From patchwork Thu Jan 28 03:02:37 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Gabriel L. Somlo" X-Patchwork-Id: 574514 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id D3444140273 for ; Thu, 28 Jan 2016 14:04:21 +1100 (AEDT) Received: from localhost ([::1]:53637 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aOcsd-0006WI-S9 for incoming@patchwork.ozlabs.org; Wed, 27 Jan 2016 22:04:19 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53832) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aOcrb-0003wi-DK for qemu-devel@nongnu.org; Wed, 27 Jan 2016 22:03:16 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aOcrY-00062e-7l for qemu-devel@nongnu.org; Wed, 27 Jan 2016 22:03:15 -0500 Received: from relay-04.andrew.cmu.edu ([128.2.105.169]:51445 helo=relay.andrew.cmu.edu) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aOcrY-00062Z-2y for qemu-devel@nongnu.org; Wed, 27 Jan 2016 22:03:12 -0500 Received: from HEDWIG.ini.cmu.edu (HEDWIG.INI.CMU.EDU [128.2.16.51]) by relay.andrew.cmu.edu (8.14.8/8.14.8) with ESMTP id u0S32fAX025905; Wed, 27 Jan 2016 22:02:42 -0500 From: "Gabriel L. Somlo" To: gregkh@linuxfoundation.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, arnd@arndb.de, lersek@redhat.com, ralf@linux-mips.org, rmk+kernel@arm.linux.org.uk, eric@anholt.net, hanjun.guo@linaro.org, zajec5@gmail.com, sudeep.holla@arm.com, agross@codeaurora.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Date: Wed, 27 Jan 2016 22:02:37 -0500 Message-Id: <1453950161-13252-2-git-send-email-somlo@cmu.edu> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1453950161-13252-1-git-send-email-somlo@cmu.edu> References: <1453950161-13252-1-git-send-email-somlo@cmu.edu> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.74 on 128.2.105.169 X-MIME-Autoconverted: from 8bit to quoted-printable by relay.andrew.cmu.edu id u0S32fAX025905 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x X-Received-From: 128.2.105.169 Cc: peter.maydell@linaro.org, ehabkost@redhat.com, ard.biesheuvel@linaro.org, matt@codeblueprint.co.uk, stefanha@gmail.com, mst@redhat.com, qemu-devel@nongnu.org, leif.lindholm@linaro.org, luto@amacapital.net, kraxel@redhat.com, pbonzini@redhat.com, imammedo@redhat.com, revol@free.fr, rth@twiddle.net Subject: [Qemu-devel] [PATCH v6 1/5] fw_cfg: expose control register size in fw_cfg.h X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Expose the size of the control register (FW_CFG_CTL_SIZE) in fw_cfg.h. Add comment to fw_cfg_io_realize() pointing out that since the 8-bit data register is always subsumed by the 16-bit control register in the port I/O case, we use the control register width as the *total* width of the (classic, non-DMA) port I/O region reserved for the device. Cc: Marc Marí Signed-off-by: Gabriel Somlo Reviewed-by: Laszlo Ersek Reviewed-by: Marc Marí --- hw/nvram/fw_cfg.c | 4 +++- include/hw/nvram/fw_cfg.h | 3 +++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index a1d650d..06a4ff0 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -31,7 +31,6 @@ #include "qemu/error-report.h" #include "qemu/config-file.h" -#define FW_CFG_CTL_SIZE 2 #define FW_CFG_NAME "fw_cfg" #define FW_CFG_PATH "/machine/" FW_CFG_NAME @@ -881,6 +880,9 @@ static void fw_cfg_io_realize(DeviceState *dev, Error **errp) FWCfgIoState *s = FW_CFG_IO(dev); SysBusDevice *sbd = SYS_BUS_DEVICE(dev); + /* when using port i/o, the 8-bit data register ALWAYS overlaps + * with half of the 16-bit control register. Hence, the total size + * of the i/o region used is FW_CFG_CTL_SIZE */ memory_region_init_io(&s->comb_iomem, OBJECT(s), &fw_cfg_comb_mem_ops, FW_CFG(s), "fwcfg", FW_CFG_CTL_SIZE); sysbus_add_io(sbd, s->iobase, &s->comb_iomem); diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index 664eaf6..2667ca9 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -46,6 +46,9 @@ #define FW_CFG_INVALID 0xffff +/* width in bytes of fw_cfg control register */ +#define FW_CFG_CTL_SIZE 0x02 + #define FW_CFG_MAX_FILE_PATH 56 #ifndef NO_QEMU_PROTOS