From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 3xhJXH2rSPzDqXl for ; Tue, 29 Aug 2017 16:25:03 +1000 (AEST) Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 3xhJXH19Jkz8vmR for ; Tue, 29 Aug 2017 16:25:03 +1000 (AEST) 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 3xhJXG2KkSz9sP5 for ; Tue, 29 Aug 2017 16:25:02 +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 v7T6OwE3009519 for ; Tue, 29 Aug 2017 02:25:00 -0400 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0a-001b2d01.pphosted.com with ESMTP id 2cmurp0mea-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 29 Aug 2017 02:24:59 -0400 Received: from localhost by e12.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 29 Aug 2017 02:24:07 -0400 From: Sukadev Bhattiprolu To: Michael Ellerman Cc: Benjamin Herrenschmidt , mikey@neuling.org, stewart@linux.vnet.ibm.com, apopple@au1.ibm.com, hbabu@us.ibm.com, oohall@gmail.com, linuxppc-dev@ozlabs.org, Subject: [PATCH v8 08/10] powerpc/vas: Define vas_win_close() interface Date: Mon, 28 Aug 2017 23:23:38 -0700 In-Reply-To: <1503987820-31933-1-git-send-email-sukadev@linux.vnet.ibm.com> References: <1503987820-31933-1-git-send-email-sukadev@linux.vnet.ibm.com> Message-Id: <1503987820-31933-9-git-send-email-sukadev@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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[v8] - [Michael Ellerman] Set task_state() and pass correct values to schedule_timeout(). 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. Conflicts: arch/powerpc/platforms/powernv/vas-window.c --- arch/powerpc/include/asm/vas.h | 7 ++ arch/powerpc/platforms/powernv/vas-window.c | 101 ++++++++++++++++++++++++++-- 2 files changed, 103 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/vas.h b/arch/powerpc/include/asm/vas.h index 5ce800a..e124856 100644 --- a/arch/powerpc/include/asm/vas.h +++ b/arch/powerpc/include/asm/vas.h @@ -96,4 +96,11 @@ 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 783c8c6..39aa0e4 100644 --- a/arch/powerpc/platforms/powernv/vas-window.c +++ b/arch/powerpc/platforms/powernv/vas-window.c @@ -130,7 +130,7 @@ static void unmap_region(void *addr, u64 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; u64 busaddr_start; @@ -522,7 +522,7 @@ static 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; @@ -560,6 +560,14 @@ static struct vas_window *vas_window_alloc(struct vas_instance *vinst) return ERR_PTR(-ENOMEM); } +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); +} + /* * Get the VAS receive window associated with NX engine identified * by @cop and if applicable, @pswid. @@ -627,7 +635,7 @@ 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; @@ -839,8 +847,91 @@ 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; + u64 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; + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ); + goto retry; + } +} + +static void poll_window_castout(struct vas_window *window) +{ + int cached; + u64 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); + + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(HZ); + 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; + u64 val; + + if (!window) + return 0; + + if (!window->tx_win && atomic_read(&window->num_txwins) != 0) { + pr_devel("Attempting to close an active Rx window!\n"); + WARN_ON_ONCE(1); + return -EBUSY; + } + + 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); -- 2.7.4