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// SPDX-License-Identifier: GPL-2.0
#include <linux/export.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/jump_label.h>
#include <linux/kvm_para.h>
#include <linux/static_call.h>
#include <asm/paravirt.h>
struct static_key paravirt_steal_enabled;
struct static_key paravirt_steal_rq_enabled;
static u64 native_steal_clock(int cpu)
{
return 0;
}
DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
#ifdef CONFIG_SMP
static void pv_send_ipi_single(int cpu, unsigned int action)
{
int min, old;
irq_cpustat_t *info = &per_cpu(irq_stat, cpu);
old = atomic_fetch_or(BIT(action), &info->message);
if (old)
return;
min = cpu_logical_map(cpu);
kvm_hypercall3(KVM_HCALL_FUNC_IPI, 1, 0, min);
}
#define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG)
static void pv_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
int i, cpu, min = 0, max = 0, old;
__uint128_t bitmap = 0;
irq_cpustat_t *info;
if (cpumask_empty(mask))
return;
action = BIT(action);
for_each_cpu(i, mask) {
info = &per_cpu(irq_stat, i);
old = atomic_fetch_or(action, &info->message);
if (old)
continue;
cpu = cpu_logical_map(i);
if (!bitmap) {
min = max = cpu;
} else if (cpu < min && cpu > (max - KVM_IPI_CLUSTER_SIZE)) {
/* cpu < min, and bitmap still enough */
bitmap <<= min - cpu;
min = cpu;
} else if (cpu > min && cpu < (min + KVM_IPI_CLUSTER_SIZE)) {
/* cpu > min, and bitmap still enough */
max = cpu > max ? cpu : max;
} else {
/*
* With cpu, bitmap will exceed KVM_IPI_CLUSTER_SIZE,
* send IPI here directly and skip the remaining CPUs.
*/
kvm_hypercall3(KVM_HCALL_FUNC_IPI, (unsigned long)bitmap,
(unsigned long)(bitmap >> BITS_PER_LONG), min);
min = max = cpu;
bitmap = 0;
}
__set_bit(cpu - min, (unsigned long *)&bitmap);
}
if (bitmap)
kvm_hypercall3(KVM_HCALL_FUNC_IPI, (unsigned long)bitmap,
(unsigned long)(bitmap >> BITS_PER_LONG), min);
}
static irqreturn_t pv_ipi_interrupt(int irq, void *dev)
{
u32 action;
irq_cpustat_t *info;
/* Clear SWI interrupt */
clear_csr_estat(1 << INT_SWI0);
info = this_cpu_ptr(&irq_stat);
action = atomic_xchg(&info->message, 0);
if (action & SMP_RESCHEDULE) {
scheduler_ipi();
info->ipi_irqs[IPI_RESCHEDULE]++;
}
if (action & SMP_CALL_FUNCTION) {
generic_smp_call_function_interrupt();
info->ipi_irqs[IPI_CALL_FUNCTION]++;
}
return IRQ_HANDLED;
}
static void pv_init_ipi(void)
{
int r, swi;
swi = get_percpu_irq(INT_SWI0);
if (swi < 0)
panic("SWI0 IRQ mapping failed\n");
irq_set_percpu_devid(swi);
r = request_percpu_irq(swi, pv_ipi_interrupt, "SWI0-IPI", &irq_stat);
if (r < 0)
panic("SWI0 IRQ request failed\n");
}
#endif
static bool kvm_para_available(void)
{
int config;
static int hypervisor_type;
if (!hypervisor_type) {
config = read_cpucfg(CPUCFG_KVM_SIG);
if (!memcmp(&config, KVM_SIGNATURE, 4))
hypervisor_type = HYPERVISOR_KVM;
}
return hypervisor_type == HYPERVISOR_KVM;
}
int __init pv_ipi_init(void)
{
int feature;
if (!cpu_has_hypervisor)
return 0;
if (!kvm_para_available())
return 0;
feature = read_cpucfg(CPUCFG_KVM_FEATURE);
if (!(feature & KVM_FEATURE_IPI))
return 0;
#ifdef CONFIG_SMP
mp_ops.init_ipi = pv_init_ipi;
mp_ops.send_ipi_single = pv_send_ipi_single;
mp_ops.send_ipi_mask = pv_send_ipi_mask;
#endif
return 0;
}
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