Merge tag 'x86_microcode_for_v6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 microcode loading updates from Borislac Petkov:
 "Major microcode loader restructuring, cleanup and improvements by
  Thomas Gleixner:

   - Restructure the code needed for it and add a temporary initrd
     mapping on 32-bit so that the loader can access the microcode
     blobs. This in itself is a preparation for the next major
     improvement:

   - Do not load microcode on 32-bit before paging has been enabled.

     Handling this has caused an endless stream of headaches, issues,
     ugly code and unnecessary hacks in the past. And there really
     wasn't any sensible reason to do that in the first place. So switch
     the 32-bit loading to happen after paging has been enabled and turn
     the loader code "real purrty" again

   - Drop mixed microcode steppings loading on Intel - there, a single
     patch loaded on the whole system is sufficient

   - Rework late loading to track which CPUs have updated microcode
     successfully and which haven't, act accordingly

   - Move late microcode loading on Intel in NMI context in order to
     guarantee concurrent loading on all threads

   - Make the late loading CPU-hotplug-safe and have the offlined
     threads be woken up for the purpose of the update

   - Add support for a minimum revision which determines whether late
     microcode loading is safe on a machine and the microcode does not
     change software visible features which the machine cannot use
     anyway since feature detection has happened already. Roughly, the
     minimum revision is the smallest revision number which must be
     loaded currently on the system so that late updates can be allowed

   - Other nice leanups, fixess, etc all over the place"

* tag 'x86_microcode_for_v6.7_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
  x86/microcode/intel: Add a minimum required revision for late loading
  x86/microcode: Prepare for minimal revision check
  x86/microcode: Handle "offline" CPUs correctly
  x86/apic: Provide apic_force_nmi_on_cpu()
  x86/microcode: Protect against instrumentation
  x86/microcode: Rendezvous and load in NMI
  x86/microcode: Replace the all-in-one rendevous handler
  x86/microcode: Provide new control functions
  x86/microcode: Add per CPU control field
  x86/microcode: Add per CPU result state
  x86/microcode: Sanitize __wait_for_cpus()
  x86/microcode: Clarify the late load logic
  x86/microcode: Handle "nosmt" correctly
  x86/microcode: Clean up mc_cpu_down_prep()
  x86/microcode: Get rid of the schedule work indirection
  x86/microcode: Mop up early loading leftovers
  x86/microcode/amd: Use cached microcode for AP load
  x86/microcode/amd: Cache builtin/initrd microcode early
  x86/microcode/amd: Cache builtin microcode too
  x86/microcode/amd: Use correct per CPU ucode_cpu_info
  ...

1 files changed, 16 insertions, 5 deletions

diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index bbbe9d744977d..695e569159c1d 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -23,6 +23,8 @@ static inline void load_ucode_ap(void) { }
 static inline void microcode_bsp_resume(void) { }
 #endif
 
+extern unsigned long initrd_start_early;
+
 #ifdef CONFIG_CPU_SUP_INTEL
 /* Intel specific microcode defines. Public for IFS */
 struct microcode_header_intel {
@@ -36,7 +38,8 @@ struct microcode_header_intel {
 	unsigned int	datasize;
 	unsigned int	totalsize;
 	unsigned int	metasize;
-	unsigned int	reserved[2];
+	unsigned int	min_req_ver;
+	unsigned int	reserved;
 };
 
 struct microcode_intel {
@@ -68,11 +71,19 @@ static inline u32 intel_get_microcode_revision(void)
 
 	return rev;
 }
+#endif /* !CONFIG_CPU_SUP_INTEL */
 
-void show_ucode_info_early(void);
+bool microcode_nmi_handler(void);
+void microcode_offline_nmi_handler(void);
 
-#else /* CONFIG_CPU_SUP_INTEL */
-static inline void show_ucode_info_early(void) { }
-#endif /* !CONFIG_CPU_SUP_INTEL */
+#ifdef CONFIG_MICROCODE_LATE_LOADING
+DECLARE_STATIC_KEY_FALSE(microcode_nmi_handler_enable);
+static __always_inline bool microcode_nmi_handler_enabled(void)
+{
+	return static_branch_unlikely(&microcode_nmi_handler_enable);
+}
+#else
+static __always_inline bool microcode_nmi_handler_enabled(void) { return false; }
+#endif
 
 #endif /* _ASM_X86_MICROCODE_H */