linux/drivers/hv/hv.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2009, Microsoft Corporation.
 *
 * Authors:
 *   Haiyang Zhang <[email protected]>
 *   Hank Janssen  <[email protected]>
 */
#define pr_fmt(fmt) …

#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <linux/random.h>
#include <linux/clockchips.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <clocksource/hyperv_timer.h>
#include <asm/mshyperv.h>
#include <linux/set_memory.h>
#include "hyperv_vmbus.h"

/* The one and only */
struct hv_context hv_context;

/*
 * hv_init - Main initialization routine.
 *
 * This routine must be called before any other routines in here are called
 */
int hv_init(void)
{ … }

/*
 * hv_post_message - Post a message using the hypervisor message IPC.
 *
 * This involves a hypercall.
 */
int hv_post_message(union hv_connection_id connection_id,
			enum hv_message_type message_type,
			void *payload, size_t payload_size)
{ … }

int hv_synic_alloc(void)
{ … }

void hv_synic_free(void)
{ … }

/*
 * hv_synic_init - Initialize the Synthetic Interrupt Controller.
 *
 * If it is already initialized by another entity (ie x2v shim), we need to
 * retrieve the initialized message and event pages.  Otherwise, we create and
 * initialize the message and event pages.
 */
void hv_synic_enable_regs(unsigned int cpu)
{ … }

int hv_synic_init(unsigned int cpu)
{ … }

void hv_synic_disable_regs(unsigned int cpu)
{ … }

#define HV_MAX_TRIES …
/*
 * Scan the event flags page of 'this' CPU looking for any bit that is set.  If we find one
 * bit set, then wait for a few milliseconds.  Repeat these steps for a maximum of 3 times.
 * Return 'true', if there is still any set bit after this operation; 'false', otherwise.
 *
 * If a bit is set, that means there is a pending channel interrupt.  The expectation is
 * that the normal interrupt handling mechanism will find and process the channel interrupt
 * "very soon", and in the process clear the bit.
 */
static bool hv_synic_event_pending(void)
{ … }

/*
 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 */
int hv_synic_cleanup(unsigned int cpu)
{ … }