From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58449) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceDKj-0007Iu-AA for qemu-devel@nongnu.org; Wed, 15 Feb 2017 23:06:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ceDKg-0005yg-5U for qemu-devel@nongnu.org; Wed, 15 Feb 2017 23:06:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38364) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ceDKf-0005xk-VJ for qemu-devel@nongnu.org; Wed, 15 Feb 2017 23:06:14 -0500 From: Peter Xu Date: Thu, 16 Feb 2017 12:06:01 +0800 Message-Id: <1487217961-885-1-git-send-email-peterx@redhat.com> Subject: [Qemu-devel] [PATCH v2] pcie: simplify pcie_add_capability() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Marcel Apfelbaum , Alex Williamson , caoj.fnst@cn.fujitsu.com, "\\ Michael S . Tsirkin \\ " , peterx@redhat.com When we add PCIe extended capabilities, we should be following the rule that we add the head extended cap (at offset 0x100) first, then the rest of them. Meanwhile, we are always adding new capability bits at the end of the list. Here the "next" looks meaningless in all cases since it should always be zero (along with the "header"). Simplify the function a bit, and it looks more readable now. Signed-off-by: Peter Xu --- v2: - rebased to mst's patch "pci/pcie: don't assume cap id 0 is reserved" - avoid having side-effect code in assertion. [Marcel] (I removed it directly since after mst's fix it would never return nonzero now) --- hw/pci/pcie.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c index f4dd177..fc54bfd 100644 --- a/hw/pci/pcie.c +++ b/hw/pci/pcie.c @@ -665,32 +665,24 @@ void pcie_add_capability(PCIDevice *dev, uint16_t cap_id, uint8_t cap_ver, uint16_t offset, uint16_t size) { - uint32_t header; - uint16_t next; - assert(offset >= PCI_CONFIG_SPACE_SIZE); assert(offset < offset + size); assert(offset + size <= PCIE_CONFIG_SPACE_SIZE); assert(size >= 8); assert(pci_is_express(dev)); - if (offset == PCI_CONFIG_SPACE_SIZE) { - header = pci_get_long(dev->config + offset); - next = PCI_EXT_CAP_NEXT(header); - } else { + if (offset != PCI_CONFIG_SPACE_SIZE) { uint16_t prev; /* * 0xffffffff is not a valid cap id (it's a 16 bit field). use * internally to find the last capability in the linked list. */ - next = pcie_find_capability_list(dev, 0xffffffff, &prev); - + pcie_find_capability_list(dev, 0xffffffff, &prev); assert(prev >= PCI_CONFIG_SPACE_SIZE); - assert(next == 0); pcie_ext_cap_set_next(dev, prev, offset); } - pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, next)); + pci_set_long(dev->config + offset, PCI_EXT_CAP(cap_id, cap_ver, 0)); /* Make capability read-only by default */ memset(dev->wmask + offset, 0, size); -- 2.7.4