Commit-ID: 777284b66f2326c7cb4c541e2224b638b562a9d3 Gitweb: http://git.kernel.org/tip/777284b66f2326c7cb4c541e2224b638b562a9d3 Author: Borislav Petkov <[email protected]> AuthorDate: Tue, 25 Oct 2016 11:55:11 +0200 Committer: Ingo Molnar <[email protected]> CommitDate: Tue, 25 Oct 2016 12:28:57 +0200
x86/microcode: Run the AP-loading routine only on the application processors cpu_init() is run also on the BSP (in addition to the APs): x86_64_start_kernel |-> x86_64_start_reservations |-> start_kernel |-> trap_init |-> cpu_init |-> load_ucode_ap ... but we run the AP (Application Processors) microcode loading routine there too even though we have a BSP-specific routine for that: load_ucode_bsp(). Which is unnecessary. So let's limit the AP microcode loading routine to the APs only. Remove a useless comment while at it. Signed-off-by: Borislav Petkov <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/cpu/common.c | 7 ++----- arch/x86/kernel/cpu/microcode/amd.c | 5 ----- 2 files changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9bd910a..1a1d668 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1462,11 +1462,8 @@ void cpu_init(void) */ cr4_init_shadow(); - /* - * Load microcode on this cpu if a valid microcode is available. - * This is early microcode loading procedure. - */ - load_ucode_ap(); + if (cpu) + load_ucode_ap(); t = &per_cpu(cpu_tss, cpu); oist = &per_cpu(orig_ist, cpu); diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 620ab06..6b3929e 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -357,17 +357,12 @@ static void __init get_bsp_sig(void) #else void load_ucode_amd_ap(void) { - unsigned int cpu = smp_processor_id(); struct equiv_cpu_entry *eq; struct microcode_amd *mc; u8 *cont = container; u32 rev, eax; u16 eq_id; - /* Exit if called on the BSP. */ - if (!cpu) - return; - if (!container) return;
