From b0f0bf5eef5fac6ba30b7cac15ca4cb01f8a6ca9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 2 Oct 2023 13:59:39 +0200 Subject: [PATCH] x86/microcode/intel: Simplify scan_microcode() Make it readable and comprehensible. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov (AMD) 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 03a55bfa88c5..26f759b7b7fa 100644 --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -266,22 +266,16 @@ 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); @@ -289,27 +283,19 @@ 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) -- 2.20.1