lkml.org 
[lkml]   [2021]   [Feb]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC v1 14/26] ACPI: tables: Add multiprocessor wake-up support
Date
As per Guest-Host Communication Interface (GHCI)
Specification for Intel TDX, sec 4.1, a new sub
structure – multiprocessor wake-up structure - is added to the
ACPI Multiple APIC Description Table (MADT) to describe the
information of the mailbox. If a platform firmware produces the
multiprocessor wake-up structure, then the BSP in OS may use this
new mailbox-based mechanism to wake up the APs.

Add ACPI MADT wake table parsing support and if MADT wake table is
present, update apic->wakeup_secondary_cpu with new API which
uses MADT wake mailbox to wake-up CPU.

Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/include/asm/apic.h | 3 ++
arch/x86/kernel/acpi/boot.c | 56 +++++++++++++++++++++++++++++++++
arch/x86/kernel/apic/probe_32.c | 8 +++++
arch/x86/kernel/apic/probe_64.c | 8 +++++
drivers/acpi/tables.c | 9 ++++++
include/acpi/actbl2.h | 21 ++++++++++++-
6 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 34cb3c159481..63f970c61cbe 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -497,6 +497,9 @@ static inline unsigned int read_apic_id(void)
return apic->get_apic_id(reg);
}

+typedef int (*wakeup_cpu_handler)(int apicid, unsigned long start_eip);
+extern void acpi_wake_cpu_handler_update(wakeup_cpu_handler handler);
+
extern int default_apic_id_valid(u32 apicid);
extern int default_acpi_madt_oem_check(char *, char *);
extern void default_setup_apic_routing(void);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 7bdc0239a943..37ada1908fb7 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -65,6 +65,9 @@ int acpi_fix_pin2_polarity __initdata;
static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
#endif

+static struct acpi_madt_mp_wake_mailbox *acpi_mp_wake_mailbox;
+static u64 acpi_mp_wake_mailbox_paddr;
+
#ifdef CONFIG_X86_IO_APIC
/*
* Locks related to IOAPIC hotplug
@@ -329,6 +332,29 @@ acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long e
return 0;
}

+static void acpi_mp_wake_mailbox_init(void)
+{
+ if (acpi_mp_wake_mailbox)
+ return;
+
+ acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
+ sizeof(*acpi_mp_wake_mailbox), MEMREMAP_WB);
+}
+
+static int acpi_wakeup_cpu(int apicid, unsigned long start_ip)
+{
+ acpi_mp_wake_mailbox_init();
+
+ if (!acpi_mp_wake_mailbox)
+ return -EINVAL;
+
+ WRITE_ONCE(acpi_mp_wake_mailbox->apic_id, apicid);
+ WRITE_ONCE(acpi_mp_wake_mailbox->wakeup_vector, start_ip);
+ WRITE_ONCE(acpi_mp_wake_mailbox->command, ACPI_MP_WAKE_COMMAND_WAKEUP);
+
+ return 0;
+}
+
#endif /*CONFIG_X86_LOCAL_APIC */

#ifdef CONFIG_X86_IO_APIC
@@ -1086,6 +1112,30 @@ static int __init acpi_parse_madt_lapic_entries(void)
}
return 0;
}
+
+static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
+ const unsigned long end)
+{
+ struct acpi_madt_mp_wake *mp_wake = NULL;
+
+ if (!IS_ENABLED(CONFIG_SMP))
+ return -ENODEV;
+
+ mp_wake = (struct acpi_madt_mp_wake *)header;
+ if (BAD_MADT_ENTRY(mp_wake, end))
+ return -EINVAL;
+
+ if (acpi_mp_wake_mailbox)
+ return -EINVAL;
+
+ acpi_table_print_madt_entry(&header->common);
+
+ acpi_mp_wake_mailbox_paddr = mp_wake->mailbox_address;
+
+ acpi_wake_cpu_handler_update(acpi_wakeup_cpu);
+
+ return 0;
+}
#endif /* CONFIG_X86_LOCAL_APIC */

#ifdef CONFIG_X86_IO_APIC
@@ -1284,6 +1334,12 @@ static void __init acpi_process_madt(void)

smp_found_config = 1;
}
+
+ /*
+ * Parse MADT MP Wake entry.
+ */
+ acpi_table_parse_madt(ACPI_MADT_TYPE_MP_WAKE,
+ acpi_parse_mp_wake, 1);
}
if (error == -EINVAL) {
/*
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index a61f642b1b90..d450014841b2 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -207,3 +207,11 @@ int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
}
return 0;
}
+
+void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler)
+{
+ struct apic **drv;
+
+ for (drv = __apicdrivers; drv < __apicdrivers_end; drv++)
+ (*drv)->wakeup_secondary_cpu = handler;
+}
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index c46720f185c0..986dbb68d3c4 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -50,3 +50,11 @@ int __init default_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
}
return 0;
}
+
+void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler)
+{
+ struct apic **drv;
+
+ for (drv = __apicdrivers; drv < __apicdrivers_end; drv++)
+ (*drv)->wakeup_secondary_cpu = handler;
+}
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index e48690a006a4..5e38748c5db1 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -207,6 +207,15 @@ void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
}
break;

+ case ACPI_MADT_TYPE_MP_WAKE:
+ {
+ struct acpi_madt_mp_wake *p =
+ (struct acpi_madt_mp_wake *)header;
+ pr_debug("MP Wake (version[%d] mailbox_address[%llx])\n",
+ p->version, p->mailbox_address);
+ }
+ break;
+
default:
pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
header->type);
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index ec66779cb193..be953b638499 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -517,7 +517,8 @@ enum acpi_madt_type {
ACPI_MADT_TYPE_GENERIC_MSI_FRAME = 13,
ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR = 14,
ACPI_MADT_TYPE_GENERIC_TRANSLATOR = 15,
- ACPI_MADT_TYPE_RESERVED = 16 /* 16 and greater are reserved */
+ ACPI_MADT_TYPE_MP_WAKE = 16,
+ ACPI_MADT_TYPE_RESERVED = 17 /* 17 and greater are reserved */
};

/*
@@ -724,6 +725,24 @@ struct acpi_madt_generic_translator {
u32 reserved2;
};

+/* 16: MP Wake (ACPI 6.?) */
+
+struct acpi_madt_mp_wake {
+ struct acpi_subtable_header header;
+ u16 version;
+ u32 reserved2;
+ u64 mailbox_address;
+};
+
+struct acpi_madt_mp_wake_mailbox {
+ u16 command;
+ u16 flags;
+ u32 apic_id;
+ u64 wakeup_vector;
+};
+
+#define ACPI_MP_WAKE_COMMAND_WAKEUP 1
+
/*
* Common flags fields for MADT subtables
*/
--
2.25.1
\
 
 \ /
  Last update: 2021-02-06 05:59    [W:0.722 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site