Re: [tip:x86/microcode] x86, microcode, amd: Fix warnings and errors on with CONFIG_MICROCODE=m

[Jacob Shin <jacob.shin@amd.com>]

On Tue, Jun 04, 2013 at 04:36:00PM -0500, Jacob Shin wrote:
> On Tue, Jun 04, 2013 at 02:02:43PM -0700, Yinghai Lu wrote:
> > On Fri, May 31, 2013 at 2:59 PM, tip-bot for Jacob Shin
> > <tipbot@zytor.com> wrote:
> > > Commit-ID:  6b3389ac21b5e557b957f1497d0ff22bf733e8c3
> > > Gitweb:     http://git.kernel.org/tip/6b3389ac21b5e557b957f1497d0ff22bf733e8c3
> > > Author:     Jacob Shin <jacob.shin@amd.com>
> > > AuthorDate: Fri, 31 May 2013 01:53:24 -0500
> > > Committer:  H. Peter Anvin <hpa@linux.intel.com>
> > > CommitDate: Fri, 31 May 2013 13:56:58 -0700
> > >
> > > x86, microcode, amd: Fix warnings and errors on with CONFIG_MICROCODE=m
> > >
> > > Fix section mismatch warnings on microcode_amd_early.
> > > Compile error occurs when CONFIG_MICROCODE=m, change so that early
> > > loading depends on microcode_core.
> > >
> > > Reported-by: Yinghai Lu <yinghai@kernel.org>
> > > Reported-by: Borislav Petkov <bp@alien8.de>
> > > Signed-off-by: Jacob Shin <jacob.shin@amd.com>
> > > Link: http://lkml.kernel.org/r/20130531150241.GA12006@jshin-Toonie
> > > Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> > > ---
> > >  arch/x86/Kconfig                      | 2 +-
> > >  arch/x86/include/asm/microcode_amd.h  | 2 +-
> > >  arch/x86/kernel/microcode_amd_early.c | 8 ++++----
> > >  3 files changed, 6 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > > index 28dba52..2705532 100644
> > > --- a/arch/x86/Kconfig
> > > +++ b/arch/x86/Kconfig
> > > @@ -1065,7 +1065,7 @@ config MICROCODE_AMD_EARLY
> > >
> > >  config MICROCODE_EARLY
> > >         bool "Early load microcode"
> > > -       depends on (MICROCODE_INTEL || MICROCODE_AMD) && BLK_DEV_INITRD
> > > +       depends on MICROCODE=y && BLK_DEV_INITRD
> > >         select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
> > >         select MICROCODE_AMD_EARLY if MICROCODE_AMD
> > >         default y
> > > diff --git a/arch/x86/include/asm/microcode_amd.h b/arch/x86/include/asm/microcode_amd.h
> > > index 24254aa..c6b043f 100644
> > > --- a/arch/x86/include/asm/microcode_amd.h
> > > +++ b/arch/x86/include/asm/microcode_amd.h
> > > @@ -64,7 +64,7 @@ extern enum ucode_state load_microcode_amd(int cpu, const u8 *data, size_t size)
> > >  #ifdef CONFIG_MICROCODE_AMD_EARLY
> > >  #ifdef CONFIG_X86_32
> > >  #define MPB_MAX_SIZE PAGE_SIZE
> > > -extern u8 __cpuinitdata amd_bsp_mpb[MPB_MAX_SIZE];
> > > +extern u8 amd_bsp_mpb[MPB_MAX_SIZE];
> > >  #endif
> > >  extern void __init load_ucode_amd_bsp(void);
> > >  extern void __cpuinit load_ucode_amd_ap(void);
> > > diff --git a/arch/x86/kernel/microcode_amd_early.c b/arch/x86/kernel/microcode_amd_early.c
> > > index 7e54d97..9618805 100644
> > > --- a/arch/x86/kernel/microcode_amd_early.c
> > > +++ b/arch/x86/kernel/microcode_amd_early.c
> > > @@ -21,9 +21,9 @@ static u32 ucode_new_rev;
> > >   * Microcode patch container file is prepended to the initrd in cpio format.
> > >   * See Documentation/x86/early-microcode.txt
> > >   */
> > > -static __initdata char ucode_path[] = "kernel/x86/microcode/AuthenticAMD.bin";
> > > +static __cpuinitdata char ucode_path[] = "kernel/x86/microcode/AuthenticAMD.bin";
> > >
> > > -static struct cpio_data __init find_ucode_in_initrd(void)
> > > +static struct cpio_data __cpuinit find_ucode_in_initrd(void)
> > >  {
> > >         long offset = 0;
> > >         struct cpio_data cd;
> > 
> > does not like right fix.
> > 
> > find_ucode_in_initrd should be __init.
> > 
> > > @@ -62,7 +62,7 @@ static struct cpio_data __init find_ucode_in_initrd(void)
> > >   * load_microcode_amd() to save equivalent cpu table and microcode patches in
> > >   * kernel heap memory.
> > >   */
> > > -static void __init apply_ucode_in_initrd(void)
> > > +static void __cpuinit apply_ucode_in_initrd(void)
> > >  {
> > >         struct cpio_data cd;
> > >         struct equiv_cpu_entry *eq;
> > 
> > it should not call find_ucode_in_initrd or
> > it should be __init.
> 
> It's because the load_ucode_amd_ap() (which is __cpuinit because it
> can be called during CPU hotplug on).

Sorry, let me clarify. find_ucode_in_initrd() is called by
load_ucode_amd_ap() during cold boot. However, since
load_ucode_amd_ap() is also called during suspend/resume (CPU hotplug)
it has to be __cpuinit. Of course during suspend/resume code path,
find_ucode_in_initrd() is not called, since it is no longer there in memory.

> 
> Hm.. but yes, I do agree with you, I'm waiting for feedback on this
> follow up patch to allow multiple concatanated microcode files:
> 
>   https://lkml.org/lkml/2013/5/31/664
> 
> I'll submit multi-patch patchset to address your feedback as well.
> 
> Thank you,