linux/arch/x86/kernel/cpu/acrn.c
Fei Li 81a71f51b8 x86/acrn: Set up timekeeping
ACRN Hypervisor reports timing information via CPUID leaf 0x40000010.
Get the TSC and CPU frequency via CPUID leaf 0x40000010 and set the
kernel values accordingly.

Signed-off-by: Fei Li <fei1.li@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Conghui <conghui.chen@intel.com>
Link: https://lore.kernel.org/r/20220804055903.365211-1-fei1.li@intel.com
2022-08-04 11:11:59 +02:00

82 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* ACRN detection support
*
* Copyright (C) 2019 Intel Corporation. All rights reserved.
*
* Jason Chen CJ <jason.cj.chen@intel.com>
* Zhao Yakui <yakui.zhao@intel.com>
*
*/
#include <linux/interrupt.h>
#include <asm/acrn.h>
#include <asm/apic.h>
#include <asm/cpufeatures.h>
#include <asm/desc.h>
#include <asm/hypervisor.h>
#include <asm/idtentry.h>
#include <asm/irq_regs.h>
static u32 __init acrn_detect(void)
{
return acrn_cpuid_base();
}
static void __init acrn_init_platform(void)
{
/* Setup the IDT for ACRN hypervisor callback */
alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_acrn_hv_callback);
x86_platform.calibrate_tsc = acrn_get_tsc_khz;
x86_platform.calibrate_cpu = acrn_get_tsc_khz;
}
static bool acrn_x2apic_available(void)
{
return boot_cpu_has(X86_FEATURE_X2APIC);
}
static void (*acrn_intr_handler)(void);
DEFINE_IDTENTRY_SYSVEC(sysvec_acrn_hv_callback)
{
struct pt_regs *old_regs = set_irq_regs(regs);
/*
* The hypervisor requires that the APIC EOI should be acked.
* If the APIC EOI is not acked, the APIC ISR bit for the
* HYPERVISOR_CALLBACK_VECTOR will not be cleared and then it
* will block the interrupt whose vector is lower than
* HYPERVISOR_CALLBACK_VECTOR.
*/
ack_APIC_irq();
inc_irq_stat(irq_hv_callback_count);
if (acrn_intr_handler)
acrn_intr_handler();
set_irq_regs(old_regs);
}
void acrn_setup_intr_handler(void (*handler)(void))
{
acrn_intr_handler = handler;
}
EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
void acrn_remove_intr_handler(void)
{
acrn_intr_handler = NULL;
}
EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);
const __initconst struct hypervisor_x86 x86_hyper_acrn = {
.name = "ACRN",
.detect = acrn_detect,
.type = X86_HYPER_ACRN,
.init.init_platform = acrn_init_platform,
.init.x2apic_available = acrn_x2apic_available,
};