Merge tag 'x86_cc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 confidential computing updates from Borislav Petkov:
 "Unrelated x86/cc changes queued here to avoid ugly cross-merges and
  conflicts:

   - Carve out CPU hotplug function declarations into a separate header
     with the goal to be able to use the lockdep assertions in a more
     flexible manner

   - As a result, refactor cacheinfo code after carving out a function
     to return the cache ID associated with a given cache level

   - Cleanups

  Add support to be able to kexec TDX guests:

   - Expand ACPI MADT CPU offlining support

   - Add machinery to prepare CoCo guests memory before kexec-ing into a
     new kernel

   - Cleanup, readjust and massage related code"

* tag 'x86_cc_for_v6.11_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  ACPI: tables: Print MULTIPROC_WAKEUP when MADT is parsed
  x86/acpi: Add support for CPU offlining for ACPI MADT wakeup method
  x86/mm: Introduce kernel_ident_mapping_free()
  x86/smp: Add smp_ops.stop_this_cpu() callback
  x86/acpi: Do not attempt to bring up secondary CPUs in the kexec case
  x86/acpi: Rename fields in the acpi_madt_multiproc_wakeup structure
  x86/mm: Do not zap page table entries mapping unaccepted memory table during kdump
  x86/mm: Make e820__end_ram_pfn() cover E820_TYPE_ACPI ranges
  x86/tdx: Convert shared memory back to private on kexec
  x86/mm: Add callbacks to prepare encrypted memory for kexec
  x86/tdx: Account shared memory
  x86/mm: Return correct level from lookup_address() if pte is none
  x86/mm: Make x86_platform.guest.enc_status_change_*() return an error
  x86/kexec: Keep CR4.MCE set during kexec for TDX guest
  x86/relocate_kernel: Use named labels for less confusion
  cpu/hotplug, x86/acpi: Disable CPU offlining for ACPI MADT wakeup
  cpu/hotplug: Add support for declaring CPU offlining not supported
  x86/apic: Mark acpi_mp_wake_* variables as __ro_after_init
  x86/acpi: Extract ACPI MADT wakeup code into a separate file
  x86/kexec: Remove spurious unconditional JMP from from identity_mapped()
  ...

1 files changed, 28 insertions, 0 deletions

diff --git a/arch/x86/kernel/acpi/madt_playdead.S b/arch/x86/kernel/acpi/madt_playdead.S
new file mode 100644
index 000000000000..4e498d28cdc8
--- /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)