From 96d593f1f58e8e178357e9856232cd19cacf98b7 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Mon, 4 May 2020 14:21:40 +0200 Subject: [PATCH] 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 --- arch/s390/include/asm/pci.h | 1 + arch/s390/pci/pci.c | 34 ++++++++++++++++++++-------------- 2 files changed, 21 insertions(+), 14 deletions(-) diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index 6087a4e9b2bf..7850e8c8c79a 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -28,6 +28,7 @@ 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 diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index 6105b1b6e49b..0af46683dd66 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -39,8 +39,9 @@ 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_BAR_COUNT / 2), \ @@ -651,39 +652,44 @@ struct dev_pm_ops pcibios_pm_ops = { 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", + zdev->fid, zdev->domain); 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); - 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); } -- 2.17.1