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>
---
lib/x86/acpi.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++
lib/x86/acpi.h | 85 ++++++++++++++++++++++++
lib/x86/setup.c | 4 ++
3 files changed, 260 insertions(+)
diff --git a/lib/x86/acpi.c b/lib/x86/acpi.c
index 1a82ced0b90f..6fb8ece7eabe 100644
--- a/lib/x86/acpi.c
+++ b/lib/x86/acpi.c
@@ -1,7 +1,12 @@
#include "libcflat.h"
+#include "errno.h"
#include "acpi.h"
+#include "apic.h"
+#include "asm/barrier.h"
+#include "processor.h"
#ifdef TARGET_EFI
+unsigned char online_cpus[(MAX_TEST_CPUS + 7) / 8];
struct rsdp_descriptor *efi_rsdp = NULL;
void set_efi_rsdp(struct rsdp_descriptor *rsdp)
@@ -16,6 +21,172 @@ static struct rsdp_descriptor *get_rsdp(void)
}
return efi_rsdp;
}
+
+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)
+{
+ 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, online_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 (timeout) {
+ /*
+ * If the CPU wakeup process is successful, store the
+ * status in online_cpus to prevent re-wakeup
+ * requests.
+ */
+ set_bit(apicid, online_cpus);
+ return 0;
+ }
+
+ /* If timed out (timeout == 0), return error */
+ return -EIO;
+}
+
+static bool parse_madt_table(struct acpi_table *madt)
+{
+ 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(void)
+{
+ struct acpi_table *tb;
+
+ tb = find_acpi_table_addr(MADT_SIGNATURE);
+ if (tb)
+ return parse_madt_table(tb);
+
+ return false;
+}
#else
static struct rsdp_descriptor *get_rsdp(void)
{
diff --git a/lib/x86/acpi.h b/lib/x86/acpi.h
index 67ba3899b1d7..509d9b5bb0b4 100644
--- a/lib/x86/acpi.h
+++ b/lib/x86/acpi.h
@@ -10,6 +10,7 @@
#define RSDT_SIGNATURE ACPI_SIGNATURE('R','S','D','T')
#define FACP_SIGNATURE ACPI_SIGNATURE('F','A','C','P')
#define FACS_SIGNATURE ACPI_SIGNATURE('F','A','C','S')
+#define MADT_SIGNATURE ACPI_SIGNATURE('A','P','I','C')
#define ACPI_SIGNATURE_8BYTE(c1, c2, c3, c4, c5, c6, c7, c8) \
@@ -46,6 +47,88 @@ struct acpi_table {
char data[0];
};
+/*******************************************************************************
+ *
+ * MADT - Multiple APIC Description Table
+ * Version 3
+ *
+ ******************************************************************************/
+
+struct acpi_table_madt {
+ ACPI_TABLE_HEADER_DEF
+ u32 address; /* Physical address of local APIC */
+ u32 flags;
+};
+
+/* Generic subtable header (used in MADT, SRAT, etc.) */
+
+struct acpi_subtable_header {
+ u8 type;
+ u8 length;
+};
+
+#define ACPI_MADT_TYPE_LOCAL_APIC 0
+#define ACPI_MADT_TYPE_LOCAL_X2APIC 9
+#define ACPI_MADT_TYPE_MULTIPROC_WAKEUP 16
+
+#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 */
+
struct rsdt_descriptor_rev1 {
ACPI_TABLE_HEADER_DEF
u32 table_offset_entry[0];
@@ -108,5 +191,7 @@ struct facs_descriptor_rev1
void set_efi_rsdp(struct rsdp_descriptor *rsdp);
void* find_acpi_table_addr(u32 sig);
+int acpi_wakeup_cpu(int apicid, unsigned long start_ip);
+bool parse_acpi_table(void);
#endif
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index 29202478ae0d..63c4dbb25064 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c
@@ -314,6 +314,10 @@ efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
return status;
}
+ /* Parse all acpi tables, currently only MADT table */
+ if (!parse_acpi_table())
+ return EFI_NOT_FOUND;
+
phase = "AMD SEV";
status = setup_amd_sev();
--
2.25.1
