Commit 969ae01b authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Vasily Gorbik
Browse files

s390/pci: Fix zpci_alloc_domain() over allocation 



Until now zpci_alloc_domain() only prevented more than
CONFIG_PCI_NR_FUNCTIONS from being added when using automatic domain
allocation. When explicit UIDs were defined UIDs above
CONFIG_PCI_NR_FUNCTIONS were not counted at all.
When more PCI functions are added this could lead to various errors
including under sized IRQ vectors and similar issues.

Fix this by explicitly tracking the number of allocated domains.

Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: default avatarPierre Morel <pmorel@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 92892240

arch/s390/include/asm/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ int pci_proc_domain(struct pci_bus *); 


#define ZPCI_NR_DMA_SPACES		1

#define ZPCI_NR_DEVICES			CONFIG_PCI_NR_FUNCTIONS

#define ZPCI_DOMAIN_BITMAP_SIZE		(1 << 16)



/* PCI Function Controls */

#define ZPCI_FC_FN_ENABLED		0x80

arch/s390/pci/pci.c

+18 −16
Original line number Diff line number Diff line
@@ -40,8 +40,9 @@ 
static LIST_HEAD(zpci_list);

static DEFINE_SPINLOCK(zpci_list_lock);



static DECLARE_BITMAP(zpci_domain, ZPCI_NR_DEVICES);

static DECLARE_BITMAP(zpci_domain, ZPCI_DOMAIN_BITMAP_SIZE);

static DEFINE_SPINLOCK(zpci_domain_lock);

static unsigned int zpci_num_domains_allocated;



#define ZPCI_IOMAP_ENTRIES						\

	min(((unsigned long) ZPCI_NR_DEVICES * PCI_STD_NUM_BARS / 2),	\
@@ -609,12 +610,16 @@ void pcibios_disable_device(struct pci_dev *pdev) 


static int zpci_alloc_domain(struct zpci_dev *zdev)

{

	spin_lock(&zpci_domain_lock);

	if (zpci_num_domains_allocated > (ZPCI_NR_DEVICES - 1)) {

		spin_unlock(&zpci_domain_lock);

		pr_err("Adding PCI function %08x failed because the configured limit of %d is reached\n",

			zdev->fid, ZPCI_NR_DEVICES);

		return -ENOSPC;

	}



	if (zpci_unique_uid) {

		zdev->domain = (u16) zdev->uid;

		if (zdev->domain >= ZPCI_NR_DEVICES)

			return 0;



		spin_lock(&zpci_domain_lock);

		if (test_bit(zdev->domain, zpci_domain)) {

			spin_unlock(&zpci_domain_lock);

			pr_err("Adding PCI function %08x failed because domain %04x is already assigned\n",
@@ -622,30 +627,27 @@ static int zpci_alloc_domain(struct zpci_dev *zdev) 
			return -EEXIST;

		}

		set_bit(zdev->domain, zpci_domain);

		zpci_num_domains_allocated++;

		spin_unlock(&zpci_domain_lock);

		return 0;

	}



	spin_lock(&zpci_domain_lock);

	/*

	 * We can always auto allocate domains below ZPCI_NR_DEVICES.

	 * There is either a free domain or we have reached the maximum in

	 * which case we would have bailed earlier.

	 */

	zdev->domain = find_first_zero_bit(zpci_domain, ZPCI_NR_DEVICES);

	if (zdev->domain == ZPCI_NR_DEVICES) {

		spin_unlock(&zpci_domain_lock);

		pr_err("Adding PCI function %08x failed because the configured limit of %d is reached\n",

			zdev->fid, ZPCI_NR_DEVICES);

		return -ENOSPC;

	}

	set_bit(zdev->domain, zpci_domain);

	zpci_num_domains_allocated++;

	spin_unlock(&zpci_domain_lock);

	return 0;

}



static void zpci_free_domain(struct zpci_dev *zdev)

{

	if (zdev->domain >= ZPCI_NR_DEVICES)

		return;



	spin_lock(&zpci_domain_lock);

	clear_bit(zdev->domain, zpci_domain);

	zpci_num_domains_allocated--;

	spin_unlock(&zpci_domain_lock);

}

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