v4.19.13 snapshot.
diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
new file mode 100644
index 0000000..2c43e30
--- /dev/null
+++ b/arch/x86/hyperv/hv_apic.c
@@ -0,0 +1,266 @@
+// 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>
+#include <asm/apic.h>
+
+#include <asm/trace/hyperv.h>
+
+static struct apic orig_apic;
+
+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);
+}
+
+/*
+ * IPI implementation on Hyper-V.
+ */
+static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
+{
+ struct hv_send_ipi_ex **arg;
+ struct hv_send_ipi_ex *ipi_arg;
+ unsigned long flags;
+ int nr_bank = 0;
+ int ret = 1;
+
+ if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
+ return false;
+
+ local_irq_save(flags);
+ arg = (struct hv_send_ipi_ex **)this_cpu_ptr(hyperv_pcpu_input_arg);
+
+ ipi_arg = *arg;
+ if (unlikely(!ipi_arg))
+ goto ipi_mask_ex_done;
+
+ ipi_arg->vector = vector;
+ ipi_arg->reserved = 0;
+ ipi_arg->vp_set.valid_bank_mask = 0;
+
+ if (!cpumask_equal(mask, cpu_present_mask)) {
+ ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
+ nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
+ }
+ if (nr_bank < 0)
+ goto ipi_mask_ex_done;
+ if (!nr_bank)
+ ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
+
+ ret = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank,
+ ipi_arg, NULL);
+
+ipi_mask_ex_done:
+ local_irq_restore(flags);
+ return ((ret == 0) ? true : false);
+}
+
+static bool __send_ipi_mask(const struct cpumask *mask, int vector)
+{
+ int cur_cpu, vcpu;
+ struct hv_send_ipi ipi_arg;
+ int ret = 1;
+
+ trace_hyperv_send_ipi_mask(mask, vector);
+
+ if (cpumask_empty(mask))
+ return true;
+
+ if (!hv_hypercall_pg)
+ return false;
+
+ if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
+ return false;
+
+ /*
+ * From the supplied CPU set we need to figure out if we can get away
+ * with cheaper HVCALL_SEND_IPI hypercall. This is possible when the
+ * highest VP number in the set is < 64. As VP numbers are usually in
+ * ascending order and match Linux CPU ids, here is an optimization:
+ * we check the VP number for the highest bit in the supplied set first
+ * so we can quickly find out if using HVCALL_SEND_IPI_EX hypercall is
+ * a must. We will also check all VP numbers when walking the supplied
+ * CPU set to remain correct in all cases.
+ */
+ if (hv_cpu_number_to_vp_number(cpumask_last(mask)) >= 64)
+ goto do_ex_hypercall;
+
+ ipi_arg.vector = vector;
+ ipi_arg.cpu_mask = 0;
+
+ for_each_cpu(cur_cpu, mask) {
+ vcpu = hv_cpu_number_to_vp_number(cur_cpu);
+ if (vcpu == VP_INVAL)
+ return false;
+
+ /*
+ * This particular version of the IPI hypercall can
+ * only target upto 64 CPUs.
+ */
+ if (vcpu >= 64)
+ goto do_ex_hypercall;
+
+ __set_bit(vcpu, (unsigned long *)&ipi_arg.cpu_mask);
+ }
+
+ ret = hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector,
+ ipi_arg.cpu_mask);
+ return ((ret == 0) ? true : false);
+
+do_ex_hypercall:
+ return __send_ipi_mask_ex(mask, vector);
+}
+
+static bool __send_ipi_one(int cpu, int vector)
+{
+ struct cpumask mask = CPU_MASK_NONE;
+
+ cpumask_set_cpu(cpu, &mask);
+ return __send_ipi_mask(&mask, vector);
+}
+
+static void hv_send_ipi(int cpu, int vector)
+{
+ if (!__send_ipi_one(cpu, vector))
+ orig_apic.send_IPI(cpu, vector);
+}
+
+static void hv_send_ipi_mask(const struct cpumask *mask, int vector)
+{
+ if (!__send_ipi_mask(mask, vector))
+ orig_apic.send_IPI_mask(mask, vector);
+}
+
+static void hv_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
+{
+ unsigned int this_cpu = smp_processor_id();
+ struct cpumask new_mask;
+ const struct cpumask *local_mask;
+
+ cpumask_copy(&new_mask, mask);
+ cpumask_clear_cpu(this_cpu, &new_mask);
+ local_mask = &new_mask;
+ if (!__send_ipi_mask(local_mask, vector))
+ orig_apic.send_IPI_mask_allbutself(mask, vector);
+}
+
+static void hv_send_ipi_allbutself(int vector)
+{
+ hv_send_ipi_mask_allbutself(cpu_online_mask, vector);
+}
+
+static void hv_send_ipi_all(int vector)
+{
+ if (!__send_ipi_mask(cpu_online_mask, vector))
+ orig_apic.send_IPI_all(vector);
+}
+
+static void hv_send_ipi_self(int vector)
+{
+ if (!__send_ipi_one(smp_processor_id(), vector))
+ orig_apic.send_IPI_self(vector);
+}
+
+void __init hv_apic_init(void)
+{
+ if (ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) {
+ pr_info("Hyper-V: Using IPI hypercalls\n");
+ /*
+ * Set the IPI entry points.
+ */
+ orig_apic = *apic;
+
+ apic->send_IPI = hv_send_ipi;
+ apic->send_IPI_mask = hv_send_ipi_mask;
+ apic->send_IPI_mask_allbutself = hv_send_ipi_mask_allbutself;
+ apic->send_IPI_allbutself = hv_send_ipi_allbutself;
+ apic->send_IPI_all = hv_send_ipi_all;
+ apic->send_IPI_self = hv_send_ipi_self;
+ }
+
+ 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;
+ }
+}