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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, Borislav Petkov <bp@alien8.de>
Subject: [patch V5 09/39] x86/microcode/intel: Simplify scan_microcode()
Date: Tue, 17 Oct 2023 23:23:35 +0200 (CEST)	[thread overview]
Message-ID: <20231017211722.460700412@linutronix.de> (raw)
In-Reply-To: 20231017200758.877560658@linutronix.de

From: Thomas Gleixner <tglx@linutronix.de>

Make it readable and comprehensible.

Signed-off-by: Thomas Gleixner <tglx@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 1f45f5c44246..24dd4835d544 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)


  parent reply	other threads:[~2023-10-17 21:24 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-17 21:23 [patch V5 00/39] x86/microcode: Cleanup and late loading enhancements Thomas Gleixner
2023-10-17 21:23 ` [patch V5 01/39] x86/boot/32: Disable stackprotector and tracing for mk_early_pgtbl_32() Thomas Gleixner
2023-10-17 21:23 ` [patch V5 02/39] x86/boot: Use __pa_nodebug() in mk_early_pgtbl_32() Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 03/39] x86/boot/32: De-uglify the 2/3 level paging difference " Thomas Gleixner
2023-10-18 10:00   ` Borislav Petkov
2023-10-18 13:20     ` Thomas Gleixner
2023-10-18 16:28       ` Borislav Petkov
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 04/39] x86/boot/32: Restructure mk_early_pgtbl_32() Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 05/39] x86/microcode: Provide CONFIG_MICROCODE_INITRD32 Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 06/39] x86/boot/32: Temporarily map initrd for microcode loading Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 07/39] x86/microcode/32: Move early loading after paging enable Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 08/39] x86/microcode/intel: Rip out mixed stepping support for Intel CPUs Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Ashok Raj
2023-10-17 21:23 ` Thomas Gleixner [this message]
2023-10-17 21:23 ` [patch V5 10/39] x86/microcode/intel: Simplify and rename generic_load_microcode() Thomas Gleixner
2023-10-17 21:23 ` [patch V5 11/39] x86/microcode/intel: Cleanup code further Thomas Gleixner
2023-10-17 21:23 ` [patch V5 12/39] x86/microcode/intel: Simplify early loading Thomas Gleixner
2023-10-20 11:38   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 13/39] x86/microcode/intel: Save the microcode only after a successful late-load Thomas Gleixner
2023-10-17 21:23 ` [patch V5 14/39] x86/microcode/intel: Switch to kvmalloc() Thomas Gleixner
2023-10-17 21:23 ` [patch V5 15/39] x86/microcode/intel: Unify microcode apply() functions Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 16/39] x86/microcode/intel: Rework intel_cpu_collect_info() Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 17/39] x86/microcode/intel: Reuse intel_cpu_collect_info() Thomas Gleixner
2023-10-17 21:23 ` [patch V5 18/39] x86/microcode/intel: Rework intel_find_matching_signature() Thomas Gleixner
2023-10-17 21:23 ` [patch V5 19/39] x86/microcode: Remove pointless apply() invocation Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 20/39] x86/microcode/amd: Use correct per CPU ucode_cpu_info Thomas Gleixner
2023-10-17 21:23 ` [patch V5 21/39] x86/microcode/amd: Cache builtin microcode too Thomas Gleixner
2023-10-17 21:23 ` [patch V5 22/39] x86/microcode/amd: Cache builtin/initrd microcode early Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 23/39] x86/microcode/amd: Use cached microcode for AP load Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 24/39] x86/microcode: Mop up early loading leftovers Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 25/39] x86/microcode: Get rid of the schedule work indirection Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:23 ` [patch V5 26/39] x86/microcode: Clean up mc_cpu_down_prep() Thomas Gleixner
2023-10-17 21:24 ` [patch V5 27/39] x86/microcode: Handle "nosmt" correctly Thomas Gleixner
2023-10-17 21:24 ` [patch V5 28/39] x86/microcode: Clarify the late load logic Thomas Gleixner
2023-10-17 21:24 ` [patch V5 29/39] x86/microcode: Sanitize __wait_for_cpus() Thomas Gleixner
2023-10-17 21:24 ` [patch V5 30/39] x86/microcode: Add per CPU result state Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:24 ` [patch V5 31/39] x86/microcode: Add per CPU control field Thomas Gleixner
2023-10-17 21:24 ` [patch V5 32/39] x86/microcode: Provide new control functions Thomas Gleixner
2023-10-17 21:24 ` [patch V5 33/39] x86/microcode: Replace the all-in-one rendevous handler Thomas Gleixner
2023-10-17 21:24 ` [patch V5 34/39] x86/microcode: Rendezvous and load in NMI Thomas Gleixner
2023-10-17 21:24 ` [patch V5 35/39] x86/microcode: Protect against instrumentation Thomas Gleixner
2023-10-17 21:24 ` [patch V5 36/39] x86/apic: Provide apic_force_nmi_on_cpu() Thomas Gleixner
2023-10-17 21:24 ` [patch V5 37/39] x86/microcode: Handle "offline" CPUs correctly Thomas Gleixner
2023-10-17 21:24 ` [patch V5 38/39] x86/microcode: Prepare for minimal revision check Thomas Gleixner
2023-10-20 11:37   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-17 21:24 ` [patch V5 39/39] x86/microcode/intel: Add a minimum required revision for late loading Thomas Gleixner

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