diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index ceacac2b335d5e5c4d8b274b2b16435ad8a8ff6d..21bc53f5ed0c8108c9129558293e2a9ff944903c 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -83,6 +83,8 @@ union acpi_subtable_headers;
int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
const unsigned long end);
+void asm_acpi_mp_play_dead(u64 reset_vector, u64 pgd_pa);
+
/*
* Check if the CPU can handle C2 and deeper
*/
diff --git a/arch/x86/kernel/acpi/Makefile b/arch/x86/kernel/acpi/Makefile
index 2feba7257665adb4ed7ad45c7ba742d7dad72054..842a5f449404c45840a420f1d921c2f1aac5a2c7 100644
--- a/arch/x86/kernel/acpi/Makefile
+++ b/arch/x86/kernel/acpi/Makefile
@@ -4,7 +4,7 @@ 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_MADT_WAKEUP) += madt_wakeup.o
+obj-$(CONFIG_ACPI_MADT_WAKEUP) += madt_wakeup.o madt_playdead.o
ifneq ($(CONFIG_ACPI_PROCESSOR),)
obj-y += cstate.o
diff --git a/arch/x86/kernel/acpi/madt_playdead.S b/arch/x86/kernel/acpi/madt_playdead.S
new file mode 100644
index 0000000000000000000000000000000000000000..4e498d28cdc85933a36fd00c621b1e2c949e5fef
--- /dev/null
+++ b/arch/x86/kernel/acpi/madt_playdead.S
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/linkage.h>
+#include <asm/nospec-branch.h>
+#include <asm/page_types.h>
+#include <asm/processor-flags.h>
+
+ .text
+ .align PAGE_SIZE
+
+/*
+ * asm_acpi_mp_play_dead() - Hand over control of the CPU to the BIOS
+ *
+ * rdi: Address of the ACPI MADT MPWK ResetVector
+ * rsi: PGD of the identity mapping
+ */
+SYM_FUNC_START(asm_acpi_mp_play_dead)
+ /* Turn off global entries. Following CR3 write will flush them. */
+ movq %cr4, %rdx
+ andq $~(X86_CR4_PGE), %rdx
+ movq %rdx, %cr4
+
+ /* Switch to identity mapping */
+ movq %rsi, %cr3
+
+ /* Jump to reset vector */
+ ANNOTATE_RETPOLINE_SAFE
+ jmp *%rdi
+SYM_FUNC_END(asm_acpi_mp_play_dead)
diff --git a/arch/x86/kernel/acpi/madt_wakeup.c b/arch/x86/kernel/acpi/madt_wakeup.c
index 30820f9de5afde5c15e4a16d02b79eaf633016c8..6cfe762be28bbc72c01cf88c13a7178369d6ada1 100644
--- a/arch/x86/kernel/acpi/madt_wakeup.c
+++ b/arch/x86/kernel/acpi/madt_wakeup.c
@@ -1,10 +1,19 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/acpi.h>
#include <linux/cpu.h>
+#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/pgtable.h>
+#include <linux/sched/hotplug.h>
#include <asm/apic.h>
#include <asm/barrier.h>
+#include <asm/init.h>
+#include <asm/intel_pt.h>
+#include <asm/nmi.h>
#include <asm/processor.h>
+#include <asm/reboot.h>
/* Physical address of the Multiprocessor Wakeup Structure mailbox */
static u64 acpi_mp_wake_mailbox_paddr __ro_after_init;
@@ -12,6 +21,154 @@ static u64 acpi_mp_wake_mailbox_paddr __ro_after_init;
/* Virtual address of the Multiprocessor Wakeup Structure mailbox */
static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox __ro_after_init;
+static u64 acpi_mp_pgd __ro_after_init;
+static u64 acpi_mp_reset_vector_paddr __ro_after_init;
+
+static void acpi_mp_stop_this_cpu(void)
+{
+ asm_acpi_mp_play_dead(acpi_mp_reset_vector_paddr, acpi_mp_pgd);
+}
+
+static void acpi_mp_play_dead(void)
+{
+ play_dead_common();
+ asm_acpi_mp_play_dead(acpi_mp_reset_vector_paddr, acpi_mp_pgd);
+}
+
+static void acpi_mp_cpu_die(unsigned int cpu)
+{
+ u32 apicid = per_cpu(x86_cpu_to_apicid, cpu);
+ unsigned long timeout;
+
+ /*
+ * Use TEST mailbox command to prove that BIOS got control over
+ * the CPU before declaring it dead.
+ *
+ * BIOS has to clear 'command' field of the mailbox.
+ */
+ acpi_mp_wake_mailbox->apic_id = apicid;
+ smp_store_release(&acpi_mp_wake_mailbox->command,
+ ACPI_MP_WAKE_COMMAND_TEST);
+
+ /* Don't wait longer than a second. */
+ timeout = USEC_PER_SEC;
+ while (READ_ONCE(acpi_mp_wake_mailbox->command) && --timeout)
+ udelay(1);
+
+ if (!timeout)
+ pr_err("Failed to hand over CPU %d to BIOS\n", cpu);
+}
+
+/* The argument is required to match type of x86_mapping_info::alloc_pgt_page */
+static void __init *alloc_pgt_page(void *dummy)
+{
+ return memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+}
+
+static void __init free_pgt_page(void *pgt, void *dummy)
+{
+ return memblock_free(pgt, PAGE_SIZE);
+}
+
+/*
+ * Make sure asm_acpi_mp_play_dead() is present in the identity mapping at
+ * the same place as in the kernel page tables. asm_acpi_mp_play_dead() switches
+ * to the identity mapping and the function has be present at the same spot in
+ * the virtual address space before and after switching page tables.
+ */
+static int __init init_transition_pgtable(pgd_t *pgd)
+{
+ pgprot_t prot = PAGE_KERNEL_EXEC_NOENC;
+ unsigned long vaddr, paddr;
+ p4d_t *p4d;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ vaddr = (unsigned long)asm_acpi_mp_play_dead;
+ pgd += pgd_index(vaddr);
+ if (!pgd_present(*pgd)) {
+ p4d = (p4d_t *)alloc_pgt_page(NULL);
+ if (!p4d)
+ return -ENOMEM;
+ set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE));
+ }
+ p4d = p4d_offset(pgd, vaddr);
+ if (!p4d_present(*p4d)) {
+ pud = (pud_t *)alloc_pgt_page(NULL);
+ if (!pud)
+ return -ENOMEM;
+ set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));
+ }
+ pud = pud_offset(p4d, vaddr);
+ if (!pud_present(*pud)) {
+ pmd = (pmd_t *)alloc_pgt_page(NULL);
+ if (!pmd)
+ return -ENOMEM;
+ set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
+ }
+ pmd = pmd_offset(pud, vaddr);
+ if (!pmd_present(*pmd)) {
+ pte = (pte_t *)alloc_pgt_page(NULL);
+ if (!pte)
+ return -ENOMEM;
+ set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
+ }
+ pte = pte_offset_kernel(pmd, vaddr);
+
+ paddr = __pa(vaddr);
+ set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
+
+ return 0;
+}
+
+static int __init acpi_mp_setup_reset(u64 reset_vector)
+{
+ struct x86_mapping_info info = {
+ .alloc_pgt_page = alloc_pgt_page,
+ .free_pgt_page = free_pgt_page,
+ .page_flag = __PAGE_KERNEL_LARGE_EXEC,
+ .kernpg_flag = _KERNPG_TABLE_NOENC,
+ };
+ pgd_t *pgd;
+
+ pgd = alloc_pgt_page(NULL);
+ if (!pgd)
+ return -ENOMEM;
+
+ for (int i = 0; i < nr_pfn_mapped; i++) {
+ unsigned long mstart, mend;
+
+ mstart = pfn_mapped[i].start << PAGE_SHIFT;
+ mend = pfn_mapped[i].end << PAGE_SHIFT;
+ if (kernel_ident_mapping_init(&info, pgd, mstart, mend)) {
+ kernel_ident_mapping_free(&info, pgd);
+ return -ENOMEM;
+ }
+ }
+
+ if (kernel_ident_mapping_init(&info, pgd,
+ PAGE_ALIGN_DOWN(reset_vector),
+ PAGE_ALIGN(reset_vector + 1))) {
+ kernel_ident_mapping_free(&info, pgd);
+ return -ENOMEM;
+ }
+
+ if (init_transition_pgtable(pgd)) {
+ kernel_ident_mapping_free(&info, pgd);
+ return -ENOMEM;
+ }
+
+ smp_ops.play_dead = acpi_mp_play_dead;
+ smp_ops.stop_this_cpu = acpi_mp_stop_this_cpu;
+ smp_ops.cpu_die = acpi_mp_cpu_die;
+
+ acpi_mp_reset_vector_paddr = reset_vector;
+ acpi_mp_pgd = __pa(pgd);
+
+ return 0;
+}
+
static int acpi_wakeup_cpu(u32 apicid, unsigned long start_ip)
{
if (!acpi_mp_wake_mailbox_paddr) {
@@ -97,14 +254,37 @@ int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
struct acpi_madt_multiproc_wakeup *mp_wake;
mp_wake = (struct acpi_madt_multiproc_wakeup *)header;
- if (BAD_MADT_ENTRY(mp_wake, end))
+
+ /*
+ * Cannot use the standard BAD_MADT_ENTRY() to sanity check the @mp_wake
+ * entry. 'sizeof (struct acpi_madt_multiproc_wakeup)' can be larger
+ * than the actual size of the MP wakeup entry in ACPI table because the
+ * 'reset_vector' is only available in the V1 MP wakeup structure.
+ */
+ if (!mp_wake)
+ return -EINVAL;
+ if (end - (unsigned long)mp_wake < ACPI_MADT_MP_WAKEUP_SIZE_V0)
+ return -EINVAL;
+ if (mp_wake->header.length < ACPI_MADT_MP_WAKEUP_SIZE_V0)
return -EINVAL;
acpi_table_print_madt_entry(&header->common);
acpi_mp_wake_mailbox_paddr = mp_wake->mailbox_address;
- acpi_mp_disable_offlining(mp_wake);
+ if (mp_wake->version >= ACPI_MADT_MP_WAKEUP_VERSION_V1 &&
+ mp_wake->header.length >= ACPI_MADT_MP_WAKEUP_SIZE_V1) {
+ if (acpi_mp_setup_reset(mp_wake->reset_vector)) {
+ pr_warn("Failed to setup MADT reset vector\n");
+ acpi_mp_disable_offlining(mp_wake);
+ }
+ } else {
+ /*
+ * CPU offlining requires version 1 of the ACPI MADT wakeup
+ * structure.
+ */
+ acpi_mp_disable_offlining(mp_wake);
+ }
apic_update_callback(wakeup_secondary_cpu_64, acpi_wakeup_cpu);
diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index fa63362469aaafe9ef5d97be5531ad7c2ac410b5..e27958ef82642fc6a741723cefe61d83c97dda0c 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -1197,8 +1197,20 @@ struct acpi_madt_multiproc_wakeup {
u16 version;
u32 reserved; /* reserved - must be zero */
u64 mailbox_address;
+ u64 reset_vector;
};
+/* Values for Version field above */
+
+enum acpi_madt_multiproc_wakeup_version {
+ ACPI_MADT_MP_WAKEUP_VERSION_NONE = 0,
+ ACPI_MADT_MP_WAKEUP_VERSION_V1 = 1,
+ ACPI_MADT_MP_WAKEUP_VERSION_RESERVED = 2, /* 2 and greater are reserved */
+};
+
+#define ACPI_MADT_MP_WAKEUP_SIZE_V0 16
+#define ACPI_MADT_MP_WAKEUP_SIZE_V1 24
+
#define ACPI_MULTIPROC_WAKEUP_MB_OS_SIZE 2032
#define ACPI_MULTIPROC_WAKEUP_MB_FIRMWARE_SIZE 2048
@@ -1211,7 +1223,8 @@ struct acpi_madt_multiproc_wakeup_mailbox {
u8 reserved_firmware[ACPI_MULTIPROC_WAKEUP_MB_FIRMWARE_SIZE]; /* reserved for firmware use */
};
-#define ACPI_MP_WAKE_COMMAND_WAKEUP 1
+#define ACPI_MP_WAKE_COMMAND_WAKEUP 1
+#define ACPI_MP_WAKE_COMMAND_TEST 2
/* 17: CPU Core Interrupt Controller (ACPI 6.5) */