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[209.132.180.67]) by mx.google.com with ESMTP id qz9si2554303pab.94.2016.03.07.22.36.09; Mon, 07 Mar 2016 22:36:10 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dkim=pass header.i=@linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753987AbcCHGgI (ORCPT + 30 others); Tue, 8 Mar 2016 01:36:08 -0500 Received: from mail-pa0-f45.google.com ([209.85.220.45]:34662 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753495AbcCHGgG (ORCPT ); Tue, 8 Mar 2016 01:36:06 -0500 Received: by mail-pa0-f45.google.com with SMTP id fy10so5870968pac.1 for ; Mon, 07 Mar 2016 22:36:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=GpKpmPWQae9gS6WhbldZix2OTytBimIacqnCtVJAshE=; b=buAKJPPAy1DwkRMmyxku696S5wnxDQqEszYldiEIgJrOAnzANf0BtZAThW/Fk36WIX 9yNhKJq9uU6CJjrGX56t7B2rBktZL7RMJnQ8F5lfpPsz76OQs7LrFw5osR8vUy9vBJWZ dOsDi34M9F0mv7Ydt1A6B3p5bPlXJ6LY16UIE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=GpKpmPWQae9gS6WhbldZix2OTytBimIacqnCtVJAshE=; b=FQqdxbkT4zmo1AErp62R4LZrY6immoHfQs0KB4i+7JmHNmtra6vMZR63paT4zznHm9 3C7QSaLGa0iRLstgXNZCaWiljwANf8BVdLVG5v6K2QzX3qSKajDwrCNV5USZ/Fz+v1yG ndA6fPmCSPgXSFDTZOM5F95A+rCzAltQH1TQM/7hpBG+0GgAIEKxRYNptJ5vBqN54w3/ 3M7upMpvjwv46FLsuioNjYHBDhZqCrSslw5kmG2Pg2XQrELqgXnem/tHhJyQw/Advo0i UbpiGSsZ2vouDjU6Z1eEP/dwz1FVrQsx8ystvaK3Z/JTEUl8+7Gc4GPrZfUt44X/2oM4 04sQ== X-Gm-Message-State: AD7BkJK5JoCrJr7GYvrQ5+wkDTDMc13EZaXpPKAmI/4Ixly1BCnupy0+8u/KESO9aVpTRdK2 X-Received: by 10.67.12.175 with SMTP id er15mr39024595pad.70.1457418964229; Mon, 07 Mar 2016 22:36:04 -0800 (PST) Received: from zcy-ubuntu.spreadtrum.com ([175.111.195.49]) by smtp.gmail.com with ESMTPSA id fn3sm1986372pab.20.2016.03.07.22.35.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 07 Mar 2016 22:36:02 -0800 (PST) From: Chunyan Zhang To: mathieu.poirier@linaro.org, alexander.shishkin@linux.intel.com Cc: mike.leach@arm.com, Michael.Williams@arm.com, al.grant@arm.com, tor@ti.com, nicolas.guion@st.com, pratikp@codeaurora.org, zhang.lyra@gmail.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org Subject: [RESEND PATCH V4 1/4] stm class: provision for statically assigned masterIDs Date: Tue, 8 Mar 2016 14:33:52 +0800 Message-Id: <1457418835-31417-2-git-send-email-zhang.chunyan@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1457418835-31417-1-git-send-email-zhang.chunyan@linaro.org> References: <1457418835-31417-1-git-send-email-zhang.chunyan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mathieu Poirier Some architecture like ARM assign masterIDs at the HW design phase. Those are therefore unreachable to users, making masterID management in the generic STM core irrelevant. In this kind of configuration channels are shared between masters rather than being allocated on a per master basis. This patch adds a new 'mshared' flag to struct stm_data that tells the core that this specific STM device doesn't need explicit masterID management. In the core sw_start/end of masterID are set to '1', i.e there is only one masterID to deal with. Also this patch depends on [1], so that the number of masterID is '1' too. Finally the lower and upper bound for masterIDs as presented in ($SYSFS)/class/stm/XYZ.stm/masters and ($SYSFS)/../stp-policy/XYZ.stm.my_policy/some_device/masters are set to '-1'. That way users can't confuse them with architecture where masterID management is required (where any other value would be valid). [1] https://lkml.org/lkml/2015/12/22/348 Signed-off-by: Mathieu Poirier Signed-off-by: Chunyan Zhang --- drivers/hwtracing/stm/core.c | 17 +++++++++++++++-- drivers/hwtracing/stm/policy.c | 18 ++++++++++++++++-- include/linux/stm.h | 8 ++++++++ 3 files changed, 39 insertions(+), 4 deletions(-) -- 1.9.1 diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 66cec56..0d7f1c5 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -44,9 +44,15 @@ static ssize_t masters_show(struct device *dev, char *buf) { struct stm_device *stm = to_stm_device(dev); - int ret; + int ret, sw_start, sw_end; + + sw_start = stm->data->sw_start; + sw_end = stm->data->sw_end; + + if (stm->data->mshared) + sw_start = sw_end = STM_SHARED_MASTERID; - ret = sprintf(buf, "%u %u\n", stm->data->sw_start, stm->data->sw_end); + ret = sprintf(buf, "%d %d\n", sw_start, sw_end); return ret; } @@ -618,6 +624,13 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data, if (!stm_data->packet || !stm_data->sw_nchannels) return -EINVAL; + /* + * MasterIDs are assigned at HW design phase. As such the core is + * using a single master for interaction with this device. + */ + if (stm_data->mshared) + stm_data->sw_start = stm_data->sw_end = 1; + nmasters = stm_data->sw_end - stm_data->sw_start + 1; stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL); if (!stm) diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c index 17a1416..19455db 100644 --- a/drivers/hwtracing/stm/policy.c +++ b/drivers/hwtracing/stm/policy.c @@ -80,10 +80,17 @@ static ssize_t stp_policy_node_masters_show(struct config_item *item, char *page) { struct stp_policy_node *policy_node = to_stp_policy_node(item); + struct stm_device *stm = policy_node->policy->stm; + int first_master, last_master; ssize_t count; - count = sprintf(page, "%u %u\n", policy_node->first_master, - policy_node->last_master); + first_master = policy_node->first_master; + last_master = policy_node->last_master; + + if (stm && stm->data->mshared) + first_master = last_master = STM_SHARED_MASTERID; + + count = sprintf(page, "%d %d\n", first_master, last_master); return count; } @@ -106,6 +113,13 @@ stp_policy_node_masters_store(struct config_item *item, const char *page, if (!stm) goto unlock; + /* + * masterIDs are allocated in HW, no point in trying to + * change their values. + */ + if (stm->data->mshared) + goto unlock; + /* must be within [sw_start..sw_end], which is an inclusive range */ if (first > INT_MAX || last > INT_MAX || first > last || first < stm->data->sw_start || diff --git a/include/linux/stm.h b/include/linux/stm.h index 9d0083d..6fac8b1 100644 --- a/include/linux/stm.h +++ b/include/linux/stm.h @@ -18,6 +18,11 @@ #include /** + * The masterIDs are set in hardware and can't be queried + */ +#define STM_SHARED_MASTERID -1 + +/** * enum stp_packet_type - STP packets that an STM driver sends */ enum stp_packet_type { @@ -46,6 +51,8 @@ struct stm_device; * struct stm_data - STM device description and callbacks * @name: device name * @stm: internal structure, only used by stm class code + * @mshared: true if masterIDs are assigned in HW. If so @sw_start + * and @sw_end are set to '1' by the core. * @sw_start: first STP master available to software * @sw_end: last STP master available to software * @sw_nchannels: number of STP channels per master @@ -71,6 +78,7 @@ struct stm_device; struct stm_data { const char *name; struct stm_device *stm; + bool mshared; unsigned int sw_start; unsigned int sw_end; unsigned int sw_nchannels;