/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright © 2018 Intel Corporation
 */

#include <linux/random.h>

#include "gem/selftests/igt_gem_utils.h"
#include "gem/selftests/mock_context.h"
#include "gem/i915_gem_pm.h"
#include "gt/intel_gt.h"
#include "gt/intel_gt_pm.h"

#include "i915_selftest.h"

#include "igt_flush_test.h"
#include "mock_drm.h"

static int switch_to_context(struct i915_gem_context *ctx)
{
        struct i915_gem_engines_iter it;
        struct intel_context *ce;
        int err = 0;

        for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
                struct i915_request *rq;

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

                i915_request_add(rq);
        }
        i915_gem_context_unlock_engines(ctx);

        return err;
}

static void trash_stolen(struct drm_i915_private *i915)
{
        struct i915_ggtt *ggtt = &i915->ggtt;
        const u64 slot = ggtt->error_capture.start;
        const resource_size_t size = resource_size(&i915->dsm);
        unsigned long page;
        u32 prng = 0x12345678;

        /* XXX: fsck. needs some more thought... */
        if (!i915_ggtt_has_aperture(ggtt))
                return;

        for (page = 0; page < size; page += PAGE_SIZE) {
                const dma_addr_t dma = i915->dsm.start + page;
                u32 __iomem *s;
                int x;

                ggtt->vm.insert_page(&ggtt->vm, dma, slot, I915_CACHE_NONE, 0);

                s = io_mapping_map_atomic_wc(&ggtt->iomap, slot);
                for (x = 0; x < PAGE_SIZE / sizeof(u32); x++) {
                        prng = next_pseudo_random32(prng);
                        iowrite32(prng, &s[x]);
                }
                io_mapping_unmap_atomic(s);
        }

        ggtt->vm.clear_range(&ggtt->vm, slot, PAGE_SIZE);
}

static void simulate_hibernate(struct drm_i915_private *i915)
{
        intel_wakeref_t wakeref;

        wakeref = intel_runtime_pm_get(&i915->runtime_pm);

        /*
         * As a final sting in the tail, invalidate stolen. Under a real S4,
         * stolen is lost and needs to be refilled on resume. However, under
         * CI we merely do S4-device testing (as full S4 is too unreliable
         * for automated testing across a cluster), so to simulate the effect
         * of stolen being trashed across S4, we trash it ourselves.
         */
        trash_stolen(i915);

        intel_runtime_pm_put(&i915->runtime_pm, wakeref);
}

static int igt_pm_prepare(struct drm_i915_private *i915)
{
        i915_gem_suspend(i915);

        return 0;
}

static void igt_pm_suspend(struct drm_i915_private *i915)
{
        intel_wakeref_t wakeref;

        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                i915_ggtt_suspend(&i915->ggtt);
                i915_gem_suspend_late(i915);
        }
}

static void igt_pm_hibernate(struct drm_i915_private *i915)
{
        intel_wakeref_t wakeref;

        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                i915_ggtt_suspend(&i915->ggtt);

                i915_gem_freeze(i915);
                i915_gem_freeze_late(i915);
        }
}

static void igt_pm_resume(struct drm_i915_private *i915)
{
        intel_wakeref_t wakeref;

        /*
         * Both suspend and hibernate follow the same wakeup path and assume
         * that runtime-pm just works.
         */
        with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
                i915_ggtt_resume(&i915->ggtt);
                i915_gem_resume(i915);
        }
}

static int igt_gem_suspend(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct i915_gem_context *ctx;
        struct file *file;
        int err;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        err = -ENOMEM;
        ctx = live_context(i915, file);
        if (!IS_ERR(ctx))
                err = switch_to_context(ctx);
        if (err)
                goto out;

        err = igt_pm_prepare(i915);
        if (err)
                goto out;

        igt_pm_suspend(i915);

        /* Here be dragons! Note that with S3RST any S3 may become S4! */
        simulate_hibernate(i915);

        igt_pm_resume(i915);

        err = switch_to_context(ctx);
out:
        fput(file);
        return err;
}

static int igt_gem_hibernate(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct i915_gem_context *ctx;
        struct file *file;
        int err;

        file = mock_file(i915);
        if (IS_ERR(file))
                return PTR_ERR(file);

        err = -ENOMEM;
        ctx = live_context(i915, file);
        if (!IS_ERR(ctx))
                err = switch_to_context(ctx);
        if (err)
                goto out;

        err = igt_pm_prepare(i915);
        if (err)
                goto out;

        igt_pm_hibernate(i915);

        /* Here be dragons! */
        simulate_hibernate(i915);

        igt_pm_resume(i915);

        err = switch_to_context(ctx);
out:
        fput(file);
        return err;
}

static int igt_gem_ww_ctx(void *arg)
{
        struct drm_i915_private *i915 = arg;
        struct drm_i915_gem_object *obj, *obj2;
        struct i915_gem_ww_ctx ww;
        int err = 0;

        obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
        if (IS_ERR(obj))
                return PTR_ERR(obj);

        obj2 = i915_gem_object_create_internal(i915, PAGE_SIZE);
        if (IS_ERR(obj2)) {
                err = PTR_ERR(obj2);
                goto put1;
        }

        i915_gem_ww_ctx_init(&ww, true);
retry:
        /* Lock the objects, twice for good measure (-EALREADY handling) */
        err = i915_gem_object_lock(obj, &ww);
        if (!err)
                err = i915_gem_object_lock_interruptible(obj, &ww);
        if (!err)
                err = i915_gem_object_lock_interruptible(obj2, &ww);
        if (!err)
                err = i915_gem_object_lock(obj2, &ww);

        if (err == -EDEADLK) {
                err = i915_gem_ww_ctx_backoff(&ww);
                if (!err)
                        goto retry;
        }
        i915_gem_ww_ctx_fini(&ww);
        i915_gem_object_put(obj2);
put1:
        i915_gem_object_put(obj);
        return err;
}

int i915_gem_live_selftests(struct drm_i915_private *i915)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_gem_suspend),
                SUBTEST(igt_gem_hibernate),
                SUBTEST(igt_gem_ww_ctx),
        };

        if (intel_gt_is_wedged(&i915->gt))
                return 0;

        return i915_live_subtests(tests, i915);
}