root/drivers/firmware/tegra/bpmp-tegra186.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, NVIDIA CORPORATION.
 */

#include <linux/genalloc.h>
#include <linux/io.h>
#include <linux/mailbox_client.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>

#include <soc/tegra/bpmp.h>
#include <soc/tegra/bpmp-abi.h>
#include <soc/tegra/ivc.h>

#include "bpmp-private.h"

struct tegra186_bpmp {
        struct tegra_bpmp *parent;

        struct {
                struct gen_pool *pool;
                union {
                        void __iomem *sram;
                        void *dram;
                };
                dma_addr_t phys;
        } tx, rx;

        struct {
                struct mbox_client client;
                struct mbox_chan *channel;
        } mbox;
};

static inline struct tegra_bpmp *
mbox_client_to_bpmp(struct mbox_client *client)
{
        struct tegra186_bpmp *priv;

        priv = container_of(client, struct tegra186_bpmp, mbox.client);

        return priv->parent;
}

static bool tegra186_bpmp_is_message_ready(struct tegra_bpmp_channel *channel)
{
        int err;

        err = tegra_ivc_read_get_next_frame(channel->ivc, &channel->ib);
        if (err) {
                iosys_map_clear(&channel->ib);
                return false;
        }

        return true;
}

static bool tegra186_bpmp_is_channel_free(struct tegra_bpmp_channel *channel)
{
        int err;

        err = tegra_ivc_write_get_next_frame(channel->ivc, &channel->ob);
        if (err) {
                iosys_map_clear(&channel->ob);
                return false;
        }

        return true;
}

static int tegra186_bpmp_ack_message(struct tegra_bpmp_channel *channel)
{
        return tegra_ivc_read_advance(channel->ivc);
}

static int tegra186_bpmp_post_message(struct tegra_bpmp_channel *channel)
{
        return tegra_ivc_write_advance(channel->ivc);
}

static int tegra186_bpmp_ring_doorbell(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv = bpmp->priv;
        int err;

        err = mbox_send_message(priv->mbox.channel, NULL);
        if (err < 0)
                return err;

        mbox_client_txdone(priv->mbox.channel, 0);

        return 0;
}

static void tegra186_bpmp_ivc_notify(struct tegra_ivc *ivc, void *data)
{
        struct tegra_bpmp *bpmp = data;
        struct tegra186_bpmp *priv = bpmp->priv;

        if (WARN_ON(priv->mbox.channel == NULL))
                return;

        tegra186_bpmp_ring_doorbell(bpmp);
}

static int tegra186_bpmp_channel_init(struct tegra_bpmp_channel *channel,
                                      struct tegra_bpmp *bpmp,
                                      unsigned int index)
{
        struct tegra186_bpmp *priv = bpmp->priv;
        size_t message_size, queue_size;
        struct iosys_map rx, tx;
        unsigned int offset;
        int err;

        channel->ivc = devm_kzalloc(bpmp->dev, sizeof(*channel->ivc),
                                    GFP_KERNEL);
        if (!channel->ivc)
                return -ENOMEM;

        message_size = tegra_ivc_align(MSG_MIN_SZ);
        queue_size = tegra_ivc_total_queue_size(message_size);
        offset = queue_size * index;

        if (priv->rx.pool) {
                iosys_map_set_vaddr_iomem(&rx, priv->rx.sram + offset);
                iosys_map_set_vaddr_iomem(&tx, priv->tx.sram + offset);
        } else {
                iosys_map_set_vaddr(&rx, priv->rx.dram + offset);
                iosys_map_set_vaddr(&tx, priv->tx.dram + offset);
        }

        err = tegra_ivc_init(channel->ivc, NULL, &rx, priv->rx.phys + offset, &tx,
                             priv->tx.phys + offset, 1, message_size, tegra186_bpmp_ivc_notify,
                             bpmp);
        if (err < 0) {
                dev_err(bpmp->dev, "failed to setup IVC for channel %u: %d\n",
                        index, err);
                return err;
        }

        init_completion(&channel->completion);
        channel->bpmp = bpmp;

        return 0;
}

static void tegra186_bpmp_channel_reset(struct tegra_bpmp_channel *channel)
{
        /* reset the channel state */
        tegra_ivc_reset(channel->ivc);

        /* sync the channel state with BPMP */
        while (tegra_ivc_notified(channel->ivc))
                ;
}

static void tegra186_bpmp_channel_cleanup(struct tegra_bpmp_channel *channel)
{
        tegra_ivc_cleanup(channel->ivc);
}

static void mbox_handle_rx(struct mbox_client *client, void *data)
{
        struct tegra_bpmp *bpmp = mbox_client_to_bpmp(client);

        tegra_bpmp_handle_rx(bpmp);
}

static void tegra186_bpmp_teardown_channels(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv = bpmp->priv;
        unsigned int i;

        for (i = 0; i < bpmp->threaded.count; i++) {
                if (!bpmp->threaded_channels[i].bpmp)
                        continue;

                tegra186_bpmp_channel_cleanup(&bpmp->threaded_channels[i]);
        }

        tegra186_bpmp_channel_cleanup(bpmp->rx_channel);
        tegra186_bpmp_channel_cleanup(bpmp->tx_channel);

        if (priv->tx.pool) {
                gen_pool_free(priv->tx.pool, (unsigned long)priv->tx.sram, 4096);
                gen_pool_free(priv->rx.pool, (unsigned long)priv->rx.sram, 4096);
        }
}

static int tegra186_bpmp_dram_init(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv = bpmp->priv;
        struct resource res;
        size_t size;
        int err;

        err = of_reserved_mem_region_to_resource(bpmp->dev->of_node, 0, &res);
        if (err < 0) {
                if (err != -ENODEV)
                        dev_warn(bpmp->dev,
                                 "failed to parse memory region: %d\n", err);

                return err;
        }

        size = resource_size(&res);

        if (size < SZ_8K) {
                dev_warn(bpmp->dev, "DRAM region must be larger than 8 KiB\n");
                return -EINVAL;
        }

        priv->tx.phys = res.start;
        priv->rx.phys = res.start + SZ_4K;

        priv->tx.dram = devm_memremap(bpmp->dev, priv->tx.phys, size,
                                      MEMREMAP_WC);
        if (IS_ERR(priv->tx.dram)) {
                err = PTR_ERR(priv->tx.dram);
                dev_warn(bpmp->dev, "failed to map DRAM region: %d\n", err);
                return err;
        }

        priv->rx.dram = priv->tx.dram + SZ_4K;

        return 0;
}

static int tegra186_bpmp_sram_init(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv = bpmp->priv;
        int err;

        priv->tx.pool = of_gen_pool_get(bpmp->dev->of_node, "shmem", 0);
        if (!priv->tx.pool) {
                dev_err(bpmp->dev, "TX shmem pool not found\n");
                return -EPROBE_DEFER;
        }

        priv->tx.sram = (void __iomem *)gen_pool_dma_alloc(priv->tx.pool, 4096,
                                                           &priv->tx.phys);
        if (!priv->tx.sram) {
                dev_err(bpmp->dev, "failed to allocate from TX pool\n");
                return -ENOMEM;
        }

        priv->rx.pool = of_gen_pool_get(bpmp->dev->of_node, "shmem", 1);
        if (!priv->rx.pool) {
                dev_err(bpmp->dev, "RX shmem pool not found\n");
                err = -EPROBE_DEFER;
                goto free_tx;
        }

        priv->rx.sram = (void __iomem *)gen_pool_dma_alloc(priv->rx.pool, 4096,
                                                           &priv->rx.phys);
        if (!priv->rx.sram) {
                dev_err(bpmp->dev, "failed to allocate from RX pool\n");
                err = -ENOMEM;
                goto free_tx;
        }

        return 0;

free_tx:
        gen_pool_free(priv->tx.pool, (unsigned long)priv->tx.sram, 4096);

        return err;
}

static int tegra186_bpmp_setup_channels(struct tegra_bpmp *bpmp)
{
        unsigned int i;
        int err;

        err = tegra186_bpmp_dram_init(bpmp);
        if (err == -ENODEV) {
                err = tegra186_bpmp_sram_init(bpmp);
                if (err < 0)
                        return err;
        }

        err = tegra186_bpmp_channel_init(bpmp->tx_channel, bpmp,
                                         bpmp->soc->channels.cpu_tx.offset);
        if (err < 0)
                return err;

        err = tegra186_bpmp_channel_init(bpmp->rx_channel, bpmp,
                                         bpmp->soc->channels.cpu_rx.offset);
        if (err < 0) {
                tegra186_bpmp_channel_cleanup(bpmp->tx_channel);
                return err;
        }

        for (i = 0; i < bpmp->threaded.count; i++) {
                unsigned int index = bpmp->soc->channels.thread.offset + i;

                err = tegra186_bpmp_channel_init(&bpmp->threaded_channels[i],
                                                 bpmp, index);
                if (err < 0)
                        break;
        }

        if (err < 0)
                tegra186_bpmp_teardown_channels(bpmp);

        return err;
}

static void tegra186_bpmp_reset_channels(struct tegra_bpmp *bpmp)
{
        unsigned int i;

        /* reset message channels */
        tegra186_bpmp_channel_reset(bpmp->tx_channel);
        tegra186_bpmp_channel_reset(bpmp->rx_channel);

        for (i = 0; i < bpmp->threaded.count; i++)
                tegra186_bpmp_channel_reset(&bpmp->threaded_channels[i]);
}

static int tegra186_bpmp_init(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv;
        int err;

        priv = devm_kzalloc(bpmp->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->parent = bpmp;
        bpmp->priv = priv;

        err = tegra186_bpmp_setup_channels(bpmp);
        if (err < 0)
                return err;

        /* mbox registration */
        priv->mbox.client.dev = bpmp->dev;
        priv->mbox.client.rx_callback = mbox_handle_rx;
        priv->mbox.client.tx_block = false;
        priv->mbox.client.knows_txdone = false;

        priv->mbox.channel = mbox_request_channel(&priv->mbox.client, 0);
        if (IS_ERR(priv->mbox.channel)) {
                err = PTR_ERR(priv->mbox.channel);
                dev_err(bpmp->dev, "failed to get HSP mailbox: %d\n", err);
                tegra186_bpmp_teardown_channels(bpmp);
                return err;
        }

        tegra186_bpmp_reset_channels(bpmp);

        return 0;
}

static void tegra186_bpmp_deinit(struct tegra_bpmp *bpmp)
{
        struct tegra186_bpmp *priv = bpmp->priv;

        mbox_free_channel(priv->mbox.channel);

        tegra186_bpmp_teardown_channels(bpmp);
}

static int tegra186_bpmp_resume(struct tegra_bpmp *bpmp)
{
        tegra186_bpmp_reset_channels(bpmp);

        return 0;
}

const struct tegra_bpmp_ops tegra186_bpmp_ops = {
        .init = tegra186_bpmp_init,
        .deinit = tegra186_bpmp_deinit,
        .is_response_ready = tegra186_bpmp_is_message_ready,
        .is_request_ready = tegra186_bpmp_is_message_ready,
        .ack_response = tegra186_bpmp_ack_message,
        .ack_request = tegra186_bpmp_ack_message,
        .is_response_channel_free = tegra186_bpmp_is_channel_free,
        .is_request_channel_free = tegra186_bpmp_is_channel_free,
        .post_response = tegra186_bpmp_post_message,
        .post_request = tegra186_bpmp_post_message,
        .ring_doorbell = tegra186_bpmp_ring_doorbell,
        .resume = tegra186_bpmp_resume,
};