// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Broadcom. All Rights Reserved. The term
 * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
 */

#include "efct_driver.h"
#include "efct_hw.h"
#include "efct_io.h"

struct efct_io_pool {
        struct efct *efct;
        spinlock_t lock;        /* IO pool lock */
        u32 io_num_ios;         /* Total IOs allocated */
        struct efct_io *ios[EFCT_NUM_SCSI_IOS];
        struct list_head freelist;

};

struct efct_io_pool *
efct_io_pool_create(struct efct *efct, u32 num_sgl)
{
        u32 i = 0;
        struct efct_io_pool *io_pool;
        struct efct_io *io;

        /* Allocate the IO pool */
        io_pool = kzalloc_obj(*io_pool);
        if (!io_pool)
                return NULL;

        io_pool->efct = efct;
        INIT_LIST_HEAD(&io_pool->freelist);
        /* initialize IO pool lock */
        spin_lock_init(&io_pool->lock);

        for (i = 0; i < EFCT_NUM_SCSI_IOS; i++) {
                io = kzalloc_obj(*io);
                if (!io)
                        break;

                io_pool->io_num_ios++;
                io_pool->ios[i] = io;
                io->tag = i;
                io->instance_index = i;

                /* Allocate a response buffer */
                io->rspbuf.size = SCSI_RSP_BUF_LENGTH;
                io->rspbuf.virt = dma_alloc_coherent(&efct->pci->dev,
                                                     io->rspbuf.size,
                                                     &io->rspbuf.phys, GFP_KERNEL);
                if (!io->rspbuf.virt) {
                        efc_log_err(efct, "dma_alloc rspbuf failed\n");
                        efct_io_pool_free(io_pool);
                        return NULL;
                }

                /* Allocate SGL */
                io->sgl = kzalloc(sizeof(*io->sgl) * num_sgl, GFP_KERNEL);
                if (!io->sgl) {
                        efct_io_pool_free(io_pool);
                        return NULL;
                }

                io->sgl_allocated = num_sgl;
                io->sgl_count = 0;

                INIT_LIST_HEAD(&io->list_entry);
                list_add_tail(&io->list_entry, &io_pool->freelist);
        }

        return io_pool;
}

int
efct_io_pool_free(struct efct_io_pool *io_pool)
{
        struct efct *efct;
        u32 i;
        struct efct_io *io;

        if (io_pool) {
                efct = io_pool->efct;

                for (i = 0; i < io_pool->io_num_ios; i++) {
                        io = io_pool->ios[i];
                        if (!io)
                                continue;

                        kfree(io->sgl);
                        dma_free_coherent(&efct->pci->dev,
                                          io->rspbuf.size, io->rspbuf.virt,
                                          io->rspbuf.phys);
                        memset(&io->rspbuf, 0, sizeof(struct efc_dma));
                }

                kfree(io_pool);
                efct->xport->io_pool = NULL;
        }

        return 0;
}

struct efct_io *
efct_io_pool_io_alloc(struct efct_io_pool *io_pool)
{
        struct efct_io *io = NULL;
        struct efct *efct;
        unsigned long flags = 0;

        efct = io_pool->efct;

        spin_lock_irqsave(&io_pool->lock, flags);

        if (!list_empty(&io_pool->freelist)) {
                io = list_first_entry(&io_pool->freelist, struct efct_io,
                                      list_entry);
                list_del_init(&io->list_entry);
        }

        spin_unlock_irqrestore(&io_pool->lock, flags);

        if (!io)
                return NULL;

        io->io_type = EFCT_IO_TYPE_MAX;
        io->hio_type = EFCT_HW_IO_MAX;
        io->hio = NULL;
        io->transferred = 0;
        io->efct = efct;
        io->timeout = 0;
        io->sgl_count = 0;
        io->tgt_task_tag = 0;
        io->init_task_tag = 0;
        io->hw_tag = 0;
        io->display_name = "pending";
        io->seq_init = 0;
        io->io_free = 0;
        io->release = NULL;
        atomic_add_return(1, &efct->xport->io_active_count);
        atomic_add_return(1, &efct->xport->io_total_alloc);
        return io;
}

/* Free an object used to track an IO */
void
efct_io_pool_io_free(struct efct_io_pool *io_pool, struct efct_io *io)
{
        struct efct *efct;
        struct efct_hw_io *hio = NULL;
        unsigned long flags = 0;

        efct = io_pool->efct;

        spin_lock_irqsave(&io_pool->lock, flags);
        hio = io->hio;
        io->hio = NULL;
        io->io_free = 1;
        INIT_LIST_HEAD(&io->list_entry);
        list_add(&io->list_entry, &io_pool->freelist);
        spin_unlock_irqrestore(&io_pool->lock, flags);

        if (hio)
                efct_hw_io_free(&efct->hw, hio);

        atomic_sub_return(1, &efct->xport->io_active_count);
        atomic_add_return(1, &efct->xport->io_total_free);
}

/* Find an I/O given it's node and ox_id */
struct efct_io *
efct_io_find_tgt_io(struct efct *efct, struct efct_node *node,
                    u16 ox_id, u16 rx_id)
{
        struct efct_io  *io = NULL;
        unsigned long flags = 0;
        u8 found = false;

        spin_lock_irqsave(&node->active_ios_lock, flags);
        list_for_each_entry(io, &node->active_ios, list_entry) {
                if ((io->cmd_tgt && io->init_task_tag == ox_id) &&
                    (rx_id == 0xffff || io->tgt_task_tag == rx_id)) {
                        if (kref_get_unless_zero(&io->ref))
                                found = true;
                        break;
                }
        }
        spin_unlock_irqrestore(&node->active_ios_lock, flags);
        return found ? io : NULL;
}