From d1f99b7bedf3c7edf7d3c68b88faad09f8fd6e84 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 8 Jan 2013 10:16:55 +0100 Subject: [PATCH] passthrough/PCI: replace improper uses of pci_find_next_cap() Using pci_find_next_cap() without prior pci_find_cap_offset() is bogus (and possibly wrong, given that the latter doesn't check the PCI_STATUS_CAP_LIST flag, which so far was checked in an open-coded way only for the non-bridge case). Once at it, fold the two calls into one, as we need its result in any case. Question is whether, without any caller left, pci_find_next_cap() should be purged as well. Signed-off-by: Jan Beulich Acked-by: Xiantao Zhang xen-unstable changeset: 26179:ae6fb202b233 xen-unstable date: Tue Nov 20 07:58:31 UTC 2012 --- xen/drivers/passthrough/pci.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c index 111ac96087..32595e911d 100644 --- a/xen/drivers/passthrough/pci.c +++ b/xen/drivers/passthrough/pci.c @@ -345,16 +345,13 @@ void pci_release_devices(struct domain *d) int pdev_type(u8 bus, u8 devfn) { - u16 class_device; - u16 status, creg; - int pos; + u16 class_device, creg; u8 d = PCI_SLOT(devfn), f = PCI_FUNC(devfn); + int pos = pci_find_cap_offset(bus, d, f, PCI_CAP_ID_EXP); class_device = pci_conf_read16(bus, d, f, PCI_CLASS_DEVICE); if ( class_device == PCI_CLASS_BRIDGE_PCI ) { - pos = pci_find_next_cap(bus, devfn, - PCI_CAPABILITY_LIST, PCI_CAP_ID_EXP); if ( !pos ) return DEV_TYPE_LEGACY_PCI_BRIDGE; creg = pci_conf_read16(bus, d, f, pos + PCI_EXP_FLAGS); @@ -362,14 +359,7 @@ int pdev_type(u8 bus, u8 devfn) DEV_TYPE_PCIe2PCI_BRIDGE : DEV_TYPE_PCIe_BRIDGE; } - status = pci_conf_read16(bus, d, f, PCI_STATUS); - if ( !(status & PCI_STATUS_CAP_LIST) ) - return DEV_TYPE_PCI; - - if ( pci_find_next_cap(bus, devfn, PCI_CAPABILITY_LIST, PCI_CAP_ID_EXP) ) - return DEV_TYPE_PCIe_ENDPOINT; - - return DEV_TYPE_PCI; + return pos ? DEV_TYPE_PCIe_ENDPOINT : DEV_TYPE_PCI; } /*