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: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Niklas Schnelle 2020-03-17 12:59:37 +01:00 committed by Vasily Gorbik
parent 9289224040
commit 969ae01bab
2 changed files with 19 additions and 16 deletions

View file

@ -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

View file

@ -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);
}