diff options
| author | Borislav Petkov <bp@suse.de> | 2016-06-06 17:10:50 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-08 11:04:20 +0200 |
| commit | 9f3cc2a0772d7744d1d7195d39ac4794af622fe6 (patch) | |
| tree | a80793b7c643d79ab8cda25dd7ab241242fc54e5 /arch/x86/kernel/cpu | |
| parent | a13004a2449c56a83d5816e81d850ea92b6837c2 (diff) | |
Documentation/microcode: Document some aspects for more clarity
Document that builtin microcode is 64-bit only. Also, improve/add
comments to places.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/1465225850-7352-10-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/microcode/intel.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c index 359e2034b558..8962d6acee39 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -40,9 +40,13 @@ #include <asm/msr.h> /* - * Temporary microcode blobs pointers storage. We note here the pointers to - * microcode blobs we've got from whatever storage (detached initrd, builtin). - * Later on, we put those into final storage mc_saved_data.mc_saved. + * Temporary microcode blobs pointers storage. We note here during early load + * the pointers to microcode blobs we've got from whatever storage (detached + * initrd, builtin). Later on, we put those into final storage + * mc_saved_data.mc_saved. + * + * Important: those are offsets from the beginning of initrd or absolute + * addresses within the kernel image when built-in. */ static unsigned long mc_tmp_ptrs[MAX_UCODE_COUNT]; @@ -57,6 +61,7 @@ static struct ucode_blobs { bool valid; } blobs; +/* Go through saved patches and find the one suitable for the current CPU. */ static enum ucode_state find_microcode_patch(struct microcode_intel **saved, unsigned int num_saved, struct ucode_cpu_info *uci) @@ -466,6 +471,7 @@ static void show_saved_mc(void) static void save_mc_for_early(u8 *mc) { #ifdef CONFIG_HOTPLUG_CPU + /* Synchronization during CPU hotplug. */ static DEFINE_MUTEX(x86_cpu_microcode_mutex); struct microcode_intel *mc_saved_tmp[MAX_UCODE_COUNT]; @@ -474,10 +480,6 @@ static void save_mc_for_early(u8 *mc) struct microcode_intel **mc_saved; int ret, i; - /* - * Hold hotplug lock so mc_saved_data is not accessed by a CPU in - * hotplug. - */ mutex_lock(&x86_cpu_microcode_mutex); mc_saved_count_init = mc_saved_data.num_saved; |