/*
 * 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/export.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)
{
	int ret;

	down_read(&mlx4_priv(dev)->cmd.switch_sem);
	if (mlx4_priv(dev)->cmd.use_events)
		ret = mlx4_cmd_wait(dev, in_param, out_param, out_is_imm,
				    in_modifier, op_modifier, op, timeout);
	else
		ret = mlx4_cmd_poll(dev, in_param, out_param, out_is_imm,
				    in_modifier, op_modifier, op, timeout);

	up_read(&mlx4_priv(dev)->cmd.switch_sem);
	return ret;
}
EXPORT_SYMBOL_GPL(__mlx4_cmd);

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

	init_rwsem(&priv->cmd.switch_sem);
	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;

	down_write(&priv->cmd.switch_sem);
	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;
	up_write(&priv->cmd.switch_sem);

	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;

	down_write(&priv->cmd.switch_sem);
	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);
	up_write(&priv->cmd.switch_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);
