diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_lrc.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_lrc.c | 2853 |
1 files changed, 2853 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c new file mode 100644 index 000000000..13e97faab --- /dev/null +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -0,0 +1,2853 @@ +/* + * 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 <drm/drmP.h> +#include <drm/i915_drm.h> +#include "i915_drv.h" +#include "i915_gem_render_state.h" +#include "i915_vgpu.h" +#include "intel_lrc_reg.h" +#include "intel_mocs.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) + +/* 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) + +static int execlists_context_deferred_alloc(struct i915_gem_context *ctx, + struct intel_engine_cs *engine, + struct intel_context *ce); +static void execlists_init_reg_state(u32 *reg_state, + struct i915_gem_context *ctx, + struct intel_engine_cs *engine, + struct intel_ring *ring); + +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 inline bool need_preempt(const struct intel_engine_cs *engine, + const struct i915_request *last, + int prio) +{ + return (intel_engine_has_preemption(engine) && + __execlists_need_preempt(prio, rq_prio(last)) && + !i915_request_completed(last)); +} + +/* + * 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 void +intel_lr_context_descriptor_update(struct i915_gem_context *ctx, + struct intel_engine_cs *engine, + struct intel_context *ce) +{ + 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 = ctx->desc_template; /* bits 0-11 */ + GEM_BUG_ON(desc & GENMASK_ULL(63, 12)); + + desc |= i915_ggtt_offset(ce->state) + LRC_HEADER_PAGES * PAGE_SIZE; + /* bits 12-31 */ + GEM_BUG_ON(desc & GENMASK_ULL(63, 32)); + + /* + * 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(ctx->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 */ + } + + ce->lrc_desc = desc; +} + +static struct i915_priolist * +lookup_priolist(struct intel_engine_cs *engine, int prio) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct i915_priolist *p; + struct rb_node **parent, *rb; + bool first = true; + + if (unlikely(execlists->no_priolist)) + prio = I915_PRIORITY_NORMAL; + +find_priolist: + /* most positive priority is scheduled first, equal priorities fifo */ + rb = NULL; + parent = &execlists->queue.rb_root.rb_node; + while (*parent) { + rb = *parent; + p = to_priolist(rb); + if (prio > p->priority) { + parent = &rb->rb_left; + } else if (prio < p->priority) { + parent = &rb->rb_right; + first = false; + } else { + return p; + } + } + + if (prio == I915_PRIORITY_NORMAL) { + p = &execlists->default_priolist; + } else { + p = kmem_cache_alloc(engine->i915->priorities, GFP_ATOMIC); + /* Convert an allocation failure to a priority bump */ + if (unlikely(!p)) { + prio = I915_PRIORITY_NORMAL; /* recurses just once */ + + /* To maintain ordering with all rendering, after an + * allocation failure we have to disable all scheduling. + * Requests will then be executed in fifo, and schedule + * will ensure that dependencies are emitted in fifo. + * There will be still some reordering with existing + * requests, so if userspace lied about their + * dependencies that reordering may be visible. + */ + execlists->no_priolist = true; + goto find_priolist; + } + } + + p->priority = prio; + INIT_LIST_HEAD(&p->requests); + rb_link_node(&p->node, rb, parent); + rb_insert_color_cached(&p->node, &execlists->queue, first); + + return p; +} + +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 void __unwind_incomplete_requests(struct intel_engine_cs *engine) +{ + struct i915_request *rq, *rn; + struct i915_priolist *uninitialized_var(p); + int last_prio = I915_PRIORITY_INVALID; + + lockdep_assert_held(&engine->timeline.lock); + + list_for_each_entry_safe_reverse(rq, rn, + &engine->timeline.requests, + link) { + if (i915_request_completed(rq)) + return; + + __i915_request_unsubmit(rq); + unwind_wa_tail(rq); + + GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID); + if (rq_prio(rq) != last_prio) { + last_prio = rq_prio(rq); + p = lookup_priolist(engine, last_prio); + } + + GEM_BUG_ON(p->priority != rq_prio(rq)); + list_add(&rq->sched.link, &p->requests); + } +} + +void +execlists_unwind_incomplete_requests(struct intel_engine_execlists *execlists) +{ + struct intel_engine_cs *engine = + container_of(execlists, typeof(*engine), execlists); + unsigned long flags; + + spin_lock_irqsave(&engine->timeline.lock, flags); + + __unwind_incomplete_requests(engine); + + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +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); +} + +inline void +execlists_user_begin(struct intel_engine_execlists *execlists, + const struct execlist_port *port) +{ + execlists_set_active_once(execlists, EXECLISTS_ACTIVE_USER); +} + +inline void +execlists_user_end(struct intel_engine_execlists *execlists) +{ + execlists_clear_active(execlists, EXECLISTS_ACTIVE_USER); +} + +static inline void +execlists_context_schedule_in(struct i915_request *rq) +{ + execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN); + intel_engine_context_in(rq->engine); +} + +static inline void +execlists_context_schedule_out(struct i915_request *rq, unsigned long status) +{ + intel_engine_context_out(rq->engine); + execlists_context_status_change(rq, status); + trace_i915_request_out(rq); +} + +static void +execlists_update_context_pdps(struct i915_hw_ppgtt *ppgtt, u32 *reg_state) +{ + ASSIGN_CTX_PDP(ppgtt, reg_state, 3); + ASSIGN_CTX_PDP(ppgtt, reg_state, 2); + ASSIGN_CTX_PDP(ppgtt, reg_state, 1); + ASSIGN_CTX_PDP(ppgtt, reg_state, 0); +} + +static u64 execlists_update_context(struct i915_request *rq) +{ + struct intel_context *ce = rq->hw_context; + struct i915_hw_ppgtt *ppgtt = + rq->gem_context->ppgtt ?: rq->i915->mm.aliasing_ppgtt; + u32 *reg_state = ce->lrc_reg_state; + + reg_state[CTX_RING_TAIL+1] = intel_ring_set_tail(rq->ring, rq->tail); + + /* + * True 32b PPGTT with dynamic page allocation: update PDP + * registers and point the unallocated PDPs to scratch page. + * PML4 is allocated during ppgtt init, so this is not needed + * in 48-bit mode. + */ + if (ppgtt && !i915_vm_is_48bit(&ppgtt->vm)) + execlists_update_context_pdps(ppgtt, reg_state); + + /* + * 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(); + return ce->lrc_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 void execlists_submit_ports(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists *execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + unsigned int n; + + /* + * 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(!engine->i915->gt.awake); + + /* + * 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; + unsigned int count; + u64 desc; + + rq = port_unpack(&port[n], &count); + if (rq) { + GEM_BUG_ON(count > !n); + if (!count++) + execlists_context_schedule_in(rq); + port_set(&port[n], port_pack(rq, count)); + desc = execlists_update_context(rq); + GEM_DEBUG_EXEC(port[n].context_id = upper_32_bits(desc)); + + GEM_TRACE("%s in[%d]: ctx=%d.%d, global=%d (fence %llx:%d) (current %d), prio=%d\n", + engine->name, n, + port[n].context_id, count, + rq->global_seqno, + rq->fence.context, rq->fence.seqno, + intel_engine_get_seqno(engine), + rq_prio(rq)); + } else { + GEM_BUG_ON(!n); + desc = 0; + } + + write_desc(execlists, desc, n); + } + + /* we need to manually load the submit queue */ + if (execlists->ctrl_reg) + writel(EL_CTRL_LOAD, execlists->ctrl_reg); + + execlists_clear_active(execlists, EXECLISTS_ACTIVE_HWACK); +} + +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 void port_assign(struct execlist_port *port, struct i915_request *rq) +{ + GEM_BUG_ON(rq == port_request(port)); + + if (port_isset(port)) + i915_request_put(port_request(port)); + + port_set(port, port_pack(i915_request_get(rq), port_count(port))); +} + +static void inject_preempt_context(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists *execlists = &engine->execlists; + struct intel_context *ce = + to_intel_context(engine->i915->preempt_context, engine); + unsigned int n; + + GEM_BUG_ON(execlists->preempt_complete_status != + upper_32_bits(ce->lrc_desc)); + GEM_BUG_ON((ce->lrc_reg_state[CTX_CONTEXT_CONTROL + 1] & + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT)) != + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT)); + + /* + * Switch to our empty preempt context so + * the state of the GPU is known (idle). + */ + GEM_TRACE("%s\n", engine->name); + for (n = execlists_num_ports(execlists); --n; ) + write_desc(execlists, 0, n); + + write_desc(execlists, ce->lrc_desc, n); + + /* we need to manually load the submit queue */ + if (execlists->ctrl_reg) + writel(EL_CTRL_LOAD, execlists->ctrl_reg); + + execlists_clear_active(execlists, EXECLISTS_ACTIVE_HWACK); + execlists_set_active(execlists, EXECLISTS_ACTIVE_PREEMPT); +} + +static void complete_preempt_context(struct intel_engine_execlists *execlists) +{ + GEM_BUG_ON(!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT)); + + if (inject_preempt_hang(execlists)) + return; + + execlists_cancel_port_requests(execlists); + __unwind_incomplete_requests(container_of(execlists, + struct intel_engine_cs, + execlists)); +} + +static void execlists_dequeue(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + const struct execlist_port * const last_port = + &execlists->port[execlists->port_mask]; + struct i915_request *last = port_request(port); + 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. + */ + + if (last) { + /* + * Don't resubmit or switch until all outstanding + * preemptions (lite-restore) are seen. Then we + * know the next preemption status we see corresponds + * to this ELSP update. + */ + GEM_BUG_ON(!execlists_is_active(execlists, + EXECLISTS_ACTIVE_USER)); + GEM_BUG_ON(!port_count(&port[0])); + + /* + * If we write to ELSP a second time before the HW has had + * a chance to respond to the previous write, we can confuse + * the HW and hit "undefined behaviour". After writing to ELSP, + * we must then wait until we see a context-switch event from + * the HW to indicate that it has had a chance to respond. + */ + if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_HWACK)) + return; + + if (need_preempt(engine, last, execlists->queue_priority)) { + inject_preempt_context(engine); + return; + } + + /* + * In theory, we could coalesce more requests onto + * the second port (the first port is active, with + * no preemptions pending). However, that means we + * then have to deal with the possible lite-restore + * of the second port (as we submit the ELSP, there + * may be a context-switch) but also we may complete + * the resubmission before the context-switch. Ergo, + * coalescing onto the second port will cause a + * preemption event, but we cannot predict whether + * that will affect port[0] or port[1]. + * + * If the second port is already active, we can wait + * until the next context-switch before contemplating + * new requests. The GPU will be busy and we should be + * able to resubmit the new ELSP before it idles, + * avoiding pipeline bubbles (momentary pauses where + * the driver is unable to keep up the supply of new + * work). However, we have to double check that the + * priorities of the ports haven't been switch. + */ + if (port_count(&port[1])) + return; + + /* + * WaIdleLiteRestore:bdw,skl + * Apply the wa NOOPs to prevent + * ring:HEAD == rq:TAIL as we resubmit the + * request. See gen8_emit_breadcrumb() for + * where we prepare the padding after the + * end of the request. + */ + last->tail = last->wa_tail; + } + + while ((rb = rb_first_cached(&execlists->queue))) { + struct i915_priolist *p = to_priolist(rb); + struct i915_request *rq, *rn; + + list_for_each_entry_safe(rq, rn, &p->requests, sched.link) { + /* + * 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_ctx(rq->hw_context, last->hw_context)) { + /* + * If we are on the second port and cannot + * combine this request with the last, then we + * are done. + */ + if (port == last_port) { + __list_del_many(&p->requests, + &rq->sched.link); + 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)) { + __list_del_many(&p->requests, + &rq->sched.link); + goto done; + } + + GEM_BUG_ON(last->hw_context == rq->hw_context); + + if (submit) + port_assign(port, last); + port++; + + GEM_BUG_ON(port_isset(port)); + } + + INIT_LIST_HEAD(&rq->sched.link); + __i915_request_submit(rq); + trace_i915_request_in(rq, port_index(port, execlists)); + last = rq; + submit = true; + } + + rb_erase_cached(&p->node, &execlists->queue); + INIT_LIST_HEAD(&p->requests); + if (p->priority != I915_PRIORITY_NORMAL) + kmem_cache_free(engine->i915->priorities, p); + } + +done: + /* + * Here be a bit of magic! Or sleight-of-hand, whichever you prefer. + * + * We choose queue_priority 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 queue_priority 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 queue_priority is bumped to that + * request triggering preemption on the next dequeue (or subsequent + * interrupt for secondary ports). + */ + execlists->queue_priority = + port != execlists->port ? rq_prio(last) : INT_MIN; + + if (submit) { + port_assign(port, last); + execlists_submit_ports(engine); + } + + /* We must always keep the beast fed if we have work piled up */ + GEM_BUG_ON(rb_first_cached(&execlists->queue) && + !port_isset(execlists->port)); + + /* Re-evaluate the executing context setup after each preemptive kick */ + if (last) + execlists_user_begin(execlists, execlists->port); + + /* If the engine is now idle, so should be the flag; and vice versa. */ + GEM_BUG_ON(execlists_is_active(&engine->execlists, + EXECLISTS_ACTIVE_USER) == + !port_isset(engine->execlists.port)); +} + +void +execlists_cancel_port_requests(struct intel_engine_execlists * const execlists) +{ + struct execlist_port *port = execlists->port; + unsigned int num_ports = execlists_num_ports(execlists); + + while (num_ports-- && port_isset(port)) { + struct i915_request *rq = port_request(port); + + GEM_TRACE("%s:port%u global=%d (fence %llx:%d), (current %d)\n", + rq->engine->name, + (unsigned int)(port - execlists->port), + rq->global_seqno, + rq->fence.context, rq->fence.seqno, + intel_engine_get_seqno(rq->engine)); + + GEM_BUG_ON(!execlists->active); + execlists_context_schedule_out(rq, + i915_request_completed(rq) ? + INTEL_CONTEXT_SCHEDULE_OUT : + INTEL_CONTEXT_SCHEDULE_PREEMPTED); + + i915_request_put(rq); + + memset(port, 0, sizeof(*port)); + port++; + } + + execlists_clear_all_active(execlists); +} + +static void reset_csb_pointers(struct intel_engine_execlists *execlists) +{ + /* + * 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 = execlists->csb_write_reset; + WRITE_ONCE(*execlists->csb_write, execlists->csb_write_reset); +} + +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 current %d\n", + engine->name, intel_engine_get_seqno(engine)); + + /* + * 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->timeline.lock, flags); + + /* Cancel the requests on the HW and clear the ELSP tracker. */ + execlists_cancel_port_requests(execlists); + execlists_user_end(execlists); + + /* Mark all executing requests as skipped. */ + list_for_each_entry(rq, &engine->timeline.requests, link) { + GEM_BUG_ON(!rq->global_seqno); + if (!i915_request_completed(rq)) + dma_fence_set_error(&rq->fence, -EIO); + } + + /* Flush the queued requests to the timeline list (for retiring). */ + while ((rb = rb_first_cached(&execlists->queue))) { + struct i915_priolist *p = to_priolist(rb); + + list_for_each_entry_safe(rq, rn, &p->requests, sched.link) { + INIT_LIST_HEAD(&rq->sched.link); + + dma_fence_set_error(&rq->fence, -EIO); + __i915_request_submit(rq); + } + + rb_erase_cached(&p->node, &execlists->queue); + INIT_LIST_HEAD(&p->requests); + if (p->priority != I915_PRIORITY_NORMAL) + kmem_cache_free(engine->i915->priorities, p); + } + + /* Remaining _unready_ requests will be nop'ed when submitted */ + + execlists->queue_priority = INT_MIN; + execlists->queue = RB_ROOT_CACHED; + GEM_BUG_ON(port_isset(execlists->port)); + + GEM_BUG_ON(__tasklet_is_enabled(&execlists->tasklet)); + execlists->tasklet.func = nop_submission_tasklet; + + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static inline bool +reset_in_progress(const struct intel_engine_execlists *execlists) +{ + return unlikely(!__tasklet_is_enabled(&execlists->tasklet)); +} + +static void process_csb(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct execlist_port *port = execlists->port; + const u32 * const buf = execlists->csb_status; + u8 head, tail; + + /* + * 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 { + struct i915_request *rq; + unsigned int status; + unsigned int count; + + if (++head == GEN8_CSB_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, active=0x%x\n", + engine->name, head, + buf[2 * head + 0], buf[2 * head + 1], + execlists->active); + + status = buf[2 * head]; + if (status & (GEN8_CTX_STATUS_IDLE_ACTIVE | + GEN8_CTX_STATUS_PREEMPTED)) + execlists_set_active(execlists, + EXECLISTS_ACTIVE_HWACK); + if (status & GEN8_CTX_STATUS_ACTIVE_IDLE) + execlists_clear_active(execlists, + EXECLISTS_ACTIVE_HWACK); + + if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK)) + continue; + + /* We should never get a COMPLETED | IDLE_ACTIVE! */ + GEM_BUG_ON(status & GEN8_CTX_STATUS_IDLE_ACTIVE); + + if (status & GEN8_CTX_STATUS_COMPLETE && + buf[2*head + 1] == execlists->preempt_complete_status) { + GEM_TRACE("%s preempt-idle\n", engine->name); + complete_preempt_context(execlists); + continue; + } + + if (status & GEN8_CTX_STATUS_PREEMPTED && + execlists_is_active(execlists, + EXECLISTS_ACTIVE_PREEMPT)) + continue; + + GEM_BUG_ON(!execlists_is_active(execlists, + EXECLISTS_ACTIVE_USER)); + + rq = port_unpack(port, &count); + GEM_TRACE("%s out[0]: ctx=%d.%d, global=%d (fence %llx:%d) (current %d), prio=%d\n", + engine->name, + port->context_id, count, + rq ? rq->global_seqno : 0, + rq ? rq->fence.context : 0, + rq ? rq->fence.seqno : 0, + intel_engine_get_seqno(engine), + rq ? rq_prio(rq) : 0); + + /* Check the context/desc id for this event matches */ + GEM_DEBUG_BUG_ON(buf[2 * head + 1] != port->context_id); + + GEM_BUG_ON(count == 0); + if (--count == 0) { + /* + * On the final event corresponding to the + * submission of this context, we expect either + * an element-switch event or a completion + * event (and on completion, the active-idle + * marker). No more preemptions, lite-restore + * or otherwise. + */ + GEM_BUG_ON(status & GEN8_CTX_STATUS_PREEMPTED); + GEM_BUG_ON(port_isset(&port[1]) && + !(status & GEN8_CTX_STATUS_ELEMENT_SWITCH)); + GEM_BUG_ON(!port_isset(&port[1]) && + !(status & GEN8_CTX_STATUS_ACTIVE_IDLE)); + + /* + * 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(rq)); + + execlists_context_schedule_out(rq, + INTEL_CONTEXT_SCHEDULE_OUT); + i915_request_put(rq); + + GEM_TRACE("%s completed ctx=%d\n", + engine->name, port->context_id); + + port = execlists_port_complete(execlists, port); + if (port_isset(port)) + execlists_user_begin(execlists, port); + else + execlists_user_end(execlists); + } else { + port_set(port, port_pack(rq, count)); + } + } while (head != tail); + + execlists->csb_head = head; +} + +static void __execlists_submission_tasklet(struct intel_engine_cs *const engine) +{ + lockdep_assert_held(&engine->timeline.lock); + + process_csb(engine); + if (!execlists_is_active(&engine->execlists, EXECLISTS_ACTIVE_PREEMPT)) + execlists_dequeue(engine); +} + +/* + * 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; + + GEM_TRACE("%s awake?=%d, active=%x\n", + engine->name, + engine->i915->gt.awake, + engine->execlists.active); + + spin_lock_irqsave(&engine->timeline.lock, flags); + __execlists_submission_tasklet(engine); + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static void queue_request(struct intel_engine_cs *engine, + struct i915_sched_node *node, + int prio) +{ + list_add_tail(&node->link, + &lookup_priolist(engine, prio)->requests); +} + +static void __update_queue(struct intel_engine_cs *engine, int prio) +{ + engine->execlists.queue_priority = 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, int prio) +{ + if (prio > engine->execlists.queue_priority) { + __update_queue(engine, prio); + __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->timeline.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, rq_prio(request)); + + spin_unlock_irqrestore(&engine->timeline.lock, flags); +} + +static struct i915_request *sched_to_request(struct i915_sched_node *node) +{ + return container_of(node, struct i915_request, sched); +} + +static struct intel_engine_cs * +sched_lock_engine(struct i915_sched_node *node, struct intel_engine_cs *locked) +{ + struct intel_engine_cs *engine = sched_to_request(node)->engine; + + GEM_BUG_ON(!locked); + + if (engine != locked) { + spin_unlock(&locked->timeline.lock); + spin_lock(&engine->timeline.lock); + } + + return engine; +} + +static void execlists_schedule(struct i915_request *request, + const struct i915_sched_attr *attr) +{ + struct i915_priolist *uninitialized_var(pl); + struct intel_engine_cs *engine, *last; + struct i915_dependency *dep, *p; + struct i915_dependency stack; + const int prio = attr->priority; + LIST_HEAD(dfs); + + GEM_BUG_ON(prio == I915_PRIORITY_INVALID); + + if (i915_request_completed(request)) + return; + + if (prio <= READ_ONCE(request->sched.attr.priority)) + return; + + /* Need BKL in order to use the temporary link inside i915_dependency */ + lockdep_assert_held(&request->i915->drm.struct_mutex); + + stack.signaler = &request->sched; + list_add(&stack.dfs_link, &dfs); + + /* + * Recursively bump all dependent priorities to match the new request. + * + * A naive approach would be to use recursion: + * static void update_priorities(struct i915_sched_node *node, prio) { + * list_for_each_entry(dep, &node->signalers_list, signal_link) + * update_priorities(dep->signal, prio) + * queue_request(node); + * } + * but that may have unlimited recursion depth and so runs a very + * real risk of overunning the kernel stack. Instead, we build + * a flat list of all dependencies starting with the current request. + * As we walk the list of dependencies, we add all of its dependencies + * to the end of the list (this may include an already visited + * request) and continue to walk onwards onto the new dependencies. The + * end result is a topological list of requests in reverse order, the + * last element in the list is the request we must execute first. + */ + list_for_each_entry(dep, &dfs, dfs_link) { + struct i915_sched_node *node = dep->signaler; + + /* + * Within an engine, there can be no cycle, but we may + * refer to the same dependency chain multiple times + * (redundant dependencies are not eliminated) and across + * engines. + */ + list_for_each_entry(p, &node->signalers_list, signal_link) { + GEM_BUG_ON(p == dep); /* no cycles! */ + + if (i915_sched_node_signaled(p->signaler)) + continue; + + GEM_BUG_ON(p->signaler->attr.priority < node->attr.priority); + if (prio > READ_ONCE(p->signaler->attr.priority)) + list_move_tail(&p->dfs_link, &dfs); + } + } + + /* + * If we didn't need to bump any existing priorities, and we haven't + * yet submitted this request (i.e. there is no potential race with + * execlists_submit_request()), we can set our own priority and skip + * acquiring the engine locks. + */ + if (request->sched.attr.priority == I915_PRIORITY_INVALID) { + GEM_BUG_ON(!list_empty(&request->sched.link)); + request->sched.attr = *attr; + if (stack.dfs_link.next == stack.dfs_link.prev) + return; + __list_del_entry(&stack.dfs_link); + } + + last = NULL; + engine = request->engine; + spin_lock_irq(&engine->timeline.lock); + + /* Fifo and depth-first replacement ensure our deps execute before us */ + list_for_each_entry_safe_reverse(dep, p, &dfs, dfs_link) { + struct i915_sched_node *node = dep->signaler; + + INIT_LIST_HEAD(&dep->dfs_link); + + engine = sched_lock_engine(node, engine); + + if (prio <= node->attr.priority) + continue; + + node->attr.priority = prio; + if (!list_empty(&node->link)) { + if (last != engine) { + pl = lookup_priolist(engine, prio); + last = engine; + } + GEM_BUG_ON(pl->priority != prio); + list_move_tail(&node->link, &pl->requests); + } + + if (prio > engine->execlists.queue_priority && + i915_sw_fence_done(&sched_to_request(node)->submit)) { + /* defer submission until after all of our updates */ + __update_queue(engine, prio); + tasklet_hi_schedule(&engine->execlists.tasklet); + } + } + + spin_unlock_irq(&engine->timeline.lock); +} + +static void execlists_context_destroy(struct intel_context *ce) +{ + GEM_BUG_ON(ce->pin_count); + + if (!ce->state) + return; + + intel_ring_free(ce->ring); + + GEM_BUG_ON(i915_gem_object_is_active(ce->state->obj)); + i915_gem_object_put(ce->state->obj); +} + +static void execlists_context_unpin(struct intel_context *ce) +{ + intel_ring_unpin(ce->ring); + + ce->state->obj->pin_global--; + i915_gem_object_unpin_map(ce->state->obj); + i915_vma_unpin(ce->state); + + i915_gem_context_put(ce->gem_context); +} + +static int __context_pin(struct i915_gem_context *ctx, struct i915_vma *vma) +{ + unsigned int flags; + int err; + + /* + * Clear this page out of any CPU caches for coherent swap-in/out. + * We only want to do this on the first bind so that we do not stall + * on an active context (which by nature is already on the GPU). + */ + if (!(vma->flags & I915_VMA_GLOBAL_BIND)) { + err = i915_gem_object_set_to_gtt_domain(vma->obj, true); + if (err) + return err; + } + + flags = PIN_GLOBAL | PIN_HIGH; + if (ctx->ggtt_offset_bias) + flags |= PIN_OFFSET_BIAS | ctx->ggtt_offset_bias; + + return i915_vma_pin(vma, 0, GEN8_LR_CONTEXT_ALIGN, flags); +} + +static struct intel_context * +__execlists_context_pin(struct intel_engine_cs *engine, + struct i915_gem_context *ctx, + struct intel_context *ce) +{ + void *vaddr; + int ret; + + ret = execlists_context_deferred_alloc(ctx, engine, ce); + if (ret) + goto err; + GEM_BUG_ON(!ce->state); + + ret = __context_pin(ctx, ce->state); + if (ret) + goto err; + + vaddr = i915_gem_object_pin_map(ce->state->obj, I915_MAP_WB); + if (IS_ERR(vaddr)) { + ret = PTR_ERR(vaddr); + goto unpin_vma; + } + + ret = intel_ring_pin(ce->ring, ctx->i915, ctx->ggtt_offset_bias); + if (ret) + goto unpin_map; + + intel_lr_context_descriptor_update(ctx, engine, ce); + + ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE; + ce->lrc_reg_state[CTX_RING_BUFFER_START+1] = + i915_ggtt_offset(ce->ring->vma); + GEM_BUG_ON(!intel_ring_offset_valid(ce->ring, ce->ring->head)); + ce->lrc_reg_state[CTX_RING_HEAD+1] = ce->ring->head; + + ce->state->obj->pin_global++; + i915_gem_context_get(ctx); + return ce; + +unpin_map: + i915_gem_object_unpin_map(ce->state->obj); +unpin_vma: + __i915_vma_unpin(ce->state); +err: + ce->pin_count = 0; + return ERR_PTR(ret); +} + +static const struct intel_context_ops execlists_context_ops = { + .unpin = execlists_context_unpin, + .destroy = execlists_context_destroy, +}; + +static struct intel_context * +execlists_context_pin(struct intel_engine_cs *engine, + struct i915_gem_context *ctx) +{ + struct intel_context *ce = to_intel_context(ctx, engine); + + lockdep_assert_held(&ctx->i915->drm.struct_mutex); + + if (likely(ce->pin_count++)) + return ce; + GEM_BUG_ON(!ce->pin_count); /* no overflow please! */ + + ce->ops = &execlists_context_ops; + + return __execlists_context_pin(engine, ctx, ce); +} + +static int execlists_request_alloc(struct i915_request *request) +{ + int ret; + + GEM_BUG_ON(!request->hw_context->pin_count); + + /* 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; + + ret = intel_ring_wait_for_space(request->ring, request->reserved_space); + if (ret) + return ret; + + /* 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. + */ + + 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) +{ + *batch++ = MI_STORE_REGISTER_MEM_GEN8 | MI_SRM_LRM_GLOBAL_GTT; + *batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4); + *batch++ = i915_ggtt_offset(engine->scratch) + 256; + *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++ = i915_ggtt_offset(engine->scratch) + 256; + *batch++ = 0; + + return batch; +} + +/* + * 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, + i915_ggtt_offset(engine->scratch) + + 2 * CACHELINE_BYTES); + + *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); + + /* WaClearSlmSpaceAtContextSwitch:skl,bxt,kbl,glk,cfl */ + batch = gen8_emit_pipe_control(batch, + PIPE_CONTROL_FLUSH_L3 | + PIPE_CONTROL_GLOBAL_GTT_IVB | + PIPE_CONTROL_CS_STALL | + PIPE_CONTROL_QW_WRITE, + i915_ggtt_offset(engine->scratch) + + 2 * CACHELINE_BYTES); + + batch = emit_lri(batch, lri, ARRAY_SIZE(lri)); + + /* WaClearSlmSpaceAtContextSwitch:kbl */ + /* Actual scratch location is at 128 bytes offset */ + if (IS_KBL_REVID(engine->i915, 0, KBL_REVID_A0)) { + batch = gen8_emit_pipe_control(batch, + PIPE_CONTROL_FLUSH_L3 | + PIPE_CONTROL_GLOBAL_GTT_IVB | + PIPE_CONTROL_CS_STALL | + PIPE_CONTROL_QW_WRITE, + i915_ggtt_offset(engine->scratch) + + 2 * CACHELINE_BYTES); + } + + /* 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(engine->i915, CTX_WA_BB_OBJ_SIZE); + if (IS_ERR(obj)) + return PTR_ERR(obj); + + vma = i915_vma_instance(obj, &engine->i915->ggtt.vm, NULL); + if (IS_ERR(vma)) { + err = PTR_ERR(vma); + goto err; + } + + err = i915_vma_pin(vma, 0, PAGE_SIZE, 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); +} + +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 (GEM_WARN_ON(engine->id != RCS)) + return -EINVAL; + + switch (INTEL_GEN(engine->i915)) { + 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_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) +{ + struct drm_i915_private *dev_priv = engine->i915; + + I915_WRITE(RING_HWSTAM(engine->mmio_base), 0xffffffff); + + /* + * Make sure we're not enabling the new 12-deep CSB + * FIFO as that requires a slightly updated handling + * in the ctx switch irq. Since we're currently only + * using only 2 elements of the enhanced execlists the + * deeper FIFO it's not needed and it's not worth adding + * more statements to the irq handler to support it. + */ + if (INTEL_GEN(dev_priv) >= 11) + I915_WRITE(RING_MODE_GEN7(engine), + _MASKED_BIT_DISABLE(GEN11_GFX_DISABLE_LEGACY_MODE)); + else + I915_WRITE(RING_MODE_GEN7(engine), + _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE)); + + I915_WRITE(RING_MI_MODE(engine->mmio_base), + _MASKED_BIT_DISABLE(STOP_RING)); + + I915_WRITE(RING_HWS_PGA(engine->mmio_base), + engine->status_page.ggtt_offset); + POSTING_READ(RING_HWS_PGA(engine->mmio_base)); +} + +static bool unexpected_starting_state(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + bool unexpected = false; + + if (I915_READ(RING_MI_MODE(engine->mmio_base)) & STOP_RING) { + DRM_DEBUG_DRIVER("STOP_RING still set in RING_MI_MODE\n"); + unexpected = true; + } + + return unexpected; +} + +static int gen8_init_common_ring(struct intel_engine_cs *engine) +{ + int ret; + + ret = intel_mocs_init_engine(engine); + if (ret) + return ret; + + 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 int gen8_init_render_ring(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + int ret; + + ret = gen8_init_common_ring(engine); + if (ret) + return ret; + + intel_whitelist_workarounds_apply(engine); + + /* We need to disable the AsyncFlip performance optimisations in order + * to use MI_WAIT_FOR_EVENT within the CS. It should already be + * programmed to '1' on all products. + * + * WaDisableAsyncFlipPerfMode:snb,ivb,hsw,vlv,bdw,chv + */ + I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(ASYNC_FLIP_PERF_DISABLE)); + + I915_WRITE(INSTPM, _MASKED_BIT_ENABLE(INSTPM_FORCE_ORDERING)); + + return 0; +} + +static int gen9_init_render_ring(struct intel_engine_cs *engine) +{ + int ret; + + ret = gen8_init_common_ring(engine); + if (ret) + return ret; + + intel_whitelist_workarounds_apply(engine); + + return 0; +} + +static struct i915_request * +execlists_reset_prepare(struct intel_engine_cs *engine) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + struct i915_request *request, *active; + unsigned long flags; + + GEM_TRACE("%s\n", engine->name); + + /* + * 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->init_hw() and also writing the ELSP. + * Turning off the execlists->tasklet until the reset is over + * prevents the race. + */ + __tasklet_disable_sync_once(&execlists->tasklet); + + spin_lock_irqsave(&engine->timeline.lock, flags); + + /* + * We want to flush the pending context switches, having disabled + * the tasklet above, we can assume exclusive access to the execlists. + * For this allows us to catch up with an inflight preemption event, + * and avoid blaming an innocent request if the stall was due to the + * preemption itself. + */ + process_csb(engine); + + /* + * The last active request can then be no later than the last request + * now in ELSP[0]. So search backwards from there, so that if the GPU + * has advanced beyond the last CSB update, it will be pardoned. + */ + active = NULL; + request = port_request(execlists->port); + if (request) { + /* + * Prevent the breadcrumb from advancing before we decide + * which request is currently active. + */ + intel_engine_stop_cs(engine); + + list_for_each_entry_from_reverse(request, + &engine->timeline.requests, + link) { + if (__i915_request_completed(request, + request->global_seqno)) + break; + + active = request; + } + } + + spin_unlock_irqrestore(&engine->timeline.lock, flags); + + return active; +} + +static void execlists_reset(struct intel_engine_cs *engine, + struct i915_request *request) +{ + struct intel_engine_execlists * const execlists = &engine->execlists; + unsigned long flags; + u32 *regs; + + GEM_TRACE("%s request global=%x, current=%d\n", + engine->name, request ? request->global_seqno : 0, + intel_engine_get_seqno(engine)); + + spin_lock_irqsave(&engine->timeline.lock, flags); + + /* + * Catch up with any missed context-switch interrupts. + * + * Ideally we would just read the remaining CSB entries now that we + * know the gpu is idle. However, the CSB registers are sometimes^W + * often trashed across a GPU reset! Instead we have to rely on + * guessing the missed context-switch events by looking at what + * requests were completed. + */ + execlists_cancel_port_requests(execlists); + + /* Push back any incomplete requests for replay after the reset. */ + __unwind_incomplete_requests(engine); + + /* Following the reset, we need to reload the CSB read/write pointers */ + reset_csb_pointers(&engine->execlists); + + spin_unlock_irqrestore(&engine->timeline.lock, flags); + + /* + * 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. + */ + if (!request || request->fence.error != -EIO) + return; + + /* + * 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 = request->hw_context->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, + request->gem_context, engine, request->ring); + + /* Move the RING_HEAD onto the breadcrumb, past the hanging batch */ + regs[CTX_RING_BUFFER_START + 1] = i915_ggtt_offset(request->ring->vma); + + request->ring->head = intel_ring_wrap(request->ring, request->postfix); + regs[CTX_RING_HEAD + 1] = request->ring->head; + + intel_ring_update_space(request->ring); + + /* Reset WaIdleLiteRestore:bdw,skl as well */ + unwind_wa_tail(request); +} + +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 */ + if (!RB_EMPTY_ROOT(&execlists->queue.rb_root)) + tasklet_schedule(&execlists->tasklet); + + /* + * Flush the tasklet while we still have the forcewake to be sure + * that it is not allowed to sleep before we restart and reload a + * context. + * + * As before (with execlists_reset_prepare) we rely on the caller + * serialising multiple attempts to reset so that we know that we + * are the only one manipulating tasklet state. + */ + __tasklet_enable_sync_once(&execlists->tasklet); + + GEM_TRACE("%s\n", engine->name); +} + +static int intel_logical_ring_emit_pdps(struct i915_request *rq) +{ + struct i915_hw_ppgtt *ppgtt = rq->gem_context->ppgtt; + struct intel_engine_cs *engine = rq->engine; + const int num_lri_cmds = GEN8_3LVL_PDPES * 2; + u32 *cs; + int i; + + cs = intel_ring_begin(rq, num_lri_cmds * 2 + 2); + if (IS_ERR(cs)) + return PTR_ERR(cs); + + *cs++ = MI_LOAD_REGISTER_IMM(num_lri_cmds); + for (i = GEN8_3LVL_PDPES - 1; i >= 0; i--) { + const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i); + + *cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(engine, i)); + *cs++ = upper_32_bits(pd_daddr); + *cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(engine, i)); + *cs++ = lower_32_bits(pd_daddr); + } + + *cs++ = MI_NOOP; + intel_ring_advance(rq, cs); + + return 0; +} + +static int gen8_emit_bb_start(struct i915_request *rq, + u64 offset, u32 len, + const unsigned int flags) +{ + u32 *cs; + int ret; + + /* Don't rely in hw updating PDPs, specially in lite-restore. + * Ideally, we should set Force PD Restore in ctx descriptor, + * but we can't. Force Restore would be a second option, but + * it is unsafe in case of lite-restore (because the ctx is + * not idle). PML4 is allocated during ppgtt init so this is + * not needed in 48-bit.*/ + if (rq->gem_context->ppgtt && + (intel_engine_flag(rq->engine) & rq->gem_context->ppgtt->pd_dirty_rings) && + !i915_vm_is_48bit(&rq->gem_context->ppgtt->vm) && + !intel_vgpu_active(rq->i915)) { + ret = intel_logical_ring_emit_pdps(rq); + if (ret) + return ret; + + rq->gem_context->ppgtt->pd_dirty_rings &= ~intel_engine_flag(rq->engine); + } + + cs = intel_ring_begin(rq, 6); + 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, there doesn't seem to be a downside to + * being paranoid and making sure it is set before each batch and + * every context-switch. + * + * Note that if we fail to enable arbitration before the request + * is complete, then we do not see the context-switch interrupt and + * the engine hangs (with RING_HEAD == RING_TAIL). + * + * That satisfies both the GPGPU w/a and our heavy-handed paranoia. + */ + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; + + /* FIXME(BDW): Address space and security selectors. */ + *cs++ = MI_BATCH_BUFFER_START_GEN8 | + (flags & I915_DISPATCH_SECURE ? 0 : BIT(8)) | + (flags & I915_DISPATCH_RS ? MI_BATCH_RESOURCE_STREAMER : 0); + *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) +{ + struct drm_i915_private *dev_priv = engine->i915; + I915_WRITE_IMR(engine, + ~(engine->irq_enable_mask | engine->irq_keep_mask)); + POSTING_READ_FW(RING_IMR(engine->mmio_base)); +} + +static void gen8_logical_ring_disable_irq(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + I915_WRITE_IMR(engine, ~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->id == VCS) + 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 = + i915_ggtt_offset(engine->scratch) + 2 * CACHELINE_BYTES; + 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_GEN9(request->i915)) + 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; +} + +/* + * 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 void 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); +} + +static void gen8_emit_breadcrumb(struct i915_request *request, u32 *cs) +{ + /* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */ + BUILD_BUG_ON(I915_GEM_HWS_INDEX_ADDR & (1 << 5)); + + cs = gen8_emit_ggtt_write(cs, request->global_seqno, + intel_hws_seqno_address(request->engine)); + *cs++ = MI_USER_INTERRUPT; + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; + request->tail = intel_ring_offset(request, cs); + assert_ring_tail_valid(request->ring, request->tail); + + gen8_emit_wa_tail(request, cs); +} +static const int gen8_emit_breadcrumb_sz = 6 + WA_TAIL_DWORDS; + +static void gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs) +{ + /* We're using qword write, seqno should be aligned to 8 bytes. */ + BUILD_BUG_ON(I915_GEM_HWS_INDEX & 1); + + cs = gen8_emit_ggtt_write_rcs(cs, request->global_seqno, + intel_hws_seqno_address(request->engine)); + *cs++ = MI_USER_INTERRUPT; + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; + request->tail = intel_ring_offset(request, cs); + assert_ring_tail_valid(request->ring, request->tail); + + gen8_emit_wa_tail(request, cs); +} +static const int gen8_emit_breadcrumb_rcs_sz = 8 + WA_TAIL_DWORDS; + +static int gen8_init_rcs_context(struct i915_request *rq) +{ + int ret; + + ret = intel_ctx_workarounds_emit(rq); + if (ret) + return ret; + + ret = intel_rcs_context_init_mocs(rq); + /* + * Failing to program the MOCS is non-fatal.The system will not + * run at peak performance. So generate an error and carry on. + */ + if (ret) + DRM_ERROR("MOCS failed to program: expect performance issues.\n"); + + return i915_gem_render_state_emit(rq); +} + +/** + * intel_logical_ring_cleanup() - deallocate the Engine Command Streamer + * @engine: Engine Command Streamer. + */ +void intel_logical_ring_cleanup(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv; + + /* + * Tasklet cannot be active at this point due intel_mark_active/idle + * so this is just for documentation. + */ + if (WARN_ON(test_bit(TASKLET_STATE_SCHED, + &engine->execlists.tasklet.state))) + tasklet_kill(&engine->execlists.tasklet); + + dev_priv = engine->i915; + + if (engine->buffer) { + WARN_ON((I915_READ_MODE(engine) & MODE_IDLE) == 0); + } + + if (engine->cleanup) + engine->cleanup(engine); + + intel_engine_cleanup_common(engine); + + lrc_destroy_wa_ctx(engine); + + engine->i915 = NULL; + dev_priv->engine[engine->id] = NULL; + kfree(engine); +} + +void intel_execlists_set_default_submission(struct intel_engine_cs *engine) +{ + engine->submit_request = execlists_submit_request; + engine->cancel_requests = execlists_cancel_requests; + engine->schedule = execlists_schedule; + engine->execlists.tasklet.func = execlists_submission_tasklet; + + engine->reset.prepare = execlists_reset_prepare; + + engine->park = NULL; + engine->unpark = NULL; + + engine->flags |= I915_ENGINE_SUPPORTS_STATS; + if (engine->i915->preempt_context) + engine->flags |= I915_ENGINE_HAS_PREEMPTION; + + engine->i915->caps.scheduler = + I915_SCHEDULER_CAP_ENABLED | + I915_SCHEDULER_CAP_PRIORITY; + if (intel_engine_has_preemption(engine)) + engine->i915->caps.scheduler |= I915_SCHEDULER_CAP_PREEMPTION; +} + +static void +logical_ring_default_vfuncs(struct intel_engine_cs *engine) +{ + /* Default vfuncs which can be overriden by each engine. */ + engine->init_hw = gen8_init_common_ring; + + engine->reset.prepare = execlists_reset_prepare; + engine->reset.reset = execlists_reset; + engine->reset.finish = execlists_reset_finish; + + engine->context_pin = execlists_context_pin; + engine->request_alloc = execlists_request_alloc; + + engine->emit_flush = gen8_emit_flush; + engine->emit_breadcrumb = gen8_emit_breadcrumb; + engine->emit_breadcrumb_sz = gen8_emit_breadcrumb_sz; + + engine->set_default_submission = intel_execlists_set_default_submission; + + if (INTEL_GEN(engine->i915) < 11) { + engine->irq_enable = gen8_logical_ring_enable_irq; + engine->irq_disable = gen8_logical_ring_disable_irq; + } else { + /* + * TODO: On Gen11 interrupt masks need to be clear + * to allow C6 entry. Keep interrupts enabled at + * and take the hit of generating extra interrupts + * until a more refined solution exists. + */ + } + engine->emit_bb_start = gen8_emit_bb_start; +} + +static inline void +logical_ring_default_irqs(struct intel_engine_cs *engine) +{ + unsigned int shift = 0; + + if (INTEL_GEN(engine->i915) < 11) { + const u8 irq_shifts[] = { + [RCS] = GEN8_RCS_IRQ_SHIFT, + [BCS] = GEN8_BCS_IRQ_SHIFT, + [VCS] = GEN8_VCS1_IRQ_SHIFT, + [VCS2] = GEN8_VCS2_IRQ_SHIFT, + [VECS] = GEN8_VECS_IRQ_SHIFT, + }; + + shift = irq_shifts[engine->id]; + } + + engine->irq_enable_mask = GT_RENDER_USER_INTERRUPT << shift; + engine->irq_keep_mask = GT_CONTEXT_SWITCH_INTERRUPT << shift; +} + +static void +logical_ring_setup(struct intel_engine_cs *engine) +{ + intel_engine_setup_common(engine); + + /* Intentionally left blank. */ + engine->buffer = NULL; + + tasklet_init(&engine->execlists.tasklet, + execlists_submission_tasklet, (unsigned long)engine); + + logical_ring_default_vfuncs(engine); + logical_ring_default_irqs(engine); +} + +static bool csb_force_mmio(struct drm_i915_private *i915) +{ + /* Older GVT emulation depends upon intercepting CSB mmio */ + return intel_vgpu_active(i915) && !intel_vgpu_has_hwsp_emulation(i915); +} + +static int logical_ring_init(struct intel_engine_cs *engine) +{ + struct drm_i915_private *i915 = engine->i915; + struct intel_engine_execlists * const execlists = &engine->execlists; + int ret; + + ret = intel_engine_init_common(engine); + if (ret) + goto error; + + if (HAS_LOGICAL_RING_ELSQ(i915)) { + execlists->submit_reg = i915->regs + + i915_mmio_reg_offset(RING_EXECLIST_SQ_CONTENTS(engine)); + execlists->ctrl_reg = i915->regs + + i915_mmio_reg_offset(RING_EXECLIST_CONTROL(engine)); + } else { + execlists->submit_reg = i915->regs + + i915_mmio_reg_offset(RING_ELSP(engine)); + } + + execlists->preempt_complete_status = ~0u; + if (i915->preempt_context) { + struct intel_context *ce = + to_intel_context(i915->preempt_context, engine); + + execlists->preempt_complete_status = + upper_32_bits(ce->lrc_desc); + } + + execlists->csb_read = + i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_PTR(engine)); + if (csb_force_mmio(i915)) { + execlists->csb_status = (u32 __force *) + (i915->regs + i915_mmio_reg_offset(RING_CONTEXT_STATUS_BUF_LO(engine, 0))); + + execlists->csb_write = (u32 __force *)execlists->csb_read; + execlists->csb_write_reset = + _MASKED_FIELD(GEN8_CSB_WRITE_PTR_MASK, + GEN8_CSB_ENTRIES - 1); + } else { + execlists->csb_status = + &engine->status_page.page_addr[I915_HWS_CSB_BUF0_INDEX]; + + execlists->csb_write = + &engine->status_page.page_addr[intel_hws_csb_write_index(i915)]; + execlists->csb_write_reset = GEN8_CSB_ENTRIES - 1; + } + reset_csb_pointers(execlists); + + return 0; + +error: + intel_logical_ring_cleanup(engine); + return ret; +} + +int logical_render_ring_init(struct intel_engine_cs *engine) +{ + struct drm_i915_private *dev_priv = engine->i915; + int ret; + + logical_ring_setup(engine); + + if (HAS_L3_DPF(dev_priv)) + engine->irq_keep_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT; + + /* Override some for render ring. */ + if (INTEL_GEN(dev_priv) >= 9) + engine->init_hw = gen9_init_render_ring; + else + engine->init_hw = gen8_init_render_ring; + engine->init_context = gen8_init_rcs_context; + engine->emit_flush = gen8_emit_flush_render; + engine->emit_breadcrumb = gen8_emit_breadcrumb_rcs; + engine->emit_breadcrumb_sz = gen8_emit_breadcrumb_rcs_sz; + + ret = intel_engine_create_scratch(engine, PAGE_SIZE); + if (ret) + return ret; + + ret = intel_init_workaround_bb(engine); + if (ret) { + /* + * We continue even if we fail to initialize WA batch + * because we only expect rare glitches but nothing + * critical to prevent us from using GPU + */ + DRM_ERROR("WA batch buffer initialization failed: %d\n", + ret); + } + + return logical_ring_init(engine); +} + +int logical_xcs_ring_init(struct intel_engine_cs *engine) +{ + logical_ring_setup(engine); + + return logical_ring_init(engine); +} + +static u32 +make_rpcs(struct drm_i915_private *dev_priv) +{ + u32 rpcs = 0; + + /* + * No explicit RPCS request is needed to ensure full + * slice/subslice/EU enablement prior to Gen9. + */ + if (INTEL_GEN(dev_priv) < 9) + return 0; + + /* + * Starting in Gen9, render power gating can leave + * slice/subslice/EU in a partially enabled state. We + * must make an explicit request through RPCS for full + * enablement. + */ + if (INTEL_INFO(dev_priv)->sseu.has_slice_pg) { + rpcs |= GEN8_RPCS_S_CNT_ENABLE; + rpcs |= hweight8(INTEL_INFO(dev_priv)->sseu.slice_mask) << + GEN8_RPCS_S_CNT_SHIFT; + rpcs |= GEN8_RPCS_ENABLE; + } + + if (INTEL_INFO(dev_priv)->sseu.has_subslice_pg) { + rpcs |= GEN8_RPCS_SS_CNT_ENABLE; + rpcs |= hweight8(INTEL_INFO(dev_priv)->sseu.subslice_mask[0]) << + GEN8_RPCS_SS_CNT_SHIFT; + rpcs |= GEN8_RPCS_ENABLE; + } + + if (INTEL_INFO(dev_priv)->sseu.has_eu_pg) { + rpcs |= INTEL_INFO(dev_priv)->sseu.eu_per_subslice << + GEN8_RPCS_EU_MIN_SHIFT; + rpcs |= INTEL_INFO(dev_priv)->sseu.eu_per_subslice << + GEN8_RPCS_EU_MAX_SHIFT; + rpcs |= GEN8_RPCS_ENABLE; + } + + return rpcs; +} + +static u32 intel_lr_indirect_ctx_offset(struct intel_engine_cs *engine) +{ + u32 indirect_ctx_offset; + + switch (INTEL_GEN(engine->i915)) { + default: + MISSING_CASE(INTEL_GEN(engine->i915)); + /* fall through */ + case 11: + indirect_ctx_offset = + GEN11_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; + break; + case 10: + indirect_ctx_offset = + GEN10_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; + break; + case 9: + indirect_ctx_offset = + GEN9_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; + break; + case 8: + indirect_ctx_offset = + GEN8_CTX_RCS_INDIRECT_CTX_OFFSET_DEFAULT; + break; + } + + return indirect_ctx_offset; +} + +static void execlists_init_reg_state(u32 *regs, + struct i915_gem_context *ctx, + struct intel_engine_cs *engine, + struct intel_ring *ring) +{ + struct drm_i915_private *dev_priv = engine->i915; + struct i915_hw_ppgtt *ppgtt = ctx->ppgtt ?: dev_priv->mm.aliasing_ppgtt; + u32 base = engine->mmio_base; + bool rcs = engine->class == RENDER_CLASS; + + /* A context is actually a big batch buffer with several + * MI_LOAD_REGISTER_IMM commands followed by (reg, value) pairs. The + * values we are setting here are only for the first context restore: + * on a subsequent save, the GPU will recreate this batchbuffer with new + * values (including all the missing MI_LOAD_REGISTER_IMM commands that + * we are not initializing here). + */ + regs[CTX_LRI_HEADER_0] = MI_LOAD_REGISTER_IMM(rcs ? 14 : 11) | + MI_LRI_FORCE_POSTED; + + CTX_REG(regs, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(engine), + _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT) | + _MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH | + (HAS_RESOURCE_STREAMER(dev_priv) ? + CTX_CTRL_RS_CTX_ENABLE : 0))); + CTX_REG(regs, CTX_RING_HEAD, RING_HEAD(base), 0); + CTX_REG(regs, CTX_RING_TAIL, RING_TAIL(base), 0); + CTX_REG(regs, CTX_RING_BUFFER_START, RING_START(base), 0); + CTX_REG(regs, CTX_RING_BUFFER_CONTROL, RING_CTL(base), + RING_CTL_SIZE(ring->size) | RING_VALID); + CTX_REG(regs, CTX_BB_HEAD_U, RING_BBADDR_UDW(base), 0); + CTX_REG(regs, CTX_BB_HEAD_L, RING_BBADDR(base), 0); + CTX_REG(regs, CTX_BB_STATE, RING_BBSTATE(base), RING_BB_PPGTT); + CTX_REG(regs, CTX_SECOND_BB_HEAD_U, RING_SBBADDR_UDW(base), 0); + CTX_REG(regs, CTX_SECOND_BB_HEAD_L, RING_SBBADDR(base), 0); + CTX_REG(regs, CTX_SECOND_BB_STATE, RING_SBBSTATE(base), 0); + if (rcs) { + struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx; + + CTX_REG(regs, CTX_RCS_INDIRECT_CTX, RING_INDIRECT_CTX(base), 0); + CTX_REG(regs, CTX_RCS_INDIRECT_CTX_OFFSET, + RING_INDIRECT_CTX_OFFSET(base), 0); + if (wa_ctx->indirect_ctx.size) { + u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma); + + regs[CTX_RCS_INDIRECT_CTX + 1] = + (ggtt_offset + wa_ctx->indirect_ctx.offset) | + (wa_ctx->indirect_ctx.size / CACHELINE_BYTES); + + regs[CTX_RCS_INDIRECT_CTX_OFFSET + 1] = + intel_lr_indirect_ctx_offset(engine) << 6; + } + + CTX_REG(regs, CTX_BB_PER_CTX_PTR, RING_BB_PER_CTX_PTR(base), 0); + if (wa_ctx->per_ctx.size) { + u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma); + + regs[CTX_BB_PER_CTX_PTR + 1] = + (ggtt_offset + wa_ctx->per_ctx.offset) | 0x01; + } + } + + regs[CTX_LRI_HEADER_1] = MI_LOAD_REGISTER_IMM(9) | MI_LRI_FORCE_POSTED; + + CTX_REG(regs, CTX_CTX_TIMESTAMP, RING_CTX_TIMESTAMP(base), 0); + /* PDP values well be assigned later if needed */ + CTX_REG(regs, CTX_PDP3_UDW, GEN8_RING_PDP_UDW(engine, 3), 0); + CTX_REG(regs, CTX_PDP3_LDW, GEN8_RING_PDP_LDW(engine, 3), 0); + CTX_REG(regs, CTX_PDP2_UDW, GEN8_RING_PDP_UDW(engine, 2), 0); + CTX_REG(regs, CTX_PDP2_LDW, GEN8_RING_PDP_LDW(engine, 2), 0); + CTX_REG(regs, CTX_PDP1_UDW, GEN8_RING_PDP_UDW(engine, 1), 0); + CTX_REG(regs, CTX_PDP1_LDW, GEN8_RING_PDP_LDW(engine, 1), 0); + CTX_REG(regs, CTX_PDP0_UDW, GEN8_RING_PDP_UDW(engine, 0), 0); + CTX_REG(regs, CTX_PDP0_LDW, GEN8_RING_PDP_LDW(engine, 0), 0); + + if (ppgtt && i915_vm_is_48bit(&ppgtt->vm)) { + /* 64b PPGTT (48bit canonical) + * PDP0_DESCRIPTOR contains the base address to PML4 and + * other PDP Descriptors are ignored. + */ + ASSIGN_CTX_PML4(ppgtt, regs); + } + + if (rcs) { + regs[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1); + CTX_REG(regs, CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE, + make_rpcs(dev_priv)); + + i915_oa_init_reg_state(engine, ctx, regs); + } +} + +static int +populate_lr_context(struct i915_gem_context *ctx, + struct drm_i915_gem_object *ctx_obj, + struct intel_engine_cs *engine, + struct intel_ring *ring) +{ + void *vaddr; + u32 *regs; + int ret; + + ret = i915_gem_object_set_to_cpu_domain(ctx_obj, true); + if (ret) { + DRM_DEBUG_DRIVER("Could not set to CPU domain\n"); + return ret; + } + + vaddr = i915_gem_object_pin_map(ctx_obj, I915_MAP_WB); + if (IS_ERR(vaddr)) { + ret = PTR_ERR(vaddr); + DRM_DEBUG_DRIVER("Could not map object pages! (%d)\n", ret); + return ret; + } + ctx_obj->mm.dirty = true; + + if (engine->default_state) { + /* + * We only want to copy over the template context state; + * skipping over the headers reserved for GuC communication, + * leaving those as zero. + */ + const unsigned long start = LRC_HEADER_PAGES * PAGE_SIZE; + void *defaults; + + defaults = i915_gem_object_pin_map(engine->default_state, + I915_MAP_WB); + if (IS_ERR(defaults)) { + ret = PTR_ERR(defaults); + goto err_unpin_ctx; + } + + memcpy(vaddr + start, defaults + start, engine->context_size); + i915_gem_object_unpin_map(engine->default_state); + } + + /* The second page of the context object contains some fields which must + * be set up prior to the first execution. */ + regs = vaddr + LRC_STATE_PN * PAGE_SIZE; + execlists_init_reg_state(regs, ctx, engine, ring); + if (!engine->default_state) + regs[CTX_CONTEXT_CONTROL + 1] |= + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT); + if (ctx == ctx->i915->preempt_context && INTEL_GEN(engine->i915) < 11) + regs[CTX_CONTEXT_CONTROL + 1] |= + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT); + +err_unpin_ctx: + i915_gem_object_unpin_map(ctx_obj); + return ret; +} + +static int execlists_context_deferred_alloc(struct i915_gem_context *ctx, + struct intel_engine_cs *engine, + struct intel_context *ce) +{ + struct drm_i915_gem_object *ctx_obj; + struct i915_vma *vma; + uint32_t context_size; + struct intel_ring *ring; + struct i915_timeline *timeline; + int ret; + + if (ce->state) + return 0; + + context_size = round_up(engine->context_size, I915_GTT_PAGE_SIZE); + + /* + * Before the actual start of the context image, we insert a few pages + * for our own use and for sharing with the GuC. + */ + context_size += LRC_HEADER_PAGES * PAGE_SIZE; + + ctx_obj = i915_gem_object_create(ctx->i915, context_size); + if (IS_ERR(ctx_obj)) + return PTR_ERR(ctx_obj); + + vma = i915_vma_instance(ctx_obj, &ctx->i915->ggtt.vm, NULL); + if (IS_ERR(vma)) { + ret = PTR_ERR(vma); + goto error_deref_obj; + } + + timeline = i915_timeline_create(ctx->i915, ctx->name); + if (IS_ERR(timeline)) { + ret = PTR_ERR(timeline); + goto error_deref_obj; + } + + ring = intel_engine_create_ring(engine, timeline, ctx->ring_size); + i915_timeline_put(timeline); + if (IS_ERR(ring)) { + ret = PTR_ERR(ring); + goto error_deref_obj; + } + + ret = populate_lr_context(ctx, ctx_obj, engine, ring); + if (ret) { + DRM_DEBUG_DRIVER("Failed to populate LRC: %d\n", ret); + goto error_ring_free; + } + + ce->ring = ring; + ce->state = vma; + + return 0; + +error_ring_free: + intel_ring_free(ring); +error_deref_obj: + i915_gem_object_put(ctx_obj); + return ret; +} + +void intel_lr_context_resume(struct drm_i915_private *dev_priv) +{ + struct intel_engine_cs *engine; + struct i915_gem_context *ctx; + enum intel_engine_id id; + + /* 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. + * + * So to avoid that we reset the context images upon resume. For + * simplicity, we just zero everything out. + */ + list_for_each_entry(ctx, &dev_priv->contexts.list, link) { + for_each_engine(engine, dev_priv, id) { + struct intel_context *ce = + to_intel_context(ctx, engine); + u32 *reg; + + if (!ce->state) + continue; + + reg = i915_gem_object_pin_map(ce->state->obj, + I915_MAP_WB); + if (WARN_ON(IS_ERR(reg))) + continue; + + reg += LRC_STATE_PN * PAGE_SIZE / sizeof(*reg); + reg[CTX_RING_HEAD+1] = 0; + reg[CTX_RING_TAIL+1] = 0; + + ce->state->obj->mm.dirty = true; + i915_gem_object_unpin_map(ce->state->obj); + + intel_ring_reset(ce->ring, 0); + } + } +} + +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) +#include "selftests/intel_lrc.c" +#endif |