linux-kernel - [tip: x86/microcode] x86/microcode: Get rid of the schedule work indirection

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Message-ID: <169815365881.3135.12389169576692651192.tip-bot2@tip-bot2>
Date:   Tue, 24 Oct 2023 13:20:58 -0000
From:   "tip-bot2 for Thomas Gleixner" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        "Borislav Petkov (AMD)" <bp@...en8.de>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/microcode] x86/microcode: Get rid of the schedule work indirection

The following commit has been merged into the x86/microcode branch of tip:

Commit-ID:     2e1997335ceb6fc819862804f51d4fe83593c138
Gitweb:        https://git.kernel.org/tip/2e1997335ceb6fc819862804f51d4fe83593c138
Author:        Thomas Gleixner <tglx@...utronix.de>
AuthorDate:    Tue, 17 Oct 2023 23:23:58 +02:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Tue, 24 Oct 2023 15:05:54 +02:00

x86/microcode: Get rid of the schedule work indirection

Scheduling work on all CPUs to collect the microcode information is just
another extra step for no value. Let the CPU hotplug callback registration
do it.

Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Link: https://lore.kernel.org/r/20231017211723.354748138@linutronix.de
---
 arch/x86/kernel/cpu/microcode/core.c | 29 +++++++++------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 37145cf..0ed96d2 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -481,8 +481,16 @@ static struct syscore_ops mc_syscore_ops = {
 
 static int mc_cpu_online(unsigned int cpu)
 {
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
 	struct device *dev = get_cpu_device(cpu);
 
+	memset(uci, 0, sizeof(*uci));
+
+	microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);
+	cpu_data(cpu).microcode = uci->cpu_sig.rev;
+	if (!cpu)
+		boot_cpu_data.microcode = uci->cpu_sig.rev;
+
 	if (sysfs_create_group(&dev->kobj, &mc_attr_group))
 		pr_err("Failed to create group for CPU%d\n", cpu);
 	return 0;
@@ -503,20 +511,6 @@ static int mc_cpu_down_prep(unsigned int cpu)
 	return 0;
 }
 
-static void setup_online_cpu(struct work_struct *work)
-{
-	int cpu = smp_processor_id();
-	struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
-
-	memset(uci, 0, sizeof(*uci));
-
-	microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);
-	cpu_data(cpu).microcode = uci->cpu_sig.rev;
-	if (!cpu)
-		boot_cpu_data.microcode = uci->cpu_sig.rev;
-	mc_cpu_online(cpu);
-}
-
 static struct attribute *cpu_root_microcode_attrs[] = {
 #ifdef CONFIG_MICROCODE_LATE_LOADING
 	&dev_attr_reload.attr,
@@ -562,12 +556,9 @@ static int __init microcode_init(void)
 		}
 	}
 
-	/* Do per-CPU setup */
-	schedule_on_each_cpu(setup_online_cpu);
-
 	register_syscore_ops(&mc_syscore_ops);
-	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
-				  mc_cpu_online, mc_cpu_down_prep);
+	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
+			  mc_cpu_online, mc_cpu_down_prep);
 
 	pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);