From owner-svn-src-all@freebsd.org Tue Mar 19 15:03:21 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9F7BF1553271; Tue, 19 Mar 2019 15:03:21 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3DCD088CAB; Tue, 19 Mar 2019 15:03:21 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 0DE81AE38; Tue, 19 Mar 2019 15:03:21 +0000 (UTC) (envelope-from imp@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x2JF3KhI077036; Tue, 19 Mar 2019 15:03:20 GMT (envelope-from imp@FreeBSD.org) Received: (from imp@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x2JF3KZL077035; Tue, 19 Mar 2019 15:03:20 GMT (envelope-from imp@FreeBSD.org) Message-Id: <201903191503.x2JF3KZL077035@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: imp set sender to imp@FreeBSD.org using -f From: Warner Losh Date: Tue, 19 Mar 2019 15:03:20 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r345298 - head/sys/dev/pci X-SVN-Group: head X-SVN-Commit-Author: imp X-SVN-Commit-Paths: head/sys/dev/pci X-SVN-Commit-Revision: 345298 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 3DCD088CAB X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.94 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.998,0]; NEURAL_HAM_SHORT(-0.94)[-0.942,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Mar 2019 15:03:21 -0000 Author: imp Date: Tue Mar 19 15:03:20 2019 New Revision: 345298 URL: https://svnweb.freebsd.org/changeset/base/345298 Log: Add comment about why we bother to use endian macros here, and why we must use bitfields. Modified: head/sys/dev/pci/pcivar.h Modified: head/sys/dev/pci/pcivar.h ============================================================================== --- head/sys/dev/pci/pcivar.h Tue Mar 19 14:34:53 2019 (r345297) +++ head/sys/dev/pci/pcivar.h Tue Mar 19 15:03:20 2019 (r345298) @@ -259,6 +259,14 @@ typedef struct { extern uint32_t pci_numdevs; +/* + * The bitfield has to be stable an match the fields below (so that + * match_flag_vendor must be bit 0) so we have to do the endian + * dance. We can't use enums or #define constants because then the + * the macros for subsetting matches wouldn't work. These tables + * are parsed by devmatch and others to connect modules with + * devices on the PCI bus. + */ struct pci_device_table { #if BYTE_ORDER == LITTLE_ENDIAN uint16_t