From 987046ad65361a8b038fbf8d76d152237fb7acf1 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 28 Apr 2016 09:56:46 +0100 Subject: [PATCH] drm/i915: Unify intel_ring_begin() Combine the near identical implementations of intel_logical_ring_begin() and intel_ring_begin() - the only difference is that the logical wait has to check for a matching ring (which is assumed by legacy). In the process some debug messages are culled as there were following a WARN if we hit an actual error. v2: Updated commentary Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Cc: Tvrtko Ursulin Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/1461833819-3991-12-git-send-email-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_lrc.c | 146 ++----------------------- drivers/gpu/drm/i915/intel_lrc.h | 1 - drivers/gpu/drm/i915/intel_mocs.c | 12 +- drivers/gpu/drm/i915/intel_ringbuffer.c | 188 +++++++++++++------------------- drivers/gpu/drm/i915/intel_ringbuffer.h | 3 - 5 files changed, 89 insertions(+), 261 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 1b065e7..b07daf2 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -721,48 +721,6 @@ int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request return ret; } -static int logical_ring_wait_for_space(struct drm_i915_gem_request *req, - int bytes) -{ - struct intel_ringbuffer *ringbuf = req->ringbuf; - struct intel_engine_cs *engine = req->engine; - struct drm_i915_gem_request *target; - unsigned space; - int ret; - - if (intel_ring_space(ringbuf) >= bytes) - return 0; - - /* The whole point of reserving space is to not wait! */ - WARN_ON(ringbuf->reserved_in_use); - - list_for_each_entry(target, &engine->request_list, list) { - /* - * The request queue is per-engine, so can contain requests - * from multiple ringbuffers. Here, we must ignore any that - * aren't from the ringbuffer we're considering. - */ - if (target->ringbuf != ringbuf) - continue; - - /* Would completion of this request free enough space? */ - space = __intel_ring_space(target->postfix, ringbuf->tail, - ringbuf->size); - if (space >= bytes) - break; - } - - if (WARN_ON(&target->list == &engine->request_list)) - return -ENOSPC; - - ret = i915_wait_request(target); - if (ret) - return ret; - - ringbuf->space = space; - return 0; -} - /* * intel_logical_ring_advance_and_submit() - advance the tail and submit the workload * @request: Request to advance the logical ringbuffer of. @@ -814,92 +772,6 @@ intel_logical_ring_advance_and_submit(struct drm_i915_gem_request *request) return 0; } -static void __wrap_ring_buffer(struct intel_ringbuffer *ringbuf) -{ - uint32_t __iomem *virt; - int rem = ringbuf->size - ringbuf->tail; - - virt = ringbuf->virtual_start + ringbuf->tail; - rem /= 4; - while (rem--) - iowrite32(MI_NOOP, virt++); - - ringbuf->tail = 0; - intel_ring_update_space(ringbuf); -} - -static int logical_ring_prepare(struct drm_i915_gem_request *req, int bytes) -{ - struct intel_ringbuffer *ringbuf = req->ringbuf; - int remain_usable = ringbuf->effective_size - ringbuf->tail; - int remain_actual = ringbuf->size - ringbuf->tail; - int ret, total_bytes, wait_bytes = 0; - bool need_wrap = false; - - if (ringbuf->reserved_in_use) - total_bytes = bytes; - else - total_bytes = bytes + ringbuf->reserved_size; - - if (unlikely(bytes > remain_usable)) { - /* - * Not enough space for the basic request. So need to flush - * out the remainder and then wait for base + reserved. - */ - wait_bytes = remain_actual + total_bytes; - need_wrap = true; - } else { - if (unlikely(total_bytes > remain_usable)) { - /* - * The base request will fit but the reserved space - * falls off the end. So don't need an immediate wrap - * and only need to effectively wait for the reserved - * size space from the start of ringbuffer. - */ - wait_bytes = remain_actual + ringbuf->reserved_size; - } else if (total_bytes > ringbuf->space) { - /* No wrapping required, just waiting. */ - wait_bytes = total_bytes; - } - } - - if (wait_bytes) { - ret = logical_ring_wait_for_space(req, wait_bytes); - if (unlikely(ret)) - return ret; - - if (need_wrap) - __wrap_ring_buffer(ringbuf); - } - - return 0; -} - -/** - * intel_logical_ring_begin() - prepare the logical ringbuffer to accept some commands - * - * @req: The request to start some new work for - * @num_dwords: number of DWORDs that we plan to write to the ringbuffer. - * - * The ringbuffer might not be ready to accept the commands right away (maybe it needs to - * be wrapped, or wait a bit for the tail to be updated). This function takes care of that - * and also preallocates a request (every workload submission is still mediated through - * requests, same as it did with legacy ringbuffer submission). - * - * Return: non-zero if the ringbuffer is not ready to be written to. - */ -int intel_logical_ring_begin(struct drm_i915_gem_request *req, int num_dwords) -{ - int ret; - - ret = logical_ring_prepare(req, num_dwords * sizeof(uint32_t)); - if (ret) - return ret; - - req->ringbuf->space -= num_dwords * sizeof(uint32_t); - return 0; -} - int intel_logical_ring_reserve_space(struct drm_i915_gem_request *request) { /* @@ -912,7 +784,7 @@ int intel_logical_ring_reserve_space(struct drm_i915_gem_request *request) */ intel_ring_reserved_space_reserve(request->ringbuf, MIN_SPACE_FOR_ADD_REQUEST); - return intel_logical_ring_begin(request, 0); + return intel_ring_begin(request, 0); } /** @@ -982,7 +854,7 @@ int intel_execlists_submission(struct i915_execbuffer_params *params, if (engine == &dev_priv->engine[RCS] && instp_mode != dev_priv->relative_constants_mode) { - ret = intel_logical_ring_begin(params->request, 4); + ret = intel_ring_begin(params->request, 4); if (ret) return ret; @@ -1178,7 +1050,7 @@ static int intel_logical_ring_workarounds_emit(struct drm_i915_gem_request *req) if (ret) return ret; - ret = intel_logical_ring_begin(req, w->count * 2 + 2); + ret = intel_ring_begin(req, w->count * 2 + 2); if (ret) return ret; @@ -1671,7 +1543,7 @@ static int intel_logical_ring_emit_pdps(struct drm_i915_gem_request *req) const int num_lri_cmds = GEN8_LEGACY_PDPES * 2; int i, ret; - ret = intel_logical_ring_begin(req, num_lri_cmds * 2 + 2); + ret = intel_ring_begin(req, num_lri_cmds * 2 + 2); if (ret) return ret; @@ -1718,7 +1590,7 @@ static int gen8_emit_bb_start(struct drm_i915_gem_request *req, req->ctx->ppgtt->pd_dirty_rings &= ~intel_engine_flag(req->engine); } - ret = intel_logical_ring_begin(req, 4); + ret = intel_ring_begin(req, 4); if (ret) return ret; @@ -1780,7 +1652,7 @@ static int gen8_emit_flush(struct drm_i915_gem_request *request, uint32_t cmd; int ret; - ret = intel_logical_ring_begin(request, 4); + ret = intel_ring_begin(request, 4); if (ret) return ret; @@ -1848,7 +1720,7 @@ static int gen8_emit_flush_render(struct drm_i915_gem_request *request, vf_flush_wa = true; } - ret = intel_logical_ring_begin(request, vf_flush_wa ? 12 : 6); + ret = intel_ring_begin(request, vf_flush_wa ? 12 : 6); if (ret) return ret; @@ -1922,7 +1794,7 @@ static int gen8_emit_request(struct drm_i915_gem_request *request) struct intel_ringbuffer *ringbuf = request->ringbuf; int ret; - ret = intel_logical_ring_begin(request, 6 + WA_TAIL_DWORDS); + ret = intel_ring_begin(request, 6 + WA_TAIL_DWORDS); if (ret) return ret; @@ -1946,7 +1818,7 @@ static int gen8_emit_request_render(struct drm_i915_gem_request *request) struct intel_ringbuffer *ringbuf = request->ringbuf; int ret; - ret = intel_logical_ring_begin(request, 8 + WA_TAIL_DWORDS); + ret = intel_ring_begin(request, 8 + WA_TAIL_DWORDS); if (ret) return ret; diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h index 461f1ef..60a7385 100644 --- a/drivers/gpu/drm/i915/intel_lrc.h +++ b/drivers/gpu/drm/i915/intel_lrc.h @@ -63,7 +63,6 @@ int intel_logical_ring_reserve_space(struct drm_i915_gem_request *request); void intel_logical_ring_stop(struct intel_engine_cs *engine); void intel_logical_ring_cleanup(struct intel_engine_cs *engine); int intel_logical_rings_init(struct drm_device *dev); -int intel_logical_ring_begin(struct drm_i915_gem_request *req, int num_dwords); int logical_ring_flush_all_caches(struct drm_i915_gem_request *req); /** diff --git a/drivers/gpu/drm/i915/intel_mocs.c b/drivers/gpu/drm/i915/intel_mocs.c index 23b8545..6ba4bf7 100644 --- a/drivers/gpu/drm/i915/intel_mocs.c +++ b/drivers/gpu/drm/i915/intel_mocs.c @@ -239,11 +239,9 @@ static int emit_mocs_control_table(struct drm_i915_gem_request *req, if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES)) return -ENODEV; - ret = intel_logical_ring_begin(req, 2 + 2 * GEN9_NUM_MOCS_ENTRIES); - if (ret) { - DRM_DEBUG("intel_logical_ring_begin failed %d\n", ret); + ret = intel_ring_begin(req, 2 + 2 * GEN9_NUM_MOCS_ENTRIES); + if (ret) return ret; - } intel_logical_ring_emit(ringbuf, MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES)); @@ -305,11 +303,9 @@ static int emit_mocs_l3cc_table(struct drm_i915_gem_request *req, if (WARN_ON(table->size > GEN9_NUM_MOCS_ENTRIES)) return -ENODEV; - ret = intel_logical_ring_begin(req, 2 + GEN9_NUM_MOCS_ENTRIES); - if (ret) { - DRM_DEBUG("intel_logical_ring_begin failed %d\n", ret); + ret = intel_ring_begin(req, 2 + GEN9_NUM_MOCS_ENTRIES); + if (ret) return ret; - } intel_logical_ring_emit(ringbuf, MI_LOAD_REGISTER_IMM(GEN9_NUM_MOCS_ENTRIES / 2)); diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 461ea71..87822b6 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -53,12 +53,6 @@ void intel_ring_update_space(struct intel_ringbuffer *ringbuf) ringbuf->tail, ringbuf->size); } -int intel_ring_space(struct intel_ringbuffer *ringbuf) -{ - intel_ring_update_space(ringbuf); - return ringbuf->space; -} - bool intel_engine_stopped(struct intel_engine_cs *engine) { struct drm_i915_private *dev_priv = engine->dev->dev_private; @@ -2325,51 +2319,6 @@ void intel_cleanup_engine(struct intel_engine_cs *engine) engine->dev = NULL; } -static int ring_wait_for_space(struct intel_engine_cs *engine, int n) -{ - struct intel_ringbuffer *ringbuf = engine->buffer; - struct drm_i915_gem_request *request; - unsigned space; - int ret; - - if (intel_ring_space(ringbuf) >= n) - return 0; - - /* The whole point of reserving space is to not wait! */ - WARN_ON(ringbuf->reserved_in_use); - - list_for_each_entry(request, &engine->request_list, list) { - space = __intel_ring_space(request->postfix, ringbuf->tail, - ringbuf->size); - if (space >= n) - break; - } - - if (WARN_ON(&request->list == &engine->request_list)) - return -ENOSPC; - - ret = i915_wait_request(request); - if (ret) - return ret; - - ringbuf->space = space; - return 0; -} - -static void __wrap_ring_buffer(struct intel_ringbuffer *ringbuf) -{ - uint32_t __iomem *virt; - int rem = ringbuf->size - ringbuf->tail; - - virt = ringbuf->virtual_start + ringbuf->tail; - rem /= 4; - while (rem--) - iowrite32(MI_NOOP, virt++); - - ringbuf->tail = 0; - intel_ring_update_space(ringbuf); -} - int intel_engine_idle(struct intel_engine_cs *engine) { struct drm_i915_gem_request *req; @@ -2411,63 +2360,82 @@ int intel_ring_reserve_space(struct drm_i915_gem_request *request) void intel_ring_reserved_space_reserve(struct intel_ringbuffer *ringbuf, int size) { - WARN_ON(ringbuf->reserved_size); - WARN_ON(ringbuf->reserved_in_use); - + GEM_BUG_ON(ringbuf->reserved_size); ringbuf->reserved_size = size; } void intel_ring_reserved_space_cancel(struct intel_ringbuffer *ringbuf) { - WARN_ON(ringbuf->reserved_in_use); - + GEM_BUG_ON(!ringbuf->reserved_size); ringbuf->reserved_size = 0; - ringbuf->reserved_in_use = false; } void intel_ring_reserved_space_use(struct intel_ringbuffer *ringbuf) { - WARN_ON(ringbuf->reserved_in_use); - - ringbuf->reserved_in_use = true; - ringbuf->reserved_tail = ringbuf->tail; + GEM_BUG_ON(!ringbuf->reserved_size); + ringbuf->reserved_size = 0; } void intel_ring_reserved_space_end(struct intel_ringbuffer *ringbuf) { - WARN_ON(!ringbuf->reserved_in_use); - if (ringbuf->tail > ringbuf->reserved_tail) { - WARN(ringbuf->tail > ringbuf->reserved_tail + ringbuf->reserved_size, - "request reserved size too small: %d vs %d!\n", - ringbuf->tail - ringbuf->reserved_tail, ringbuf->reserved_size); - } else { + GEM_BUG_ON(ringbuf->reserved_size); +} + +static int wait_for_space(struct drm_i915_gem_request *req, int bytes) +{ + struct intel_ringbuffer *ringbuf = req->ringbuf; + struct intel_engine_cs *engine = req->engine; + struct drm_i915_gem_request *target; + + intel_ring_update_space(ringbuf); + if (ringbuf->space >= bytes) + return 0; + + /* + * Space is reserved in the ringbuffer for finalising the request, + * as that cannot be allowed to fail. During request finalisation, + * reserved_space is set to 0 to stop the overallocation and the + * assumption is that then we never need to wait (which has the + * risk of failing with EINTR). + * + * See also i915_gem_request_alloc() and i915_add_request(). + */ + GEM_BUG_ON(!ringbuf->reserved_size); + + list_for_each_entry(target, &engine->request_list, list) { + unsigned space; + /* - * The ring was wrapped while the reserved space was in use. - * That means that some unknown amount of the ring tail was - * no-op filled and skipped. Thus simply adding the ring size - * to the tail and doing the above space check will not work. - * Rather than attempt to track how much tail was skipped, - * it is much simpler to say that also skipping the sanity - * check every once in a while is not a big issue. + * The request queue is per-engine, so can contain requests + * from multiple ringbuffers. Here, we must ignore any that + * aren't from the ringbuffer we're considering. */ + if (target->ringbuf != ringbuf) + continue; + + /* Would completion of this request free enough space? */ + space = __intel_ring_space(target->postfix, ringbuf->tail, + ringbuf->size); + if (space >= bytes) + break; } - ringbuf->reserved_size = 0; - ringbuf->reserved_in_use = false; + if (WARN_ON(&target->list == &engine->request_list)) + return -ENOSPC; + + return i915_wait_request(target); } -static int __intel_ring_prepare(struct intel_engine_cs *engine, int bytes) +int intel_ring_begin(struct drm_i915_gem_request *req, int num_dwords) { - struct intel_ringbuffer *ringbuf = engine->buffer; - int remain_usable = ringbuf->effective_size - ringbuf->tail; + struct intel_ringbuffer *ringbuf = req->ringbuf; int remain_actual = ringbuf->size - ringbuf->tail; - int ret, total_bytes, wait_bytes = 0; + int remain_usable = ringbuf->effective_size - ringbuf->tail; + int bytes = num_dwords * sizeof(u32); + int total_bytes, wait_bytes; bool need_wrap = false; - if (ringbuf->reserved_in_use) - total_bytes = bytes; - else - total_bytes = bytes + ringbuf->reserved_size; + total_bytes = bytes + ringbuf->reserved_size; if (unlikely(bytes > remain_usable)) { /* @@ -2476,44 +2444,40 @@ static int __intel_ring_prepare(struct intel_engine_cs *engine, int bytes) */ wait_bytes = remain_actual + total_bytes; need_wrap = true; + } else if (unlikely(total_bytes > remain_usable)) { + /* + * The base request will fit but the reserved space + * falls off the end. So we don't need an immediate wrap + * and only need to effectively wait for the reserved + * size space from the start of ringbuffer. + */ + wait_bytes = remain_actual + ringbuf->reserved_size; } else { - if (unlikely(total_bytes > remain_usable)) { - /* - * The base request will fit but the reserved space - * falls off the end. So don't need an immediate wrap - * and only need to effectively wait for the reserved - * size space from the start of ringbuffer. - */ - wait_bytes = remain_actual + ringbuf->reserved_size; - } else if (total_bytes > ringbuf->space) { - /* No wrapping required, just waiting. */ - wait_bytes = total_bytes; - } + /* No wrapping required, just waiting. */ + wait_bytes = total_bytes; } - if (wait_bytes) { - ret = ring_wait_for_space(engine, wait_bytes); + if (wait_bytes > ringbuf->space) { + int ret = wait_for_space(req, wait_bytes); if (unlikely(ret)) return ret; - if (need_wrap) - __wrap_ring_buffer(ringbuf); + intel_ring_update_space(ringbuf); } - return 0; -} + if (unlikely(need_wrap)) { + GEM_BUG_ON(remain_actual > ringbuf->space); + GEM_BUG_ON(ringbuf->tail + remain_actual > ringbuf->size); -int intel_ring_begin(struct drm_i915_gem_request *req, - int num_dwords) -{ - struct intel_engine_cs *engine = req->engine; - int ret; - - ret = __intel_ring_prepare(engine, num_dwords * sizeof(uint32_t)); - if (ret) - return ret; + /* Fill the tail with MI_NOOP */ + memset(ringbuf->virtual_start + ringbuf->tail, + 0, remain_actual); + ringbuf->tail = 0; + ringbuf->space -= remain_actual; + } - engine->buffer->space -= num_dwords * sizeof(uint32_t); + ringbuf->space -= bytes; + GEM_BUG_ON(ringbuf->space < 0); return 0; } diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index 2ade194..201e775 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -108,8 +108,6 @@ struct intel_ringbuffer { int size; int effective_size; int reserved_size; - int reserved_tail; - bool reserved_in_use; /** We track the position of the requests in the ring buffer, and * when each is retired we increment last_retired_head as the GPU @@ -459,7 +457,6 @@ static inline void intel_ring_advance(struct intel_engine_cs *engine) } int __intel_ring_space(int head, int tail, int size); void intel_ring_update_space(struct intel_ringbuffer *ringbuf); -int intel_ring_space(struct intel_ringbuffer *ringbuf); bool intel_engine_stopped(struct intel_engine_cs *engine); int __must_check intel_engine_idle(struct intel_engine_cs *engine); -- 2.7.4