From patchwork Wed Mar 30 08:49:57 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Leon Alrae X-Patchwork-Id: 603265 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qZhNG0X10z9s6r for ; Wed, 30 Mar 2016 19:57:02 +1100 (AEDT) Received: from localhost ([::1]:52587 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alBvw-0006BZ-6o for incoming@patchwork.ozlabs.org; Wed, 30 Mar 2016 04:57:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34213) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alBpq-0002pd-Mw for qemu-devel@nongnu.org; Wed, 30 Mar 2016 04:50:46 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1alBpp-0001rV-GC for qemu-devel@nongnu.org; Wed, 30 Mar 2016 04:50:42 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:32322) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alBpp-0001r2-Au for qemu-devel@nongnu.org; Wed, 30 Mar 2016 04:50:41 -0400 Received: from hhmail02.hh.imgtec.org (unknown [10.100.10.20]) by Websense Email Security Gateway with ESMTPS id 122FE34244D44 for ; Wed, 30 Mar 2016 09:50:38 +0100 (IST) 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, 30 Mar 2016 09:50:40 +0100 From: Leon Alrae To: Date: Wed, 30 Mar 2016 09:49:57 +0100 Message-ID: <1459327802-5102-17-git-send-email-leon.alrae@imgtec.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1459327802-5102-1-git-send-email-leon.alrae@imgtec.com> References: <1459327802-5102-1-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 Subject: [Qemu-devel] [PULL v2 16/21] 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 595d2d2..8461d23 100644 --- a/hw/misc/mips_itu.c +++ b/hw/misc/mips_itu.c @@ -182,6 +182,27 @@ 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) @@ -348,6 +369,9 @@ 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; @@ -380,6 +404,9 @@ 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;