Add spinlock to serialize Intel microcode updates
Updating microcode on several threads in a core at once
can be harmful. Hence add a spinlock to make sure that
does not happen.
Change-Id: I0c9526b6194202ae7ab5c66361fe04ce137372cc
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1778
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/cpu/intel/microcode/microcode.c b/src/cpu/intel/microcode/microcode.c
index a4471ca..15d6513 100644
--- a/src/cpu/intel/microcode/microcode.c
+++ b/src/cpu/intel/microcode/microcode.c
@@ -28,12 +28,16 @@
#include <cpu/x86/msr.h>
#include <cpu/intel/microcode.h>
-#if CONFIG_CPU_MICROCODE_IN_CBFS
#ifdef __PRE_RAM__
+#if CONFIG_CPU_MICROCODE_IN_CBFS
#include <arch/cbfs.h>
+#endif
#else
+#if CONFIG_CPU_MICROCODE_IN_CBFS
#include <cbfs.h>
#endif
+#include <smp/spinlock.h>
+DECLARE_SPIN_LOCK(microcode_lock)
#endif
struct microcode {
@@ -112,6 +116,9 @@
printk(BIOS_DEBUG, "microcode: sig=0x%x pf=0x%x revision=0x%x\n",
sig, pf, rev);
#endif
+#if !defined(__ROMCC__) && !defined(__PRE_RAM__)
+ spin_lock(µcode_lock);
+#endif
m = microcode_updates;
for(c = microcode_updates; m->hdrver; m = (const struct microcode *)c) {
@@ -142,6 +149,10 @@
c += 2048;
}
}
+
+#if !defined(__ROMCC__) && !defined(__PRE_RAM__)
+ spin_unlock(µcode_lock);
+#endif
}
#if CONFIG_CPU_MICROCODE_IN_CBFS