Commit 6b48cb5f authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Thomas Gleixner

X86/Hyper-V: Enlighten APIC access

Hyper-V supports MSR based APIC access; implement
the enlightenment.
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Cc: olaf@aepfle.de
Cc: sthemmin@microsoft.com
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: Michael.H.Kelley@microsoft.com
Cc: hpa@zytor.com
Cc: apw@canonical.com
Cc: devel@linuxdriverproject.org
Cc: vkuznets@redhat.com
Link: https://lkml.kernel.org/r/20180516215334.6547-1-kys@linuxonhyperv.com
parent 73fcb1a3
obj-y := hv_init.o mmu.o
obj-y := hv_init.o mmu.o hv_apic.o
// SPDX-License-Identifier: GPL-2.0
/*
* Hyper-V specific APIC code.
*
* Copyright (C) 2018, Microsoft, Inc.
*
* Author : K. Y. Srinivasan <kys@microsoft.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*
*/
#include <linux/types.h>
#include <linux/version.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/clockchips.h>
#include <linux/hyperv.h>
#include <linux/slab.h>
#include <linux/cpuhotplug.h>
#include <asm/hypervisor.h>
#include <asm/mshyperv.h>
#ifdef CONFIG_X86_64
#if IS_ENABLED(CONFIG_HYPERV)
static u64 hv_apic_icr_read(void)
{
u64 reg_val;
rdmsrl(HV_X64_MSR_ICR, reg_val);
return reg_val;
}
static void hv_apic_icr_write(u32 low, u32 id)
{
u64 reg_val;
reg_val = SET_APIC_DEST_FIELD(id);
reg_val = reg_val << 32;
reg_val |= low;
wrmsrl(HV_X64_MSR_ICR, reg_val);
}
static u32 hv_apic_read(u32 reg)
{
u32 reg_val, hi;
switch (reg) {
case APIC_EOI:
rdmsr(HV_X64_MSR_EOI, reg_val, hi);
return reg_val;
case APIC_TASKPRI:
rdmsr(HV_X64_MSR_TPR, reg_val, hi);
return reg_val;
default:
return native_apic_mem_read(reg);
}
}
static void hv_apic_write(u32 reg, u32 val)
{
switch (reg) {
case APIC_EOI:
wrmsr(HV_X64_MSR_EOI, val, 0);
break;
case APIC_TASKPRI:
wrmsr(HV_X64_MSR_TPR, val, 0);
break;
default:
native_apic_mem_write(reg, val);
}
}
static void hv_apic_eoi_write(u32 reg, u32 val)
{
wrmsr(HV_X64_MSR_EOI, val, 0);
}
void __init hv_apic_init(void)
{
if (ms_hyperv.hints & HV_X64_APIC_ACCESS_RECOMMENDED) {
pr_info("Hyper-V: Using MSR based APIC access\n");
apic_set_eoi_write(hv_apic_eoi_write);
apic->read = hv_apic_read;
apic->write = hv_apic_write;
apic->icr_write = hv_apic_icr_write;
apic->icr_read = hv_apic_icr_read;
}
}
#endif /* CONFIG_HYPERV */
#endif /* CONFIG_X86_64 */
......@@ -242,8 +242,9 @@ static int hv_cpu_die(unsigned int cpu)
*
* 1. Setup the hypercall page.
* 2. Register Hyper-V specific clocksource.
* 3. Setup Hyper-V specific APIC entry points.
*/
void hyperv_init(void)
void __init hyperv_init(void)
{
u64 guest_id, required_msrs;
union hv_x64_msr_hypercall_contents hypercall_msr;
......@@ -298,6 +299,8 @@ void hyperv_init(void)
hyper_alloc_mmu();
hv_apic_init();
/*
* Register Hyper-V specific clocksource.
*/
......
......@@ -258,7 +258,7 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number)
return hv_vp_index[cpu_number];
}
void hyperv_init(void);
void __init hyperv_init(void);
void hyperv_setup_mmu_ops(void);
void hyper_alloc_mmu(void);
void hyperv_report_panic(struct pt_regs *regs, long err);
......@@ -269,6 +269,7 @@ void hyperv_reenlightenment_intr(struct pt_regs *regs);
void set_hv_tscchange_cb(void (*cb)(void));
void clear_hv_tscchange_cb(void);
void hyperv_stop_tsc_emulation(void);
void hv_apic_init(void);
#else /* CONFIG_HYPERV */
static inline void hyperv_init(void) {}
static inline bool hv_is_hyperv_initialized(void) { return false; }
......@@ -277,6 +278,7 @@ static inline void hyperv_setup_mmu_ops(void) {}
static inline void set_hv_tscchange_cb(void (*cb)(void)) {}
static inline void clear_hv_tscchange_cb(void) {}
static inline void hyperv_stop_tsc_emulation(void) {};
static inline void hv_apic_init(void) {}
static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
{
return NULL;
......
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