// SPDX-License-Identifier: MIT
/*
 * Copyright(c) 2024 Intel Corporation.
 */

#include "xe_pxp.h"

#include <drm/drm_managed.h>
#include <uapi/drm/xe_drm.h>

#include "xe_bo.h"
#include "xe_bo_types.h"
#include "xe_device_types.h"
#include "xe_exec_queue.h"
#include "xe_force_wake.h"
#include "xe_guc_submit.h"
#include "xe_gsc_proxy.h"
#include "xe_gt_types.h"
#include "xe_huc.h"
#include "xe_mmio.h"
#include "xe_pm.h"
#include "xe_pxp_submit.h"
#include "xe_pxp_types.h"
#include "xe_uc_fw.h"
#include "regs/xe_irq_regs.h"
#include "regs/xe_pxp_regs.h"

/**
 * DOC: PXP
 *
 * PXP (Protected Xe Path) allows execution and flip to display of protected
 * (i.e. encrypted) objects. This feature is currently only supported in
 * integrated parts.
 */

#define ARB_SESSION DRM_XE_PXP_HWDRM_DEFAULT_SESSION /* shorter define */

/*
 * A submission to GSC can take up to 250ms to complete, so use a 300ms
 * timeout for activation where only one of those is involved. Termination
 * additionally requires a submission to VCS and an interaction with KCR, so
 * bump the timeout to 500ms for that.
 */
#define PXP_ACTIVATION_TIMEOUT_MS 300
#define PXP_TERMINATION_TIMEOUT_MS 500

bool xe_pxp_is_supported(const struct xe_device *xe)
{
        return xe->info.has_pxp && IS_ENABLED(CONFIG_INTEL_MEI_GSC_PROXY);
}

bool xe_pxp_is_enabled(const struct xe_pxp *pxp)
{
        return pxp;
}

static bool pxp_prerequisites_done(const struct xe_pxp *pxp)
{
        struct xe_gt *gt = pxp->gt;
        bool ready;

        CLASS(xe_force_wake, fw_ref)(gt_to_fw(gt), XE_FORCEWAKE_ALL);

        /*
         * If force_wake fails we could falsely report the prerequisites as not
         * done even if they are; the consequence of this would be that the
         * callers won't go ahead with using PXP, but if force_wake doesn't work
         * the GT is very likely in a bad state so not really a problem to abort
         * PXP. Therefore, we can just log the force_wake error and not escalate
         * it.
         */
        XE_WARN_ON(!xe_force_wake_ref_has_domain(fw_ref.domains, XE_FORCEWAKE_ALL));

        /* PXP requires both HuC authentication via GSC and GSC proxy initialized */
        ready = xe_huc_is_authenticated(&gt->uc.huc, XE_HUC_AUTH_VIA_GSC) &&
                xe_gsc_proxy_init_done(&gt->uc.gsc);

        return ready;
}

/**
 * xe_pxp_get_readiness_status - check whether PXP is ready for userspace use
 * @pxp: the xe_pxp pointer (can be NULL if PXP is disabled)
 *
 * Returns: 0 if PXP is not ready yet, 1 if it is ready, a negative errno value
 * if PXP is not supported/enabled or if something went wrong in the
 * initialization of the prerequisites. Note that the return values of this
 * function follow the uapi (see drm_xe_query_pxp_status), so they can be used
 * directly in the query ioctl.
 */
int xe_pxp_get_readiness_status(struct xe_pxp *pxp)
{
        int ret = 0;

        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        /* if the GSC or HuC FW are in an error state, PXP will never work */
        if (xe_uc_fw_status_to_error(pxp->gt->uc.huc.fw.status) ||
            xe_uc_fw_status_to_error(pxp->gt->uc.gsc.fw.status))
                return -EIO;

        guard(xe_pm_runtime)(pxp->xe);

        /* PXP requires both HuC loaded and GSC proxy initialized */
        if (pxp_prerequisites_done(pxp))
                ret = 1;

        return ret;
}

static bool pxp_session_is_in_play(struct xe_pxp *pxp, u32 id)
{
        struct xe_gt *gt = pxp->gt;

        return xe_mmio_read32(&gt->mmio, KCR_SIP) & BIT(id);
}

static int pxp_wait_for_session_state(struct xe_pxp *pxp, u32 id, bool in_play)
{
        struct xe_gt *gt = pxp->gt;
        u32 mask = BIT(id);

        return xe_mmio_wait32(&gt->mmio, KCR_SIP, mask, in_play ? mask : 0,
                              250, NULL, false);
}

static void pxp_invalidate_queues(struct xe_pxp *pxp);

static int pxp_terminate_hw(struct xe_pxp *pxp)
{
        struct xe_gt *gt = pxp->gt;
        int ret = 0;

        drm_dbg(&pxp->xe->drm, "Terminating PXP\n");

        CLASS(xe_force_wake, fw_ref)(gt_to_fw(gt), XE_FW_GT);
        if (!xe_force_wake_ref_has_domain(fw_ref.domains, XE_FW_GT))
                return -EIO;

        /* terminate the hw session */
        ret = xe_pxp_submit_session_termination(pxp, ARB_SESSION);
        if (ret)
                return ret;

        ret = pxp_wait_for_session_state(pxp, ARB_SESSION, false);
        if (ret)
                return ret;

        /* Trigger full HW cleanup */
        xe_mmio_write32(&gt->mmio, KCR_GLOBAL_TERMINATE, 1);

        /* now we can tell the GSC to clean up its own state */
        return xe_pxp_submit_session_invalidation(&pxp->gsc_res, ARB_SESSION);
}

static void mark_termination_in_progress(struct xe_pxp *pxp)
{
        lockdep_assert_held(&pxp->mutex);

        reinit_completion(&pxp->termination);
        pxp->status = XE_PXP_TERMINATION_IN_PROGRESS;
}

static void pxp_terminate(struct xe_pxp *pxp)
{
        int ret = 0;
        struct xe_device *xe = pxp->xe;

        if (!wait_for_completion_timeout(&pxp->activation,
                                         msecs_to_jiffies(PXP_ACTIVATION_TIMEOUT_MS)))
                drm_err(&xe->drm, "failed to wait for PXP start before termination\n");

        mutex_lock(&pxp->mutex);

        if (pxp->status == XE_PXP_ACTIVE)
                pxp->key_instance++;

        /*
         * we'll mark the status as needing termination on resume, so no need to
         * emit a termination now.
         */
        if (pxp->status == XE_PXP_SUSPENDED) {
                mutex_unlock(&pxp->mutex);
                return;
        }

        /*
         * If we have a termination already in progress, we need to wait for
         * it to complete before queueing another one. Once the first
         * termination is completed we'll set the state back to
         * NEEDS_TERMINATION and leave it to the pxp start code to issue it.
         */
        if (pxp->status == XE_PXP_TERMINATION_IN_PROGRESS) {
                pxp->status = XE_PXP_NEEDS_ADDITIONAL_TERMINATION;
                mutex_unlock(&pxp->mutex);
                return;
        }

        mark_termination_in_progress(pxp);

        mutex_unlock(&pxp->mutex);

        pxp_invalidate_queues(pxp);

        ret = pxp_terminate_hw(pxp);
        if (ret) {
                drm_err(&xe->drm, "PXP termination failed: %pe\n", ERR_PTR(ret));
                mutex_lock(&pxp->mutex);
                pxp->status = XE_PXP_ERROR;
                complete_all(&pxp->termination);
                mutex_unlock(&pxp->mutex);
        }
}

static void pxp_terminate_complete(struct xe_pxp *pxp)
{
        /*
         * We expect PXP to be in one of 3 states when we get here:
         * - XE_PXP_TERMINATION_IN_PROGRESS: a single termination event was
         * requested and it is now completing, so we're ready to start.
         * - XE_PXP_NEEDS_ADDITIONAL_TERMINATION: a second termination was
         * requested while the first one was still being processed.
         * - XE_PXP_SUSPENDED: PXP is now suspended, so we defer everything to
         * when we come back on resume.
         */
        mutex_lock(&pxp->mutex);

        switch (pxp->status) {
        case XE_PXP_TERMINATION_IN_PROGRESS:
                pxp->status = XE_PXP_READY_TO_START;
                break;
        case XE_PXP_NEEDS_ADDITIONAL_TERMINATION:
                pxp->status = XE_PXP_NEEDS_TERMINATION;
                break;
        case XE_PXP_SUSPENDED:
                /* Nothing to do */
                break;
        default:
                drm_err(&pxp->xe->drm,
                        "PXP termination complete while status was %u\n",
                        pxp->status);
        }

        complete_all(&pxp->termination);

        mutex_unlock(&pxp->mutex);
}

static void pxp_irq_work(struct work_struct *work)
{
        struct xe_pxp *pxp = container_of(work, typeof(*pxp), irq.work);
        struct xe_device *xe = pxp->xe;
        u32 events = 0;

        spin_lock_irq(&xe->irq.lock);
        events = pxp->irq.events;
        pxp->irq.events = 0;
        spin_unlock_irq(&xe->irq.lock);

        if (!events)
                return;

        /*
         * If we're processing a termination irq while suspending then don't
         * bother, we're going to re-init everything on resume anyway.
         */
        if ((events & PXP_TERMINATION_REQUEST) && !xe_pm_runtime_get_if_active(xe))
                return;

        if (events & PXP_TERMINATION_REQUEST) {
                events &= ~PXP_TERMINATION_COMPLETE;
                pxp_terminate(pxp);
        }

        if (events & PXP_TERMINATION_COMPLETE)
                pxp_terminate_complete(pxp);

        if (events & PXP_TERMINATION_REQUEST)
                xe_pm_runtime_put(xe);
}

/**
 * xe_pxp_irq_handler - Handles PXP interrupts.
 * @xe: the xe_device structure
 * @iir: interrupt vector
 */
void xe_pxp_irq_handler(struct xe_device *xe, u16 iir)
{
        struct xe_pxp *pxp = xe->pxp;

        if (!xe_pxp_is_enabled(pxp)) {
                drm_err(&xe->drm, "PXP irq 0x%x received with PXP disabled!\n", iir);
                return;
        }

        lockdep_assert_held(&xe->irq.lock);

        if (unlikely(!iir))
                return;

        if (iir & (KCR_PXP_STATE_TERMINATED_INTERRUPT |
                   KCR_APP_TERMINATED_PER_FW_REQ_INTERRUPT))
                pxp->irq.events |= PXP_TERMINATION_REQUEST;

        if (iir & KCR_PXP_STATE_RESET_COMPLETE_INTERRUPT)
                pxp->irq.events |= PXP_TERMINATION_COMPLETE;

        if (pxp->irq.events)
                queue_work(pxp->irq.wq, &pxp->irq.work);
}

static int kcr_pxp_set_status(const struct xe_pxp *pxp, bool enable)
{
        u32 val = enable ? _MASKED_BIT_ENABLE(KCR_INIT_ALLOW_DISPLAY_ME_WRITES) :
                  _MASKED_BIT_DISABLE(KCR_INIT_ALLOW_DISPLAY_ME_WRITES);

        CLASS(xe_force_wake, fw_ref)(gt_to_fw(pxp->gt), XE_FW_GT);
        if (!xe_force_wake_ref_has_domain(fw_ref.domains, XE_FW_GT))
                return -EIO;

        xe_mmio_write32(&pxp->gt->mmio, KCR_INIT, val);

        return 0;
}

static int kcr_pxp_enable(const struct xe_pxp *pxp)
{
        return kcr_pxp_set_status(pxp, true);
}

static int kcr_pxp_disable(const struct xe_pxp *pxp)
{
        return kcr_pxp_set_status(pxp, false);
}

static void pxp_fini(void *arg)
{
        struct xe_pxp *pxp = arg;

        destroy_workqueue(pxp->irq.wq);
        xe_pxp_destroy_execution_resources(pxp);

        /* no need to explicitly disable KCR since we're going to do an FLR */
}

/**
 * xe_pxp_init - initialize PXP support
 * @xe: the xe_device structure
 *
 * Initialize the HW state and allocate the objects required for PXP support.
 * Note that some of the requirement for PXP support (GSC proxy init, HuC auth)
 * are performed asynchronously as part of the GSC init. PXP can only be used
 * after both this function and the async worker have completed.
 *
 * Returns 0 if PXP is not supported or if PXP initialization is successful,
 * other errno value if there is an error during the init.
 */
int xe_pxp_init(struct xe_device *xe)
{
        struct xe_gt *gt = xe->tiles[0].media_gt;
        struct xe_pxp *pxp;
        int err;

        if (!xe_pxp_is_supported(xe))
                return 0;

        /* we only support PXP on single tile devices with a media GT */
        if (xe->info.tile_count > 1 || !gt)
                return 0;

        /* The GSCCS is required for submissions to the GSC FW */
        if (!(gt->info.engine_mask & BIT(XE_HW_ENGINE_GSCCS0)))
                return 0;

        /* PXP requires both GSC and HuC firmwares to be available */
        if (!xe_uc_fw_is_loadable(&gt->uc.gsc.fw) ||
            !xe_uc_fw_is_loadable(&gt->uc.huc.fw)) {
                drm_info(&xe->drm, "skipping PXP init due to missing FW dependencies");
                return 0;
        }

        /*
         * On PTL, older GSC FWs have a bug that can cause them to crash during
         * PXP invalidation events, which leads to a complete loss of power
         * management on the media GT. Therefore, we can't use PXP on FWs that
         * have this bug, which was fixed in PTL GSC build 1396.
         */
        if (xe->info.platform == XE_PANTHERLAKE &&
            gt->uc.gsc.fw.versions.found[XE_UC_FW_VER_RELEASE].build < 1396) {
                drm_info(&xe->drm, "PXP requires PTL GSC build 1396 or newer\n");
                return 0;
        }

        pxp = drmm_kzalloc(&xe->drm, sizeof(struct xe_pxp), GFP_KERNEL);
        if (!pxp) {
                err = -ENOMEM;
                goto out;
        }

        INIT_LIST_HEAD(&pxp->queues.list);
        spin_lock_init(&pxp->queues.lock);
        INIT_WORK(&pxp->irq.work, pxp_irq_work);
        pxp->xe = xe;
        pxp->gt = gt;

        pxp->key_instance = 1;
        pxp->last_suspend_key_instance = 1;

        /*
         * we'll use the completions to check if there is an action pending,
         * so we start them as completed and we reinit it when an action is
         * triggered.
         */
        init_completion(&pxp->activation);
        init_completion(&pxp->termination);
        complete_all(&pxp->termination);
        complete_all(&pxp->activation);

        mutex_init(&pxp->mutex);

        pxp->irq.wq = alloc_ordered_workqueue("pxp-wq", 0);
        if (!pxp->irq.wq) {
                err = -ENOMEM;
                goto out_free;
        }

        err = kcr_pxp_enable(pxp);
        if (err)
                goto out_wq;

        err = xe_pxp_allocate_execution_resources(pxp);
        if (err)
                goto out_kcr_disable;

        xe->pxp = pxp;

        return devm_add_action_or_reset(xe->drm.dev, pxp_fini, pxp);

out_kcr_disable:
        kcr_pxp_disable(pxp);
out_wq:
        destroy_workqueue(pxp->irq.wq);
out_free:
        drmm_kfree(&xe->drm, pxp);
out:
        drm_err(&xe->drm, "PXP initialization failed: %pe\n", ERR_PTR(err));
        return err;
}

static int __pxp_start_arb_session(struct xe_pxp *pxp)
{
        int ret;

        CLASS(xe_force_wake, fw_ref)(gt_to_fw(pxp->gt), XE_FW_GT);
        if (!xe_force_wake_ref_has_domain(fw_ref.domains, XE_FW_GT))
                return -EIO;

        if (pxp_session_is_in_play(pxp, ARB_SESSION))
                return -EEXIST;

        ret = xe_pxp_submit_session_init(&pxp->gsc_res, ARB_SESSION);
        if (ret) {
                drm_err(&pxp->xe->drm, "Failed to init PXP arb session: %pe\n", ERR_PTR(ret));
                return ret;
        }

        ret = pxp_wait_for_session_state(pxp, ARB_SESSION, true);
        if (ret) {
                drm_err(&pxp->xe->drm, "PXP ARB session failed to go in play%pe\n", ERR_PTR(ret));
                return ret;
        }

        drm_dbg(&pxp->xe->drm, "PXP ARB session is active\n");
        return 0;
}

/**
 * xe_pxp_exec_queue_set_type - Mark a queue as using PXP
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 * @q: the queue to mark as using PXP
 * @type: the type of PXP session this queue will use
 *
 * Returns 0 if the selected PXP type is supported, -ENODEV otherwise.
 */
int xe_pxp_exec_queue_set_type(struct xe_pxp *pxp, struct xe_exec_queue *q, u8 type)
{
        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        /* we only support HWDRM sessions right now */
        xe_assert(pxp->xe, type == DRM_XE_PXP_TYPE_HWDRM);

        q->pxp.type = type;

        return 0;
}

static int __exec_queue_add(struct xe_pxp *pxp, struct xe_exec_queue *q)
{
        int ret = 0;

        /*
         * A queue can be added to the list only if the PXP is in active status,
         * otherwise the termination might not handle it correctly.
         */
        mutex_lock(&pxp->mutex);

        if (pxp->status == XE_PXP_ACTIVE) {
                spin_lock_irq(&pxp->queues.lock);
                list_add_tail(&q->pxp.link, &pxp->queues.list);
                spin_unlock_irq(&pxp->queues.lock);
        } else if (pxp->status == XE_PXP_ERROR || pxp->status == XE_PXP_SUSPENDED) {
                ret = -EIO;
        } else {
                ret = -EBUSY; /* try again later */
        }

        mutex_unlock(&pxp->mutex);

        return ret;
}

static int pxp_start(struct xe_pxp *pxp, u8 type)
{
        int ret = 0;
        bool restart;

        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        /* we only support HWDRM sessions right now */
        xe_assert(pxp->xe, type == DRM_XE_PXP_TYPE_HWDRM);

        /* get_readiness_status() returns 0 for in-progress and 1 for done */
        ret = xe_pxp_get_readiness_status(pxp);
        if (ret <= 0)
                return ret ?: -EBUSY;

        ret = 0;

wait_for_idle:
        /*
         * if there is an action in progress, wait for it. We need to wait
         * outside the lock because the completion is done from within the lock.
         * Note that the two actions should never be pending at the same time.
         */
        if (!wait_for_completion_timeout(&pxp->termination,
                                         msecs_to_jiffies(PXP_TERMINATION_TIMEOUT_MS)))
                return -ETIMEDOUT;

        if (!wait_for_completion_timeout(&pxp->activation,
                                         msecs_to_jiffies(PXP_ACTIVATION_TIMEOUT_MS)))
                return -ETIMEDOUT;

        restart = false;

        mutex_lock(&pxp->mutex);

        /* If PXP is not already active, turn it on */
        switch (pxp->status) {
        case XE_PXP_ERROR:
                ret = -EIO;
                goto out_unlock;
        case XE_PXP_ACTIVE:
                goto out_unlock;
        case XE_PXP_READY_TO_START:
                pxp->status = XE_PXP_START_IN_PROGRESS;
                reinit_completion(&pxp->activation);
                break;
        case XE_PXP_START_IN_PROGRESS:
                /* If a start is in progress then the completion must not be done */
                XE_WARN_ON(completion_done(&pxp->activation));
                restart = true;
                goto out_unlock;
        case XE_PXP_NEEDS_TERMINATION:
                mark_termination_in_progress(pxp);
                break;
        case XE_PXP_TERMINATION_IN_PROGRESS:
        case XE_PXP_NEEDS_ADDITIONAL_TERMINATION:
                /* If a termination is in progress then the completion must not be done */
                XE_WARN_ON(completion_done(&pxp->termination));
                restart = true;
                goto out_unlock;
        case XE_PXP_SUSPENDED:
        default:
                drm_err(&pxp->xe->drm, "unexpected state during PXP start: %u\n", pxp->status);
                ret = -EIO;
                goto out_unlock;
        }

        mutex_unlock(&pxp->mutex);

        if (!completion_done(&pxp->termination)) {
                ret = pxp_terminate_hw(pxp);
                if (ret) {
                        drm_err(&pxp->xe->drm, "PXP termination failed before start\n");
                        mutex_lock(&pxp->mutex);
                        pxp->status = XE_PXP_ERROR;
                        complete_all(&pxp->termination);

                        goto out_unlock;
                }

                goto wait_for_idle;
        }

        /* All the cases except for start should have exited earlier */
        XE_WARN_ON(completion_done(&pxp->activation));
        ret = __pxp_start_arb_session(pxp);

        mutex_lock(&pxp->mutex);

        complete_all(&pxp->activation);

        /*
         * Any other process should wait until the state goes away from
         * XE_PXP_START_IN_PROGRESS, so if the state is not that something went
         * wrong. Mark the status as needing termination and try again.
         */
        if (pxp->status != XE_PXP_START_IN_PROGRESS) {
                drm_err(&pxp->xe->drm, "unexpected state after PXP start: %u\n", pxp->status);
                pxp->status = XE_PXP_NEEDS_TERMINATION;
                restart = true;
                goto out_unlock;
        }

        /* If everything went ok, update the status and add the queue to the list */
        if (!ret)
                pxp->status = XE_PXP_ACTIVE;
        else
                pxp->status = XE_PXP_ERROR;

out_unlock:
        mutex_unlock(&pxp->mutex);

        if (restart)
                goto wait_for_idle;

        return ret;
}

/**
 * xe_pxp_exec_queue_add - add a queue to the PXP list
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 * @q: the queue to add to the list
 *
 * If PXP is enabled and the prerequisites are done, start the PXP default
 * session (if not already running) and add the queue to the PXP list.
 *
 * Returns 0 if the PXP session is running and the queue is in the list,
 * -ENODEV if PXP is disabled, -EBUSY if the PXP prerequisites are not done,
 * other errno value if something goes wrong during the session start.
 */
int xe_pxp_exec_queue_add(struct xe_pxp *pxp, struct xe_exec_queue *q)
{
        int ret;

        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        /*
         * Runtime suspend kills PXP, so we take a reference to prevent it from
         * happening while we have active queues that use PXP
         */
        xe_pm_runtime_get(pxp->xe);

start:
        ret = pxp_start(pxp, q->pxp.type);

        if (!ret) {
                ret = __exec_queue_add(pxp, q);
                if (ret == -EBUSY)
                        goto start;
        }

        /*
         * in the successful case the PM ref is released from
         * xe_pxp_exec_queue_remove
         */
        if (ret)
                xe_pm_runtime_put(pxp->xe);

        return ret;
}
ALLOW_ERROR_INJECTION(xe_pxp_exec_queue_add, ERRNO);

static void __pxp_exec_queue_remove(struct xe_pxp *pxp, struct xe_exec_queue *q, bool lock)
{
        bool need_pm_put = false;

        if (!xe_pxp_is_enabled(pxp))
                return;

        if (lock)
                spin_lock_irq(&pxp->queues.lock);

        if (!list_empty(&q->pxp.link)) {
                list_del_init(&q->pxp.link);
                need_pm_put = true;
        }

        q->pxp.type = DRM_XE_PXP_TYPE_NONE;

        if (lock)
                spin_unlock_irq(&pxp->queues.lock);

        if (need_pm_put)
                xe_pm_runtime_put(pxp->xe);
}

/**
 * xe_pxp_exec_queue_remove - remove a queue from the PXP list
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 * @q: the queue to remove from the list
 *
 * If PXP is enabled and the exec_queue is in the list, the queue will be
 * removed from the list and its PM reference will be released. It is safe to
 * call this function multiple times for the same queue.
 */
void xe_pxp_exec_queue_remove(struct xe_pxp *pxp, struct xe_exec_queue *q)
{
        __pxp_exec_queue_remove(pxp, q, true);
}

static void pxp_invalidate_queues(struct xe_pxp *pxp)
{
        struct xe_exec_queue *tmp, *q;
        LIST_HEAD(to_clean);

        spin_lock_irq(&pxp->queues.lock);

        list_for_each_entry_safe(q, tmp, &pxp->queues.list, pxp.link) {
                q = xe_exec_queue_get_unless_zero(q);
                if (!q)
                        continue;

                list_move_tail(&q->pxp.link, &to_clean);
        }
        spin_unlock_irq(&pxp->queues.lock);

        list_for_each_entry_safe(q, tmp, &to_clean, pxp.link) {
                xe_exec_queue_kill(q);

                /*
                 * We hold a ref to the queue so there is no risk of racing with
                 * the calls to exec_queue_remove coming from exec_queue_destroy.
                 */
                __pxp_exec_queue_remove(pxp, q, false);

                xe_exec_queue_put(q);
        }
}

/**
 * xe_pxp_key_assign - mark a BO as using the current PXP key iteration
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 * @bo: the BO to mark
 *
 * Returns: -ENODEV if PXP is disabled, 0 otherwise.
 */
int xe_pxp_key_assign(struct xe_pxp *pxp, struct xe_bo *bo)
{
        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        xe_assert(pxp->xe, !bo->pxp_key_instance);

        /*
         * Note that the PXP key handling is inherently racey, because the key
         * can theoretically change at any time (although it's unlikely to do
         * so without triggers), even right after we copy it. Taking a lock
         * wouldn't help because the value might still change as soon as we
         * release the lock.
         * Userspace needs to handle the fact that their BOs can go invalid at
         * any point.
         */
        bo->pxp_key_instance = pxp->key_instance;

        return 0;
}

/**
 * xe_pxp_bo_key_check - check if the key used by a xe_bo is valid
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 * @bo: the BO we want to check
 *
 * Checks whether a BO was encrypted with the current key or an obsolete one.
 *
 * Returns: 0 if the key is valid, -ENODEV if PXP is disabled, -EINVAL if the
 * BO is not using PXP,  -ENOEXEC if the key is not valid.
 */
int xe_pxp_bo_key_check(struct xe_pxp *pxp, struct xe_bo *bo)
{
        if (!xe_pxp_is_enabled(pxp))
                return -ENODEV;

        if (!xe_bo_is_protected(bo))
                return -EINVAL;

        xe_assert(pxp->xe, bo->pxp_key_instance);

        /*
         * Note that the PXP key handling is inherently racey, because the key
         * can theoretically change at any time (although it's unlikely to do
         * so without triggers), even right after we check it. Taking a lock
         * wouldn't help because the value might still change as soon as we
         * release the lock.
         * We mitigate the risk by checking the key at multiple points (on each
         * submission involving the BO and right before flipping it on the
         * display), but there is still a very small chance that we could
         * operate on an invalid BO for a single submission or a single frame
         * flip. This is a compromise made to protect the encrypted data (which
         * is what the key termination is for).
         */
        if (bo->pxp_key_instance != pxp->key_instance)
                return -ENOEXEC;

        return 0;
}

/**
 * xe_pxp_obj_key_check - check if the key used by a drm_gem_obj is valid
 * @obj: the drm_gem_obj we want to check
 *
 * Checks whether a drm_gem_obj was encrypted with the current key or an
 * obsolete one.
 *
 * Returns: 0 if the key is valid, -ENODEV if PXP is disabled, -EINVAL if the
 * obj is not using PXP,  -ENOEXEC if the key is not valid.
 */
int xe_pxp_obj_key_check(struct drm_gem_object *obj)
{
        struct xe_bo *bo = gem_to_xe_bo(obj);
        struct xe_device *xe = xe_bo_device(bo);
        struct xe_pxp *pxp = xe->pxp;

        return xe_pxp_bo_key_check(pxp, bo);
}

/**
 * xe_pxp_pm_suspend - prepare PXP for HW suspend
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 *
 * Makes sure all PXP actions have completed and invalidates all PXP queues
 * and objects before we go into a suspend state.
 *
 * Returns: 0 if successful, a negative errno value otherwise.
 */
int xe_pxp_pm_suspend(struct xe_pxp *pxp)
{
        bool needs_queue_inval = false;
        int ret = 0;

        if (!xe_pxp_is_enabled(pxp))
                return 0;

wait_for_activation:
        if (!wait_for_completion_timeout(&pxp->activation,
                                         msecs_to_jiffies(PXP_ACTIVATION_TIMEOUT_MS)))
                ret = -ETIMEDOUT;

        mutex_lock(&pxp->mutex);

        switch (pxp->status) {
        case XE_PXP_ERROR:
        case XE_PXP_READY_TO_START:
        case XE_PXP_SUSPENDED:
        case XE_PXP_TERMINATION_IN_PROGRESS:
        case XE_PXP_NEEDS_ADDITIONAL_TERMINATION:
                /*
                 * If PXP is not running there is nothing to cleanup. If there
                 * is a termination pending then no need to issue another one.
                 */
                break;
        case XE_PXP_START_IN_PROGRESS:
                mutex_unlock(&pxp->mutex);
                goto wait_for_activation;
        case XE_PXP_NEEDS_TERMINATION:
                /* If PXP was never used we can skip the cleanup */
                if (pxp->key_instance == pxp->last_suspend_key_instance)
                        break;
                fallthrough;
        case XE_PXP_ACTIVE:
                pxp->key_instance++;
                needs_queue_inval = true;
                break;
        }

        /*
         * We set this even if we were in error state, hoping the suspend clears
         * the error. Worse case we fail again and go in error state again.
         */
        pxp->status = XE_PXP_SUSPENDED;

        mutex_unlock(&pxp->mutex);

        if (needs_queue_inval)
                pxp_invalidate_queues(pxp);

        /*
         * if there is a termination in progress, wait for it.
         * We need to wait outside the lock because the completion is done from
         * within the lock
         */
        if (!wait_for_completion_timeout(&pxp->termination,
                                         msecs_to_jiffies(PXP_TERMINATION_TIMEOUT_MS)))
                ret = -ETIMEDOUT;

        pxp->last_suspend_key_instance = pxp->key_instance;

        return ret;
}

/**
 * xe_pxp_pm_resume - re-init PXP after HW suspend
 * @pxp: the xe->pxp pointer (it will be NULL if PXP is disabled)
 */
void xe_pxp_pm_resume(struct xe_pxp *pxp)
{
        int err;

        if (!xe_pxp_is_enabled(pxp))
                return;

        err = kcr_pxp_enable(pxp);

        mutex_lock(&pxp->mutex);

        xe_assert(pxp->xe, pxp->status == XE_PXP_SUSPENDED);

        if (err)
                pxp->status = XE_PXP_ERROR;
        else
                pxp->status = XE_PXP_NEEDS_TERMINATION;

        mutex_unlock(&pxp->mutex);
}