// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "sdmmc-block-device.h"

#include <inttypes.h>

#include <ddk/debug.h>
#include <fbl/alloc_checker.h>
#include <hw/sdmmc.h>
#include <lib/fzl/vmo-mapper.h>
#include <zircon/process.h>
#include <zircon/threads.h>

namespace {

constexpr size_t kTranMaxAttempts = 10;

constexpr uint32_t kBlockOp(uint32_t op) {
    return op & BLOCK_OP_MASK;
}

}  // namespace

namespace sdmmc {

zx_status_t SdmmcBlockDevice::Create(zx_device_t* parent, const SdmmcDevice& sdmmc,
                                     fbl::RefPtr<SdmmcBlockDevice>* out_dev) {
    fbl::AllocChecker ac;
    auto dev = fbl::MakeRefCountedChecked<SdmmcBlockDevice>(&ac, parent, sdmmc);
    if (!ac.check()) {
        zxlogf(ERROR, "sdmmc: failed to allocate device memory\n");
        return ZX_ERR_NO_MEMORY;
    }

    *out_dev = dev;
    return ZX_OK;
}

zx_status_t SdmmcBlockDevice::AddDevice() {
    // Device must be in TRAN state at this point
    zx_status_t st = WaitForTran();
    if (st != ZX_OK) {
        zxlogf(ERROR, "sdmmc: waiting for TRAN state failed, retcode = %d\n", st);
        return ZX_ERR_TIMED_OUT;
    }

    int rc = thrd_create_with_name(
        &worker_thread_,
        [](void* ctx) -> int { return reinterpret_cast<SdmmcBlockDevice*>(ctx)->WorkerThread(); },
        this, "sdmmc-block-worker");
    if (rc != thrd_success) {
        st = thrd_status_to_zx_status(rc);
        return st;
    }

    st = DdkAdd(is_sd_ ? "sdmmc-sd" : "sdmmc-mmc");
    if (st != ZX_OK) {
        zxlogf(ERROR, "sdmmc: Failed to add block device, retcode = %d\n", st);
    }

    return st;
}

void SdmmcBlockDevice::DdkUnbind() {
    if (dead_) {
        // Already in middle of release.
        return;
    }
    dead_ = true;
    DdkRemove();
}

void SdmmcBlockDevice::DdkRelease() {
    dead_ = true;

    if (worker_thread_) {
        {
            fbl::AutoLock lock(&lock_);
            worker_event_.Broadcast();
        }

        thrd_join(worker_thread_, nullptr);

        // error out all pending requests
        trace_async_id_t async_id = async_id_;
        lock_.Acquire();
        for (std::optional<BlockOperation> txn = txn_list_.pop(); txn; txn = txn_list_.pop()) {
            lock_.Release();
            BlockComplete(&(*txn), ZX_ERR_BAD_STATE, async_id);
            lock_.Acquire();
        }
        lock_.Release();
    }

    __UNUSED bool dummy = Release();
}

void SdmmcBlockDevice::BlockComplete(BlockOperation* txn, zx_status_t status,
                                     trace_async_id_t async_id) {
    const block_op_t* bop = txn->operation();
    if (txn->node()->complete_cb()) {
        // If tracing is not enabled this is a no-op.
        TRACE_ASYNC_END("sdmmc", "sdmmc_do_txn", async_id_,
                        "command", TA_INT32(bop->rw.command),
                        "extra", TA_INT32(bop->rw.extra),
                        "length", TA_INT32(bop->rw.length),
                        "offset_vmo", TA_INT64(bop->rw.offset_vmo),
                        "offset_dev", TA_INT64(bop->rw.offset_dev),
                        "txn_status", TA_INT32(status));
        txn->Complete(status);
    } else {
        zxlogf(TRACE, "sdmmc: block op %p completion_cb unset!\n", bop);
    }
}

void SdmmcBlockDevice::DoTxn(BlockOperation* txn) {
    // The TRACE_*() event macros are empty if driver tracing isn't enabled.
    // But that doesn't work for our call to trace_state().
    if (TRACE_ENABLED()) {
        async_id_ = TRACE_NONCE();
        TRACE_ASYNC_BEGIN("sdmmc", "sdmmc_do_txn", async_id_,
                          "command", TA_INT32(txn->operation()->rw.command),
                          "extra", TA_INT32(txn->operation()->rw.extra),
                          "length", TA_INT32(txn->operation()->rw.length),
                          "offset_vmo", TA_INT64(txn->operation()->rw.offset_vmo),
                          "offset_dev", TA_INT64(txn->operation()->rw.offset_dev));
    }

    uint32_t cmd_idx = 0;
    uint32_t cmd_flags = 0;

    // Figure out which SD command we need to issue.
    switch (kBlockOp(txn->operation()->command)) {
    case BLOCK_OP_READ:
        if (txn->operation()->rw.length > 1) {
            cmd_idx = SDMMC_READ_MULTIPLE_BLOCK;
            cmd_flags = SDMMC_READ_MULTIPLE_BLOCK_FLAGS;
        } else {
            cmd_idx = SDMMC_READ_BLOCK;
            cmd_flags = SDMMC_READ_BLOCK_FLAGS;
        }
        break;
    case BLOCK_OP_WRITE:
        if (txn->operation()->rw.length > 1) {
            cmd_idx = SDMMC_WRITE_MULTIPLE_BLOCK;
            cmd_flags = SDMMC_WRITE_MULTIPLE_BLOCK_FLAGS;
        } else {
            cmd_idx = SDMMC_WRITE_BLOCK;
            cmd_flags = SDMMC_WRITE_BLOCK_FLAGS;
        }
        break;
    case BLOCK_OP_FLUSH:
        BlockComplete(txn, ZX_OK, async_id_);
        return;
    default:
        // should not get here
        zxlogf(ERROR, "sdmmc: do_txn invalid block op %d\n", kBlockOp(txn->operation()->command));
        ZX_DEBUG_ASSERT(true);
        BlockComplete(txn, ZX_ERR_INVALID_ARGS, async_id_);
        return;
    }

    zxlogf(TRACE,
           "sdmmc: do_txn blockop 0x%x offset_vmo 0x%" PRIx64 " length 0x%x blocksize 0x%x"
           " max_transfer_size 0x%x\n",
           txn->operation()->command, txn->operation()->rw.offset_vmo, txn->operation()->rw.length,
           block_info_.block_size, block_info_.max_transfer_size);

    sdmmc_req_t* req = &req_;
    memset(req, 0, sizeof(*req));
    req->cmd_idx = cmd_idx;
    req->cmd_flags = cmd_flags;
    req->arg = static_cast<uint32_t>(txn->operation()->rw.offset_dev);
    req->blockcount = static_cast<uint16_t>(txn->operation()->rw.length);
    req->blocksize = static_cast<uint16_t>(block_info_.block_size);

    // convert offset_vmo and length to bytes
    uint64_t offset_vmo = txn->operation()->rw.offset_vmo * block_info_.block_size;
    uint64_t length = txn->operation()->rw.length * block_info_.block_size;

    fzl::VmoMapper mapper;

    zx_status_t st = ZX_OK;
    if (sdmmc_.UseDma()) {
        req->use_dma = true;
        req->virt_buffer = nullptr;
        req->pmt = ZX_HANDLE_INVALID;
        req->dma_vmo = txn->operation()->rw.vmo;
        req->buf_offset = offset_vmo;
    } else {
        req->use_dma = false;
        st = mapper.Map(*zx::unowned_vmo(txn->operation()->rw.vmo), offset_vmo, length,
                        ZX_VM_PERM_READ | ZX_VM_PERM_WRITE);
        if (st != ZX_OK) {
            zxlogf(TRACE, "sdmmc: do_txn vmo map error %d\n", st);
            BlockComplete(txn, st, async_id_);
            return;
        }
        req->virt_buffer = mapper.start();
        req->virt_size = length;
    }

    st = sdmmc_.host().Request(req);
    if (st != ZX_OK) {
        zxlogf(TRACE, "sdmmc: do_txn error %d\n", st);
    } else {
        if ((req->blockcount > 1) && !(sdmmc_.host_info().caps & SDMMC_HOST_CAP_AUTO_CMD12)) {
            st = sdmmc_.SdmmcStopTransmission();
            if (st != ZX_OK) {
                zxlogf(TRACE, "sdmmc: do_txn stop transmission error %d\n", st);
            }
        }
    }

    BlockComplete(txn, st, async_id_);
    zxlogf(TRACE, "sdmmc: do_txn complete\n");
}

zx_off_t SdmmcBlockDevice::DdkGetSize() {
    return block_info_.block_count * block_info_.block_size;
}

void SdmmcBlockDevice::BlockImplQuery(block_info_t* info_out, size_t* block_op_size_out) {
    memcpy(info_out, &block_info_, sizeof(*info_out));
    *block_op_size_out = BlockOperation::OperationSize(sizeof(block_op_t));
}

void SdmmcBlockDevice::BlockImplQueue(block_op_t* btxn, block_impl_queue_callback completion_cb,
                                      void* cookie) {
    BlockOperation txn(btxn, completion_cb, cookie, sizeof(block_op_t));
    trace_async_id_t async_id = async_id_;

    switch (kBlockOp(btxn->command)) {
    case BLOCK_OP_READ:
    case BLOCK_OP_WRITE: {
        uint64_t max = block_info_.block_count;
        if ((btxn->rw.offset_dev >= max) || ((max - btxn->rw.offset_dev) < btxn->rw.length)) {
            BlockComplete(&txn, ZX_ERR_OUT_OF_RANGE, async_id);
            return;
        }
        if (btxn->rw.length == 0) {
            BlockComplete(&txn, ZX_OK, async_id);
            return;
        }
        break;
    }
    case BLOCK_OP_FLUSH:
        // queue the flush op. because there is no out of order execution in this
        // driver, when this op gets processed all previous ops are complete.
        break;
    default:
        BlockComplete(&txn, ZX_ERR_NOT_SUPPORTED, async_id);
        return;
    }

    fbl::AutoLock lock(&lock_);

    txn_list_.push(std::move(txn));
    // Wake up the worker thread.
    worker_event_.Broadcast();
}

int SdmmcBlockDevice::WorkerThread() {
    fbl::AutoLock lock(&lock_);

    for (;;) {
        for (std::optional<BlockOperation> txn = txn_list_.pop(); txn; txn = txn_list_.pop()) {
            DoTxn(&(*txn));
        }

        worker_event_.Wait(&lock_);
        if (dead_) {
            break;
        }
    }

    zxlogf(TRACE, "sdmmc: worker thread terminated successfully\n");
    return thrd_success;
}

zx_status_t SdmmcBlockDevice::WaitForTran() {
    uint32_t current_state;
    size_t attempt = 0;
    for (; attempt <= kTranMaxAttempts; attempt++) {
        uint32_t response;
        zx_status_t st = sdmmc_.SdmmcSendStatus(&response);
        if (st != ZX_OK) {
            zxlogf(SPEW, "sdmmc: SDMMC_SEND_STATUS error, retcode = %d\n", st);
            return st;
        }

        current_state = MMC_STATUS_CURRENT_STATE(response);
        if (current_state == MMC_STATUS_CURRENT_STATE_RECV) {
            st = sdmmc_.SdmmcStopTransmission();
            continue;
        } else if (current_state == MMC_STATUS_CURRENT_STATE_TRAN) {
            break;
        }

        zx_nanosleep(zx_deadline_after(ZX_MSEC(10)));
    }

    if (attempt == kTranMaxAttempts) {
        // Too many retries, fail.
        return ZX_ERR_TIMED_OUT;
    } else {
        return ZX_OK;
    }
}

}  // namespace sdmmc