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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>,
	"Chang S. Bae" <chang.seok.bae@intel.com>,
	Arjan van de Ven <arjan@linux.intel.com>,
	Nikolay Borisov <nik.borisov@suse.com>
Subject: [patch V4 04/30] x86/microcode/intel: Simplify scan_microcode()
Date: Mon,  2 Oct 2023 13:59:39 +0200 (CEST)	[thread overview]
Message-ID: <20231002115902.271940980@linutronix.de> (raw)
In-Reply-To: 20231002115506.217091296@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(-)

--- 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 *d
 	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 CPUs 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,
 		    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:[~2023-10-02 11:59 UTC|newest]

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-02 11:59 [patch V4 00/30] x86/microcode: Cleanup and late loading enhancements Thomas Gleixner
2023-10-02 11:59 ` [patch V4 01/30] x86/microcode/32: Move early loading after paging enable Thomas Gleixner
2023-10-02 11:59 ` [patch V4 02/30] x86/boot/32: Disable stackprotector and tracing for mk_early_pgtbl_32() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:38   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 03/30] x86/microcode/intel: Rip out mixed stepping support for Intel CPUs Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Ashok Raj
2023-10-02 11:59 ` Thomas Gleixner [this message]
2023-10-09 12:29   ` [tip: x86/microcode] x86/microcode/intel: Simplify scan_microcode() tip-bot2 for Thomas Gleixner
2023-10-20 11:38   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 05/30] x86/microcode/intel: Simplify and rename generic_load_microcode() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:38   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 06/30] x86/microcode/intel: Cleanup code further Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:38   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 07/30] x86/microcode/intel: Simplify early loading Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 08/30] x86/microcode/intel: Save the microcode only after a successful late-load Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 09/30] x86/microcode/intel: Switch to kvmalloc() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 10/30] x86/microcode/intel: Unify microcode apply() functions Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 11/30] x86/microcode/intel: Rework intel_cpu_collect_info() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 12/30] x86/microcode/intel: Reuse intel_cpu_collect_info() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 13/30] x86/microcode/intel: Rework intel_find_matching_signature() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:21   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 14/30] x86/microcode/amd: Read revision from hardware in collect_cpu_info_amd() Thomas Gleixner
2023-10-04  8:32   ` Borislav Petkov
2023-10-02 11:59 ` [patch V4 15/30] x86/microcode: Remove pointless apply() invocation Thomas Gleixner
2023-10-06 13:26   ` Borislav Petkov
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 16/30] x86/microcode: Get rid of the schedule work indirection Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 17/30] x86/microcode: Clean up mc_cpu_down_prep() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 18/30] x86/microcode: Handle "nosmt" correctly Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 19/30] x86/microcode: Clarify the late load logic Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 11:59 ` [patch V4 20/30] x86/microcode: Sanitize __wait_for_cpus() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 21/30] x86/microcode: Add per CPU result state Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 22/30] x86/microcode: Add per CPU control field Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 23/30] x86/microcode: Provide new control functions Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 24/30] x86/microcode: Replace the all in one rendevouz handler Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] x86/microcode: Replace the all-in-one rendevous handler tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 25/30] x86/microcode: Rendezvous and load in NMI Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 26/30] x86/microcode: Protect against instrumentation Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 27/30] x86/apic: Provide apic_force_nmi_on_cpu() Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 28/30] x86/microcode: Handle "offline" CPUs correctly Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-20 11:37   ` tip-bot2 for Thomas Gleixner
2023-10-24 13:20   ` tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 29/30] x86/microcode: Prepare for minimal revision check Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] " tip-bot2 for Thomas Gleixner
2023-10-02 12:00 ` [patch V4 30/30] x86/microcode/intel: Add a minimum required revision for late-loads Thomas Gleixner
2023-10-09 12:29   ` [tip: x86/microcode] x86/microcode/intel: Add a minimum required revision for late loading tip-bot2 for Ashok Raj
2023-10-20 11:37   ` tip-bot2 for Ashok Raj
2023-10-24 13:20   ` tip-bot2 for Ashok Raj
2023-10-08  8:54 ` [patch V4 00/30] x86/microcode: Cleanup and late loading enhancements Qiuxu Zhuo
2023-10-08 13:08   ` Borislav Petkov
2023-10-09  5:03     ` Zhuo, Qiuxu
2023-10-10  8:00     ` Zhuo, Qiuxu
2023-10-10  8:11       ` Borislav Petkov

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