linux-kernel - [patch V4 05/30] x86/microcode/intel: Simplify and rename generic_load

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Date:   Mon,  2 Oct 2023 13:59:40 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Borislav Petkov <bp@...en8.de>,
        "Chang S. Bae" <chang.seok.bae@...el.com>,
        Arjan van de Ven <arjan@...ux.intel.com>,
        Nikolay Borisov <nik.borisov@...e.com>
Subject: [patch V4 05/30] x86/microcode/intel: Simplify and rename
 generic_load_microcode()

so it becomes less obfuscated and rename it because there is nothing
generic about it.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
V3: Rename to parse_microcode_blobs() - Borislav
---
 arch/x86/kernel/cpu/microcode/intel.c |   47 ++++++++++++----------------------
 1 file changed, 17 insertions(+), 30 deletions(-)

--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -240,19 +240,6 @@ int intel_microcode_sanity_check(void *m
 }
 EXPORT_SYMBOL_GPL(intel_microcode_sanity_check);
 
-/*
- * Returns 1 if update has been found, 0 otherwise.
- */
-static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev)
-{
-	struct microcode_header_intel *mc_hdr = mc;
-
-	if (mc_hdr->rev <= new_rev)
-		return 0;
-
-	return intel_find_matching_signature(mc, csig, cpf);
-}
-
 static void save_microcode_patch(void *data, unsigned int size)
 {
 	struct microcode_header_intel *p;
@@ -561,14 +548,12 @@ static enum ucode_state apply_microcode_
 	return ret;
 }
 
-static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)
+static enum ucode_state parse_microcode_blobs(int cpu, struct iov_iter *iter)
 {
 	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 	unsigned int curr_mc_size = 0, new_mc_size = 0;
-	enum ucode_state ret = UCODE_OK;
-	int new_rev = uci->cpu_sig.rev;
+	int cur_rev = uci->cpu_sig.rev;
 	u8 *new_mc = NULL, *mc = NULL;
-	unsigned int csig, cpf;
 
 	while (iov_iter_count(iter)) {
 		struct microcode_header_intel mc_header;
@@ -585,6 +570,7 @@ static enum ucode_state generic_load_mic
 			pr_err("error! Bad data in microcode data file (totalsize too small)\n");
 			break;
 		}
+
 		data_size = mc_size - sizeof(mc_header);
 		if (data_size > iov_iter_count(iter)) {
 			pr_err("error! Bad data in microcode data file (truncated file?)\n");
@@ -607,16 +593,17 @@ static enum ucode_state generic_load_mic
 			break;
 		}
 
-		csig = uci->cpu_sig.sig;
-		cpf = uci->cpu_sig.pf;
-		if (has_newer_microcode(mc, csig, cpf, new_rev)) {
-			vfree(new_mc);
-			new_rev = mc_header.rev;
-			new_mc  = mc;
-			new_mc_size = mc_size;
-			mc = NULL;	/* trigger new vmalloc */
-			ret = UCODE_NEW;
-		}
+		if (cur_rev >= mc_header.rev)
+			continue;
+
+		if (!intel_find_matching_signature(mc, uci->cpu_sig.sig, uci->cpu_sig.pf))
+			continue;
+
+		vfree(new_mc);
+		cur_rev = mc_header.rev;
+		new_mc  = mc;
+		new_mc_size = mc_size;
+		mc = NULL;
 	}
 
 	vfree(mc);
@@ -636,9 +623,9 @@ static enum ucode_state generic_load_mic
 	save_microcode_patch(new_mc, new_mc_size);
 
 	pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",
-		 cpu, new_rev, uci->cpu_sig.rev);
+		 cpu, cur_rev, uci->cpu_sig.rev);
 
-	return ret;
+	return UCODE_NEW;
 }
 
 static bool is_blacklisted(unsigned int cpu)
@@ -687,7 +674,7 @@ static enum ucode_state request_microcod
 	kvec.iov_base = (void *)firmware->data;
 	kvec.iov_len = firmware->size;
 	iov_iter_kvec(&iter, ITER_SOURCE, &kvec, 1, firmware->size);
-	ret = generic_load_microcode(cpu, &iter);
+	ret = parse_microcode_blobs(cpu, &iter);
 
 	release_firmware(firmware);