Re: [EXTERNAL] Re: [PATCH v4 2/5] soc: ti: pruss: Add pruss_{request,release}_mem_region() API

Md Danish Anwar
2023-03-21T05:24:24Z

Hi Andrew, Roger,

On 20/03/23 21:48, Andrew Davis wrote:
> 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.
>

If we plan on continuing the original idea, then I think keeping the header
files as it is will be the best. Because if we move anything that deals with
'struct pruss' to include/linux/pruss_driver.h and anything that deals with
pru_rproc (i.e. struct rproc) to include/linux/remoteproc/pruss.h, then the
consumer drivers will need to do,

#include <linux/remoteproc/pruss.h>
#include <linux/pruss_driver.h>

Roger, should I keep the header files arrangement as it is?

> 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
>>

--
Thanks and Regards,
Danish.