From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50642) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIEDx-0000DE-F4 for qemu-devel@nongnu.org; Mon, 02 Feb 2015 05:27:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YIEDt-0006bH-GI for qemu-devel@nongnu.org; Mon, 02 Feb 2015 05:27:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47271) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YIEDt-0006bC-8h for qemu-devel@nongnu.org; Mon, 02 Feb 2015 05:27:17 -0500 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t12ARFix029358 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 2 Feb 2015 05:27:16 -0500 Message-ID: <54CF50FE.5090906@redhat.com> Date: Mon, 02 Feb 2015 11:27:10 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1422643333-27926-1-git-send-email-jsnow@redhat.com> <1422643333-27926-5-git-send-email-jsnow@redhat.com> In-Reply-To: <1422643333-27926-5-git-send-email-jsnow@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 04/19] libqos/ahci: Add command header helpers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow , qemu-devel@nongnu.org Cc: famz@redhat.com, armbru@redhat.com, stefanha@redhat.com, mst@redhat.com On 30/01/2015 19:41, John Snow wrote: > +/* Set the #cx'th command of port #px. */ > +void ahci_set_command_header(AHCIQState *ahci, uint8_t px, > + uint8_t cx, AHCICommandHeader *cmd) > +{ > + uint64_t ba = ahci->port[px].clb; > + ba += cx * sizeof(AHCICommandHeader); > + > + cmd->flags = cpu_to_le16(cmd->flags); > + cmd->prdtl = cpu_to_le16(cmd->prdtl); > + cmd->prdbc = cpu_to_le32(cmd->prdbc); > + cmd->ctba = cpu_to_le64(cmd->ctba); Modifying cmd is uglyish, and especially it might hide bugs that only happen on big endian system. Please copy to a local AHCICommandHeader variable before adjusting for host endianness. Paolo > + memwrite(ba, cmd, sizeof(AHCICommandHeader)); > +}