[EXTERNAL] Re: [PATCH v7 2/5] remoteproc: pru: Add APIs to get and put the PRU cores
Roger Quadros
rogerq at kernel.org
Tue Nov 8 05:25:39 PST 2022
On 08/11/2022 12:08, Md Danish Anwar wrote:
> Hi Roger,
>
> On 04/11/22 18:25, Roger Quadros wrote:
>> Hi Danish,
>>
>> On 31/10/2022 09:37, MD Danish Anwar wrote:
>>> From: Tero Kristo <t-kristo at ti.com>
>>>
>>> Add two new APIs, pru_rproc_get() and pru_rproc_put(), to the PRU
>>> driver to allow client drivers to acquire and release the remoteproc
>>> device associated with a PRU core. The PRU cores are treated as
>>> resources with only one client owning it at a time.
>>>
>>> The pru_rproc_get() function returns the rproc handle corresponding
>>> to a PRU core identified by the device tree "ti,prus" property under
>>> the client node. The pru_rproc_put() is the complementary function
>>> to pru_rproc_get().
>>>
>>> Co-developed-by: Suman Anna <s-anna at ti.com>
>>> Signed-off-by: Suman Anna <s-anna at ti.com>
>>> Signed-off-by: Tero Kristo <t-kristo at ti.com>
>>> Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
>>> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
>>> Co-developed-by: Puranjay Mohan <p-mohan at ti.com>
>>> Signed-off-by: Puranjay Mohan <p-mohan at ti.com>
>>> Signed-off-by: MD Danish Anwar <danishanwar at ti.com>
>>> ---
>>> drivers/remoteproc/pru_rproc.c | 142 +++++++++++++++++++++++++++++++--
>>> include/linux/pruss.h | 56 +++++++++++++
>>> 2 files changed, 193 insertions(+), 5 deletions(-)
>>> create mode 100644 include/linux/pruss.h
>>>
>>> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
>>> index 128bf9912f2c..9ba73cfc29e2 100644
>>> --- a/drivers/remoteproc/pru_rproc.c
>>> +++ b/drivers/remoteproc/pru_rproc.c
>>> @@ -2,12 +2,14 @@
>>> /*
>>> * PRU-ICSS remoteproc driver for various TI SoCs
>>> *
>>> - * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
>>> + * Copyright (C) 2014-2022 Texas Instruments Incorporated - https://www.ti.com/
>>> *
>>> * Author(s):
>>> * Suman Anna <s-anna at ti.com>
>>> * Andrew F. Davis <afd at ti.com>
>>> * Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org> for Texas Instruments
>>> + * Puranjay Mohan <p-mohan at ti.com>
>>> + * Md Danish Anwar <danishanwar at ti.com>
>>> */
>>>
>>> #include <linux/bitops.h>
>>> @@ -16,6 +18,7 @@
>>> #include <linux/module.h>
>>> #include <linux/of_device.h>
>>> #include <linux/of_irq.h>
>>> +#include <linux/pruss.h>
>>> #include <linux/pruss_driver.h>
>>> #include <linux/remoteproc.h>
>>>
>>> @@ -111,6 +114,8 @@ struct pru_private_data {
>>> * @rproc: remoteproc pointer for this PRU core
>>> * @data: PRU core specific data
>>> * @mem_regions: data for each of the PRU memory regions
>>> + * @client_np: client device node
>>> + * @lock: mutex to protect client usage
>>> * @fw_name: name of firmware image used during loading
>>> * @mapped_irq: virtual interrupt numbers of created fw specific mapping
>>> * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
>>> @@ -126,6 +131,8 @@ struct pru_rproc {
>>> struct rproc *rproc;
>>> const struct pru_private_data *data;
>>> struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
>>> + struct device_node *client_np;
>>> + struct mutex lock; /* client access lock */
>>> const char *fw_name;
>>> unsigned int *mapped_irq;
>>> struct pru_irq_rsc *pru_interrupt_map;
>>> @@ -146,6 +153,127 @@ void pru_control_write_reg(struct pru_rproc *pru, unsigned int reg, u32 val)
>>> writel_relaxed(val, pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
>>> }
>>>
>>> +static struct rproc *__pru_rproc_get(struct device_node *np, int index)
>>> +{
>>> + struct rproc *rproc;
>>> + phandle rproc_phandle;
>>> + int ret;
>>> +
>>> + ret = of_property_read_u32_index(np, "ti,prus", index, &rproc_phandle);
>>> + if (ret)
>>> + return ERR_PTR(ret);
>>> +
>>> + rproc = rproc_get_by_phandle(rproc_phandle);
>>> + if (!rproc) {
>>> + ret = -EPROBE_DEFER;
>>> + goto err_no_rproc_handle;
>>> + }
>>> +
>>> + /* make sure it is PRU rproc */
>>> + if (!is_pru_rproc(rproc->dev.parent)) {
>>> + rproc_put(rproc);
>>> + return ERR_PTR(-ENODEV);
>>> + }
>>> +
>>> + get_device(&rproc->dev);
>>
>> Why do you need a get_device() here?
>> rproc_get_by_phandle() does it right?
>>
>
> Yes, this get_device() is not required. I'll remove it.
>
>>> +
>>> + return rproc;
>>> +
>>> +err_no_rproc_handle:
>>> + rproc_put(rproc);
>>> + return ERR_PTR(ret);
>>> +}
>>> +
>>> +/**
>>> + * pru_rproc_get() - get the PRU rproc instance from a device node
>>> + * @np: the user/client device node
>>> + * @index: index to use for the ti,prus property
>>> + * @pru_id: optional pointer to return the PRU remoteproc processor id
>>> + *
>>> + * This function looks through a client device node's "ti,prus" property at
>>> + * index @index and returns the rproc handle for a valid PRU remote processor if
>>> + * found. The function allows only one user to own the PRU rproc resource at a
>>> + * time. Caller must call pru_rproc_put() when done with using the rproc, not
>>> + * required if the function returns a failure.
>>> + *
>>> + * When optional @pru_id pointer is passed the PRU remoteproc processor id is
>>> + * returned.
>>> + *
>>> + * Return: rproc handle on success, and an ERR_PTR on failure using one
>>> + * of the following error values
>>> + * -ENODEV if device is not found
>>> + * -EBUSY if PRU is already acquired by anyone
>>> + * -EPROBE_DEFER is PRU device is not probed yet
>>> + */
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> + enum pruss_pru_id *pru_id)
>>> +{
>>> + struct rproc *rproc;
>>> + struct pru_rproc *pru;
>>> + struct device *dev;
>>> + int ret;
>>> +
>>> + rproc = __pru_rproc_get(np, index);
>>> + if (IS_ERR(rproc))
>>> + return rproc;
>>
>> Why bother doing __pru_rproc_get() if pru->client_np exists?
>>
>> You could do the below if check first and exit if pru->client_np exists.
>>
>
> In order to do the below if check, we need to have pru. pru is obtained from
> rproc->priv and rproc is obtained from __pru_rproc_get() API. So in order to
> run the below if check we need to call the __pru_rproc_get() API first.
>
> So, first we are obtaining rproc from __pru_rproc_get() API and then checking
> and exiting if pru->client_np exists.
Indeed. sorry for the noise.
>
>>> +
>>> + pru = rproc->priv;
>>> + dev = &rproc->dev;
>>> +
>>> + mutex_lock(&pru->lock);
>>> +
>>> + if (pru->client_np) {
>>> + mutex_unlock(&pru->lock);
>>> + put_device(dev);
>>> + ret = -EBUSY;
>>> + goto err_no_rproc_handle;
>>> + }
>>> +
>>> + pru->client_np = np;
>>> +
>>> + mutex_unlock(&pru->lock);
>>> +
>>> + if (pru_id)
>>> + *pru_id = pru->id;
>>> +
>>> + return rproc;
>>> +
>>> +err_no_rproc_handle:
>>> + rproc_put(rproc);
>>> + return ERR_PTR(ret);
>>> +}
>>> +EXPORT_SYMBOL_GPL(pru_rproc_get);
>>> +
>>> +/**
>>> + * pru_rproc_put() - release the PRU rproc resource
>>> + * @rproc: the rproc resource to release
>>> + *
>>> + * Releases the PRU rproc resource and makes it available to other
>>> + * users.
>>> + */
>>> +void pru_rproc_put(struct rproc *rproc)
>>> +{
>>> + struct pru_rproc *pru;
>>> +
>>> + if (IS_ERR_OR_NULL(rproc) || !is_pru_rproc(rproc->dev.parent))
>>> + return;
>>> +
>>> + pru = rproc->priv;
>>> +
>>> + mutex_lock(&pru->lock);
>>> +
>>> + if (!pru->client_np) {
>>> + mutex_unlock(&pru->lock);
>>> + return;
>>> + }
>>> +
>>> + pru->client_np = NULL;
>>> + mutex_unlock(&pru->lock);
>>> +
>>> + rproc_put(rproc);
>>> +}
>>> +EXPORT_SYMBOL_GPL(pru_rproc_put);
>>> +
>>> static inline u32 pru_debug_read_reg(struct pru_rproc *pru, unsigned int reg)
>>> {
>>> return readl_relaxed(pru->mem_regions[PRU_IOMEM_DEBUG].va + reg);
>>> @@ -438,7 +566,7 @@ static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
>>> dram0 = pruss->mem_regions[PRUSS_MEM_DRAM0];
>>> dram1 = pruss->mem_regions[PRUSS_MEM_DRAM1];
>>> /* PRU1 has its local RAM addresses reversed */
>>> - if (pru->id == 1)
>>> + if (pru->id == PRUSS_PRU1)
>>
>> Introduction of PRUSS_PRU0/1 enum could have been a separate patch.
>>
>>> swap(dram0, dram1);
>>> shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
>>>
>>> @@ -747,14 +875,14 @@ static int pru_rproc_set_id(struct pru_rproc *pru)
>>> case RTU0_IRAM_ADDR_MASK:
>>> fallthrough;
>>> case PRU0_IRAM_ADDR_MASK:
>>> - pru->id = 0;
>>> + pru->id = PRUSS_PRU0;
>>> break;
>>> case TX_PRU1_IRAM_ADDR_MASK:
>>> fallthrough;
>>> case RTU1_IRAM_ADDR_MASK:
>>> fallthrough;
>>> case PRU1_IRAM_ADDR_MASK:
>>> - pru->id = 1;
>>> + pru->id = PRUSS_PRU1;
>>> break;
>>> default:
>>> ret = -EINVAL;
>>> @@ -816,6 +944,8 @@ static int pru_rproc_probe(struct platform_device *pdev)
>>> pru->pruss = platform_get_drvdata(ppdev);
>>> pru->rproc = rproc;
>>> pru->fw_name = fw_name;
>>> + pru->client_np = NULL;
>>> + mutex_init(&pru->lock);
>>>
>>> for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
>>> res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
>>> @@ -904,7 +1034,7 @@ MODULE_DEVICE_TABLE(of, pru_rproc_match);
>>>
>>> static struct platform_driver pru_rproc_driver = {
>>> .driver = {
>>> - .name = "pru-rproc",
>>> + .name = PRU_RPROC_DRVNAME,
>>> .of_match_table = pru_rproc_match,
>>> .suppress_bind_attrs = true,
>>> },
>>> @@ -916,5 +1046,7 @@ module_platform_driver(pru_rproc_driver);
>>> MODULE_AUTHOR("Suman Anna <s-anna at ti.com>");
>>> MODULE_AUTHOR("Andrew F. Davis <afd at ti.com>");
>>> MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>");
>>> +MODULE_AUTHOR("Puranjay Mohan <p-mohan at ti.com>");
>>> +MODULE_AUTHOR("Md Danish Anwar <danishanwar at ti.com>");
>>> MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
>>> MODULE_LICENSE("GPL v2");
>>> diff --git a/include/linux/pruss.h b/include/linux/pruss.h
>>> new file mode 100644
>>> index 000000000000..fdc719b43db0
>>> --- /dev/null
>>> +++ b/include/linux/pruss.h
>>> @@ -0,0 +1,56 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/**
>>> + * PRU-ICSS Subsystem user interfaces
>>> + *
>>> + * Copyright (C) 2015-2022 Texas Instruments Incorporated - http://www.ti.com
>>> + * Suman Anna <s-anna at ti.com>
>>> + */
>>> +
>>> +#ifndef __LINUX_PRUSS_H
>>> +#define __LINUX_PRUSS_H
>>> +
>>> +#include <linux/device.h>
>>> +#include <linux/types.h>
>>> +
>>> +#define PRU_RPROC_DRVNAME "pru-rproc"
>>> +
>>> +/*
>>> + * enum pruss_pru_id - PRU core identifiers
>>> + */
>>> +enum pruss_pru_id {
>>> + PRUSS_PRU0 = 0,
>>> + PRUSS_PRU1,
>>> + PRUSS_NUM_PRUS,
>>> +};
>>> +
>>> +struct device_node;
>>> +
>>> +#if IS_ENABLED(CONFIG_PRU_REMOTEPROC)
>>> +
>>> +struct rproc *pru_rproc_get(struct device_node *np, int index,
>>> + enum pruss_pru_id *pru_id);
>>> +void pru_rproc_put(struct rproc *rproc);
>>> +
>>> +#else
>>> +
>>> +static inline struct rproc *
>>> +pru_rproc_get(struct device_node *np, int index, enum pruss_pru_id *pru_id)
>>> +{
>>> + return ERR_PTR(-EOPNOTSUPP);
>>> +}
>>> +
>>> +static inline void pru_rproc_put(struct rproc *rproc) { }
>>> +
>>> +#endif /* CONFIG_PRU_REMOTEPROC */
>>> +
>>> +static inline bool is_pru_rproc(struct device *dev)
>>> +{
>>> + const char *drv_name = dev_driver_string(dev);
>>> +
>>> + if (strncmp(drv_name, PRU_RPROC_DRVNAME, sizeof(PRU_RPROC_DRVNAME)))
>>> + return false;
>>> +
>>> + return true;
>>> +}
>>> +
>>> +#endif /* __LINUX_PRUSS_H */
>>
>> cheers,
>> -roger
>
> Thanks and Regards,
> Danish.
cheers,
-roger
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