_ring_wrap(ce->ring, rq->head);
/*
* If this request hasn't started yet, e.g. it is waiting on a
* semaphore, we need to avoid skipping the request or else we
* break the signaling chain. However, if the context is corrupt
* the request will not restart and we will be stuck with a wedged
* device. It is quite often the case that if we issue a reset
* while the GPU is loading the context image, that the context
* image becomes corrupt.
*
* Otherwise, if we have not started yet, the request should replay
* perfectly and we do not need to flag the result as being erroneous.
*/
if (!i915_request_started(rq))
goto out_replay;
/*
* If the request was innocent, we leave the request in the ELSP
* and will try to replay it on restarting. The context image may
* have been corrupted by the reset, in which case we may have
* to service a new GPU hang, but more likely we can continue on
* without impact.
*
* If the request was guilty, we presume the context is corrupt
* and have to at least restore the RING register in the context
* image back to the expected values to skip over the guilty request.
*/
__i915_request_reset(rq, stalled);
if (!stalled)
goto out_replay;
/*
* We want a simple context + ring to execute the breadcrumb update.
* We cannot rely on the context being intact across the GPU hang,
* so clear it and rebuild just what we need for the breadcrumb.
* All pending requests for this context will be zapped, and any
* future request will be after userspace has had the opportunity
* to recreate its own state.
*/
regs = ce->lrc_reg_state;
if (engine->pinned_default_state) {
memcpy(regs, /* skip restoring the vanilla PPHWSP */
engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE,
engine->context_size - PAGE_SIZE);
}
execlists_init_reg_state(regs, ce, engine, ce->ring);
out_replay:
GEM_TRACE("%s replay {head:%04x, tail:%04x\n",
engine->name, ce->ring->head, ce->ring->tail);
intel_ring_update_space(ce->ring);
__execlists_update_reg_state(ce, engine);
unwind:
/* Push back any incomplete requests for replay after the reset. */
cancel_port_requests(execlists);
__unwind_incomplete_requests(engine);
}
static void execlists_reset(struct intel_engine_cs *engine, bool stalled)
{
unsigned long flags;
GEM_TRACE("%s\n", engine->name);
spin_lock_irqsave(&engine->active.lock, flags);
__execlists_reset(engine, stalled);
spin_unlock_irqrestore(&engine->active.lock, flags);
}
static void nop_submission_tasklet(unsigned long data)
{
/* The driver is wedged; don't process any more events. */
}
static void execlists_cancel_requests(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
struct i915_request *rq, *rn;
struct rb_node *rb;
unsigned long flags;
GEM_TRACE("%s\n", engine->name);
/*
* Before we call engine->cancel_requests(), we should have exclusive
* access to the submission state. This is arranged for us by the
* caller disabling the interrupt generation, the tasklet and other
* threads that may then access the same state, giving us a free hand
* to reset state. However, we still need to let lockdep be aware that
* we know this state may be accessed in hardirq context, so we
* disable the irq around this manipulation and we want to keep
* the spinlock focused on its duties and not accidentally conflate
* coverage to the submission's irq state. (Similarly, although we
* shouldn't need to disable irq around the manipulation of the
* submission's irq state, we also wish to remind ourselves that
* it is irq state.)
*/
spin_lock_irqsave(&engine->active.lock, flags);
__execlists_reset(engine, true);
/* Mark all executing requests as skipped. */
list_for_each_entry(rq, &engine->active.requests, sched.link)
mark_eio(rq);
/* Flush the queued requests to the timeline list (for retiring). */
while ((rb = rb_first_cached(&execlists->queue))) {
struct i915_priolist *p = to_priolist(rb);
int i;
priolist_for_each_request_consume(rq, rn, p, i) {
mark_eio(rq);
__i915_request_submit(rq);
}
rb_erase_cached(&p->node, &execlists->queue);
i915_priolist_free(p);
}
/* Cancel all attached virtual engines */
while ((rb = rb_first_cached(&execlists->virtual))) {
struct virtual_engine *ve =
rb_entry(rb, typeof(*ve), nodes[engine->id].rb);
rb_erase_cached(rb, &execlists->virtual);
RB_CLEAR_NODE(rb);
spin_lock(&ve->base.active.lock);
rq = fetch_and_zero(&ve->request);
if (rq) {
mark_eio(rq);
rq->engine = engine;
__i915_request_submit(rq);
i915_request_put(rq);
ve->base.execlists.queue_priority_hint = INT_MIN;
}
spin_unlock(&ve->base.active.lock);
}
/* Remaining _unready_ requests will be nop'ed when submitted */
execlists->queue_priority_hint = INT_MIN;
execlists->queue = RB_ROOT_CACHED;
GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet));
execlists->tasklet.func = nop_submission_tasklet;
spin_unlock_irqrestore(&engine->active.lock, flags);
}
static void execlists_reset_finish(struct intel_engine_cs *engine)
{
struct intel_engine_execlists * const execlists = &engine->execlists;
/*
* After a GPU reset, we may have requests to replay. Do so now while
* we still have the forcewake to be sure that the GPU is not allowed
* to sleep before we restart and reload a context.
*/
GEM_BUG_ON(!reset_in_progress(execlists));
if (!RB_EMPTY_ROOT(&execlists->queue.rb_root))
execlists->tasklet.func(execlists->tasklet.data);
if (__tasklet_enable(&execlists->tasklet))
/* And kick in case we missed a new request submission. */
tasklet_hi_schedule(&execlists->tasklet);
GEM_TRACE("%s: depth->%d\n", engine->name,
atomic_read(&execlists->tasklet.count));
}
static int gen8_emit_bb_start(struct i915_request *rq,
u64 offset, u32 len,
const unsigned int flags)
{
u32 *cs;
cs = intel_ring_begin(rq, 4);
if (IS_ERR(cs))
return PTR_ERR(cs);
/*
* WaDisableCtxRestoreArbitration:bdw,chv
*
* We don't need to perform MI_ARB_ENABLE as often as we do (in
* particular all the gen that do not need the w/a at all!), if we
* took care to make sure that on every switch into this context
* (both ordinary and for preemption) that arbitrartion was enabled
* we would be fine. However, for gen8 there is another w/a that
* requires us to not preempt inside GPGPU execution, so we keep
* arbitration disabled for gen8 batches. Arbitration will be
* re-enabled before we close the request
* (engine->emit_fini_breadcrumb).
*/
*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
/* FIXME(BDW+): Address space and security selectors. */
*cs++ = MI_BATCH_BUFFER_START_GEN8 |
(flags & I915_DISPATCH_SECURE ? 0 : BIT(8));
*cs++ = lower_32_bits(offset);
*cs++ = upper_32_bits(offset);
intel_ring_advance(rq, cs);
return 0;
}
static int gen9_emit_bb_start(struct i915_request *rq,
u64 offset, u32 len,
const unsigned int flags)
{
u32 *cs;
cs = intel_ring_begin(rq, 6);
if (IS_ERR(cs))
return PTR_ERR(cs);
*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
*cs++ = MI_BATCH_BUFFER_START_GEN8 |
(flags & I915_DISPATCH_SECURE ? 0 : BIT(8));
*cs++ = lower_32_bits(offset);
*cs++ = upper_32_bits(offset);
*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
*cs++ = MI_NOOP;
intel_ring_advance(rq, cs);
return 0;
}
static void gen8_logical_ring_enable_irq(struct intel_engine_cs *engine)
{
ENGINE_WRITE(engine, RING_IMR,
~(engine->irq_enable_mask | engine->irq_keep_mask));
ENGINE_POSTING_READ(engine, RING_IMR);
}
static void gen8_logical_ring_disable_irq(struct intel_engine_cs *engine)
{
ENGINE_WRITE(engine, RING_IMR, ~engine->irq_keep_mask);
}
static int gen8_emit_flush(struct i915_request *request, u32 mode)
{
u32 cmd, *cs;
cs = intel_ring_begin(request, 4);
if (IS_ERR(cs))
return PTR_ERR(cs);
cmd = MI_FLUSH_DW + 1;
/* We always require a command barrier so that subsequent
* commands, such as breadcrumb interrupts, are strictly ordered
* wrt the contents of the write cache being flushed to memory
* (and thus being coherent from the CPU).
*/
cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
if (mode & EMIT_INVALIDATE) {
cmd |= MI_INVALIDATE_TLB;
if (request->engine->class == VIDEO_DECODE_CLASS)
cmd |= MI_INVALIDATE_BSD;
}
*cs++ = cmd;
*cs++ = I915_GEM_HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
*cs++ = 0; /* upper addr */
*cs++ = 0; /* value */
intel_ring_advance(request, cs);
return 0;
}
static int gen8_emit_flush_render(struct i915_request *request,
u32 mode)
{
struct intel_engine_cs *engine = request->engine;
u32 scratch_addr =
intel_gt_scratch_offset(engine->gt,
INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH);
bool vf_flush_wa = false, dc_flush_wa = false;
u32 *cs, flags = 0;
int len;
flags |= PIPE_CONTROL_CS_STALL;
if (mode & EMIT_FLUSH) {
flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
flags |= PIPE_CONTROL_FLUSH_ENABLE;
}
if (mode & EMIT_INVALIDATE) {
flags |= PIPE_CONTROL_TLB_INVALIDATE;
flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_QW_WRITE;
flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
/*
* On GEN9: before VF_CACHE_INVALIDATE we need to emit a NULL
* pipe control.
*/
if (IS_GEN(request->i915, 9))
vf_flush_wa = true;
/* WaForGAMHang:kbl */
if (IS_KBL_REVID(request->i915, 0, KBL_REVID_B0))
dc_flush_wa = true;
}
len = 6;
if (vf_flush_wa)
len += 6;
if (dc_flush_wa)
len += 12;
cs = intel_ring_begin(request, len);
if (IS_ERR(cs))
return PTR_ERR(cs);
if (vf_flush_wa)
cs = gen8_emit_pipe_control(cs, 0, 0);
if (dc_flush_wa)
cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_DC_FLUSH_ENABLE,
0);
cs = gen8_emit_pipe_control(cs, flags, scratch_addr);
if (dc_flush_wa)
cs = gen8_emit_pipe_control(cs, PIPE_CONTROL_CS_STALL, 0);
intel_ring_advance(request, cs);
return 0;
}
static int gen11_emit_flush_render(struct i915_request *request,
u32 mode)
{
struct intel_engine_cs *engine = request->engine;
const u32 scratch_addr =
intel_gt_scratch_offset(engine->gt,
INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH);
if (mode & EMIT_FLUSH) {
u32 *cs;
u32 flags = 0;
flags |= PIPE_CONTROL_CS_STALL;
flags |= PIPE_CONTROL_TILE_CACHE_FLUSH;
flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
flags |= PIPE_CONTROL_FLUSH_ENABLE;
flags |= PIPE_CONTROL_QW_WRITE;
flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
cs = intel_ring_begin(request, 6);
if (IS_ERR(cs))
return PTR_ERR(cs);
cs = gen8_emit_pipe_control(cs, flags, scratch_addr);
intel_ring_advance(request, cs);
}
if (mode & EMIT_INVALIDATE) {
u32 *cs;
u32 flags = 0;
flags |= PIPE_CONTROL_CS_STALL;
flags |= PIPE_CONTROL_COMMAND_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_TLB_INVALIDATE;
flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
flags |= PIPE_CONTROL_QW_WRITE;
flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
cs = intel_ring_begin(request, 6);
if (IS_ERR(cs))
return PTR_ERR(cs);
cs = gen8_emit_pipe_control(cs, flags, scratch_addr);
intel_ring_advance(request, cs);
}
return 0;
}
/*
* Reserve space for 2 NOOPs at the end of each request to be
* used as a workaround for not being allowed to do lite
* restore with HEAD==TAIL (WaIdleLiteRestore).
*/
static u32 *gen8_emit_wa_tail(struct i915_request *request, u32 *cs)
{
/* Ensure there's always at least one preemption point per-request. */
*cs++ = MI_ARB_CHECK;
*cs++ = MI_NOOP;
request->wa_tail = intel_ring_offset(request, cs);
return cs;
}
static u32 *emit_preempt_busywait(struct i915_request *request, u32 *cs)
{
*cs++ = MI_SEMAPHORE_WAIT |
MI_SEMAPHORE_GLOBAL_GTT |
MI_SEMAPHORE_POLL |
MI_SEMAPHORE_SAD_EQ_SDD;
*cs++ = 0;
*cs++ = intel_hws_preempt_address(request->engine);
*cs++ = 0;
return cs;
}
static