From 6cdce951f7a1d8161910d5cd9bd9e6197bf5cc97 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Thu, 19 Jul 2018 15:47:07 +0200 Subject: [PATCH] x86/microcode/AMD: Simplify patch family detection Instead of traversing the equivalence table, compute the family a patch is for, from the processor revision ID in the microcode header. Signed-off-by: Borislav Petkov Cc: x86@kernel.org Link: https://lkml.kernel.org/r/20181107170218.7596-8-bp@alien8.de --- arch/x86/kernel/cpu/microcode/amd.c | 27 +++------------------------ 1 file changed, 3 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 8f012a7f88c4..b4450374f4b1 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -540,20 +540,6 @@ static u16 __find_equiv_id(unsigned int cpu) return find_equiv_id(equiv_cpu_table, uci->cpu_sig.sig); } -static u32 find_cpu_family_by_equiv_cpu(u16 equiv_cpu) -{ - int i = 0; - - BUG_ON(!equiv_cpu_table); - - while (equiv_cpu_table[i].equiv_cpu != 0) { - if (equiv_cpu == equiv_cpu_table[i].equiv_cpu) - return equiv_cpu_table[i].installed_cpu; - i++; - } - return 0; -} - /* * a small, trivial cache of per-family ucode patches */ @@ -732,7 +718,7 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) struct microcode_header_amd *mc_hdr; unsigned int patch_size, crnt_size; struct ucode_patch *patch; - u32 proc_fam; + u8 patch_fam; u16 proc_id; patch_size = verify_patch(family, fw, leftover, false); @@ -746,15 +732,8 @@ static int verify_and_add_patch(u8 family, u8 *fw, unsigned int leftover) mc_hdr = (struct microcode_header_amd *)(fw + SECTION_HDR_SIZE); proc_id = mc_hdr->processor_rev_id; - proc_fam = find_cpu_family_by_equiv_cpu(proc_id); - if (!proc_fam) { - pr_err("No patch family for equiv ID: 0x%04x\n", proc_id); - return crnt_size; - } - - /* check if patch is for the current family */ - proc_fam = ((proc_fam >> 8) & 0xf) + ((proc_fam >> 20) & 0xff); - if (proc_fam != family) + patch_fam = 0xf + (proc_id >> 12); + if (patch_fam != family) return crnt_size; if (mc_hdr->nb_dev_id || mc_hdr->sb_dev_id) {