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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/hyperv/hv_apic.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/hyperv/hv_apic.c')
-rw-r--r-- | arch/x86/hyperv/hv_apic.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c new file mode 100644 index 000000000..fb8b2c088 --- /dev/null +++ b/arch/x86/hyperv/hv_apic.c @@ -0,0 +1,317 @@ +// 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/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_XAPIC_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); + (void)hi; + return reg_val; + case APIC_TASKPRI: + rdmsr(HV_X64_MSR_TPR, reg_val, hi); + (void)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) +{ + struct hv_vp_assist_page *hvp = hv_vp_assist_page[smp_processor_id()]; + + if (hvp && (xchg(&hvp->apic_assist, 0) & 0x1)) + return; + + wrmsr(HV_X64_MSR_EOI, val, 0); +} + +/* + * IPI implementation on Hyper-V. + */ +static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector, + bool exclude_self) +{ + struct hv_send_ipi_ex **arg; + struct hv_send_ipi_ex *ipi_arg; + unsigned long flags; + int nr_bank = 0; + u64 status = HV_STATUS_INVALID_PARAMETER; + + 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; + + /* + * Use HV_GENERIC_SET_ALL and avoid converting cpumask to VP_SET + * when the IPI is sent to all currently present CPUs. + */ + if (!cpumask_equal(mask, cpu_present_mask) || exclude_self) { + ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K; + if (exclude_self) + nr_bank = cpumask_to_vpset_noself(&(ipi_arg->vp_set), mask); + else + nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask); + + /* + * 'nr_bank <= 0' means some CPUs in cpumask can't be + * represented in VP_SET. Return an error and fall back to + * native (architectural) method of sending IPIs. + */ + if (nr_bank <= 0) + goto ipi_mask_ex_done; + } else { + ipi_arg->vp_set.format = HV_GENERIC_SET_ALL; + } + + status = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank, + ipi_arg, NULL); + +ipi_mask_ex_done: + local_irq_restore(flags); + return hv_result_success(status); +} + +static bool __send_ipi_mask(const struct cpumask *mask, int vector, + bool exclude_self) +{ + int cur_cpu, vcpu, this_cpu = smp_processor_id(); + struct hv_send_ipi ipi_arg; + u64 status; + unsigned int weight; + + trace_hyperv_send_ipi_mask(mask, vector); + + weight = cpumask_weight(mask); + + /* + * Do nothing if + * 1. the mask is empty + * 2. the mask only contains self when exclude_self is true + */ + if (weight == 0 || + (exclude_self && weight == 1 && cpumask_test_cpu(this_cpu, 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) { + if (exclude_self && cur_cpu == this_cpu) + continue; + 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); + } + + status = hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector, + ipi_arg.cpu_mask); + return hv_result_success(status); + +do_ex_hypercall: + return __send_ipi_mask_ex(mask, vector, exclude_self); +} + +static bool __send_ipi_one(int cpu, int vector) +{ + int vp = hv_cpu_number_to_vp_number(cpu); + u64 status; + + trace_hyperv_send_ipi_one(cpu, vector); + + if (!hv_hypercall_pg || (vp == VP_INVAL)) + return false; + + if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR)) + return false; + + if (vp >= 64) + return __send_ipi_mask_ex(cpumask_of(cpu), vector, false); + + status = hv_do_fast_hypercall16(HVCALL_SEND_IPI, vector, BIT_ULL(vp)); + return hv_result_success(status); +} + +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, false)) + orig_apic.send_IPI_mask(mask, vector); +} + +static void hv_send_ipi_mask_allbutself(const struct cpumask *mask, int vector) +{ + if (!__send_ipi_mask(mask, vector, true)) + 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, false)) + 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 enlightened APIC (%s mode)", + x2apic_enabled() ? "x2apic" : "xapic"); + /* + * When in x2apic mode, don't use the Hyper-V specific APIC + * accessors since the field layout in the ICR register is + * different in x2apic mode. Furthermore, the architectural + * x2apic MSRs function just as well as the Hyper-V + * synthetic APIC MSRs, so there's no benefit in having + * separate Hyper-V accessors for x2apic mode. The only + * exception is hv_apic_eoi_write, because it benefits from + * lazy EOI when available, but the same accessor works for + * both xapic and x2apic because the field layout is the same. + */ + apic_set_eoi_write(hv_apic_eoi_write); + if (!x2apic_enabled()) { + apic->read = hv_apic_read; + apic->write = hv_apic_write; + apic->icr_write = hv_apic_icr_write; + apic->icr_read = hv_apic_icr_read; + } + } +} |