linux/drivers/gpu/drm/i915/intel_engine_cs.c
Chris Wilson 20311bd350 drm/i915/scheduler: Execute requests in order of priorities
Track the priority of each request and use it to determine the order in
which we submit requests to the hardware via execlists.

The priority of the request is determined by the user (eventually via
the context) but may be overridden at any time by the driver. When we set
the priority of the request, we bump the priority of all of its
dependencies to match - so that a high priority drawing operation is not
stuck behind a background task.

When the request is ready to execute (i.e. we have signaled the submit
fence following completion of all its dependencies, including third
party fences), we put the request into a priority sorted rbtree to be
submitted to the hardware. If the request is higher priority than all
pending requests, it will be submitted on the next context-switch
interrupt as soon as the hardware has completed the current request. We
do not currently preempt any current execution to immediately run a very
high priority request, at least not yet.

One more limitation, is that this is first implementation is for
execlists only so currently limited to gen8/gen9.

v2: Replace recursive priority inheritance bumping with an iterative
depth-first search list.
v3: list_next_entry() for walking lists
v4: Explain how the dfs solves the recursion problem with PI.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161114204105.29171-8-chris@chris-wilson.co.uk
2016-11-14 21:01:21 +00:00

469 lines
13 KiB
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() - allocate, populate and init the Engine Command Streamers
* @dev: DRM device.
*
* Return: non-zero if the initialization failed.
*/
int intel_engines_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
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;
int (*init)(struct intel_engine_cs *engine);
struct intel_engine_cs *engine;
enum intel_engine_id id;
unsigned int i;
int ret;
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;
if (i915.enable_execlists)
init = intel_engines[i].init_execlists;
else
init = intel_engines[i].init_legacy;
if (!init)
continue;
ret = intel_engine_setup(dev_priv, i);
if (ret)
goto cleanup;
ret = init(dev_priv->engine[i]);
if (ret)
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) {
if (i915.enable_execlists)
intel_logical_ring_cleanup(engine);
else
intel_engine_cleanup(engine);
}
return ret;
}
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->drm, 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_create(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;
ret = intel_engine_init_breadcrumbs(engine);
if (ret)
return ret;
ret = i915_gem_render_state_init(engine);
if (ret)
return ret;
return 0;
}
/**
* 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);
}
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;
}
}