intel_engine_cs.c

/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include "i915_drv.h"
#include "intel_ringbuffer.h"
#include "intel_lrc.h"

static const struct engine_info {
	const char *name;
	unsigned exec_id;
	enum intel_engine_hw_id hw_id;
	u32 mmio_base;
	unsigned irq_shift;
	int (*init_legacy)(struct intel_engine_cs *engine);
	int (*init_execlists)(struct intel_engine_cs *engine);
} intel_engines[] = {
	[RCS] = {
		.name = "render ring",
		.exec_id = I915_EXEC_RENDER,
		.hw_id = RCS_HW,
		.mmio_base = RENDER_RING_BASE,
		.irq_shift = GEN8_RCS_IRQ_SHIFT,
		.init_execlists = logical_render_ring_init,
		.init_legacy = intel_init_render_ring_buffer,
	},
	[BCS] = {
		.name = "blitter ring",
		.exec_id = I915_EXEC_BLT,
		.hw_id = BCS_HW,
		.mmio_base = BLT_RING_BASE,
		.irq_shift = GEN8_BCS_IRQ_SHIFT,
		.init_execlists = logical_xcs_ring_init,
		.init_legacy = intel_init_blt_ring_buffer,
	},
	[VCS] = {
		.name = "bsd ring",
		.exec_id = I915_EXEC_BSD,
		.hw_id = VCS_HW,
		.mmio_base = GEN6_BSD_RING_BASE,
		.irq_shift = GEN8_VCS1_IRQ_SHIFT,
		.init_execlists = logical_xcs_ring_init,
		.init_legacy = intel_init_bsd_ring_buffer,
	},
	[VCS2] = {
		.name = "bsd2 ring",
		.exec_id = I915_EXEC_BSD,
		.hw_id = VCS2_HW,
		.mmio_base = GEN8_BSD2_RING_BASE,
		.irq_shift = GEN8_VCS2_IRQ_SHIFT,
		.init_execlists = logical_xcs_ring_init,
		.init_legacy = intel_init_bsd2_ring_buffer,
	},
	[VECS] = {
		.name = "video enhancement ring",
		.exec_id = I915_EXEC_VEBOX,
		.hw_id = VECS_HW,
		.mmio_base = VEBOX_RING_BASE,
		.irq_shift = GEN8_VECS_IRQ_SHIFT,
		.init_execlists = logical_xcs_ring_init,
		.init_legacy = intel_init_vebox_ring_buffer,
	},
};

static int
intel_engine_setup(struct drm_i915_private *dev_priv,
		   enum intel_engine_id id)
{
	const struct engine_info *info = &intel_engines[id];
	struct intel_engine_cs *engine;

	GEM_BUG_ON(dev_priv->engine[id]);
	engine = kzalloc(sizeof(*engine), GFP_KERNEL);
	if (!engine)
		return -ENOMEM;

	engine->id = id;
	engine->i915 = dev_priv;
	engine->name = info->name;
	engine->exec_id = info->exec_id;
	engine->hw_id = engine->guc_id = info->hw_id;
	engine->mmio_base = info->mmio_base;
	engine->irq_shift = info->irq_shift;

	/* Nothing to do here, execute in order of dependencies */
	engine->schedule = NULL;

	dev_priv->engine[id] = engine;
	return 0;
}

/**
 * intel_engines_init_early() - allocate the Engine Command Streamers
 * @dev_priv: i915 device private
 *
 * Return: non-zero if the initialization failed.
 */
int intel_engines_init_early(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *device_info = mkwrite_device_info(dev_priv);
	unsigned int ring_mask = INTEL_INFO(dev_priv)->ring_mask;
	unsigned int mask = 0;
	struct intel_engine_cs *engine;
	enum intel_engine_id id;
	unsigned int i;
	int err;

	WARN_ON(ring_mask == 0);
	WARN_ON(ring_mask &
		GENMASK(sizeof(mask) * BITS_PER_BYTE - 1, I915_NUM_ENGINES));

	for (i = 0; i < ARRAY_SIZE(intel_engines); i++) {
		if (!HAS_ENGINE(dev_priv, i))
			continue;

		err = intel_engine_setup(dev_priv, i);
		if (err)
			goto cleanup;

		mask |= ENGINE_MASK(i);
	}

	/*
	 * Catch failures to update intel_engines table when the new engines
	 * are added to the driver by a warning and disabling the forgotten
	 * engines.
	 */
	if (WARN_ON(mask != ring_mask))
		device_info->ring_mask = mask;

	device_info->num_rings = hweight32(mask);

	return 0;

cleanup:
	for_each_engine(engine, dev_priv, id)
		kfree(engine);
	return err;
}

/**
 * intel_engines_init() - allocate, populate and init the Engine Command Streamers
 * @dev_priv: i915 device private
 *
 * Return: non-zero if the initialization failed.
 */
int intel_engines_init(struct drm_i915_private *dev_priv)
{
	struct intel_device_info *device_info = mkwrite_device_info(dev_priv);
	struct intel_engine_cs *engine;
	enum intel_engine_id id, err_id;
	unsigned int mask = 0;
	int err = 0;

	for_each_engine(engine, dev_priv, id) {
		int (*init)(struct intel_engine_cs *engine);

		if (i915.enable_execlists)
			init = intel_engines[id].init_execlists;
		else
			init = intel_engines[id].init_legacy;
		if (!init) {
			kfree(engine);
			dev_priv->engine[id] = NULL;
			continue;
		}

		err = init(engine);
		if (err) {
			err_id = id;
			goto cleanup;
		}

		mask |= ENGINE_MASK(id);
	}

	/*
	 * Catch failures to update intel_engines table when the new engines
	 * are added to the driver by a warning and disabling the forgotten
	 * engines.
	 */
	if (WARN_ON(mask != INTEL_INFO(dev_priv)->ring_mask))
		device_info->ring_mask = mask;

	device_info->num_rings = hweight32(mask);

	return 0;

cleanup:
	for_each_engine(engine, dev_priv, id) {
		if (id >= err_id)
			kfree(engine);
		else if (i915.enable_execlists)
			intel_logical_ring_cleanup(engine);
		else
			intel_engine_cleanup(engine);
	}
	return err;
}

void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
{
	struct drm_i915_private *dev_priv = engine->i915;

	/* Our semaphore implementation is strictly monotonic (i.e. we proceed
	 * so long as the semaphore value in the register/page is greater
	 * than the sync value), so whenever we reset the seqno,
	 * so long as we reset the tracking semaphore value to 0, it will
	 * always be before the next request's seqno. If we don't reset
	 * the semaphore value, then when the seqno moves backwards all
	 * future waits will complete instantly (causing rendering corruption).
	 */
	if (IS_GEN6(dev_priv) || IS_GEN7(dev_priv)) {
		I915_WRITE(RING_SYNC_0(engine->mmio_base), 0);
		I915_WRITE(RING_SYNC_1(engine->mmio_base), 0);
		if (HAS_VEBOX(dev_priv))
			I915_WRITE(RING_SYNC_2(engine->mmio_base), 0);
	}
	if (dev_priv->semaphore) {
		struct page *page = i915_vma_first_page(dev_priv->semaphore);
		void *semaphores;

		/* Semaphores are in noncoherent memory, flush to be safe */
		semaphores = kmap(page);
		memset(semaphores + GEN8_SEMAPHORE_OFFSET(engine->id, 0),
		       0, I915_NUM_ENGINES * gen8_semaphore_seqno_size);
		drm_clflush_virt_range(semaphores + GEN8_SEMAPHORE_OFFSET(engine->id, 0),
				       I915_NUM_ENGINES * gen8_semaphore_seqno_size);
		kunmap(page);
	}

	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
	if (engine->irq_seqno_barrier)
		engine->irq_seqno_barrier(engine);

	GEM_BUG_ON(i915_gem_active_isset(&engine->timeline->last_request));
	engine->timeline->last_submitted_seqno = seqno;

	engine->hangcheck.seqno = seqno;

	/* After manually advancing the seqno, fake the interrupt in case
	 * there are any waiters for that seqno.
	 */
	intel_engine_wakeup(engine);
}

static void intel_engine_init_timeline(struct intel_engine_cs *engine)
{
	engine->timeline = &engine->i915->gt.global_timeline.engine[engine->id];
}

/**
 * intel_engines_setup_common - setup engine state not requiring hw access
 * @engine: Engine to setup.
 *
 * Initializes @engine@ structure members shared between legacy and execlists
 * submission modes which do not require hardware access.
 *
 * Typically done early in the submission mode specific engine setup stage.
 */
void intel_engine_setup_common(struct intel_engine_cs *engine)
{
	engine->execlist_queue = RB_ROOT;
	engine->execlist_first = NULL;

	intel_engine_init_timeline(engine);
	intel_engine_init_hangcheck(engine);
	i915_gem_batch_pool_init(engine, &engine->batch_pool);

	intel_engine_init_cmd_parser(engine);
}

int intel_engine_create_scratch(struct intel_engine_cs *engine, int size)
{
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	int ret;

	WARN_ON(engine->scratch);

	obj = i915_gem_object_create_stolen(engine->i915, size);
	if (!obj)
		obj = i915_gem_object_create_internal(engine->i915, size);
	if (IS_ERR(obj)) {
		DRM_ERROR("Failed to allocate scratch page\n");
		return PTR_ERR(obj);
	}

	vma = i915_vma_instance(obj, &engine->i915->ggtt.base, NULL);
	if (IS_ERR(vma)) {
		ret = PTR_ERR(vma);
		goto err_unref;
	}

	ret = i915_vma_pin(vma, 0, 4096, PIN_GLOBAL | PIN_HIGH);
	if (ret)
		goto err_unref;

	engine->scratch = vma;
	DRM_DEBUG_DRIVER("%s pipe control offset: 0x%08x\n",
			 engine->name, i915_ggtt_offset(vma));
	return 0;

err_unref:
	i915_gem_object_put(obj);
	return ret;
}

static void intel_engine_cleanup_scratch(struct intel_engine_cs *engine)
{
	i915_vma_unpin_and_release(&engine->scratch);
}

/**
 * intel_engines_init_common - initialize cengine state which might require hw access
 * @engine: Engine to initialize.
 *
 * Initializes @engine@ structure members shared between legacy and execlists
 * submission modes which do require hardware access.
 *
 * Typcally done at later stages of submission mode specific engine setup.
 *
 * Returns zero on success or an error code on failure.
 */
int intel_engine_init_common(struct intel_engine_cs *engine)
{
	int ret;

	/* We may need to do things with the shrinker which
	 * require us to immediately switch back to the default
	 * context. This can cause a problem as pinning the
	 * default context also requires GTT space which may not
	 * be available. To avoid this we always pin the default
	 * context.
	 */
	ret = engine->context_pin(engine, engine->i915->kernel_context);
	if (ret)
		return ret;

	ret = intel_engine_init_breadcrumbs(engine);
	if (ret)
		goto err_unpin;

	ret = i915_gem_render_state_init(engine);
	if (ret)
		goto err_unpin;

	return 0;

err_unpin:
	engine->context_unpin(engine, engine->i915->kernel_context);
	return ret;
}

/**
 * intel_engines_cleanup_common - cleans up the engine state created by
 *                                the common initiailizers.
 * @engine: Engine to cleanup.
 *
 * This cleans up everything created by the common helpers.
 */
void intel_engine_cleanup_common(struct intel_engine_cs *engine)
{
	intel_engine_cleanup_scratch(engine);

	i915_gem_render_state_fini(engine);
	intel_engine_fini_breadcrumbs(engine);
	intel_engine_cleanup_cmd_parser(engine);
	i915_gem_batch_pool_fini(&engine->batch_pool);

	engine->context_unpin(engine, engine->i915->kernel_context);
}

u64 intel_engine_get_active_head(struct intel_engine_cs *engine)
{
	struct drm_i915_private *dev_priv = engine->i915;
	u64 acthd;

	if (INTEL_GEN(dev_priv) >= 8)
		acthd = I915_READ64_2x32(RING_ACTHD(engine->mmio_base),
					 RING_ACTHD_UDW(engine->mmio_base));
	else if (INTEL_GEN(dev_priv) >= 4)
		acthd = I915_READ(RING_ACTHD(engine->mmio_base));
	else
		acthd = I915_READ(ACTHD);

	return acthd;
}

u64 intel_engine_get_last_batch_head(struct intel_engine_cs *engine)
{
	struct drm_i915_private *dev_priv = engine->i915;
	u64 bbaddr;

	if (INTEL_GEN(dev_priv) >= 8)
		bbaddr = I915_READ64_2x32(RING_BBADDR(engine->mmio_base),
					  RING_BBADDR_UDW(engine->mmio_base));
	else
		bbaddr = I915_READ(RING_BBADDR(engine->mmio_base));

	return bbaddr;
}

const char *i915_cache_level_str(struct drm_i915_private *i915, int type)
{
	switch (type) {
	case I915_CACHE_NONE: return " uncached";
	case I915_CACHE_LLC: return HAS_LLC(i915) ? " LLC" : " snooped";
	case I915_CACHE_L3_LLC: return " L3+LLC";
	case I915_CACHE_WT: return " WT";
	default: return "";
	}
}

static inline uint32_t
read_subslice_reg(struct drm_i915_private *dev_priv, int slice,
		  int subslice, i915_reg_t reg)
{
	uint32_t mcr;
	uint32_t ret;
	enum forcewake_domains fw_domains;

	fw_domains = intel_uncore_forcewake_for_reg(dev_priv, reg,
						    FW_REG_READ);
	fw_domains |= intel_uncore_forcewake_for_reg(dev_priv,
						     GEN8_MCR_SELECTOR,
						     FW_REG_READ | FW_REG_WRITE);

	spin_lock_irq(&dev_priv->uncore.lock);
	intel_uncore_forcewake_get__locked(dev_priv, fw_domains);

	mcr = I915_READ_FW(GEN8_MCR_SELECTOR);
	/*
	 * The HW expects the slice and sublice selectors to be reset to 0
	 * after reading out the registers.
	 */
	WARN_ON_ONCE(mcr & (GEN8_MCR_SLICE_MASK | GEN8_MCR_SUBSLICE_MASK));
	mcr &= ~(GEN8_MCR_SLICE_MASK | GEN8_MCR_SUBSLICE_MASK);
	mcr |= GEN8_MCR_SLICE(slice) | GEN8_MCR_SUBSLICE(subslice);
	I915_WRITE_FW(GEN8_MCR_SELECTOR, mcr);

	ret = I915_READ_FW(reg);

	mcr &= ~(GEN8_MCR_SLICE_MASK | GEN8_MCR_SUBSLICE_MASK);
	I915_WRITE_FW(GEN8_MCR_SELECTOR, mcr);

	intel_uncore_forcewake_put__locked(dev_priv, fw_domains);
	spin_unlock_irq(&dev_priv->uncore.lock);

	return ret;
}

/* NB: please notice the memset */
void intel_engine_get_instdone(struct intel_engine_cs *engine,
			       struct intel_instdone *instdone)
{
	struct drm_i915_private *dev_priv = engine->i915;
	u32 mmio_base = engine->mmio_base;
	int slice;
	int subslice;

	memset(instdone, 0, sizeof(*instdone));

	switch (INTEL_GEN(dev_priv)) {
	default:
		instdone->instdone = I915_READ(RING_INSTDONE(mmio_base));

		if (engine->id != RCS)
			break;

		instdone->slice_common = I915_READ(GEN7_SC_INSTDONE);
		for_each_instdone_slice_subslice(dev_priv, slice, subslice) {
			instdone->sampler[slice][subslice] =
				read_subslice_reg(dev_priv, slice, subslice,
						  GEN7_SAMPLER_INSTDONE);
			instdone->row[slice][subslice] =
				read_subslice_reg(dev_priv, slice, subslice,
						  GEN7_ROW_INSTDONE);
		}
		break;
	case 7:
		instdone->instdone = I915_READ(RING_INSTDONE(mmio_base));

		if (engine->id != RCS)
			break;

		instdone->slice_common = I915_READ(GEN7_SC_INSTDONE);
		instdone->sampler[0][0] = I915_READ(GEN7_SAMPLER_INSTDONE);
		instdone->row[0][0] = I915_READ(GEN7_ROW_INSTDONE);

		break;
	case 6:
	case 5:
	case 4:
		instdone->instdone = I915_READ(RING_INSTDONE(mmio_base));

		if (engine->id == RCS)
			/* HACK: Using the wrong struct member */
			instdone->slice_common = I915_READ(GEN4_INSTDONE1);
		break;
	case 3:
	case 2:
		instdone->instdone = I915_READ(GEN2_INSTDONE);
		break;
	}
}