From patchwork Fri Dec 14 01:25:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 10730233 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E3DC991E for ; Fri, 14 Dec 2018 01:26:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CF2E02C975 for ; Fri, 14 Dec 2018 01:26:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C36A42CD40; Fri, 14 Dec 2018 01:26:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6EC272C975 for ; Fri, 14 Dec 2018 01:26:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9E9C76F291; Fri, 14 Dec 2018 01:26:47 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by gabe.freedesktop.org (Postfix) with ESMTPS id 73B516F24B; Fri, 14 Dec 2018 01:26:43 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E867330841DE; Fri, 14 Dec 2018 01:26:42 +0000 (UTC) Received: from malachite.bss.redhat.com (dhcp-10-20-1-11.bss.redhat.com [10.20.1.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8A1C66012B; Fri, 14 Dec 2018 01:26:41 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org Date: Thu, 13 Dec 2018 20:25:34 -0500 Message-Id: <20181214012604.13746-6-lyude@redhat.com> In-Reply-To: <20181214012604.13746-1-lyude@redhat.com> References: <20181214012604.13746-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Fri, 14 Dec 2018 01:26:43 +0000 (UTC) Subject: [Intel-gfx] [WIP PATCH 05/15] drm/dp_mst: Fix payload deallocation on hotplugs using malloc refs X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Maxime Ripard , linux-kernel@vger.kernel.org, David Airlie , Jerry Zuo , Harry Wentland Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Up until now, freeing payloads on remote MST hubs that just had ports removed has almost never worked because we've been relying on port validation in order to stop us from accessing ports that have already been freed from memory, but ports which need their payloads released due to being removed will never be a valid part of the topology after they've been removed. Since we've introduced malloc refs, we can replace all of the validation logic in payload helpers which are used for deallocation with some well-placed malloc krefs. This ensures that regardless of whether or not the ports are still valid and in the topology, any port which has an allocated payload will remain allocated in memory until it's payloads have been removed - finally allowing us to actually release said payloads correctly. Signed-off-by: Lyude Paul Reviewed-by: Daniel Vetter --- drivers/gpu/drm/drm_dp_mst_topology.c | 54 +++++++++++++++------------ 1 file changed, 30 insertions(+), 24 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index ae9d019af9f2..93f08bfd2ab3 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1989,10 +1989,6 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, u8 sinks[DRM_DP_MAX_SDP_STREAMS]; int i; - port = drm_dp_mst_topology_get_port_validated(mgr, port); - if (!port) - return -EINVAL; - port_num = port->port_num; mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); if (!mstb) { @@ -2000,10 +1996,8 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, port->parent, &port_num); - if (!mstb) { - drm_dp_mst_topology_put_port(port); + if (!mstb) return -EINVAL; - } } txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); @@ -2032,7 +2026,6 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, kfree(txmsg); fail_put: drm_dp_mst_topology_put_mstb(mstb); - drm_dp_mst_topology_put_port(port); return ret; } @@ -2137,15 +2130,16 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr, */ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) { - int i, j; - int cur_slots = 1; struct drm_dp_payload req_payload; struct drm_dp_mst_port *port; + int i, j; + int cur_slots = 1; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i]; struct drm_dp_payload *payload = &mgr->payloads[i]; + bool put_port = false; /* solve the current payloads - compare to the hw ones - update the hw view */ @@ -2153,12 +2147,20 @@ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) if (vcpi) { port = container_of(vcpi, struct drm_dp_mst_port, vcpi); - port = drm_dp_mst_topology_get_port_validated(mgr, - port); - if (!port) { - mutex_unlock(&mgr->payload_lock); - return -EINVAL; + + /* Validated ports don't matter if we're releasing + * VCPI + */ + if (vcpi->num_slots) { + port = drm_dp_mst_topology_get_port_validated( + mgr, port); + if (!port) { + mutex_unlock(&mgr->payload_lock); + return -EINVAL; + } + put_port = true; } + req_payload.num_slots = vcpi->num_slots; req_payload.vcpi = vcpi->vcpi; } else { @@ -2190,7 +2192,7 @@ int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr) } cur_slots += req_payload.num_slots; - if (port) + if (put_port) drm_dp_mst_topology_put_port(port); } @@ -3005,6 +3007,8 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n", pbn, port->vcpi.num_slots); + /* Keep port allocated until it's payload has been removed */ + drm_dp_mst_get_port_malloc(port); drm_dp_mst_topology_put_port(port); return true; out: @@ -3034,11 +3038,12 @@ EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots); */ void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { - port = drm_dp_mst_topology_get_port_validated(mgr, port); - if (!port) - return; + /* + * A port with VCPI will remain allocated until it's VCPI is + * released, no verified ref needed + */ + port->vcpi.num_slots = 0; - drm_dp_mst_topology_put_port(port); } EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); @@ -3050,16 +3055,17 @@ EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots); void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { - port = drm_dp_mst_topology_get_port_validated(mgr, port); - if (!port) - return; + /* + * A port with VCPI will remain allocated until it's VCPI is + * released, no verified ref needed + */ drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); port->vcpi.num_slots = 0; port->vcpi.pbn = 0; port->vcpi.aligned_pbn = 0; port->vcpi.vcpi = 0; - drm_dp_mst_topology_put_port(port); + drm_dp_mst_put_port_malloc(port); } EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);