// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright © 2019 Intel Corporation
 */

#include "i915_selftest.h"
#include "intel_engine_heartbeat.h"
#include "intel_engine_pm.h"
#include "intel_gt.h"

#include "gem/selftests/mock_context.h"
#include "selftests/igt_flush_test.h"
#include "selftests/mock_drm.h"

static int request_sync(struct i915_request *rq)
{
        struct intel_timeline *tl = i915_request_timeline(rq);
        long timeout;
        int err = 0;

        intel_timeline_get(tl);
        i915_request_get(rq);

        /* Opencode i915_request_add() so we can keep the timeline locked. */
        __i915_request_commit(rq);
        rq->sched.attr.priority = I915_PRIORITY_BARRIER;
        __i915_request_queue_bh(rq);

        timeout = i915_request_wait(rq, 0, HZ / 10);
        if (timeout < 0)
                err = timeout;
        else
                i915_request_retire_upto(rq);

        lockdep_unpin_lock(&tl->mutex, rq->cookie);
        mutex_unlock(&tl->mutex);

        i915_request_put(rq);
        intel_timeline_put(tl);

        return err;
}

static int context_sync(struct intel_context *ce)
{
        struct intel_timeline *tl = ce->timeline;
        int err = 0;

        mutex_lock(&tl->mutex);
        do {
                struct i915_request *rq;
                long timeout;

                if (list_empty(&tl->requests))
                        break;

                rq = list_last_entry(&tl->requests, typeof(*rq), link);
                i915_request_get(rq);

                timeout = i915_request_wait(rq, 0, HZ / 10);
                if (timeout < 0)
                        err = timeout;
                else
                        i915_request_retire_upto(rq);

                i915_request_put(rq);
        } while (!err);
        mutex_unlock(&tl->mutex);

        /* Wait for all barriers to complete (remote CPU) before we check */
        i915_active_unlock_wait(&ce->active);
        return err;
}

static int __live_context_size(struct intel_engine_cs *engine)
{
        struct intel_context *ce;
        struct i915_request *rq;
        void *vaddr;
        int err;

        ce = intel_context_create(engine);
        if (IS_ERR(ce))
                return PTR_ERR(ce);

        err = intel_context_pin(ce);
        if (err)
                goto err;

        vaddr = i915_gem_object_pin_map_unlocked(ce->state->obj,
                                                 i915_coherent_map_type(engine->i915,
                                                                        ce->state->obj, false));
        if (IS_ERR(vaddr)) {
                err = PTR_ERR(vaddr);
                intel_context_unpin(ce);
                goto err;
        }

        /*
         * Note that execlists also applies a redzone which it checks on
         * context unpin when debugging. We are using the same location
         * and same poison value so that our checks overlap. Despite the
         * redundancy, we want to keep this little selftest so that we
         * get coverage of any and all submission backends, and we can
         * always extend this test to ensure we trick the HW into a
         * compromising position wrt to the various sections that need
         * to be written into the context state.
         *
         * TLDR; this overlaps with the execlists redzone.
         */
        vaddr += engine->context_size - I915_GTT_PAGE_SIZE;
        memset(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE);

        rq = intel_context_create_request(ce);
        intel_context_unpin(ce);
        if (IS_ERR(rq)) {
                err = PTR_ERR(rq);
                goto err_unpin;
        }

        err = request_sync(rq);
        if (err)
                goto err_unpin;

        /* Force the context switch */
        rq = intel_engine_create_kernel_request(engine);
        if (IS_ERR(rq)) {
                err = PTR_ERR(rq);
                goto err_unpin;
        }
        err = request_sync(rq);
        if (err)
                goto err_unpin;

        if (memchr_inv(vaddr, POISON_INUSE, I915_GTT_PAGE_SIZE)) {
                pr_err("%s context overwrote trailing red-zone!", engine->name);
                err = -EINVAL;
        }

err_unpin:
        i915_gem_object_unpin_map(ce->state->obj);
err:
        intel_context_put(ce);
        return err;
}

static int live_context_size(void *arg)
{
        struct intel_gt *gt = arg;
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        int err = 0;

        /*
         * Check that our context sizes are correct by seeing if the
         * HW tries to write past the end of one.
         */

        for_each_engine(engine, gt, id) {
                struct file *saved;

                if (!engine->context_size)
                        continue;

                intel_engine_pm_get(engine);

                /*
                 * Hide the old default state -- we lie about the context size
                 * and get confused when the default state is smaller than
                 * expected. For our do nothing request, inheriting the
                 * active state is sufficient, we are only checking that we
                 * don't use more than we planned.
                 */
                saved = fetch_and_zero(&engine->default_state);

                /* Overlaps with the execlists redzone */
                engine->context_size += I915_GTT_PAGE_SIZE;

                err = __live_context_size(engine);

                engine->context_size -= I915_GTT_PAGE_SIZE;

                engine->default_state = saved;

                intel_engine_pm_put(engine);

                if (err)
                        break;
        }

        return err;
}

static int __live_active_context(struct intel_engine_cs *engine)
{
        unsigned long saved_heartbeat;
        struct intel_context *ce;
        int pass;
        int err;

        /*
         * We keep active contexts alive until after a subsequent context
         * switch as the final write from the context-save will be after
         * we retire the final request. We track when we unpin the context,
         * under the presumption that the final pin is from the last request,
         * and instead of immediately unpinning the context, we add a task
         * to unpin the context from the next idle-barrier.
         *
         * This test makes sure that the context is kept alive until a
         * subsequent idle-barrier (emitted when the engine wakeref hits 0
         * with no more outstanding requests).
         *
         * In GuC submission mode we don't use idle barriers and we instead
         * get a message from the GuC to signal that it is safe to unpin the
         * context from memory.
         */
        if (intel_engine_uses_guc(engine))
                return 0;

        if (intel_engine_pm_is_awake(engine)) {
                pr_err("%s is awake before starting %s!\n",
                       engine->name, __func__);
                return -EINVAL;
        }

        ce = intel_context_create(engine);
        if (IS_ERR(ce))
                return PTR_ERR(ce);

        saved_heartbeat = engine->props.heartbeat_interval_ms;
        engine->props.heartbeat_interval_ms = 0;

        for (pass = 0; pass <= 2; pass++) {
                struct i915_request *rq;

                intel_engine_pm_get(engine);

                rq = intel_context_create_request(ce);
                if (IS_ERR(rq)) {
                        err = PTR_ERR(rq);
                        goto out_engine;
                }

                err = request_sync(rq);
                if (err)
                        goto out_engine;

                /* Context will be kept active until after an idle-barrier. */
                if (i915_active_is_idle(&ce->active)) {
                        pr_err("context is not active; expected idle-barrier (%s pass %d)\n",
                               engine->name, pass);
                        err = -EINVAL;
                        goto out_engine;
                }

                if (!intel_engine_pm_is_awake(engine)) {
                        pr_err("%s is asleep before idle-barrier\n",
                               engine->name);
                        err = -EINVAL;
                        goto out_engine;
                }

out_engine:
                intel_engine_pm_put(engine);
                if (err)
                        goto err;
        }

        /* Now make sure our idle-barriers are flushed */
        err = intel_engine_flush_barriers(engine);
        if (err)
                goto err;

        /* Wait for the barrier and in the process wait for engine to park */
        err = context_sync(engine->kernel_context);
        if (err)
                goto err;

        if (!i915_active_is_idle(&ce->active)) {
                pr_err("context is still active!");
                err = -EINVAL;
        }

        intel_engine_pm_flush(engine);

        if (intel_engine_pm_is_awake(engine)) {
                struct drm_printer p = drm_debug_printer(__func__);

                intel_engine_dump(engine, &p,
                                  "%s is still awake:%d after idle-barriers\n",
                                  engine->name,
                                  atomic_read(&engine->wakeref.count));
                GEM_TRACE_DUMP();

                err = -EINVAL;
                goto err;
        }

err:
        engine->props.heartbeat_interval_ms = saved_heartbeat;
        intel_context_put(ce);
        return err;
}

static int live_active_context(void *arg)
{
        struct intel_gt *gt = arg;
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        int err = 0;

        for_each_engine(engine, gt, id) {
                err = __live_active_context(engine);
                if (err)
                        break;

                err = igt_flush_test(gt->i915);
                if (err)
                        break;
        }

        return err;
}

static int __remote_sync(struct intel_context *ce, struct intel_context *remote)
{
        struct i915_request *rq;
        int err;

        err = intel_context_pin(remote);
        if (err)
                return err;

        rq = intel_context_create_request(ce);
        if (IS_ERR(rq)) {
                err = PTR_ERR(rq);
                goto unpin;
        }

        err = intel_context_prepare_remote_request(remote, rq);
        if (err) {
                i915_request_add(rq);
                goto unpin;
        }

        err = request_sync(rq);

unpin:
        intel_context_unpin(remote);
        return err;
}

static int __live_remote_context(struct intel_engine_cs *engine)
{
        struct intel_context *local, *remote;
        unsigned long saved_heartbeat;
        int pass;
        int err;

        /*
         * Check that our idle barriers do not interfere with normal
         * activity tracking. In particular, check that operating
         * on the context image remotely (intel_context_prepare_remote_request),
         * which inserts foreign fences into intel_context.active, does not
         * clobber the idle-barrier.
         *
         * In GuC submission mode we don't use idle barriers.
         */
        if (intel_engine_uses_guc(engine))
                return 0;

        if (intel_engine_pm_is_awake(engine)) {
                pr_err("%s is awake before starting %s!\n",
                       engine->name, __func__);
                return -EINVAL;
        }

        remote = intel_context_create(engine);
        if (IS_ERR(remote))
                return PTR_ERR(remote);

        local = intel_context_create(engine);
        if (IS_ERR(local)) {
                err = PTR_ERR(local);
                goto err_remote;
        }

        saved_heartbeat = engine->props.heartbeat_interval_ms;
        engine->props.heartbeat_interval_ms = 0;
        intel_engine_pm_get(engine);

        for (pass = 0; pass <= 2; pass++) {
                err = __remote_sync(local, remote);
                if (err)
                        break;

                err = __remote_sync(engine->kernel_context, remote);
                if (err)
                        break;

                if (i915_active_is_idle(&remote->active)) {
                        pr_err("remote context is not active; expected idle-barrier (%s pass %d)\n",
                               engine->name, pass);
                        err = -EINVAL;
                        break;
                }
        }

        intel_engine_pm_put(engine);
        engine->props.heartbeat_interval_ms = saved_heartbeat;

        intel_context_put(local);
err_remote:
        intel_context_put(remote);
        return err;
}

static int live_remote_context(void *arg)
{
        struct intel_gt *gt = arg;
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
        int err = 0;

        for_each_engine(engine, gt, id) {
                err = __live_remote_context(engine);
                if (err)
                        break;

                err = igt_flush_test(gt->i915);
                if (err)
                        break;
        }

        return err;
}

int intel_context_live_selftests(struct drm_i915_private *i915)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(live_context_size),
                SUBTEST(live_active_context),
                SUBTEST(live_remote_context),
        };
        struct intel_gt *gt = &i915->gt;

        if (intel_gt_is_wedged(gt))
                return 0;

        return intel_gt_live_subtests(tests, gt);
}