// SPDX-License-Identifier: MIT
/*
 * Copyright © 2025 Intel Corporation
 */

#include "abi/guc_actions_abi.h"
#include "xe_guc.h"
#include "xe_guc_ct.h"
#include "xe_guc_pagefault.h"
#include "xe_pagefault.h"

static void guc_ack_fault(struct xe_pagefault *pf, int err)
{
        u32 vfid = FIELD_GET(PFD_VFID, pf->producer.msg[2]);
        u32 engine_instance = FIELD_GET(PFD_ENG_INSTANCE, pf->producer.msg[0]);
        u32 engine_class = FIELD_GET(PFD_ENG_CLASS, pf->producer.msg[0]);
        u32 pdata = FIELD_GET(PFD_PDATA_LO, pf->producer.msg[0]) |
                (FIELD_GET(PFD_PDATA_HI, pf->producer.msg[1]) <<
                 PFD_PDATA_HI_SHIFT);
        u32 action[] = {
                XE_GUC_ACTION_PAGE_FAULT_RES_DESC,

                FIELD_PREP(PFR_VALID, 1) |
                FIELD_PREP(PFR_SUCCESS, !!err) |
                FIELD_PREP(PFR_REPLY, PFR_ACCESS) |
                FIELD_PREP(PFR_DESC_TYPE, FAULT_RESPONSE_DESC) |
                FIELD_PREP(PFR_ASID, pf->consumer.asid),

                FIELD_PREP(PFR_VFID, vfid) |
                FIELD_PREP(PFR_ENG_INSTANCE, engine_instance) |
                FIELD_PREP(PFR_ENG_CLASS, engine_class) |
                FIELD_PREP(PFR_PDATA, pdata),
        };
        struct xe_guc *guc = pf->producer.private;

        xe_guc_ct_send(&guc->ct, action, ARRAY_SIZE(action), 0, 0);
}

static const struct xe_pagefault_ops guc_pagefault_ops = {
        .ack_fault = guc_ack_fault,
};

/**
 * xe_guc_pagefault_handler() - G2H page fault handler
 * @guc: GuC object
 * @msg: G2H message
 * @len: Length of G2H message
 *
 * Parse GuC to host (G2H) message into a struct xe_pagefault and forward onto
 * the Xe page fault layer.
 *
 * Return: 0 on success, errno on failure
 */
int xe_guc_pagefault_handler(struct xe_guc *guc, u32 *msg, u32 len)
{
        struct xe_pagefault pf;
        int i;

#define GUC_PF_MSG_LEN_DW       \
        (sizeof(struct xe_guc_pagefault_desc) / sizeof(u32))

        BUILD_BUG_ON(GUC_PF_MSG_LEN_DW > XE_PAGEFAULT_PRODUCER_MSG_LEN_DW);

        if (len != GUC_PF_MSG_LEN_DW)
                return -EPROTO;

        pf.gt = guc_to_gt(guc);

        /*
         * XXX: These values happen to match the enum in xe_pagefault_types.h.
         * If that changes, we’ll need to remap them here.
         */
        pf.consumer.page_addr = ((u64)FIELD_GET(PFD_VIRTUAL_ADDR_HI, msg[3])
                                      << PFD_VIRTUAL_ADDR_HI_SHIFT) |
                (FIELD_GET(PFD_VIRTUAL_ADDR_LO, msg[2]) <<
                 PFD_VIRTUAL_ADDR_LO_SHIFT);
        pf.consumer.asid = FIELD_GET(PFD_ASID, msg[1]);
        pf.consumer.access_type = FIELD_GET(PFD_ACCESS_TYPE, msg[2]);
        pf.consumer.fault_type = FIELD_GET(PFD_FAULT_TYPE, msg[2]);
        if (FIELD_GET(XE2_PFD_TRVA_FAULT, msg[0]))
                pf.consumer.fault_level = XE_PAGEFAULT_LEVEL_NACK;
        else
                pf.consumer.fault_level = FIELD_GET(PFD_FAULT_LEVEL, msg[0]);
        pf.consumer.engine_class = FIELD_GET(PFD_ENG_CLASS, msg[0]);
        pf.consumer.engine_instance = FIELD_GET(PFD_ENG_INSTANCE, msg[0]);

        pf.producer.private = guc;
        pf.producer.ops = &guc_pagefault_ops;
        for (i = 0; i < GUC_PF_MSG_LEN_DW; ++i)
                pf.producer.msg[i] = msg[i];

#undef GUC_PF_MSG_LEN_DW

        return xe_pagefault_handler(guc_to_xe(guc), &pf);
}