From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 77BEB1DF992; Wed, 13 Nov 2024 13:27:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731504432; cv=none; b=YIDXCbTQmJZkDwHnf7vgC8FXOhoYxpvizlmPwxLzh/aJKkFKlkDPovsW8rqgO7umuOEp2Wwlcs6gQlvXe4NGZPY2TCiOoycZuIue7Fv5vtqwkB9FLN8d+9fh2VGnjJxQmutnztKspOdICrXDtJ1L8JVIHm78BZDJKx8r4zLe8cE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731504432; c=relaxed/simple; bh=9d+e3lBIDxZImn7IN5EFIXhLnDccxYDpONKaPnp7V9E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=aZkcYJRO1R5uR4o/n1/kpgiPZPuaKAZQTStIyap2j3wllJnJ1sCQ2U2JxrVTWT8dWyFkQ9Y93tTKT9rm5DOWZLC10JAG1ne3swWCedljSFgFAZ1HeZZ0A7GgLQqJ2jcl6pfRJwJHFuWv9nVy61f5/hUg75bsz6Q5daOhQrmgXaE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8E1BC1655; Wed, 13 Nov 2024 05:27:38 -0800 (PST) Received: from [10.1.29.78] (Suzukis-MBP.cambridge.arm.com [10.1.29.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id AAF6B3F66E; Wed, 13 Nov 2024 05:27:06 -0800 (PST) Message-ID: <6424c536-2f2c-4a59-8b6d-f610201dc7a7@arm.com> Date: Wed, 13 Nov 2024 13:27:05 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/3] coresight: Add support to get static id for system trace sources Content-Language: en-GB To: Mao Jinlong , Mike Leach , James Clark , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Alexander Shishkin Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org References: <20241104115604.14522-1-quic_jinlmao@quicinc.com> <20241104115604.14522-3-quic_jinlmao@quicinc.com> From: Suzuki K Poulose In-Reply-To: <20241104115604.14522-3-quic_jinlmao@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 04/11/2024 11:56, Mao Jinlong wrote: > Dynamic trace id was introduced in coresight subsystem, so trace id is > allocated dynamically. However, some hardware ATB source has static trace > id and it cannot be changed via software programming. For such source, > it can call coresight_get_static_trace_id to get the fixed trace id from > device node and pass id to coresight_trace_id_get_static_system_id to > reserve the id. > > Signed-off-by: Mao Jinlong > Reviewed-by: Mike Leach > --- > .../hwtracing/coresight/coresight-platform.c | 6 +++ > .../hwtracing/coresight/coresight-trace-id.c | 39 +++++++++++++------ > .../hwtracing/coresight/coresight-trace-id.h | 9 +++++ > include/linux/coresight.h | 1 + > 4 files changed, 44 insertions(+), 11 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c > index 64e171eaad82..633d96b9577a 100644 > --- a/drivers/hwtracing/coresight/coresight-platform.c > +++ b/drivers/hwtracing/coresight/coresight-platform.c > @@ -796,6 +796,12 @@ int coresight_get_cpu(struct device *dev) > } > EXPORT_SYMBOL_GPL(coresight_get_cpu); > > +int coresight_get_static_trace_id(struct device *dev, u32 *id) > +{ > + return fwnode_property_read_u32(dev_fwnode(dev), "arm,static-trace-id", id); > +} > +EXPORT_SYMBOL_GPL(coresight_get_static_trace_id); > + > struct coresight_platform_data * > coresight_get_platform_data(struct device *dev) > { > diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c > index d98e12cb30ec..df8fe50b413f 100644 > --- a/drivers/hwtracing/coresight/coresight-trace-id.c > +++ b/drivers/hwtracing/coresight/coresight-trace-id.c > @@ -12,6 +12,12 @@ > > #include "coresight-trace-id.h" > > +enum trace_id_flags { > + TRACE_ID_ANY = 0x0, > + TRACE_ID_PREFER_ODD = 0x1, > + TRACE_ID_REQ_STATIC = 0x2, > +}; > + > /* Default trace ID map. Used in sysfs mode and for system sources */ > static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0); > static struct coresight_trace_id_map id_map_default = { > @@ -74,16 +80,18 @@ static int coresight_trace_id_find_odd_id(struct coresight_trace_id_map *id_map) > * Otherwise allocate next available ID. > */ > static int coresight_trace_id_alloc_new_id(struct coresight_trace_id_map *id_map, > - int preferred_id, bool prefer_odd_id) > + int preferred_id, unsigned int flags) > { > int id = 0; > > /* for backwards compatibility, cpu IDs may use preferred value */ > - if (IS_VALID_CS_TRACE_ID(preferred_id) && > - !test_bit(preferred_id, id_map->used_ids)) { > - id = preferred_id; > - goto trace_id_allocated; > - } else if (prefer_odd_id) { > + if (IS_VALID_CS_TRACE_ID(preferred_id)) { > + if (!test_bit(preferred_id, id_map->used_ids)) { > + id = preferred_id; > + goto trace_id_allocated; > + } else if (flags & TRACE_ID_REQ_STATIC) > + return -EINVAL; nit: EBUSY sounds like a better choice here ? Requested ID is not available. Additionally, do we need to handle a case where the preferred_id is not valid ? I think we silently allocate a new trace id in such case ? Rest looks good to me. Suzuki > + } else if (flags & TRACE_ID_PREFER_ODD) { > /* may use odd ids to avoid preferred legacy cpu IDs */ > id = coresight_trace_id_find_odd_id(id_map); > if (id) > @@ -153,7 +161,7 @@ static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map > */ > id = coresight_trace_id_alloc_new_id(id_map, > CORESIGHT_LEGACY_CPU_TRACE_ID(cpu), > - false); > + TRACE_ID_ANY); > if (!IS_VALID_CS_TRACE_ID(id)) > goto get_cpu_id_out_unlock; > > @@ -188,14 +196,14 @@ static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_ma > DUMP_ID_MAP(id_map); > } > > -static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map) > +static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map, > + int preferred_id, unsigned int traceid_flags) > { > unsigned long flags; > int id; > > spin_lock_irqsave(&id_map->lock, flags); > - /* prefer odd IDs for system components to avoid legacy CPU IDS */ > - id = coresight_trace_id_alloc_new_id(id_map, 0, true); > + id = coresight_trace_id_alloc_new_id(id_map, preferred_id, traceid_flags); > spin_unlock_irqrestore(&id_map->lock, flags); > > DUMP_ID(id); > @@ -255,10 +263,19 @@ EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id_map); > > int coresight_trace_id_get_system_id(void) > { > - return coresight_trace_id_map_get_system_id(&id_map_default); > + /* prefer odd IDs for system components to avoid legacy CPU IDS */ > + return coresight_trace_id_map_get_system_id(&id_map_default, 0, > + TRACE_ID_PREFER_ODD); > } > EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id); > > +int coresight_trace_id_get_static_system_id(int trace_id) > +{ > + return coresight_trace_id_map_get_system_id(&id_map_default, > + trace_id, TRACE_ID_REQ_STATIC); > +} > +EXPORT_SYMBOL_GPL(coresight_trace_id_get_static_system_id); > + > void coresight_trace_id_put_system_id(int id) > { > coresight_trace_id_map_put_system_id(&id_map_default, id); > diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h > index 9aae50a553ca..db68e1ec56b6 100644 > --- a/drivers/hwtracing/coresight/coresight-trace-id.h > +++ b/drivers/hwtracing/coresight/coresight-trace-id.h > @@ -116,6 +116,15 @@ int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *i > */ > int coresight_trace_id_get_system_id(void); > > +/** > + * Allocate a CoreSight static trace ID for a system component. > + * > + * Used to allocate static IDs for system trace sources such as dummy source. > + * > + * return: Trace ID or -EINVAL if allocation is impossible. > + */ > +int coresight_trace_id_get_static_system_id(int id); > + > /** > * Release an allocated system trace ID. > * > diff --git a/include/linux/coresight.h b/include/linux/coresight.h > index c13342594278..129795873072 100644 > --- a/include/linux/coresight.h > +++ b/include/linux/coresight.h > @@ -662,6 +662,7 @@ void coresight_relaxed_write64(struct coresight_device *csdev, > void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset); > > extern int coresight_get_cpu(struct device *dev); > +extern int coresight_get_static_trace_id(struct device *dev, u32 *id); > > struct coresight_platform_data *coresight_get_platform_data(struct device *dev); > struct coresight_connection *