swh:1:snp:32555a3fd8878f019c2ebd6c964bc1edcaeff337
Tip revision: b3a987b0264d3ddbb24293ebff10eddfc472f653 authored by Linus Torvalds on 13 January 2020, 00:55:08 UTC
Linux 5.5-rc6
Linux 5.5-rc6
Tip revision: b3a987b
hv.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2009, Microsoft Corporation.
*
* 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 <clocksource/hyperv_timer.h>
#include <asm/mshyperv.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_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
if (!hv_context.cpu_context)
return -ENOMEM;
return 0;
}
/*
* 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)
{
struct hv_input_post_message *aligned_msg;
struct hv_per_cpu_context *hv_cpu;
u64 status;
if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
return -EMSGSIZE;
hv_cpu = get_cpu_ptr(hv_context.cpu_context);
aligned_msg = hv_cpu->post_msg_page;
aligned_msg->connectionid = connection_id;
aligned_msg->reserved = 0;
aligned_msg->message_type = message_type;
aligned_msg->payload_size = payload_size;
memcpy((void *)aligned_msg->payload, payload, payload_size);
status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
/* Preemption must remain disabled until after the hypercall
* so some other thread can't get scheduled onto this cpu and
* corrupt the per-cpu post_msg_page
*/
put_cpu_ptr(hv_cpu);
return status & 0xFFFF;
}
int hv_synic_alloc(void)
{
int cpu;
struct hv_per_cpu_context *hv_cpu;
/*
* First, zero all per-cpu memory areas so hv_synic_free() can
* detect what memory has been allocated and cleanup properly
* after any failures.
*/
for_each_present_cpu(cpu) {
hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
memset(hv_cpu, 0, sizeof(*hv_cpu));
}
hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
GFP_KERNEL);
if (hv_context.hv_numa_map == NULL) {
pr_err("Unable to allocate NUMA map\n");
goto err;
}
for_each_present_cpu(cpu) {
hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
tasklet_init(&hv_cpu->msg_dpc,
vmbus_on_msg_dpc, (unsigned long) hv_cpu);
hv_cpu->synic_message_page =
(void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->synic_message_page == NULL) {
pr_err("Unable to allocate SYNIC message page\n");
goto err;
}
hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->synic_event_page == NULL) {
pr_err("Unable to allocate SYNIC event page\n");
goto err;
}
hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
if (hv_cpu->post_msg_page == NULL) {
pr_err("Unable to allocate post msg page\n");
goto err;
}
INIT_LIST_HEAD(&hv_cpu->chan_list);
}
return 0;
err:
/*
* Any memory allocations that succeeded will be freed when
* the caller cleans up by calling hv_synic_free()
*/
return -ENOMEM;
}
void hv_synic_free(void)
{
int cpu;
for_each_present_cpu(cpu) {
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
free_page((unsigned long)hv_cpu->synic_event_page);
free_page((unsigned long)hv_cpu->synic_message_page);
free_page((unsigned long)hv_cpu->post_msg_page);
}
kfree(hv_context.hv_numa_map);
}
/*
* 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)
{
struct hv_per_cpu_context *hv_cpu
= per_cpu_ptr(hv_context.cpu_context, cpu);
union hv_synic_simp simp;
union hv_synic_siefp siefp;
union hv_synic_sint shared_sint;
union hv_synic_scontrol sctrl;
/* Setup the Synic's message page */
hv_get_simp(simp.as_uint64);
simp.simp_enabled = 1;
simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
>> PAGE_SHIFT;
hv_set_simp(simp.as_uint64);
/* Setup the Synic's event page */
hv_get_siefp(siefp.as_uint64);
siefp.siefp_enabled = 1;
siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
>> PAGE_SHIFT;
hv_set_siefp(siefp.as_uint64);
/* Setup the shared SINT. */
hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
shared_sint.masked = false;
if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
shared_sint.auto_eoi = false;
else
shared_sint.auto_eoi = true;
hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
/* Enable the global synic bit */
hv_get_synic_state(sctrl.as_uint64);
sctrl.enable = 1;
hv_set_synic_state(sctrl.as_uint64);
}
int hv_synic_init(unsigned int cpu)
{
hv_synic_enable_regs(cpu);
hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
return 0;
}
/*
* hv_synic_cleanup - Cleanup routine for hv_synic_init().
*/
void hv_synic_disable_regs(unsigned int cpu)
{
union hv_synic_sint shared_sint;
union hv_synic_simp simp;
union hv_synic_siefp siefp;
union hv_synic_scontrol sctrl;
hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
shared_sint.masked = 1;
/* Need to correctly cleanup in the case of SMP!!! */
/* Disable the interrupt */
hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
hv_get_simp(simp.as_uint64);
simp.simp_enabled = 0;
simp.base_simp_gpa = 0;
hv_set_simp(simp.as_uint64);
hv_get_siefp(siefp.as_uint64);
siefp.siefp_enabled = 0;
siefp.base_siefp_gpa = 0;
hv_set_siefp(siefp.as_uint64);
/* Disable the global synic bit */
hv_get_synic_state(sctrl.as_uint64);
sctrl.enable = 0;
hv_set_synic_state(sctrl.as_uint64);
}
int hv_synic_cleanup(unsigned int cpu)
{
struct vmbus_channel *channel, *sc;
bool channel_found = false;
unsigned long flags;
/*
* Search for channels which are bound to the CPU we're about to
* cleanup. In case we find one and vmbus is still connected we need to
* fail, this will effectively prevent CPU offlining. There is no way
* we can re-bind channels to different CPUs for now.
*/
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (channel->target_cpu == cpu) {
channel_found = true;
break;
}
spin_lock_irqsave(&channel->lock, flags);
list_for_each_entry(sc, &channel->sc_list, sc_list) {
if (sc->target_cpu == cpu) {
channel_found = true;
break;
}
}
spin_unlock_irqrestore(&channel->lock, flags);
if (channel_found)
break;
}
mutex_unlock(&vmbus_connection.channel_mutex);
if (channel_found && vmbus_connection.conn_state == CONNECTED)
return -EBUSY;
hv_stimer_legacy_cleanup(cpu);
hv_synic_disable_regs(cpu);
return 0;
}