/*
 * Copyright © 2017 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_selftest.h"
#include "gem/i915_gem_pm.h"

/* max doorbell number + negative test for each client type */
#define ATTEMPTS (GUC_NUM_DOORBELLS + GUC_CLIENT_PRIORITY_NUM)

static struct intel_guc_client *clients[ATTEMPTS];

static bool available_dbs(struct intel_guc *guc, u32 priority)
{
        unsigned long offset;
        unsigned long end;
        u16 id;

        /* first half is used for normal priority, second half for high */
        offset = 0;
        end = GUC_NUM_DOORBELLS / 2;
        if (priority <= GUC_CLIENT_PRIORITY_HIGH) {
                offset = end;
                end += offset;
        }

        id = find_next_zero_bit(guc->doorbell_bitmap, end, offset);
        if (id < end)
                return true;

        return false;
}

static int check_all_doorbells(struct intel_guc *guc)
{
        u16 db_id;

        pr_info_once("Max number of doorbells: %d", GUC_NUM_DOORBELLS);
        for (db_id = 0; db_id < GUC_NUM_DOORBELLS; ++db_id) {
                if (!doorbell_ok(guc, db_id)) {
                        pr_err("doorbell %d, not ok\n", db_id);
                        return -EIO;
                }
        }

        return 0;
}

static int ring_doorbell_nop(struct intel_guc_client *client)
{
        struct guc_process_desc *desc = __get_process_desc(client);
        int err;

        client->use_nop_wqi = true;

        spin_lock_irq(&client->wq_lock);

        guc_wq_item_append(client, 0, 0, 0, 0);
        guc_ring_doorbell(client);

        spin_unlock_irq(&client->wq_lock);

        client->use_nop_wqi = false;

        /* if there are no issues GuC will update the WQ head and keep the
         * WQ in active status
         */
        err = wait_for(READ_ONCE(desc->head) == READ_ONCE(desc->tail), 10);
        if (err) {
                pr_err("doorbell %u ring failed!\n", client->doorbell_id);
                return -EIO;
        }

        if (desc->wq_status != WQ_STATUS_ACTIVE) {
                pr_err("doorbell %u ring put WQ in bad state (%u)!\n",
                       client->doorbell_id, desc->wq_status);
                return -EIO;
        }

        return 0;
}

/*
 * Basic client sanity check, handy to validate create_clients.
 */
static int validate_client(struct intel_guc_client *client,
                           int client_priority,
                           bool is_preempt_client)
{
        struct drm_i915_private *dev_priv = guc_to_i915(client->guc);
        struct i915_gem_context *ctx_owner = is_preempt_client ?
                        dev_priv->preempt_context : dev_priv->kernel_context;

        if (client->owner != ctx_owner ||
            client->engines != INTEL_INFO(dev_priv)->engine_mask ||
            client->priority != client_priority ||
            client->doorbell_id == GUC_DOORBELL_INVALID)
                return -EINVAL;
        else
                return 0;
}

static bool client_doorbell_in_sync(struct intel_guc_client *client)
{
        return !client || doorbell_ok(client->guc, client->doorbell_id);
}

/*
 * Check that we're able to synchronize guc_clients with their doorbells
 *
 * We're creating clients and reserving doorbells once, at module load. During
 * module lifetime, GuC, doorbell HW, and i915 state may go out of sync due to
 * GuC being reset. In other words - GuC clients are still around, but the
 * status of their doorbells may be incorrect. This is the reason behind
 * validating that the doorbells status expected by the driver matches what the
 * GuC/HW have.
 */
static int igt_guc_clients(void *args)
{
        struct drm_i915_private *dev_priv = args;
        intel_wakeref_t wakeref;
        struct intel_guc *guc;
        int err = 0;

        GEM_BUG_ON(!HAS_GUC(dev_priv));
        mutex_lock(&dev_priv->drm.struct_mutex);
        wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);

        guc = &dev_priv->guc;
        if (!guc) {
                pr_err("No guc object!\n");
                err = -EINVAL;
                goto unlock;
        }

        err = check_all_doorbells(guc);
        if (err)
                goto unlock;

        /*
         * Get rid of clients created during driver load because the test will
         * recreate them.
         */
        guc_clients_disable(guc);
        guc_clients_destroy(guc);
        if (guc->execbuf_client || guc->preempt_client) {
                pr_err("guc_clients_destroy lied!\n");
                err = -EINVAL;
                goto unlock;
        }

        err = guc_clients_create(guc);
        if (err) {
                pr_err("Failed to create clients\n");
                goto unlock;
        }
        GEM_BUG_ON(!guc->execbuf_client);

        err = validate_client(guc->execbuf_client,
                              GUC_CLIENT_PRIORITY_KMD_NORMAL, false);
        if (err) {
                pr_err("execbug client validation failed\n");
                goto out;
        }

        if (guc->preempt_client) {
                err = validate_client(guc->preempt_client,
                                      GUC_CLIENT_PRIORITY_KMD_HIGH, true);
                if (err) {
                        pr_err("preempt client validation failed\n");
                        goto out;
                }
        }

        /* each client should now have reserved a doorbell */
        if (!has_doorbell(guc->execbuf_client) ||
            (guc->preempt_client && !has_doorbell(guc->preempt_client))) {
                pr_err("guc_clients_create didn't reserve doorbells\n");
                err = -EINVAL;
                goto out;
        }

        /* Now enable the clients */
        guc_clients_enable(guc);

        /* each client should now have received a doorbell */
        if (!client_doorbell_in_sync(guc->execbuf_client) ||
            !client_doorbell_in_sync(guc->preempt_client)) {
                pr_err("failed to initialize the doorbells\n");
                err = -EINVAL;
                goto out;
        }

        /*
         * Basic test - an attempt to reallocate a valid doorbell to the
         * client it is currently assigned should not cause a failure.
         */
        err = create_doorbell(guc->execbuf_client);

out:
        /*
         * Leave clean state for other test, plus the driver always destroy the
         * clients during unload.
         */
        guc_clients_disable(guc);
        guc_clients_destroy(guc);
        guc_clients_create(guc);
        guc_clients_enable(guc);
unlock:
        intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
        mutex_unlock(&dev_priv->drm.struct_mutex);
        return err;
}

/*
 * Create as many clients as number of doorbells. Note that there's already
 * client(s)/doorbell(s) created during driver load, but this test creates
 * its own and do not interact with the existing ones.
 */
static int igt_guc_doorbells(void *arg)
{
        struct drm_i915_private *dev_priv = arg;
        intel_wakeref_t wakeref;
        struct intel_guc *guc;
        int i, err = 0;
        u16 db_id;

        GEM_BUG_ON(!HAS_GUC(dev_priv));
        mutex_lock(&dev_priv->drm.struct_mutex);
        wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);

        guc = &dev_priv->guc;
        if (!guc) {
                pr_err("No guc object!\n");
                err = -EINVAL;
                goto unlock;
        }

        err = check_all_doorbells(guc);
        if (err)
                goto unlock;

        for (i = 0; i < ATTEMPTS; i++) {
                clients[i] = guc_client_alloc(dev_priv,
                                              INTEL_INFO(dev_priv)->engine_mask,
                                              i % GUC_CLIENT_PRIORITY_NUM,
                                              dev_priv->kernel_context);

                if (!clients[i]) {
                        pr_err("[%d] No guc client\n", i);
                        err = -EINVAL;
                        goto out;
                }

                if (IS_ERR(clients[i])) {
                        if (PTR_ERR(clients[i]) != -ENOSPC) {
                                pr_err("[%d] unexpected error\n", i);
                                err = PTR_ERR(clients[i]);
                                goto out;
                        }

                        if (available_dbs(guc, i % GUC_CLIENT_PRIORITY_NUM)) {
                                pr_err("[%d] non-db related alloc fail\n", i);
                                err = -EINVAL;
                                goto out;
                        }

                        /* expected, ran out of dbs for this client type */
                        continue;
                }

                /*
                 * The check below is only valid because we keep a doorbell
                 * assigned during the whole life of the client.
                 */
                if (clients[i]->stage_id >= GUC_NUM_DOORBELLS) {
                        pr_err("[%d] more clients than doorbells (%d >= %d)\n",
                               i, clients[i]->stage_id, GUC_NUM_DOORBELLS);
                        err = -EINVAL;
                        goto out;
                }

                err = validate_client(clients[i],
                                      i % GUC_CLIENT_PRIORITY_NUM, false);
                if (err) {
                        pr_err("[%d] client_alloc sanity check failed!\n", i);
                        err = -EINVAL;
                        goto out;
                }

                db_id = clients[i]->doorbell_id;

                err = __guc_client_enable(clients[i]);
                if (err) {
                        pr_err("[%d] Failed to create a doorbell\n", i);
                        goto out;
                }

                /* doorbell id shouldn't change, we are holding the mutex */
                if (db_id != clients[i]->doorbell_id) {
                        pr_err("[%d] doorbell id changed (%d != %d)\n",
                               i, db_id, clients[i]->doorbell_id);
                        err = -EINVAL;
                        goto out;
                }

                err = check_all_doorbells(guc);
                if (err)
                        goto out;

                err = ring_doorbell_nop(clients[i]);
                if (err)
                        goto out;
        }

out:
        for (i = 0; i < ATTEMPTS; i++)
                if (!IS_ERR_OR_NULL(clients[i])) {
                        __guc_client_disable(clients[i]);
                        guc_client_free(clients[i]);
                }
unlock:
        intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
        mutex_unlock(&dev_priv->drm.struct_mutex);
        return err;
}

int intel_guc_live_selftest(struct drm_i915_private *dev_priv)
{
        static const struct i915_subtest tests[] = {
                SUBTEST(igt_guc_clients),
                SUBTEST(igt_guc_doorbells),
        };

        if (!USES_GUC_SUBMISSION(dev_priv))
                return 0;

        return i915_subtests(tests, dev_priv);
}