From patchwork Wed May 31 09:06:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Westerberg X-Patchwork-Id: 687653 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94443C7EE2F for ; Wed, 31 May 2023 09:08:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235406AbjEaJIC (ORCPT ); Wed, 31 May 2023 05:08:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235314AbjEaJHn (ORCPT ); Wed, 31 May 2023 05:07:43 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A11F6125 for ; Wed, 31 May 2023 02:07:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685524054; x=1717060054; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=PpeVzZcGbyUvYegS7OXn5u6Us4JA//RLFBzAfz0nby0=; b=S83jGbBoT9xLZFhAnprcrGbsHYvwQeMiZzqI3et5X4SlEXwLqxlJ76Pq s6PH7kzTas1wLp1LvMYSV6/4s99m1ovQ2YYIqLgSDGh6F6KiFRedTMQh1 qTgvWDeSDi+TZDylcHzbCH/+uww7PUCZt3irb9CVthDdCw0AwNyzbNsSn 6mYV2oD9sPVagM6p4fJURIVX1pdam2u67N5iORQVHWJ1m/CaZ2xOo4hMJ 1LN7nTx/q4VzBGWbAgxh5lEa25F0R0kRUVEh3tTSwyGouAUdhvnfus2mY bRkDvuvM+T5kduPS3fyQXtDae3v60UNHcS+GzsFh4M+lm2GB8y/gGipky w==; X-IronPort-AV: E=McAfee;i="6600,9927,10726"; a="354027699" X-IronPort-AV: E=Sophos;i="6.00,205,1681196400"; d="scan'208";a="354027699" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 May 2023 02:06:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10726"; a="657247277" X-IronPort-AV: E=Sophos;i="6.00,205,1681196400"; d="scan'208";a="657247277" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga003.jf.intel.com with ESMTP; 31 May 2023 02:06:46 -0700 Received: by black.fi.intel.com (Postfix, from userid 1001) id A050511DA; Wed, 31 May 2023 12:06:46 +0300 (EEST) From: Mika Westerberg To: linux-usb@vger.kernel.org Cc: Yehezkel Bernat , Michael Jamet , Lukas Wunner , Andreas Noever , Gil Fine , Christian Kellner , Mika Westerberg Subject: [PATCH 19/20] thunderbolt: Add DisplayPort 2.x tunneling support Date: Wed, 31 May 2023 12:06:44 +0300 Message-Id: <20230531090645.5573-20-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230531090645.5573-1-mika.westerberg@linux.intel.com> References: <20230531090645.5573-1-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org This adds support for the UHBR (Ultra High Bit Rate) bandwidths introduced with DisplayPort 2.0 (and refined in 2.1). These can go up to 80 Gbit/s and their support is represent in additional bits in the DP IN capability. This updates the DisplayPort tunneling to support these new rates too. Signed-off-by: Mika Westerberg --- drivers/thunderbolt/tb_regs.h | 3 + drivers/thunderbolt/tunnel.c | 100 ++++++++++++++++++++++++++++------ 2 files changed, 87 insertions(+), 16 deletions(-) diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h index c95fc7fe7adf..cf9f2370878a 100644 --- a/drivers/thunderbolt/tb_regs.h +++ b/drivers/thunderbolt/tb_regs.h @@ -450,6 +450,9 @@ struct tb_regs_port_header { #define DP_COMMON_CAP_1_LANE 0x0 #define DP_COMMON_CAP_2_LANES 0x1 #define DP_COMMON_CAP_4_LANES 0x2 +#define DP_COMMON_CAP_UHBR10 BIT(17) +#define DP_COMMON_CAP_UHBR20 BIT(18) +#define DP_COMMON_CAP_UHBR13_5 BIT(19) #define DP_COMMON_CAP_LTTPR_NS BIT(27) #define DP_COMMON_CAP_BW_MODE BIT(28) #define DP_COMMON_CAP_DPRX_DONE BIT(31) diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c index 64ec0cccc0df..620dc9d240f0 100644 --- a/drivers/thunderbolt/tunnel.c +++ b/drivers/thunderbolt/tunnel.c @@ -417,6 +417,10 @@ static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out, return -ETIMEDOUT; } +/* + * Returns maximum possible rate from capability supporting only DP 2.0 + * and below. Used when DP BW allocation mode is not enabled. + */ static inline u32 tb_dp_cap_get_rate(u32 val) { u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT; @@ -435,6 +439,28 @@ static inline u32 tb_dp_cap_get_rate(u32 val) } } +/* + * Returns maximum possible rate from capability supporting DP 2.1 + * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation + * mode is enabled. + */ +static inline u32 tb_dp_cap_get_rate_ext(u32 val) +{ + if (val & DP_COMMON_CAP_UHBR20) + return 20000; + else if (val & DP_COMMON_CAP_UHBR13_5) + return 13500; + else if (val & DP_COMMON_CAP_UHBR10) + return 10000; + + return tb_dp_cap_get_rate(val); +} + +static inline bool tb_dp_is_uhbr_rate(unsigned int rate) +{ + return rate >= 10000; +} + static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate) { val &= ~DP_COMMON_CAP_RATE_MASK; @@ -497,7 +523,9 @@ static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes) static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes) { - /* Tunneling removes the DP 8b/10b encoding */ + /* Tunneling removes the DP 8b/10b 128/132b encoding */ + if (tb_dp_is_uhbr_rate(rate)) + return rate * lanes * 128 / 132; return rate * lanes * 8 / 10; } @@ -690,6 +718,19 @@ static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel) if (ret) return ret; + /* + * Pick up granularity that supports maximum possible bandwidth. + * For that we use the UHBR rates too. + */ + in_rate = tb_dp_cap_get_rate_ext(in_dp_cap); + out_rate = tb_dp_cap_get_rate_ext(out_dp_cap); + rate = min(in_rate, out_rate); + tmp = tb_dp_bandwidth(rate, lanes); + + tb_port_dbg(in, + "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n", + rate, lanes, tmp); + for (granularity = 250; tmp / granularity > 255 && granularity <= 1000; granularity *= 2) ; @@ -805,15 +846,42 @@ static int tb_dp_activate(struct tb_tunnel *tunnel, bool active) } /* max_bw is rounded up to next granularity */ -static int tb_dp_nrd_bandwidth(struct tb_tunnel *tunnel, int *max_bw) +static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel, + int *max_bw) { struct tb_port *in = tunnel->src_port; int ret, rate, lanes, nrd_bw; + u32 cap; - ret = usb4_dp_port_nrd(in, &rate, &lanes); + /* + * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX + * read parameter values so this so we can use this to determine + * the maximum possible bandwidth over this link. + * + * See USB4 v2 spec 1.0 10.4.4.5. + */ + ret = tb_port_read(in, &cap, TB_CFG_PORT, + in->cap_adap + DP_LOCAL_CAP, 1); if (ret) return ret; + rate = tb_dp_cap_get_rate_ext(cap); + if (tb_dp_is_uhbr_rate(rate)) { + /* + * When UHBR is used there is no reduction in lanes so + * we can use this directly. + */ + lanes = tb_dp_cap_get_lanes(cap); + } else { + /* + * If there is no UHBR supported then check the + * non-reduced rate and lanes. + */ + ret = usb4_dp_port_nrd(in, &rate, &lanes); + if (ret) + return ret; + } + nrd_bw = tb_dp_bandwidth(rate, lanes); if (max_bw) { @@ -846,7 +914,7 @@ static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel, return ret; allocated_bw = ret; - ret = tb_dp_nrd_bandwidth(tunnel, &max_bw); + ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw); if (ret < 0) return ret; if (allocated_bw == max_bw) @@ -884,7 +952,7 @@ static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up return ret; allocated_bw = ret; - ret = tb_dp_nrd_bandwidth(tunnel, &max_bw); + ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw); if (ret < 0) return ret; if (allocated_bw == max_bw) @@ -914,7 +982,7 @@ static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up, if (!usb4_dp_port_bandwidth_mode_enabled(in)) return -EOPNOTSUPP; - ret = tb_dp_nrd_bandwidth(tunnel, &max_bw); + ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw); if (ret < 0) return ret; @@ -937,6 +1005,9 @@ static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up, /* Now we can use BW mode registers to figure out the bandwidth */ /* TODO: need to handle discovery too */ tunnel->bw_mode = true; + + tb_port_dbg(in, "allocated bandwidth through allocation mode %d Mb/s\n", + tmp); return 0; } @@ -1011,23 +1082,20 @@ static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up, int *max_down) { struct tb_port *in = tunnel->src_port; - u32 rate, lanes; int ret; - /* - * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX read - * parameter values so this so we can use this to determine the - * maximum possible bandwidth over this link. - */ - ret = tb_dp_read_cap(tunnel, DP_LOCAL_CAP, &rate, &lanes); - if (ret) + if (!usb4_dp_port_bandwidth_mode_enabled(in)) + return -EOPNOTSUPP; + + ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL); + if (ret < 0) return ret; if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) { *max_up = 0; - *max_down = tb_dp_bandwidth(rate, lanes); + *max_down = ret; } else { - *max_up = tb_dp_bandwidth(rate, lanes); + *max_up = ret; *max_down = 0; }