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    Subject[tip: x86/microcode] x86/microcode/intel: Simplify scan_microcode()
    The following commit has been merged into the x86/microcode branch of tip:

    Commit-ID: 6a92484124b21e24aaa04be33fc4938f42d56733
    Gitweb: https://git.kernel.org/tip/6a92484124b21e24aaa04be33fc4938f42d56733
    Author: Thomas Gleixner <tglx@linutronix.de>
    AuthorDate: Mon, 02 Oct 2023 13:59:39 +02:00
    Committer: Borislav Petkov (AMD) <bp@alien8.de>
    CommitterDate: Mon, 02 Oct 2023 18:30:44 +02:00

    x86/microcode/intel: Simplify scan_microcode()

    Make it readable and comprehensible.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
    Link: https://lore.kernel.org/r/20231002115902.271940980@linutronix.de
    ---
    arch/x86/kernel/cpu/microcode/intel.c | 28 ++++++--------------------
    1 file changed, 7 insertions(+), 21 deletions(-)

    diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
    index 1f45f5c..24dd483 100644
    --- a/arch/x86/kernel/cpu/microcode/intel.c
    +++ b/arch/x86/kernel/cpu/microcode/intel.c
    @@ -268,22 +268,16 @@ static void save_microcode_patch(void *data, unsigned int size)
    intel_ucode_patch = (struct microcode_intel *)p;
    }

    -/*
    - * Get microcode matching with BSP's model. Only CPUs with the same model as
    - * BSP can stay in the platform.
    - */
    -static struct microcode_intel *
    -scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
    +/* Scan CPIO for microcode matching the boot CPU's family, model, stepping */
    +static struct microcode_intel *scan_microcode(void *data, size_t size,
    + struct ucode_cpu_info *uci, bool save)
    {
    struct microcode_header_intel *mc_header;
    struct microcode_intel *patch = NULL;
    u32 cur_rev = uci->cpu_sig.rev;
    unsigned int mc_size;

    - while (size) {
    - if (size < sizeof(struct microcode_header_intel))
    - break;
    -
    + for (; size >= sizeof(struct microcode_header_intel); size -= mc_size, data += mc_size) {
    mc_header = (struct microcode_header_intel *)data;

    mc_size = get_totalsize(mc_header);
    @@ -291,27 +285,19 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)
    intel_microcode_sanity_check(data, false, MC_HEADER_TYPE_MICROCODE) < 0)
    break;

    - size -= mc_size;
    -
    - if (!intel_find_matching_signature(data, uci->cpu_sig.sig,
    - uci->cpu_sig.pf)) {
    - data += mc_size;
    + if (!intel_find_matching_signature(data, uci->cpu_sig.sig, uci->cpu_sig.pf))
    continue;
    - }

    /* BSP scan: Check whether there is newer microcode */
    if (!save && cur_rev >= mc_header->rev)
    - goto next;
    + continue;

    /* Save scan: Check whether there is newer or matching microcode */
    if (save && cur_rev != mc_header->rev)
    - goto next;
    + continue;

    patch = data;
    cur_rev = mc_header->rev;
    -
    -next:
    - data += mc_size;
    }

    if (size)
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