Message-ID: <13048b01-641a-1d92-178c-02b87c5fa1b9@ti.com>
Date:   Mon, 20 Mar 2023 11:18:54 -0500
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Subject: Re: [EXTERNAL] Re: [PATCH v4 2/5] soc: ti: pruss: Add
 pruss_{request,release}_mem_region() API
Content-Language: en-US
To:     Md Danish Anwar <a0501179@ti.com>,
        Roger Quadros <rogerq@kernel.org>,
        MD Danish Anwar <danishanwar@ti.com>,
        Suman Anna <s-anna@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        Nishanth Menon <nm@ti.com>
CC:     <linux-remoteproc@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <linux-omap@vger.kernel.org>,
        <srk@ti.com>, <devicetree@vger.kernel.org>,
        <netdev@vger.kernel.org>
References: <20230313111127.1229187-1-danishanwar@ti.com>
 <20230313111127.1229187-3-danishanwar@ti.com>
 <3f26b194-287c-074d-8e78-572875f9a734@kernel.org>
 <52aeb13f-1fe4-825f-9d28-ba64860ae76d@ti.com>
From:   Andrew Davis <afd@ti.com>
In-Reply-To: <52aeb13f-1fe4-825f-9d28-ba64860ae76d@ti.com>
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On 3/20/23 12:11 AM, Md Danish Anwar wrote:
> Hi Roger,
> 
> On 17/03/23 14:26, Roger Quadros wrote:
>> Hi Andrew & Danish,
>>
>>
>> On 13/03/2023 13:11, MD Danish Anwar wrote:
>>> From: "Andrew F. Davis" <afd@ti.com>
>>>
>>> Add two new API - pruss_request_mem_region() & pruss_release_mem_region(),
>>> to the PRUSS platform driver to allow client drivers to acquire and release
>>> the common memory resources present within a PRU-ICSS subsystem. This
>>> allows the client drivers to directly manipulate the respective memories,
>>> as per their design contract with the associated firmware.
>>>
>>> Co-developed-by: Suman Anna <s-anna@ti.com>
>>> Signed-off-by: Suman Anna <s-anna@ti.com>
>>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>>> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>
>>> Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
>>> Reviewed-by: Roger Quadros <rogerq@kernel.org>
>>> ---
>>>   drivers/soc/ti/pruss.c           | 77 ++++++++++++++++++++++++++++++++
>>>   include/linux/pruss_driver.h     | 27 +++--------
>>>   include/linux/remoteproc/pruss.h | 39 ++++++++++++++++
>>
>>
>> We have these 2 header files and I think anything that deals with
>> 'struct pruss' should go in include/linux/pruss_driver.h
>>
>> Anything that deals with pru_rproc (i.e. struct rproc) should go in
>> include/linux/remoteproc/pruss.h
>>
>> Do you agree?
>>
> 
> I agree with you Roger but Andrew is the right person to comment here as he is
> the author of this and several other patches.
> 
> Hi Andrew, Can you please comment on this?
> 

Original idea was a consumer driver (like "ICSSG Ethernet Driver" in your other
series) could just

#include <linux/remoteproc/pruss.h>

and get everything they need, and nothing they do not.

pruss_driver.h (which could be renamed pruss_internal.h) exists to allow
comunication between the pruss core and the pru rproc driver which live
in different subsystems.

Andrew

>>>   3 files changed, 121 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
>>> index a169aa1ed044..c8053c0d735f 100644
>>> --- a/drivers/soc/ti/pruss.c
>>> +++ b/drivers/soc/ti/pruss.c
>>> @@ -88,6 +88,82 @@ void pruss_put(struct pruss *pruss)
>>>   }
>>>   EXPORT_SYMBOL_GPL(pruss_put);
>>>   
>>> +/**
>>> + * pruss_request_mem_region() - request a memory resource
>>> + * @pruss: the pruss instance
>>> + * @mem_id: the memory resource id
>>> + * @region: pointer to memory region structure to be filled in
>>> + *
>>> + * This function allows a client driver to request a memory resource,
>>> + * and if successful, will let the client driver own the particular
>>> + * memory region until released using the pruss_release_mem_region()
>>> + * API.
>>> + *
>>> + * Return: 0 if requested memory region is available (in such case pointer to
>>> + * memory region is returned via @region), an error otherwise
>>> + */
>>> +int pruss_request_mem_region(struct pruss *pruss, enum pruss_mem mem_id,
>>> +			     struct pruss_mem_region *region)
>>> +{
>>> +	if (!pruss || !region || mem_id >= PRUSS_MEM_MAX)
>>> +		return -EINVAL;
>>> +
>>> +	mutex_lock(&pruss->lock);
>>> +
>>> +	if (pruss->mem_in_use[mem_id]) {
>>> +		mutex_unlock(&pruss->lock);
>>> +		return -EBUSY;
>>> +	}
>>> +
>>> +	*region = pruss->mem_regions[mem_id];
>>> +	pruss->mem_in_use[mem_id] = region;
>>> +
>>> +	mutex_unlock(&pruss->lock);
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(pruss_request_mem_region);
>>> +
>>> +/**
>>> + * pruss_release_mem_region() - release a memory resource
>>> + * @pruss: the pruss instance
>>> + * @region: the memory region to release
>>> + *
>>> + * This function is the complimentary function to
>>> + * pruss_request_mem_region(), and allows the client drivers to
>>> + * release back a memory resource.
>>> + *
>>> + * Return: 0 on success, an error code otherwise
>>> + */
>>> +int pruss_release_mem_region(struct pruss *pruss,
>>> +			     struct pruss_mem_region *region)
>>> +{
>>> +	int id;
>>> +
>>> +	if (!pruss || !region)
>>> +		return -EINVAL;
>>> +
>>> +	mutex_lock(&pruss->lock);
>>> +
>>> +	/* find out the memory region being released */
>>> +	for (id = 0; id < PRUSS_MEM_MAX; id++) {
>>> +		if (pruss->mem_in_use[id] == region)
>>> +			break;
>>> +	}
>>> +
>>> +	if (id == PRUSS_MEM_MAX) {
>>> +		mutex_unlock(&pruss->lock);
>>> +		return -EINVAL;
>>> +	}
>>> +
>>> +	pruss->mem_in_use[id] = NULL;
>>> +
>>> +	mutex_unlock(&pruss->lock);
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(pruss_release_mem_region);
>>> +
>>>   static void pruss_of_free_clk_provider(void *data)
>>>   {
>>>   	struct device_node *clk_mux_np = data;
>>> @@ -290,6 +366,7 @@ static int pruss_probe(struct platform_device *pdev)
>>>   		return -ENOMEM;
>>>   
>>>   	pruss->dev = dev;
>>> +	mutex_init(&pruss->lock);
>>>   
>>>   	child = of_get_child_by_name(np, "memories");
>>>   	if (!child) {
>>> diff --git a/include/linux/pruss_driver.h b/include/linux/pruss_driver.h
>>> index 86242fb5a64a..22b4b37d2536 100644
>>> --- a/include/linux/pruss_driver.h
>>> +++ b/include/linux/pruss_driver.h
>>> @@ -9,37 +9,18 @@
>>>   #ifndef _PRUSS_DRIVER_H_
>>>   #define _PRUSS_DRIVER_H_
>>>   
>>> +#include <linux/mutex.h>
>>>   #include <linux/remoteproc/pruss.h>
>>>   #include <linux/types.h>
>>>   
>>> -/*
>>> - * enum pruss_mem - PRUSS memory range identifiers
>>> - */
>>> -enum pruss_mem {
>>> -	PRUSS_MEM_DRAM0 = 0,
>>> -	PRUSS_MEM_DRAM1,
>>> -	PRUSS_MEM_SHRD_RAM2,
>>> -	PRUSS_MEM_MAX,
>>> -};
>>> -
>>> -/**
>>> - * struct pruss_mem_region - PRUSS memory region structure
>>> - * @va: kernel virtual address of the PRUSS memory region
>>> - * @pa: physical (bus) address of the PRUSS memory region
>>> - * @size: size of the PRUSS memory region
>>> - */
>>> -struct pruss_mem_region {
>>> -	void __iomem *va;
>>> -	phys_addr_t pa;
>>> -	size_t size;
>>> -};
>>> -
>>>   /**
>>>    * struct pruss - PRUSS parent structure
>>>    * @dev: pruss device pointer
>>>    * @cfg_base: base iomap for CFG region
>>>    * @cfg_regmap: regmap for config region
>>>    * @mem_regions: data for each of the PRUSS memory regions
>>> + * @mem_in_use: to indicate if memory resource is in use
>>> + * @lock: mutex to serialize access to resources
>>>    * @core_clk_mux: clk handle for PRUSS CORE_CLK_MUX
>>>    * @iep_clk_mux: clk handle for PRUSS IEP_CLK_MUX
>>>    */
>>> @@ -48,6 +29,8 @@ struct pruss {
>>>   	void __iomem *cfg_base;
>>>   	struct regmap *cfg_regmap;
>>>   	struct pruss_mem_region mem_regions[PRUSS_MEM_MAX];
>>> +	struct pruss_mem_region *mem_in_use[PRUSS_MEM_MAX];
>>> +	struct mutex lock; /* PRU resource lock */
>>>   	struct clk *core_clk_mux;
>>>   	struct clk *iep_clk_mux;
>>>   };
>>> diff --git a/include/linux/remoteproc/pruss.h b/include/linux/remoteproc/pruss.h
>>> index 93a98cac7829..33f930e0a0ce 100644
>>> --- a/include/linux/remoteproc/pruss.h
>>> +++ b/include/linux/remoteproc/pruss.h
>>> @@ -44,6 +44,28 @@ enum pru_ctable_idx {
>>>   	PRU_C31,
>>>   };
>>>   
>>> +/*
>>> + * enum pruss_mem - PRUSS memory range identifiers
>>> + */
>>> +enum pruss_mem {
>>> +	PRUSS_MEM_DRAM0 = 0,
>>> +	PRUSS_MEM_DRAM1,
>>> +	PRUSS_MEM_SHRD_RAM2,
>>> +	PRUSS_MEM_MAX,
>>> +};
>>> +
>>> +/**
>>> + * struct pruss_mem_region - PRUSS memory region structure
>>> + * @va: kernel virtual address of the PRUSS memory region
>>> + * @pa: physical (bus) address of the PRUSS memory region
>>> + * @size: size of the PRUSS memory region
>>> + */
>>> +struct pruss_mem_region {
>>> +	void __iomem *va;
>>> +	phys_addr_t pa;
>>> +	size_t size;
>>> +};
>>> +
>>>   struct device_node;
>>>   struct rproc;
>>>   struct pruss;
>>> @@ -52,6 +74,10 @@ struct pruss;
>>>   
>>>   struct pruss *pruss_get(struct rproc *rproc);
>>>   void pruss_put(struct pruss *pruss);
>>> +int pruss_request_mem_region(struct pruss *pruss, enum pruss_mem mem_id,
>>> +			     struct pruss_mem_region *region);
>>> +int pruss_release_mem_region(struct pruss *pruss,
>>> +			     struct pruss_mem_region *region);
>>>   
>>>   #else
>>>   
>>> @@ -62,6 +88,19 @@ static inline struct pruss *pruss_get(struct rproc *rproc)
>>>   
>>>   static inline void pruss_put(struct pruss *pruss) { }
>>>   
>>> +static inline int pruss_request_mem_region(struct pruss *pruss,
>>> +					   enum pruss_mem mem_id,
>>> +					   struct pruss_mem_region *region)
>>> +{
>>> +	return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static inline int pruss_release_mem_region(struct pruss *pruss,
>>> +					   struct pruss_mem_region *region)
>>> +{
>>> +	return -EOPNOTSUPP;
>>> +}
>>> +
>>>   #endif /* CONFIG_TI_PRUSS */
>>>   
>>>   #if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>>
>> cheers,
>> -roger
>