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

Roger Quadros
2023-03-17T08:56:48Z

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?

> 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