3 files changed, 21 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 6a31e2691f3a..079e81733a58 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -384,8 +384,9 @@ void load_ucode_amd_ap(unsigned int family)
 reget:
                 if (!get_builtin_microcode(&cp, family)) {
 #ifdef CONFIG_BLK_DEV_INITRD
-                        cp = find_cpio_data(ucode_path, (void *)initrd_start,
-                                            initrd_end - initrd_start, NULL);
+                        if (!initrd_gone)
+                                cp = find_cpio_data(ucode_path, (void *)initrd_start,
+                                                    initrd_end - initrd_start, NULL);
 #endif
                         if (!(cp.data && cp.size)) {
                                 /*
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 2af69d27da62..73102d932760 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -46,6 +46,8 @@
 static struct microcode_ops     *microcode_ops;
 static bool dis_ucode_ldr = true;
 
+bool initrd_gone;
+
 LIST_HEAD(microcode_cache);
 
 /*
@@ -190,21 +192,24 @@ void load_ucode_ap(void)
 static int __init save_microcode_in_initrd(void)
 {
         struct cpuinfo_x86 *c = &boot_cpu_data;
+        int ret = -EINVAL;
 
         switch (c->x86_vendor) {
         case X86_VENDOR_INTEL:
                 if (c->x86 >= 6)
-                        return save_microcode_in_initrd_intel();
+                        ret = save_microcode_in_initrd_intel();
                 break;
         case X86_VENDOR_AMD:
                 if (c->x86 >= 0x10)
-                        return save_microcode_in_initrd_amd(c->x86);
+                        ret = save_microcode_in_initrd_amd(c->x86);
                 break;
         default:
                 break;
         }
 
-        return -EINVAL;
+        initrd_gone = true;
+
+        return ret;
 }
 
 struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
@@ -247,9 +252,16 @@ struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
          * has the virtual address of the beginning of the initrd. It also
          * possibly relocates the ramdisk. In either case, initrd_start contains
          * the updated address so use that instead.
+         *
+         * initrd_gone is for the hotplug case where we've thrown out initrd
+         * already.
          */
-        if (!use_pa && initrd_start)
-                start = initrd_start;
+        if (!use_pa) {
+                if (initrd_gone)
+                        return (struct cpio_data){ NULL, 0, "" };
+                if (initrd_start)
+                        start = initrd_start;
+        }
 
         return find_cpio_data(path, (void *)start, size, NULL);
 #else /* !CONFIG_BLK_DEV_INITRD */
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 3f329b74e040..8325d8a09ab0 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -41,7 +41,7 @@
 
 static const char ucode_path[] = "kernel/x86/microcode/GenuineIntel.bin";
 
-/* Current microcode patch used in early patching */
+/* Current microcode patch used in early patching on the APs. */
 struct microcode_intel *intel_ucode_patch;
 
 static inline bool cpu_signatures_match(unsigned int s1, unsigned int p1,
@@ -607,12 +607,6 @@ int __init save_microcode_in_initrd_intel(void)
         struct ucode_cpu_info uci;
         struct cpio_data cp;
 
-        /*
-         * AP loading didn't find any microcode patch, no need to save anything.
-         */
-        if (!intel_ucode_patch || IS_ERR(intel_ucode_patch))
-                return 0;
-
         if (!load_builtin_intel_microcode(&cp))
                 cp = find_microcode_in_initrd(ucode_path, false);
 
@@ -628,7 +622,6 @@ int __init save_microcode_in_initrd_intel(void)
         return 0;
 }
 
-
 /*
  * @res_patch, output: a pointer to the patch we found.
  */