From: Frederic Weisbecker <frederic@kernel.org>
Date: Wed, 16 Jul 2025 14:18:24 +0000 (+0200)
Subject: PCI: Remove superfluous HK_TYPE_WQ check
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f803980988884213de1f1bea0c9dde380d3db84;p=thirdparty%2Flinux.git

PCI: Remove superfluous HK_TYPE_WQ check

It doesn't make sense to use nohz_full without also isolating the
related CPUs from the domain topology, either through the use of
isolcpus= or cpuset isolated partitions.

And now HK_TYPE_DOMAIN includes all kinds of domain isolated CPUs.

This means that HK_TYPE_DOMAIN should always be a subset of
HK_TYPE_KERNEL_NOISE (of which HK_TYPE_WQ is only an alias).

Therefore sane configurations verify:

	HK_TYPE_KERNEL_NOISE & HK_TYPE_DOMAIN == HK_TYPE_DOMAIN

Simplify the PCI probe target election accordingly.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: linux-pci@vger.kernel.org
---

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index b902d8adf9a58..a9590601835a0 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -384,16 +384,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
 	    pci_physfn_is_probed(dev)) {
 		error = local_pci_probe(&ddi);
 	} else {
-		cpumask_var_t wq_domain_mask;
 		struct pci_probe_arg arg = { .ddi = &ddi };
 
-		if (!zalloc_cpumask_var(&wq_domain_mask, GFP_KERNEL)) {
-			error = -ENOMEM;
-			goto out;
-		}
-
 		INIT_WORK_ONSTACK(&arg.work, local_pci_probe_callback);
-
 		/*
 		 * The target election and the enqueue of the work must be within
 		 * the same RCU read side section so that when the workqueue pool
@@ -402,12 +395,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
 		 * targets.
 		 */
 		rcu_read_lock();
-		cpumask_and(wq_domain_mask,
-			    housekeeping_cpumask(HK_TYPE_WQ),
-			    housekeeping_cpumask(HK_TYPE_DOMAIN));
-
 		cpu = cpumask_any_and(cpumask_of_node(node),
-				      wq_domain_mask);
+				      housekeeping_cpumask(HK_TYPE_DOMAIN));
+
 		if (cpu < nr_cpu_ids) {
 			struct workqueue_struct *wq = pci_probe_wq;
 
@@ -422,10 +412,9 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
 			error = local_pci_probe(&ddi);
 		}
 
-		free_cpumask_var(wq_domain_mask);
 		destroy_work_on_stack(&arg.work);
 	}
-out:
+
 	dev->is_probed = 0;
 	cpu_hotplug_enable();
 	return error;