From: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx> Support LAPIC, X2APIC and WAKEUP sub-table, other sub-table are ignored for now. Also add a wakeup wrapping function which is used by TDX. The parsed result is stored in id_map[] and acpi_mp_wake_mailbox. Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx> Reviewed-by: Yu Zhang <yu.c.zhang@xxxxxxxxx> Link: https://lore.kernel.org/r/20220303071907.650203-10-zhenzhong.duan@xxxxxxxxx Signed-off-by: Qian Wen <qian.wen@xxxxxxxxx> --- lib/acpi.c | 160 ++++++++++++++++++++++++++++++++++++++++++++++++ lib/acpi.h | 59 +++++++++++++++++- lib/x86/setup.c | 4 ++ 3 files changed, 222 insertions(+), 1 deletion(-) diff --git a/lib/acpi.c b/lib/acpi.c index 0440cddb..9db32e2a 100644 --- a/lib/acpi.c +++ b/lib/acpi.c @@ -1,5 +1,7 @@ #include "libcflat.h" #include "acpi.h" +#include "errno.h" +#include "asm/barrier.h" #ifdef CONFIG_EFI struct acpi_table_rsdp *efi_rsdp = NULL; @@ -127,3 +129,161 @@ int acpi_table_parse_madt(enum acpi_madt_type mtype, acpi_table_handler handler) return count; } + +struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox; + +#define smp_store_release(p, val) \ +do { \ + barrier(); \ + WRITE_ONCE(*p, val); \ +} while (0) + +static inline bool test_bit(int nr, const void *addr) +{ + const u32 *p = (const u32 *)addr; + return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0; +} + +int acpi_wakeup_cpu(int apicid, unsigned long start_ip, unsigned char* cpus) +{ + u8 timeout = 0xFF; + + /* + * According to the ACPI specification r6.4, sec 5.2.12.19, the + * mailbox-based wakeup mechanism cannot be used more than once + * for the same CPU, so skip sending wake commands to already + * awake CPU. + */ + if (test_bit(apicid, cpus)) { + printf("CPU already awake (APIC ID %x), skipping wakeup\n", + apicid); + return -EINVAL; + } + + /* + * Mailbox memory is shared between firmware and OS. Firmware will + * listen on mailbox command address, and once it receives the wakeup + * command, CPU associated with the given apicid will be booted. So, + * the value of apic_id and wakeup_vector has to be set before updating + * the wakeup command. So use smp_store_release to let the compiler know + * about it and preserve the order of writes. + */ + smp_store_release(&acpi_mp_wake_mailbox->apic_id, apicid); + smp_store_release(&acpi_mp_wake_mailbox->wakeup_vector, start_ip); + smp_store_release(&acpi_mp_wake_mailbox->command, + ACPI_MP_WAKE_COMMAND_WAKEUP); + + /* + * After writing wakeup command, wait for maximum timeout of 0xFF + * for firmware to reset the command address back zero to indicate + * the successful reception of command. + * NOTE: 255 as timeout value is decided based on our experiments. + * + * XXX: Change the timeout once ACPI specification comes up with + * standard maximum timeout value. + */ + while (READ_ONCE(acpi_mp_wake_mailbox->command) && timeout--) + cpu_relax(); + + /* If timed out (timeout == 0), return error. + * Otherwise, the CPU wakes up successfully. + */ + return timeout == 0 ? -EIO : 0; +} + +static bool parse_madt_table(struct acpi_table *madt, unsigned char* id_map) +{ + u64 table_start = (unsigned long)madt + sizeof(struct acpi_table_madt); + u64 table_end = (unsigned long)madt + madt->length; + struct acpi_subtable_header *sub_table; + bool failed = false; + u32 uid, apic_id; + u8 enabled; + + while (table_start < table_end && !failed) { + struct acpi_madt_local_apic *processor; + struct acpi_madt_local_x2apic *processor2; + struct acpi_madt_multiproc_wakeup *mp_wake; + + sub_table = (struct acpi_subtable_header *)table_start; + + switch (sub_table->type) { + case ACPI_MADT_TYPE_LOCAL_APIC: + processor = (struct acpi_madt_local_apic *)sub_table; + + if (BAD_MADT_ENTRY(processor, table_end)) { + failed = true; + break; + } + + uid = processor->processor_id; + apic_id = processor->id; + enabled = processor->lapic_flags & ACPI_MADT_ENABLED; + + /* Ignore invalid ID */ + if (apic_id == 0xff) + break; + if (enabled) + id_map[uid] = apic_id; + + printf("apicid %x uid %x %s\n", apic_id, uid, + enabled ? "enabled" : "disabled"); + break; + + case ACPI_MADT_TYPE_LOCAL_X2APIC: + processor2 = (struct acpi_madt_local_x2apic *)sub_table; + + if (BAD_MADT_ENTRY(processor2, table_end)) { + failed = true; + break; + } + + uid = processor2->uid; + apic_id = processor2->local_apic_id; + enabled = processor2->lapic_flags & ACPI_MADT_ENABLED; + + /* Ignore invalid ID */ + if (apic_id == 0xffffffff) + break; + if (enabled) + id_map[uid] = apic_id; + + printf("x2apicid %x uid %x %s\n", apic_id, uid, + enabled ? "enabled" : "disabled"); + break; + case ACPI_MADT_TYPE_MULTIPROC_WAKEUP: + mp_wake = (struct acpi_madt_multiproc_wakeup *)sub_table; + + if (BAD_MADT_ENTRY(mp_wake, table_end)) { + failed = true; + break; + } + + if (acpi_mp_wake_mailbox) + printf("WARN: duplicate mailbox %lx\n", (u64)acpi_mp_wake_mailbox); + + acpi_mp_wake_mailbox = (void *)mp_wake->base_address; + printf("MP Wake (Mailbox version[%d] base_address[%lx])\n", + mp_wake->mailbox_version, mp_wake->base_address); + break; + default: + /* Ignored currently */ + break; + } + if (!failed) + table_start += sub_table->length; + } + + return !failed; +} + +bool parse_acpi_table(unsigned char* id_map) +{ + struct acpi_table *tb; + + tb = find_acpi_table_addr(MADT_SIGNATURE); + if (tb) + return parse_madt_table(tb, id_map); + + return false; +} diff --git a/lib/acpi.h b/lib/acpi.h index c330c877..311fbb1b 100644 --- a/lib/acpi.h +++ b/lib/acpi.h @@ -245,9 +245,64 @@ 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_MULTIPROC_WAKEUP = 16, + ACPI_MADT_TYPE_RESERVED = 17 /* 17 and greater are reserved */ }; +#define BAD_MADT_ENTRY(entry, end) ( \ + (!entry) || (unsigned long)entry + sizeof(*entry) > end || \ + ((struct acpi_subtable_header *)entry)->length < sizeof(*entry)) + +/* + * MADT Subtables, correspond to Type in struct acpi_subtable_header + */ + +/* 0: Processor Local APIC */ + +struct acpi_madt_local_apic { + struct acpi_subtable_header header; + u8 processor_id; /* ACPI processor id */ + u8 id; /* Processor's local APIC id */ + u32 lapic_flags; +}; + +/* 9: Processor Local X2APIC (ACPI 4.0) */ + +struct acpi_madt_local_x2apic { + struct acpi_subtable_header header; + u16 reserved; /* reserved - must be zero */ + u32 local_apic_id; /* Processor x2APIC ID */ + u32 lapic_flags; + u32 uid; /* ACPI processor UID */ +}; + +/* 16: Multiprocessor wakeup (ACPI 6.4) */ + +struct acpi_madt_multiproc_wakeup { + struct acpi_subtable_header header; + u16 mailbox_version; + u32 reserved; /* reserved - must be zero */ + u64 base_address; +}; + +#define ACPI_MULTIPROC_WAKEUP_MB_OS_SIZE 2032 +#define ACPI_MULTIPROC_WAKEUP_MB_FIRMWARE_SIZE 2048 + +struct acpi_madt_multiproc_wakeup_mailbox { + u16 command; + u16 reserved; /* reserved - must be zero */ + u32 apic_id; + u64 wakeup_vector; + u8 reserved_os[ACPI_MULTIPROC_WAKEUP_MB_OS_SIZE]; /* reserved for OS use */ + u8 reserved_firmware[ACPI_MULTIPROC_WAKEUP_MB_FIRMWARE_SIZE]; /* reserved for firmware use */ +}; + +#define ACPI_MP_WAKE_COMMAND_WAKEUP 1 + +/* + * Common flags fields for MADT subtables + */ + /* MADT Local APIC flags */ #define ACPI_MADT_ENABLED (1) /* 00: Processor is usable if set */ @@ -298,5 +353,7 @@ struct acpi_table_gtdt { void set_efi_rsdp(struct acpi_table_rsdp *rsdp); void *find_acpi_table_addr(u32 sig); int acpi_table_parse_madt(enum acpi_madt_type mtype, acpi_table_handler handler); +int acpi_wakeup_cpu(int apicid, unsigned long start_ip, unsigned char* online_cpus); +bool parse_acpi_table(unsigned char* id_map); #endif diff --git a/lib/x86/setup.c b/lib/x86/setup.c index 20807700..406d04e3 100644 --- a/lib/x86/setup.c +++ b/lib/x86/setup.c @@ -339,6 +339,10 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo) return status; } + /* Parse all acpi tables, currently only MADT table */ + if (!parse_acpi_table(id_map)) + return EFI_NOT_FOUND; + phase = "AMD SEV"; status = setup_amd_sev(); -- 2.25.1
