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Diffstat (limited to 'arch/x86/kernel/acpi/boot.c')
-rw-r--r--arch/x86/kernel/acpi/boot.c102
1 files changed, 96 insertions, 6 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 0d01e7f5078c..907cc98b1938 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -65,6 +65,13 @@ static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
static bool acpi_support_online_capable;
#endif
+#ifdef CONFIG_X86_64
+/* Physical address of the Multiprocessor Wakeup Structure mailbox */
+static u64 acpi_mp_wake_mailbox_paddr;
+/* Virtual address of the Multiprocessor Wakeup Structure mailbox */
+static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox;
+#endif
+
#ifdef CONFIG_X86_IO_APIC
/*
* Locks related to IOAPIC hotplug
@@ -336,7 +343,60 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e
return 0;
}
-#endif /*CONFIG_X86_LOCAL_APIC */
+#ifdef CONFIG_X86_64
+static int acpi_wakeup_cpu(int apicid, unsigned long start_ip)
+{
+ /*
+ * Remap mailbox memory only for the first call to acpi_wakeup_cpu().
+ *
+ * Wakeup of secondary CPUs is fully serialized in the core code.
+ * No need to protect acpi_mp_wake_mailbox from concurrent accesses.
+ */
+ if (!acpi_mp_wake_mailbox) {
+ acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
+ sizeof(*acpi_mp_wake_mailbox),
+ MEMREMAP_WB);
+ }
+
+ /*
+ * Mailbox memory is shared between the firmware and OS. Firmware will
+ * listen on mailbox command address, and once it receives the wakeup
+ * command, the CPU associated with the given apicid will be booted.
+ *
+ * The value of 'apic_id' and 'wakeup_vector' must be visible to the
+ * firmware before the wakeup command is visible. smp_store_release()
+ * ensures ordering and visibility.
+ */
+ acpi_mp_wake_mailbox->apic_id = apicid;
+ acpi_mp_wake_mailbox->wakeup_vector = start_ip;
+ smp_store_release(&acpi_mp_wake_mailbox->command,
+ ACPI_MP_WAKE_COMMAND_WAKEUP);
+
+ /*
+ * Wait for the CPU to wake up.
+ *
+ * The CPU being woken up is essentially in a spin loop waiting to be
+ * woken up. It should not take long for it wake up and acknowledge by
+ * zeroing out ->command.
+ *
+ * ACPI specification doesn't provide any guidance on how long kernel
+ * has to wait for a wake up acknowledgement. It also doesn't provide
+ * a way to cancel a wake up request if it takes too long.
+ *
+ * In TDX environment, the VMM has control over how long it takes to
+ * wake up secondary. It can postpone scheduling secondary vCPU
+ * indefinitely. Giving up on wake up request and reporting error opens
+ * possible attack vector for VMM: it can wake up a secondary CPU when
+ * kernel doesn't expect it. Wait until positive result of the wake up
+ * request.
+ */
+ while (READ_ONCE(acpi_mp_wake_mailbox->command))
+ cpu_relax();
+
+ return 0;
+}
+#endif /* CONFIG_X86_64 */
+#endif /* CONFIG_X86_LOCAL_APIC */
#ifdef CONFIG_X86_IO_APIC
#define MP_ISA_BUS 0
@@ -375,7 +435,7 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
isa_irq_to_gsi[bus_irq] = gsi;
}
-static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
+static void mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
int polarity)
{
#ifdef CONFIG_X86_MPPARSE
@@ -387,9 +447,9 @@ static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
u8 pin;
if (!acpi_ioapic)
- return 0;
+ return;
if (!dev || !dev_is_pci(dev))
- return 0;
+ return;
pdev = to_pci_dev(dev);
number = pdev->bus->number;
@@ -408,7 +468,6 @@ static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
mp_save_irq(&mp_irq);
#endif
- return 0;
}
static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,
@@ -1083,6 +1142,29 @@ static int __init acpi_parse_madt_lapic_entries(void)
}
return 0;
}
+
+#ifdef CONFIG_X86_64
+static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_multiproc_wakeup *mp_wake;
+
+ if (!IS_ENABLED(CONFIG_SMP))
+ return -ENODEV;
+
+ mp_wake = (struct acpi_madt_multiproc_wakeup *)header;
+ if (BAD_MADT_ENTRY(mp_wake, end))
+ return -EINVAL;
+
+ acpi_table_print_madt_entry(&header->common);
+
+ acpi_mp_wake_mailbox_paddr = mp_wake->base_address;
+
+ acpi_wake_cpu_handler_update(acpi_wakeup_cpu);
+
+ return 0;
+}
+#endif /* CONFIG_X86_64 */
#endif /* CONFIG_X86_LOCAL_APIC */
#ifdef CONFIG_X86_IO_APIC
@@ -1278,6 +1360,14 @@ static void __init acpi_process_madt(void)
smp_found_config = 1;
}
+
+#ifdef CONFIG_X86_64
+ /*
+ * Parse MADT MP Wake entry.
+ */
+ acpi_table_parse_madt(ACPI_MADT_TYPE_MULTIPROC_WAKEUP,
+ acpi_parse_mp_wake, 1);
+#endif
}
if (error == -EINVAL) {
/*
@@ -1772,7 +1862,7 @@ int __acpi_release_global_lock(unsigned int *lock)
void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
{
- e820__range_add(addr, size, E820_TYPE_ACPI);
+ e820__range_add(addr, size, E820_TYPE_NVS);
e820__update_table_print();
}