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x86/acpi: Extract ACPI MADT wakeup code into a separate file
In order to prepare for the expansion of support for the ACPI MADT wakeup method, move the relevant code into a separate file. Introduce a new configuration option to clearly indicate dependencies without the use of ifdefs. There have been no functional changes. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Kai Huang <kai.huang@intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Tao Liu <ltao@redhat.com> Link: https://lore.kernel.org/r/20240614095904.1345461-2-kirill.shutemov@linux.intel.com
This commit is contained in:
Kirill A. Shutemov
Borislav Petkov (AMD)
parent
54183d103d
commit
2b5e22afae
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@ -1118,6 +1118,13 @@ config X86_LOCAL_APIC
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depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
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select IRQ_DOMAIN_HIERARCHY
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config ACPI_MADT_WAKEUP
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def_bool y
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depends on X86_64
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depends on ACPI
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depends on SMP
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depends on X86_LOCAL_APIC
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config X86_IO_APIC
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def_bool y
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depends on X86_LOCAL_APIC || X86_UP_IOAPIC
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@ -78,6 +78,11 @@ static inline bool acpi_skip_set_wakeup_address(void)
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#define acpi_skip_set_wakeup_address acpi_skip_set_wakeup_address
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union acpi_subtable_headers;
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int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
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const unsigned long end);
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/*
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* Check if the CPU can handle C2 and deeper
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*/
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@ -4,6 +4,7 @@ obj-$(CONFIG_ACPI) += boot.o
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obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o
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obj-$(CONFIG_ACPI_APEI) += apei.o
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obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
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obj-$(CONFIG_ACPI_MADT_WAKEUP) += madt_wakeup.o
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ifneq ($(CONFIG_ACPI_PROCESSOR),)
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obj-y += cstate.o
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@ -67,13 +67,6 @@ static bool has_lapic_cpus __initdata;
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static bool acpi_support_online_capable;
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#endif
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#ifdef CONFIG_X86_64
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/* Physical address of the Multiprocessor Wakeup Structure mailbox */
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static u64 acpi_mp_wake_mailbox_paddr;
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/* Virtual address of the Multiprocessor Wakeup Structure mailbox */
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static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox;
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#endif
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#ifdef CONFIG_X86_IO_APIC
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/*
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* Locks related to IOAPIC hotplug
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@ -341,60 +334,6 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e
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return 0;
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}
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#ifdef CONFIG_X86_64
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static int acpi_wakeup_cpu(u32 apicid, unsigned long start_ip)
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{
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/*
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* Remap mailbox memory only for the first call to acpi_wakeup_cpu().
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*
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* Wakeup of secondary CPUs is fully serialized in the core code.
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* No need to protect acpi_mp_wake_mailbox from concurrent accesses.
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*/
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if (!acpi_mp_wake_mailbox) {
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acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
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sizeof(*acpi_mp_wake_mailbox),
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MEMREMAP_WB);
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}
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/*
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* Mailbox memory is shared between the firmware and OS. Firmware will
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* listen on mailbox command address, and once it receives the wakeup
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* command, the CPU associated with the given apicid will be booted.
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*
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* The value of 'apic_id' and 'wakeup_vector' must be visible to the
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* firmware before the wakeup command is visible. smp_store_release()
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* ensures ordering and visibility.
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*/
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acpi_mp_wake_mailbox->apic_id = apicid;
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acpi_mp_wake_mailbox->wakeup_vector = start_ip;
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smp_store_release(&acpi_mp_wake_mailbox->command,
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ACPI_MP_WAKE_COMMAND_WAKEUP);
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/*
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* Wait for the CPU to wake up.
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*
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* The CPU being woken up is essentially in a spin loop waiting to be
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* woken up. It should not take long for it wake up and acknowledge by
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* zeroing out ->command.
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*
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* ACPI specification doesn't provide any guidance on how long kernel
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* has to wait for a wake up acknowledgement. It also doesn't provide
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* a way to cancel a wake up request if it takes too long.
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*
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* In TDX environment, the VMM has control over how long it takes to
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* wake up secondary. It can postpone scheduling secondary vCPU
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* indefinitely. Giving up on wake up request and reporting error opens
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* possible attack vector for VMM: it can wake up a secondary CPU when
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* kernel doesn't expect it. Wait until positive result of the wake up
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* request.
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*/
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while (READ_ONCE(acpi_mp_wake_mailbox->command))
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cpu_relax();
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return 0;
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}
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#endif /* CONFIG_X86_64 */
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#endif /* CONFIG_X86_LOCAL_APIC */
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#ifdef CONFIG_X86_IO_APIC
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@ -1124,29 +1063,6 @@ static int __init acpi_parse_madt_lapic_entries(void)
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}
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return 0;
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}
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#ifdef CONFIG_X86_64
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static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
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const unsigned long end)
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{
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struct acpi_madt_multiproc_wakeup *mp_wake;
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if (!IS_ENABLED(CONFIG_SMP))
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return -ENODEV;
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mp_wake = (struct acpi_madt_multiproc_wakeup *)header;
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if (BAD_MADT_ENTRY(mp_wake, end))
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return -EINVAL;
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acpi_table_print_madt_entry(&header->common);
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acpi_mp_wake_mailbox_paddr = mp_wake->base_address;
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apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
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return 0;
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}
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#endif /* CONFIG_X86_64 */
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#endif /* CONFIG_X86_LOCAL_APIC */
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#ifdef CONFIG_X86_IO_APIC
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@ -1343,7 +1259,7 @@ static void __init acpi_process_madt(void)
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smp_found_config = 1;
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}
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#ifdef CONFIG_X86_64
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#ifdef CONFIG_ACPI_MADT_WAKEUP
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/*
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* Parse MADT MP Wake entry.
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*/
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82
arch/x86/kernel/acpi/madt_wakeup.c
Normal file
82
arch/x86/kernel/acpi/madt_wakeup.c
Normal file
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@ -0,0 +1,82 @@
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// SPDX-License-Identifier: GPL-2.0-or-later
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#include <linux/acpi.h>
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#include <linux/io.h>
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#include <asm/apic.h>
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#include <asm/barrier.h>
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#include <asm/processor.h>
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/* Physical address of the Multiprocessor Wakeup Structure mailbox */
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static u64 acpi_mp_wake_mailbox_paddr;
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/* Virtual address of the Multiprocessor Wakeup Structure mailbox */
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static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox;
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static int acpi_wakeup_cpu(u32 apicid, unsigned long start_ip)
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{
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/*
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* Remap mailbox memory only for the first call to acpi_wakeup_cpu().
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*
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* Wakeup of secondary CPUs is fully serialized in the core code.
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* No need to protect acpi_mp_wake_mailbox from concurrent accesses.
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*/
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if (!acpi_mp_wake_mailbox) {
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acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
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sizeof(*acpi_mp_wake_mailbox),
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MEMREMAP_WB);
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}
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/*
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* Mailbox memory is shared between the firmware and OS. Firmware will
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* listen on mailbox command address, and once it receives the wakeup
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* command, the CPU associated with the given apicid will be booted.
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*
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* The value of 'apic_id' and 'wakeup_vector' must be visible to the
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* firmware before the wakeup command is visible. smp_store_release()
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* ensures ordering and visibility.
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*/
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acpi_mp_wake_mailbox->apic_id = apicid;
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acpi_mp_wake_mailbox->wakeup_vector = start_ip;
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smp_store_release(&acpi_mp_wake_mailbox->command,
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ACPI_MP_WAKE_COMMAND_WAKEUP);
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/*
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* Wait for the CPU to wake up.
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*
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* The CPU being woken up is essentially in a spin loop waiting to be
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* woken up. It should not take long for it wake up and acknowledge by
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* zeroing out ->command.
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*
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* ACPI specification doesn't provide any guidance on how long kernel
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* has to wait for a wake up acknowledgment. It also doesn't provide
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* a way to cancel a wake up request if it takes too long.
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*
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* In TDX environment, the VMM has control over how long it takes to
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* wake up secondary. It can postpone scheduling secondary vCPU
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* indefinitely. Giving up on wake up request and reporting error opens
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* possible attack vector for VMM: it can wake up a secondary CPU when
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* kernel doesn't expect it. Wait until positive result of the wake up
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* request.
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*/
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while (READ_ONCE(acpi_mp_wake_mailbox->command))
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cpu_relax();
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return 0;
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}
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int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
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const unsigned long end)
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{
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struct acpi_madt_multiproc_wakeup *mp_wake;
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mp_wake = (struct acpi_madt_multiproc_wakeup *)header;
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if (BAD_MADT_ENTRY(mp_wake, end))
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return -EINVAL;
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acpi_table_print_madt_entry(&header->common);
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acpi_mp_wake_mailbox_paddr = mp_wake->base_address;
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apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
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return 0;
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}
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