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 <[email protected]>
---
arch/x86/Kconfig | 7 +++
arch/x86/include/asm/acpi.h | 5 ++
arch/x86/kernel/acpi/Makefile | 11 ++--
arch/x86/kernel/acpi/boot.c | 86 +-----------------------------
arch/x86/kernel/acpi/madt_wakeup.c | 81 ++++++++++++++++++++++++++++
5 files changed, 100 insertions(+), 90 deletions(-)
create mode 100644 arch/x86/kernel/acpi/madt_wakeup.c
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 799102f4d909..9957a73bb386 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1108,6 +1108,13 @@ config X86_LOCAL_APIC
depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
select IRQ_DOMAIN_HIERARCHY
+config X86_ACPI_MADT_WAKEUP
+ def_bool y
+ depends on X86_64
+ depends on ACPI
+ depends on SMP
+ depends on X86_LOCAL_APIC
+
config X86_IO_APIC
def_bool y
depends on X86_LOCAL_APIC || X86_UP_IOAPIC
diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index c8a7fc23f63c..b536b5a6a57b 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -73,6 +73,11 @@ static inline bool acpi_skip_set_wakeup_address(void)
#define acpi_skip_set_wakeup_address acpi_skip_set_wakeup_address
+union acpi_subtable_headers;
+
+int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
+ const unsigned long end);
+
/*
* Check if the CPU can handle C2 and deeper
*/
diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile
index fc17b3f136fe..8c7329c88a75 100644
--- a/arch/x86/kernel/acpi/Makefile
+++ b/arch/x86/kernel/acpi/Makefile
@@ -1,11 +1,12 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_ACPI) += boot.o
-obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o
-obj-$(CONFIG_ACPI_APEI) += apei.o
-obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
+obj-$(CONFIG_ACPI) += boot.o
+obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o
+obj-$(CONFIG_ACPI_APEI) += apei.o
+obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
+obj-$(CONFIG_X86_ACPI_MADT_WAKEUP) += madt_wakeup.o
ifneq ($(CONFIG_ACPI_PROCESSOR),)
-obj-y += cstate.o
+obj-y += cstate.o
endif
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 2a0ea38955df..111bd226ad99 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -66,13 +66,6 @@ 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
@@ -357,60 +350,6 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e
return 0;
}
-
-#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
@@ -1160,29 +1099,6 @@ 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;
-
- apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
-
- return 0;
-}
-#endif /* CONFIG_X86_64 */
#endif /* CONFIG_X86_LOCAL_APIC */
#ifdef CONFIG_X86_IO_APIC
@@ -1379,7 +1295,7 @@ static void __init acpi_process_madt(void)
smp_found_config = 1;
}
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ACPI_MADT_WAKEUP
/*
* Parse MADT MP Wake entry.
*/
diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c
new file mode 100644
index 000000000000..58cdfc0b6c0a
--- /dev/null
+++ b/arch/x86/kernel/acpi/madt_wakeup.c
@@ -0,0 +1,81 @@
+#include <linux/acpi.h>
+#include <linux/io.h>
+#include <asm/apic.h>
+#include <asm/barrier.h>
+#include <asm/processor.h>
+
+/* 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;
+
+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;
+}
+
+int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_multiproc_wakeup *mp_wake;
+
+ 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;
+
+ apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
+
+ return 0;
+}
--
2.41.0
On 10/20/2023 8:12 AM, Kirill A. Shutemov wrote:
> 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 <[email protected]>
> ---
Looks good to me.
Reviewed-by: Kuppuswamy Sathyanarayanan <[email protected]>
> arch/x86/Kconfig | 7 +++
> arch/x86/include/asm/acpi.h | 5 ++
> arch/x86/kernel/acpi/Makefile | 11 ++--
> arch/x86/kernel/acpi/boot.c | 86 +-----------------------------
> arch/x86/kernel/acpi/madt_wakeup.c | 81 ++++++++++++++++++++++++++++
> 5 files changed, 100 insertions(+), 90 deletions(-)
> create mode 100644 arch/x86/kernel/acpi/madt_wakeup.c
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 799102f4d909..9957a73bb386 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -1108,6 +1108,13 @@ config X86_LOCAL_APIC
> depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
> select IRQ_DOMAIN_HIERARCHY
>
> +config X86_ACPI_MADT_WAKEUP
> + def_bool y
> + depends on X86_64
> + depends on ACPI
> + depends on SMP
> + depends on X86_LOCAL_APIC
> +
> config X86_IO_APIC
> def_bool y
> depends on X86_LOCAL_APIC || X86_UP_IOAPIC
> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
> index c8a7fc23f63c..b536b5a6a57b 100644
> --- a/arch/x86/include/asm/acpi.h
> +++ b/arch/x86/include/asm/acpi.h
> @@ -73,6 +73,11 @@ static inline bool acpi_skip_set_wakeup_address(void)
>
> #define acpi_skip_set_wakeup_address acpi_skip_set_wakeup_address
>
> +union acpi_subtable_headers;
> +
> +int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
> + const unsigned long end);
> +
> /*
> * Check if the CPU can handle C2 and deeper
> */
> diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile
> index fc17b3f136fe..8c7329c88a75 100644
> --- a/arch/x86/kernel/acpi/Makefile
> +++ b/arch/x86/kernel/acpi/Makefile
> @@ -1,11 +1,12 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -obj-$(CONFIG_ACPI) += boot.o
> -obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o
> -obj-$(CONFIG_ACPI_APEI) += apei.o
> -obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
> +obj-$(CONFIG_ACPI) += boot.o
> +obj-$(CONFIG_ACPI_SLEEP) += sleep.o wakeup_$(BITS).o
> +obj-$(CONFIG_ACPI_APEI) += apei.o
> +obj-$(CONFIG_ACPI_CPPC_LIB) += cppc.o
> +obj-$(CONFIG_X86_ACPI_MADT_WAKEUP) += madt_wakeup.o
>
> ifneq ($(CONFIG_ACPI_PROCESSOR),)
> -obj-y += cstate.o
> +obj-y += cstate.o
> endif
>
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 2a0ea38955df..111bd226ad99 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -66,13 +66,6 @@ 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
> @@ -357,60 +350,6 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e
>
> return 0;
> }
> -
> -#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
> @@ -1160,29 +1099,6 @@ 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;
> -
> - apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
> -
> - return 0;
> -}
> -#endif /* CONFIG_X86_64 */
> #endif /* CONFIG_X86_LOCAL_APIC */
>
> #ifdef CONFIG_X86_IO_APIC
> @@ -1379,7 +1295,7 @@ static void __init acpi_process_madt(void)
> smp_found_config = 1;
> }
>
> -#ifdef CONFIG_X86_64
> +#ifdef CONFIG_X86_ACPI_MADT_WAKEUP
> /*
> * Parse MADT MP Wake entry.
> */
> diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c
> new file mode 100644
> index 000000000000..58cdfc0b6c0a
> --- /dev/null
> +++ b/arch/x86/kernel/acpi/madt_wakeup.c
> @@ -0,0 +1,81 @@
> +#include <linux/acpi.h>
> +#include <linux/io.h>
> +#include <asm/apic.h>
> +#include <asm/barrier.h>
> +#include <asm/processor.h>
> +
> +/* 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;
> +
> +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;
> +}
> +
> +int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
> + const unsigned long end)
> +{
> + struct acpi_madt_multiproc_wakeup *mp_wake;
> +
> + 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;
> +
> + apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
> +
> + return 0;
> +}
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer