Commit 842a56cf authored by Joel Fernandes (Google)'s avatar Joel Fernandes (Google) Committed by Paul E. McKenney
Browse files

x86/pci: Pass lockdep condition to pcm_mmcfg_list iterator 



The pcm_mmcfg_list is traversed by list_for_each_entry_rcu() outside
of an RCU read-side critical section, which is safe because the
pci_mmcfg_lock is held.  This commit therefore adds a lockdep expression
to list_for_each_entry_rcu() in order t avoid lockdep warnings.

Acked-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
parent c2fa1e1b

arch/x86/pci/mmconfig-shared.c

+3 −2
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
static bool pci_mmcfg_running_state;

static bool pci_mmcfg_arch_init_failed;

static DEFINE_MUTEX(pci_mmcfg_lock);

#define pci_mmcfg_lock_held() lock_is_held(&(pci_mmcfg_lock).dep_map)



LIST_HEAD(pci_mmcfg_list);
@@ -54,7 +55,7 @@ static void list_add_sorted(struct pci_mmcfg_region *new) 
	struct pci_mmcfg_region *cfg;



	/* keep list sorted by segment and starting bus number */

	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list) {

	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list, pci_mmcfg_lock_held()) {

		if (cfg->segment > new->segment ||

		    (cfg->segment == new->segment &&

		     cfg->start_bus >= new->start_bus)) {
@@ -118,7 +119,7 @@ struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus) 
{

	struct pci_mmcfg_region *cfg;



	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list)

	list_for_each_entry_rcu(cfg, &pci_mmcfg_list, list, pci_mmcfg_lock_held())

		if (cfg->segment == segment &&

		    cfg->start_bus <= bus && bus <= cfg->end_bus)

			return cfg;