From patchwork Tue Aug 8 23:06:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sukadev Bhattiprolu X-Patchwork-Id: 799491 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xRr9W4p1Lz9s2G for ; Wed, 9 Aug 2017 09:25:35 +1000 (AEST) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3xRr9W3gSFzDr4d for ; Wed, 9 Aug 2017 09:25:35 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from ozlabs.org (bilbo.ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xRqmr1xw7zDqs4 for ; Wed, 9 Aug 2017 09:07:40 +1000 (AEST) Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 3xRqmq62Pvz8vqD for ; Wed, 9 Aug 2017 09:07:39 +1000 (AEST) Received: by ozlabs.org (Postfix) id 3xRqmq3dL7z9t2Q; Wed, 9 Aug 2017 09:07:39 +1000 (AEST) Delivered-To: linuxppc-dev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=linux.vnet.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=sukadev@linux.vnet.ibm.com; receiver=) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xRqmp6X4Sz9s7F for ; Wed, 9 Aug 2017 09:07:38 +1000 (AEST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v78N4DLN032808 for ; Tue, 8 Aug 2017 19:07:37 -0400 Received: from e13.ny.us.ibm.com (e13.ny.us.ibm.com [129.33.205.203]) by mx0a-001b2d01.pphosted.com with ESMTP id 2c7ng7ty94-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 08 Aug 2017 19:07:36 -0400 Received: from localhost by e13.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 8 Aug 2017 19:07:31 -0400 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v78N7VM524182922; Tue, 8 Aug 2017 23:07:31 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1ADE9B204E; Tue, 8 Aug 2017 19:04:58 -0400 (EDT) Received: from suka-w540.usor.ibm.com (unknown [9.70.94.25]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP id 3E3B0B2050; Tue, 8 Aug 2017 19:04:57 -0400 (EDT) From: Sukadev Bhattiprolu To: Michael Ellerman Subject: [PATCH v6 11/17] powerpc/vas: Define vas_win_close() interface Date: Tue, 8 Aug 2017 16:06:56 -0700 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1502233622-9330-1-git-send-email-sukadev@linux.vnet.ibm.com> References: <1502233622-9330-1-git-send-email-sukadev@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17080823-0008-0000-0000-0000026B8AAD X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007509; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000217; SDB=6.00899536; UDB=6.00450257; IPR=6.00679741; BA=6.00005519; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016602; XFM=3.00000015; UTC=2017-08-08 23:07:34 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17080823-0009-0000-0000-0000364F4005 Message-Id: <1502233622-9330-12-git-send-email-sukadev@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-08_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1708080380 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stewart@linux.vnet.ibm.com, mikey@neuling.org, linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, apopple@au1.ibm.com, oohall@gmail.com Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Define the vas_win_close() interface which should be used to close a send or receive windows. While the hardware configurations required to open send and receive windows differ, the configuration to close a window is the same for both. So we use a single interface to close the window. Signed-off-by: Sukadev Bhattiprolu --- Changelog[v4]: - Drop the poll for credits return (we can set the required credit, but cannot really find the available credit at a point in time) - Export the symbol Changelog[v3]: - Fix order of parameters in GET_FIELD(). - Update references and sequence for closing/quiescing a window. --- arch/powerpc/include/asm/vas.h | 7 ++ arch/powerpc/platforms/powernv/vas-window.c | 99 +++++++++++++++++++++++++++-- 2 files changed, 101 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h index a3778d7..e1c5376 100644 --- a/arch/powerpc/include/asm/vas.h +++ b/arch/powerpc/include/asm/vas.h @@ -91,4 +91,11 @@ extern void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, extern struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, struct vas_rx_win_attr *attr); +/* + * Close the send or receive window identified by @win. For receive windows + * return -EAGAIN if there are active send windows attached to this receive + * window. + */ +int vas_win_close(struct vas_window *win); + #endif /* _MISC_VAS_H */ diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c index dfa7e67..9704a3b 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -139,7 +139,7 @@ static void unmap_region(void *addr, uint64_t start, int len) /* * Unmap the paste address region for a window. */ -void unmap_paste_region(struct vas_window *window) +static void unmap_paste_region(struct vas_window *window) { int len; uint64_t busaddr_start; @@ -535,7 +535,7 @@ int vas_assign_window_id(struct ida *ida) return winid; } -void vas_window_free(struct vas_window *window) +static void vas_window_free(struct vas_window *window) { int winid = window->winid; struct vas_instance *vinst = window->vinst; @@ -609,6 +609,14 @@ static bool valid_permissions(struct vas_window *rxwin) return rc; } +static void put_rx_win(struct vas_window *rxwin) +{ + /* Better not be a send window! */ + WARN_ON_ONCE(rxwin->tx_win); + + atomic_dec(&rxwin->num_txwins); +} + /* * Find the user space receive window given the @pswid. * @@ -710,7 +718,7 @@ static void set_vinst_win(struct vas_instance *vinst, * Clear this window from the table(s) of windows for this VAS instance. * See also function header of set_vinst_win(). */ -void clear_vinst_win(struct vas_window *window) +static void clear_vinst_win(struct vas_window *window) { int id = window->winid; struct vas_instance *vinst = window->vinst; @@ -925,11 +933,92 @@ struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop, } EXPORT_SYMBOL_GPL(vas_rx_win_open); -/* stub for now */ +static void poll_window_busy_state(struct vas_window *window) +{ + int busy; + uint64_t val; + +retry: + /* + * Poll Window Busy flag + */ + val = read_hvwc_reg(window, VREG(WIN_STATUS)); + busy = GET_FIELD(VAS_WIN_BUSY, val); + if (busy) { + val = 0; + schedule_timeout(2000); + goto retry; + } +} + +static void poll_window_castout(struct vas_window *window) +{ + int cached; + uint64_t val; + + /* Cast window context out of the cache */ +retry: + val = read_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL)); + cached = GET_FIELD(VAS_WIN_CACHE_STATUS, val); + if (cached) { + val = 0ULL; + val = SET_FIELD(VAS_CASTOUT_REQ, val, 1); + val = SET_FIELD(VAS_PUSH_TO_MEM, val, 0); + write_hvwc_reg(window, VREG(WIN_CTX_CACHING_CTL), val); + + schedule_timeout(2000); + goto retry; + } +} + +/* + * Close a window. + * + * See Section 1.12.1 of VAS workbook v1.05 for details on closing window: + * - Disable new paste operations (unmap paste address) + * - Poll for the "Window Busy" bit to be cleared + * - Clear the Open/Enable bit for the Window. + * - Poll for return of window Credits (implies FIFO empty for Rx win?) + * - Unpin and cast window context out of cache + * + * Besides the hardware, kernel has some bookkeeping of course. + */ int vas_win_close(struct vas_window *window) { - return -1; + uint64_t val; + + if (!window) + return 0; + + if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { + pr_devel("VAS: Attempting to close an active Rx window!\n"); + WARN_ON_ONCE(1); + return -EAGAIN; + } + + unmap_paste_region(window); + + clear_vinst_win(window); + + poll_window_busy_state(window); + + /* Unpin window from cache and close it */ + val = read_hvwc_reg(window, VREG(WINCTL)); + val = SET_FIELD(VAS_WINCTL_PIN, val, 0); + val = SET_FIELD(VAS_WINCTL_OPEN, val, 0); + write_hvwc_reg(window, VREG(WINCTL), val); + + poll_window_castout(window); + + /* if send window, drop reference to matching receive window */ + if (window->tx_win) + put_rx_win(window->rxwin); + + vas_window_free(window); + + return 0; } +EXPORT_SYMBOL_GPL(vas_win_close); /* * Return a system-wide unique window id for the window @win.