/*
 * Copyright (c) 2004, 2005 Topspin Communications.  All rights reserved.
 * Copyright (c) 2005, 2006, 2007, 2008 Mellanox Technologies. All rights reserved.
 * Copyright (c) 2005, 2006, 2007 Cisco Systems, Inc.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/errno.h>

#include <linux/mlx4/cmd.h>

#include <asm/io.h>

#include "mlx4.h"

#define CMD_POLL_TOKEN 0xffff

enum {
        /* command completed successfully: */
        CMD_STAT_OK             = 0x00,
        /* Internal error (such as a bus error) occurred while processing command: */
        CMD_STAT_INTERNAL_ERR   = 0x01,
        /* Operation/command not supported or opcode modifier not supported: */
        CMD_STAT_BAD_OP         = 0x02,
        /* Parameter not supported or parameter out of range: */
        CMD_STAT_BAD_PARAM      = 0x03,
        /* System not enabled or bad system state: */
        CMD_STAT_BAD_SYS_STATE  = 0x04,
        /* Attempt to access reserved or unallocaterd resource: */
        CMD_STAT_BAD_RESOURCE   = 0x05,
        /* Requested resource is currently executing a command, or is otherwise busy: */
        CMD_STAT_RESOURCE_BUSY  = 0x06,
        /* Required capability exceeds device limits: */
        CMD_STAT_EXCEED_LIM     = 0x08,
        /* Resource is not in the appropriate state or ownership: */
        CMD_STAT_BAD_RES_STATE  = 0x09,
        /* Index out of range: */
        CMD_STAT_BAD_INDEX      = 0x0a,
        /* FW image corrupted: */
        CMD_STAT_BAD_NVMEM      = 0x0b,
        /* Error in ICM mapping (e.g. not enough auxiliary ICM pages to execute command): */
        CMD_STAT_ICM_ERROR      = 0x0c,
        /* Attempt to modify a QP/EE which is not in the presumed state: */
        CMD_STAT_BAD_QP_STATE   = 0x10,
        /* Bad segment parameters (Address/Size): */
        CMD_STAT_BAD_SEG_PARAM  = 0x20,
        /* Memory Region has Memory Windows bound to: */
        CMD_STAT_REG_BOUND      = 0x21,
        /* HCA local attached memory not present: */
        CMD_STAT_LAM_NOT_PRE    = 0x22,
        /* Bad management packet (silently discarded): */
        CMD_STAT_BAD_PKT        = 0x30,
        /* More outstanding CQEs in CQ than new CQ size: */
        CMD_STAT_BAD_SIZE       = 0x40,
        /* Multi Function device support required: */
        CMD_STAT_MULTI_FUNC_REQ = 0x50,
};

enum {
        HCR_IN_PARAM_OFFSET     = 0x00,
        HCR_IN_MODIFIER_OFFSET  = 0x08,
        HCR_OUT_PARAM_OFFSET    = 0x0c,
        HCR_TOKEN_OFFSET        = 0x14,
        HCR_STATUS_OFFSET       = 0x18,

        HCR_OPMOD_SHIFT         = 12,
        HCR_T_BIT               = 21,
        HCR_E_BIT               = 22,
        HCR_GO_BIT              = 23
};

enum {
        GO_BIT_TIMEOUT_MSECS    = 10000
};

struct mlx4_cmd_context {
        struct completion       done;
        int                     result;
        int                     next;
        u64                     out_param;
        u16                     token;
};

static int mlx4_status_to_errno(u8 status)
{
        static const int trans_table[] = {
                [CMD_STAT_INTERNAL_ERR]   = -EIO,
                [CMD_STAT_BAD_OP]         = -EPERM,
                [CMD_STAT_BAD_PARAM]      = -EINVAL,
                [CMD_STAT_BAD_SYS_STATE]  = -ENXIO,
                [CMD_STAT_BAD_RESOURCE]   = -EBADF,
                [CMD_STAT_RESOURCE_BUSY]  = -EBUSY,
                [CMD_STAT_EXCEED_LIM]     = -ENOMEM,
                [CMD_STAT_BAD_RES_STATE]  = -EBADF,
                [CMD_STAT_BAD_INDEX]      = -EBADF,
                [CMD_STAT_BAD_NVMEM]      = -EFAULT,
                [CMD_STAT_ICM_ERROR]      = -ENFILE,
                [CMD_STAT_BAD_QP_STATE]   = -EINVAL,
                [CMD_STAT_BAD_SEG_PARAM]  = -EFAULT,
                [CMD_STAT_REG_BOUND]      = -EBUSY,
                [CMD_STAT_LAM_NOT_PRE]    = -EAGAIN,
                [CMD_STAT_BAD_PKT]        = -EINVAL,
                [CMD_STAT_BAD_SIZE]       = -ENOMEM,
                [CMD_STAT_MULTI_FUNC_REQ] = -EACCES,
        };

        if (status >= ARRAY_SIZE(trans_table) ||
            (status != CMD_STAT_OK && trans_table[status] == 0))
                return -EIO;

        return trans_table[status];
}

static int cmd_pending(struct mlx4_dev *dev)
{
        u32 status = readl(mlx4_priv(dev)->cmd.hcr + HCR_STATUS_OFFSET);

        return (status & swab32(1 << HCR_GO_BIT)) ||
                (mlx4_priv(dev)->cmd.toggle ==
                 !!(status & swab32(1 << HCR_T_BIT)));
}

static int mlx4_cmd_post(struct mlx4_dev *dev, u64 in_param, u64 out_param,
                         u32 in_modifier, u8 op_modifier, u16 op, u16 token,
                         int event)
{
        struct mlx4_cmd *cmd = &mlx4_priv(dev)->cmd;
        u32 __iomem *hcr = cmd->hcr;
        int ret = -EAGAIN;
        unsigned long end;

        mutex_lock(&cmd->hcr_mutex);

        end = jiffies;
        if (event)
                end += msecs_to_jiffies(GO_BIT_TIMEOUT_MSECS);

        while (cmd_pending(dev)) {
                if (time_after_eq(jiffies, end))
                        goto out;
                cond_resched();
        }

        /*
         * We use writel (instead of something like memcpy_toio)
         * because writes of less than 32 bits to the HCR don't work
         * (and some architectures such as ia64 implement memcpy_toio
         * in terms of writeb).
         */
        __raw_writel((__force u32) cpu_to_be32(in_param >> 32),           hcr + 0);
        __raw_writel((__force u32) cpu_to_be32(in_param & 0xfffffffful),  hcr + 1);
        __raw_writel((__force u32) cpu_to_be32(in_modifier),              hcr + 2);
        __raw_writel((__force u32) cpu_to_be32(out_param >> 32),          hcr + 3);
        __raw_writel((__force u32) cpu_to_be32(out_param & 0xfffffffful), hcr + 4);
        __raw_writel((__force u32) cpu_to_be32(token << 16),              hcr + 5);

        /* __raw_writel may not order writes. */
        wmb();

        __raw_writel((__force u32) cpu_to_be32((1 << HCR_GO_BIT)                |
                                               (cmd->toggle << HCR_T_BIT)       |
                                               (event ? (1 << HCR_E_BIT) : 0)   |
                                               (op_modifier << HCR_OPMOD_SHIFT) |
                                               op),                       hcr + 6);

        /*
         * Make sure that our HCR writes don't get mixed in with
         * writes from another CPU starting a FW command.
         */
        mmiowb();

        cmd->toggle = cmd->toggle ^ 1;

        ret = 0;

out:
        mutex_unlock(&cmd->hcr_mutex);
        return ret;
}

static int mlx4_cmd_poll(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
                         int out_is_imm, u32 in_modifier, u8 op_modifier,
                         u16 op, unsigned long timeout)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        void __iomem *hcr = priv->cmd.hcr;
        int err = 0;
        unsigned long end;

        down(&priv->cmd.poll_sem);

        err = mlx4_cmd_post(dev, in_param, out_param ? *out_param : 0,
                            in_modifier, op_modifier, op, CMD_POLL_TOKEN, 0);
        if (err)
                goto out;

        end = msecs_to_jiffies(timeout) + jiffies;
        while (cmd_pending(dev) && time_before(jiffies, end))
                cond_resched();

        if (cmd_pending(dev)) {
                err = -ETIMEDOUT;
                goto out;
        }

        if (out_is_imm)
                *out_param =
                        (u64) be32_to_cpu((__force __be32)
                                          __raw_readl(hcr + HCR_OUT_PARAM_OFFSET)) << 32 |
                        (u64) be32_to_cpu((__force __be32)
                                          __raw_readl(hcr + HCR_OUT_PARAM_OFFSET + 4));

        err = mlx4_status_to_errno(be32_to_cpu((__force __be32)
                                               __raw_readl(hcr + HCR_STATUS_OFFSET)) >> 24);

out:
        up(&priv->cmd.poll_sem);
        return err;
}

void mlx4_cmd_event(struct mlx4_dev *dev, u16 token, u8 status, u64 out_param)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        struct mlx4_cmd_context *context =
                &priv->cmd.context[token & priv->cmd.token_mask];

        /* previously timed out command completing at long last */
        if (token != context->token)
                return;

        context->result    = mlx4_status_to_errno(status);
        context->out_param = out_param;

        complete(&context->done);
}

static int mlx4_cmd_wait(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
                         int out_is_imm, u32 in_modifier, u8 op_modifier,
                         u16 op, unsigned long timeout)
{
        struct mlx4_cmd *cmd = &mlx4_priv(dev)->cmd;
        struct mlx4_cmd_context *context;
        int err = 0;

        down(&cmd->event_sem);

        spin_lock(&cmd->context_lock);
        BUG_ON(cmd->free_head < 0);
        context = &cmd->context[cmd->free_head];
        context->token += cmd->token_mask + 1;
        cmd->free_head = context->next;
        spin_unlock(&cmd->context_lock);

        init_completion(&context->done);

        mlx4_cmd_post(dev, in_param, out_param ? *out_param : 0,
                      in_modifier, op_modifier, op, context->token, 1);

        if (!wait_for_completion_timeout(&context->done, msecs_to_jiffies(timeout))) {
                err = -EBUSY;
                goto out;
        }

        err = context->result;
        if (err)
                goto out;

        if (out_is_imm)
                *out_param = context->out_param;

out:
        spin_lock(&cmd->context_lock);
        context->next = cmd->free_head;
        cmd->free_head = context - cmd->context;
        spin_unlock(&cmd->context_lock);

        up(&cmd->event_sem);
        return err;
}

int __mlx4_cmd(struct mlx4_dev *dev, u64 in_param, u64 *out_param,
               int out_is_imm, u32 in_modifier, u8 op_modifier,
               u16 op, unsigned long timeout)
{
        if (mlx4_priv(dev)->cmd.use_events)
                return mlx4_cmd_wait(dev, in_param, out_param, out_is_imm,
                                     in_modifier, op_modifier, op, timeout);
        else
                return mlx4_cmd_poll(dev, in_param, out_param, out_is_imm,
                                     in_modifier, op_modifier, op, timeout);
}
EXPORT_SYMBOL_GPL(__mlx4_cmd);

int mlx4_cmd_init(struct mlx4_dev *dev)
{
        struct mlx4_priv *priv = mlx4_priv(dev);

        mutex_init(&priv->cmd.hcr_mutex);
        sema_init(&priv->cmd.poll_sem, 1);
        priv->cmd.use_events = 0;
        priv->cmd.toggle     = 1;

        priv->cmd.hcr = ioremap(pci_resource_start(dev->pdev, 0) + MLX4_HCR_BASE,
                                MLX4_HCR_SIZE);
        if (!priv->cmd.hcr) {
                mlx4_err(dev, "Couldn't map command register.");
                return -ENOMEM;
        }

        priv->cmd.pool = pci_pool_create("mlx4_cmd", dev->pdev,
                                         MLX4_MAILBOX_SIZE,
                                         MLX4_MAILBOX_SIZE, 0);
        if (!priv->cmd.pool) {
                iounmap(priv->cmd.hcr);
                return -ENOMEM;
        }

        return 0;
}

void mlx4_cmd_cleanup(struct mlx4_dev *dev)
{
        struct mlx4_priv *priv = mlx4_priv(dev);

        pci_pool_destroy(priv->cmd.pool);
        iounmap(priv->cmd.hcr);
}

/*
 * Switch to using events to issue FW commands (can only be called
 * after event queue for command events has been initialized).
 */
int mlx4_cmd_use_events(struct mlx4_dev *dev)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        int i;

        priv->cmd.context = kmalloc(priv->cmd.max_cmds *
                                   sizeof (struct mlx4_cmd_context),
                                   GFP_KERNEL);
        if (!priv->cmd.context)
                return -ENOMEM;

        for (i = 0; i < priv->cmd.max_cmds; ++i) {
                priv->cmd.context[i].token = i;
                priv->cmd.context[i].next  = i + 1;
        }

        priv->cmd.context[priv->cmd.max_cmds - 1].next = -1;
        priv->cmd.free_head = 0;

        sema_init(&priv->cmd.event_sem, priv->cmd.max_cmds);
        spin_lock_init(&priv->cmd.context_lock);

        for (priv->cmd.token_mask = 1;
             priv->cmd.token_mask < priv->cmd.max_cmds;
             priv->cmd.token_mask <<= 1)
                ; /* nothing */
        --priv->cmd.token_mask;

        priv->cmd.use_events = 1;

        down(&priv->cmd.poll_sem);

        return 0;
}

/*
 * Switch back to polling (used when shutting down the device)
 */
void mlx4_cmd_use_polling(struct mlx4_dev *dev)
{
        struct mlx4_priv *priv = mlx4_priv(dev);
        int i;

        priv->cmd.use_events = 0;

        for (i = 0; i < priv->cmd.max_cmds; ++i)
                down(&priv->cmd.event_sem);

        kfree(priv->cmd.context);

        up(&priv->cmd.poll_sem);
}

struct mlx4_cmd_mailbox *mlx4_alloc_cmd_mailbox(struct mlx4_dev *dev)
{
        struct mlx4_cmd_mailbox *mailbox;

        mailbox = kmalloc(sizeof *mailbox, GFP_KERNEL);
        if (!mailbox)
                return ERR_PTR(-ENOMEM);

        mailbox->buf = pci_pool_alloc(mlx4_priv(dev)->cmd.pool, GFP_KERNEL,
                                      &mailbox->dma);
        if (!mailbox->buf) {
                kfree(mailbox);
                return ERR_PTR(-ENOMEM);
        }

        return mailbox;
}
EXPORT_SYMBOL_GPL(mlx4_alloc_cmd_mailbox);

void mlx4_free_cmd_mailbox(struct mlx4_dev *dev, struct mlx4_cmd_mailbox *mailbox)
{
        if (!mailbox)
                return;

        pci_pool_free(mlx4_priv(dev)->cmd.pool, mailbox->buf, mailbox->dma);
        kfree(mailbox);
}
EXPORT_SYMBOL_GPL(mlx4_free_cmd_mailbox);