From patchwork Wed Feb 3 16:56:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Alrae X-Patchwork-Id: 578238 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 A107214032F for ; Thu, 4 Feb 2016 04:04:17 +1100 (AEDT) Received: from localhost ([::1]:36409 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aR0ql-0006so-Oa for incoming@patchwork.ozlabs.org; Wed, 03 Feb 2016 12:04:15 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aR0kF-0003IK-1U for qemu-devel@nongnu.org; Wed, 03 Feb 2016 11:57:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aR0kE-0005wq-4A for qemu-devel@nongnu.org; Wed, 03 Feb 2016 11:57:30 -0500 Received: from mailapp01.imgtec.com ([195.59.15.196]:26115) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aR0kD-0005wj-US for qemu-devel@nongnu.org; Wed, 03 Feb 2016 11:57:30 -0500 Received: from hhmail02.hh.imgtec.org (unknown [10.100.10.20]) by Websense Email Security Gateway with ESMTPS id 496ECC8D905E8; Wed, 3 Feb 2016 16:57:26 +0000 (GMT) Received: from lalrae-linux.kl.imgtec.org (192.168.169.37) by hhmail02.hh.imgtec.org (10.100.10.20) with Microsoft SMTP Server (TLS) id 14.3.266.1; Wed, 3 Feb 2016 16:57:28 +0000 From: Leon Alrae To: Date: Wed, 3 Feb 2016 16:56:48 +0000 Message-ID: <1454518611-26134-7-git-send-email-leon.alrae@imgtec.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1454518611-26134-1-git-send-email-leon.alrae@imgtec.com> References: <1454518611-26134-1-git-send-email-leon.alrae@imgtec.com> MIME-Version: 1.0 X-Originating-IP: [192.168.169.37] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 195.59.15.196 Cc: aurelien@aurel32.net Subject: [Qemu-devel] [PATCH 6/9] hw/mips: implement ITC Storage - Bypass View 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 Bypass View does not cause issuing thread to block and does not affect any of the cells state bit. Read from a FIFO cell returns the value of the oldest entry. Store to a FIFO cell changes the value of the newest entry. Signed-off-by: Leon Alrae --- hw/misc/mips_itu.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/hw/misc/mips_itu.c b/hw/misc/mips_itu.c index dd10b11..55241af 100644 --- a/hw/misc/mips_itu.c +++ b/hw/misc/mips_itu.c @@ -174,6 +174,27 @@ static void QEMU_NORETURN block_thread_and_exit(ITCStorageCell *c) cpu_loop_exit(current_cpu); } +/* ITC Bypass View */ + +static inline uint64_t view_bypass_read(ITCStorageCell *c) +{ + if (c->tag.FIFO) { + return c->data[c->fifo_out]; + } else { + return c->data[0]; + } +} + +static inline void view_bypass_write(ITCStorageCell *c, uint64_t val) +{ + if (c->tag.FIFO && (c->tag.FIFOPtr > 0)) { + int idx = (c->fifo_out + c->tag.FIFOPtr - 1) % ITC_CELL_DEPTH; + c->data[idx] = val; + } + + /* ignore a write to the semaphore cell */ +} + /* ITC Control View */ static inline uint64_t view_control_read(ITCStorageCell *c) @@ -340,6 +361,9 @@ static uint64_t itc_storage_read(void *opaque, hwaddr addr, unsigned size) uint64_t ret = -1; switch (view) { + case ITCVIEW_BYPASS: + ret = view_bypass_read(cell); + break; case ITCVIEW_CONTROL: ret = view_control_read(cell); break; @@ -372,6 +396,9 @@ static void itc_storage_write(void *opaque, hwaddr addr, uint64_t data, ITCView view = get_itc_view(addr); switch (view) { + case ITCVIEW_BYPASS: + view_bypass_write(cell, data); + break; case ITCVIEW_CONTROL: view_control_write(cell, data); break;