| Message ID | 20250503191515.24041-2-ricardo.neri-calderon@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | x86/hyperv/hv_vtl: Use a wakeup mailbox to boot secondary CPUs | expand |
On Sat, May 3, 2025 at 9:10 PM Ricardo Neri <ricardo.neri-calderon@linux.intel.com> wrote: > > In preparation to move the functionality to wake secondary CPUs up out of > the ACPI code, add a helper function that stores the physical address of > the mailbox and updates the wakeup_secondary_cpu_64() APIC callback. > > There is a slight change in behavior: now the APIC callback is updated > before configuring CPU hotplug offline behavior. This is fine as the APIC > callback continues to be updated unconditionally, regardless of the > restriction on CPU offlining. > > The wakeup mailbox is only supported for CONFIG_X86_64 and needed only with > CONFIG_SMP=y. > > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> > --- > Changes since v2: > - Introduced this patch. > > Changes since v1: > - N/A > --- > arch/x86/include/asm/smp.h | 4 ++++ > arch/x86/kernel/acpi/madt_wakeup.c | 10 +++++++--- > 2 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h > index 0c1c68039d6f..3622951d2ee0 100644 > --- a/arch/x86/include/asm/smp.h > +++ b/arch/x86/include/asm/smp.h > @@ -146,6 +146,10 @@ static inline struct cpumask *cpu_l2c_shared_mask(int cpu) > return per_cpu(cpu_l2c_shared_map, cpu); > } > > +#ifdef CONFIG_X86_64 > +void setup_mp_wakeup_mailbox(u64 addr); > +#endif The #ifdef is only necessary if you are going to provide an alternative for builds in which the symbol is unset. > + > #else /* !CONFIG_SMP */ > #define wbinvd_on_cpu(cpu) wbinvd() > static inline int wbinvd_on_all_cpus(void) > diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c > index f36f28405dcc..04de3db307de 100644 > --- a/arch/x86/kernel/acpi/madt_wakeup.c > +++ b/arch/x86/kernel/acpi/madt_wakeup.c > @@ -227,7 +227,7 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > > acpi_table_print_madt_entry(&header->common); > > - acpi_mp_wake_mailbox_paddr = mp_wake->mailbox_address; > + setup_mp_wakeup_mailbox(mp_wake->mailbox_address); I'd prefer acpi_setup_mp_wakeup_mailbox(). > > if (mp_wake->version >= ACPI_MADT_MP_WAKEUP_VERSION_V1 && > mp_wake->header.length >= ACPI_MADT_MP_WAKEUP_SIZE_V1) { > @@ -243,7 +243,11 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > acpi_mp_disable_offlining(mp_wake); > } > > - apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); > - > return 0; > } > + > +void __init setup_mp_wakeup_mailbox(u64 mailbox_paddr) > +{ > + acpi_mp_wake_mailbox_paddr = mailbox_paddr; > + apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); > +} > -- > 2.43.0 > >
On Mon, May 05, 2025 at 11:50:08AM +0200, Rafael J. Wysocki wrote: > On Sat, May 3, 2025 at 9:10 PM Ricardo Neri > <ricardo.neri-calderon@linux.intel.com> wrote: > > > > In preparation to move the functionality to wake secondary CPUs up out of > > the ACPI code, add a helper function that stores the physical address of > > the mailbox and updates the wakeup_secondary_cpu_64() APIC callback. > > > > There is a slight change in behavior: now the APIC callback is updated > > before configuring CPU hotplug offline behavior. This is fine as the APIC > > callback continues to be updated unconditionally, regardless of the > > restriction on CPU offlining. > > > > The wakeup mailbox is only supported for CONFIG_X86_64 and needed only with > > CONFIG_SMP=y. > > > > Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> > > --- > > Changes since v2: > > - Introduced this patch. > > > > Changes since v1: > > - N/A > > --- > > arch/x86/include/asm/smp.h | 4 ++++ > > arch/x86/kernel/acpi/madt_wakeup.c | 10 +++++++--- > > 2 files changed, 11 insertions(+), 3 deletions(-) > > > > diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h > > index 0c1c68039d6f..3622951d2ee0 100644 > > --- a/arch/x86/include/asm/smp.h > > +++ b/arch/x86/include/asm/smp.h > > @@ -146,6 +146,10 @@ static inline struct cpumask *cpu_l2c_shared_mask(int cpu) > > return per_cpu(cpu_l2c_shared_map, cpu); > > } > > > > +#ifdef CONFIG_X86_64 > > +void setup_mp_wakeup_mailbox(u64 addr); > > +#endif Thank you for your feedback, Rafael! > > The #ifdef is only necessary if you are going to provide an > alternative for builds in which the symbol is unset. I see. All callers will be built only with CONFIG_X86_64. I will remove this #ifdef. > > > + > > #else /* !CONFIG_SMP */ > > #define wbinvd_on_cpu(cpu) wbinvd() > > static inline int wbinvd_on_all_cpus(void) > > diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c > > index f36f28405dcc..04de3db307de 100644 > > --- a/arch/x86/kernel/acpi/madt_wakeup.c > > +++ b/arch/x86/kernel/acpi/madt_wakeup.c > > @@ -227,7 +227,7 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, > > > > acpi_table_print_madt_entry(&header->common); > > > > - acpi_mp_wake_mailbox_paddr = mp_wake->mailbox_address; > > + setup_mp_wakeup_mailbox(mp_wake->mailbox_address); > > I'd prefer acpi_setup_mp_wakeup_mailbox(). Sure. This looks like a more appropriate name. Thanks and BR, Ricardo
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 0c1c68039d6f..3622951d2ee0 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -146,6 +146,10 @@ static inline struct cpumask *cpu_l2c_shared_mask(int cpu) return per_cpu(cpu_l2c_shared_map, cpu); } +#ifdef CONFIG_X86_64 +void setup_mp_wakeup_mailbox(u64 addr); +#endif + #else /* !CONFIG_SMP */ #define wbinvd_on_cpu(cpu) wbinvd() static inline int wbinvd_on_all_cpus(void) diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c index f36f28405dcc..04de3db307de 100644 --- a/arch/x86/kernel/acpi/madt_wakeup.c +++ b/arch/x86/kernel/acpi/madt_wakeup.c @@ -227,7 +227,7 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, acpi_table_print_madt_entry(&header->common); - acpi_mp_wake_mailbox_paddr = mp_wake->mailbox_address; + setup_mp_wakeup_mailbox(mp_wake->mailbox_address); if (mp_wake->version >= ACPI_MADT_MP_WAKEUP_VERSION_V1 && mp_wake->header.length >= ACPI_MADT_MP_WAKEUP_SIZE_V1) { @@ -243,7 +243,11 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header, acpi_mp_disable_offlining(mp_wake); } - apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); - return 0; } + +void __init setup_mp_wakeup_mailbox(u64 mailbox_paddr) +{ + acpi_mp_wake_mailbox_paddr = mailbox_paddr; + apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu); +}
In preparation to move the functionality to wake secondary CPUs up out of the ACPI code, add a helper function that stores the physical address of the mailbox and updates the wakeup_secondary_cpu_64() APIC callback. There is a slight change in behavior: now the APIC callback is updated before configuring CPU hotplug offline behavior. This is fine as the APIC callback continues to be updated unconditionally, regardless of the restriction on CPU offlining. The wakeup mailbox is only supported for CONFIG_X86_64 and needed only with CONFIG_SMP=y. Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com> --- Changes since v2: - Introduced this patch. Changes since v1: - N/A --- arch/x86/include/asm/smp.h | 4 ++++ arch/x86/kernel/acpi/madt_wakeup.c | 10 +++++++--- 2 files changed, 11 insertions(+), 3 deletions(-)