linux-imx

/*

 * Copyright (c) 2009, Microsoft Corporation.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 * You should have received a copy of the GNU General Public License along with

 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple

 * Place - Suite 330, Boston, MA 02111-1307 USA.

 *

 * Authors:

 *   Haiyang Zhang <haiyangz@microsoft.com>

 *   Hank Janssen  <hjanssen@microsoft.com>

 *

 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/hyperv.h>

#include <linux/version.h>

#include <linux/random.h>

#include <linux/clockchips.h>

#include <asm/mshyperv.h>

#include "hyperv_vmbus.h"

​

/* The one and only */

struct hv_context hv_context;

​

/*

 * If false, we're using the old mechanism for stimer0 interrupts

 * where it sends a VMbus message when it expires. The old

 * mechanism is used when running on older versions of Hyper-V

 * that don't support Direct Mode. While Hyper-V provides

 * four stimer's per CPU, Linux uses only stimer0.

 */

static bool direct_mode_enabled;

static int stimer0_irq;

static int stimer0_vector;

​

#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */

#define HV_MAX_MAX_DELTA_TICKS 0xffffffff

#define HV_MIN_DELTA_TICKS 1

​

/*

 * hv_init - Main initialization routine.

 *

 * This routine must be called before any other routines in here are called

 */

int hv_init(void)

{

    hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);

    if (!hv_context.cpu_context)

        return -ENOMEM;

​