// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020-21 Intel Corporation.
 */

#include "iosm_ipc_imem.h"
#include "iosm_ipc_protocol.h"
#include "iosm_ipc_protocol_ops.h"
#include "iosm_ipc_pm.h"
#include "iosm_ipc_task_queue.h"

int ipc_protocol_tq_msg_send(struct iosm_protocol *ipc_protocol,
                             enum ipc_msg_prep_type msg_type,
                             union ipc_msg_prep_args *prep_args,
                             struct ipc_rsp *response)
{
        int index = ipc_protocol_msg_prep(ipc_protocol->imem, msg_type,
                                          prep_args);

        /* Store reference towards caller specified response in response ring
         * and signal CP
         */
        if (index >= 0 && index < IPC_MEM_MSG_ENTRIES) {
                ipc_protocol->rsp_ring[index] = response;
                ipc_protocol_msg_hp_update(ipc_protocol->imem);
        }

        return index;
}

/* Callback for message send */
static int ipc_protocol_tq_msg_send_cb(struct iosm_imem *ipc_imem, int arg,
                                       void *msg, size_t size)
{
        struct ipc_call_msg_send_args *send_args = msg;
        struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;

        return ipc_protocol_tq_msg_send(ipc_protocol, send_args->msg_type,
                                        send_args->prep_args,
                                        send_args->response);
}

/* Remove reference to a response. This is typically used when a requestor timed
 * out and is no longer interested in the response.
 */
static int ipc_protocol_tq_msg_remove(struct iosm_imem *ipc_imem, int arg,
                                      void *msg, size_t size)
{
        struct iosm_protocol *ipc_protocol = ipc_imem->ipc_protocol;

        ipc_protocol->rsp_ring[arg] = NULL;
        return 0;
}

int ipc_protocol_msg_send(struct iosm_protocol *ipc_protocol,
                          enum ipc_msg_prep_type prep,
                          union ipc_msg_prep_args *prep_args)
{
        struct ipc_call_msg_send_args send_args;
        unsigned int exec_timeout;
        struct ipc_rsp response;
        int index;

        exec_timeout = (ipc_protocol_get_ap_exec_stage(ipc_protocol) ==
                                        IPC_MEM_EXEC_STAGE_RUN ?
                                IPC_MSG_COMPLETE_RUN_DEFAULT_TIMEOUT :
                                IPC_MSG_COMPLETE_BOOT_DEFAULT_TIMEOUT);

        /* Trap if called from non-preemptible context */
        might_sleep();

        response.status = IPC_MEM_MSG_CS_INVALID;
        init_completion(&response.completion);

        send_args.msg_type = prep;
        send_args.prep_args = prep_args;
        send_args.response = &response;

        /* Allocate and prepare message to be sent in tasklet context.
         * A positive index returned form tasklet_call references the message
         * in case it needs to be cancelled when there is a timeout.
         */
        index = ipc_task_queue_send_task(ipc_protocol->imem,
                                         ipc_protocol_tq_msg_send_cb, 0,
                                         &send_args, 0, true);

        if (index < 0) {
                dev_err(ipc_protocol->dev, "msg %d failed", prep);
                return index;
        }

        /* Wait for the device to respond to the message */
        switch (wait_for_completion_timeout(&response.completion,
                                            msecs_to_jiffies(exec_timeout))) {
        case 0:
                /* Timeout, there was no response from the device.
                 * Remove the reference to the local response completion
                 * object as we are no longer interested in the response.
                 */
                ipc_task_queue_send_task(ipc_protocol->imem,
                                         ipc_protocol_tq_msg_remove, index,
                                         NULL, 0, true);
                dev_err(ipc_protocol->dev, "msg timeout");
                ipc_uevent_send(ipc_protocol->pcie->dev, UEVENT_MDM_TIMEOUT);
                break;
        default:
                /* We got a response in time; check completion status: */
                if (response.status != IPC_MEM_MSG_CS_SUCCESS) {
                        dev_err(ipc_protocol->dev,
                                "msg completion status error %d",
                                response.status);
                        return -EIO;
                }
        }

        return 0;
}

static int ipc_protocol_msg_send_host_sleep(struct iosm_protocol *ipc_protocol,
                                            u32 state)
{
        union ipc_msg_prep_args prep_args = {
                .sleep.target = 0,
                .sleep.state = state,
        };

        return ipc_protocol_msg_send(ipc_protocol, IPC_MSG_PREP_SLEEP,
                                     &prep_args);
}

void ipc_protocol_doorbell_trigger(struct iosm_protocol *ipc_protocol,
                                   u32 identifier)
{
        ipc_pm_signal_hpda_doorbell(&ipc_protocol->pm, identifier, true);
}

bool ipc_protocol_pm_dev_sleep_handle(struct iosm_protocol *ipc_protocol)
{
        u32 ipc_status = ipc_protocol_get_ipc_status(ipc_protocol);
        u32 requested;

        if (ipc_status != IPC_MEM_DEVICE_IPC_RUNNING) {
                dev_err(ipc_protocol->dev,
                        "irq ignored, CP IPC state is %d, should be RUNNING",
                        ipc_status);

                /* Stop further processing. */
                return false;
        }

        /* Get a copy of the requested PM state by the device and the local
         * device PM state.
         */
        requested = ipc_protocol_pm_dev_get_sleep_notification(ipc_protocol);

        return ipc_pm_dev_slp_notification(&ipc_protocol->pm, requested);
}

static int ipc_protocol_tq_wakeup_dev_slp(struct iosm_imem *ipc_imem, int arg,
                                          void *msg, size_t size)
{
        struct iosm_pm *ipc_pm = &ipc_imem->ipc_protocol->pm;

        /* Wakeup from device sleep if it is not ACTIVE */
        ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_HS, true);

        ipc_pm_trigger(ipc_pm, IPC_PM_UNIT_HS, false);

        return 0;
}

void ipc_protocol_s2idle_sleep(struct iosm_protocol *ipc_protocol, bool sleep)
{
        ipc_pm_set_s2idle_sleep(&ipc_protocol->pm, sleep);
}

bool ipc_protocol_suspend(struct iosm_protocol *ipc_protocol)
{
        if (!ipc_pm_prepare_host_sleep(&ipc_protocol->pm))
                goto err;

        ipc_task_queue_send_task(ipc_protocol->imem,
                                 ipc_protocol_tq_wakeup_dev_slp, 0, NULL, 0,
                                 true);

        if (!ipc_pm_wait_for_device_active(&ipc_protocol->pm)) {
                ipc_uevent_send(ipc_protocol->pcie->dev, UEVENT_MDM_TIMEOUT);
                goto err;
        }

        /* Send the sleep message for sync sys calls. */
        dev_dbg(ipc_protocol->dev, "send TARGET_HOST, ENTER_SLEEP");
        if (ipc_protocol_msg_send_host_sleep(ipc_protocol,
                                             IPC_HOST_SLEEP_ENTER_SLEEP)) {
                /* Sending ENTER_SLEEP message failed, we are still active */
                ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_ACTIVE;
                goto err;
        }

        ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_SLEEP;
        return true;
err:
        return false;
}

bool ipc_protocol_resume(struct iosm_protocol *ipc_protocol)
{
        if (!ipc_pm_prepare_host_active(&ipc_protocol->pm))
                return false;

        dev_dbg(ipc_protocol->dev, "send TARGET_HOST, EXIT_SLEEP");
        if (ipc_protocol_msg_send_host_sleep(ipc_protocol,
                                             IPC_HOST_SLEEP_EXIT_SLEEP)) {
                ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_SLEEP;
                return false;
        }

        ipc_protocol->pm.host_pm_state = IPC_MEM_HOST_PM_ACTIVE;

        return true;
}

struct iosm_protocol *ipc_protocol_init(struct iosm_imem *ipc_imem)
{
        struct iosm_protocol *ipc_protocol = kzalloc_obj(*ipc_protocol);
        struct ipc_protocol_context_info *p_ci;
        u64 addr;

        if (!ipc_protocol)
                return NULL;

        ipc_protocol->dev = ipc_imem->dev;
        ipc_protocol->pcie = ipc_imem->pcie;
        ipc_protocol->imem = ipc_imem;
        ipc_protocol->p_ap_shm = NULL;
        ipc_protocol->phy_ap_shm = 0;

        ipc_protocol->old_msg_tail = 0;

        ipc_protocol->p_ap_shm =
                dma_alloc_coherent(&ipc_protocol->pcie->pci->dev,
                                   sizeof(*ipc_protocol->p_ap_shm),
                                   &ipc_protocol->phy_ap_shm, GFP_KERNEL);

        if (!ipc_protocol->p_ap_shm) {
                dev_err(ipc_protocol->dev, "pci shm alloc error");
                kfree(ipc_protocol);
                return NULL;
        }

        /* Prepare the context info for CP. */
        addr = ipc_protocol->phy_ap_shm;
        p_ci = &ipc_protocol->p_ap_shm->ci;
        p_ci->device_info_addr =
                addr + offsetof(struct ipc_protocol_ap_shm, device_info);
        p_ci->head_array =
                addr + offsetof(struct ipc_protocol_ap_shm, head_array);
        p_ci->tail_array =
                addr + offsetof(struct ipc_protocol_ap_shm, tail_array);
        p_ci->msg_head = addr + offsetof(struct ipc_protocol_ap_shm, msg_head);
        p_ci->msg_tail = addr + offsetof(struct ipc_protocol_ap_shm, msg_tail);
        p_ci->msg_ring_addr =
                addr + offsetof(struct ipc_protocol_ap_shm, msg_ring);
        p_ci->msg_ring_entries = cpu_to_le16(IPC_MEM_MSG_ENTRIES);
        p_ci->msg_irq_vector = IPC_MSG_IRQ_VECTOR;
        p_ci->device_info_irq_vector = IPC_DEVICE_IRQ_VECTOR;

        ipc_mmio_set_contex_info_addr(ipc_imem->mmio, addr);

        ipc_pm_init(ipc_protocol);

        return ipc_protocol;
}

void ipc_protocol_deinit(struct iosm_protocol *proto)
{
        dma_free_coherent(&proto->pcie->pci->dev, sizeof(*proto->p_ap_shm),
                          proto->p_ap_shm, proto->phy_ap_shm);

        ipc_pm_deinit(proto);
        kfree(proto);
}