Hi Roger, On 08/12/22 16:05, Roger Quadros wrote: > Hi, > > On 07/12/2022 13:04, MD Danish Anwar wrote: >> 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(). >> >> Signed-off-by: Suman Anna <s-anna@xxxxxx> >> Signed-off-by: Tero Kristo <t-kristo@xxxxxx> >> Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@xxxxxxxxxx> >> Signed-off-by: MD Danish Anwar <danishanwar@xxxxxx> >> --- >> drivers/remoteproc/pru_rproc.c | 133 ++++++++++++++++++++++++++++++++- >> include/linux/pruss.h | 29 +++++++ >> 2 files changed, 160 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c >> index a1a208b31846..7d4ed39b3772 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@xxxxxx> >> * Andrew F. Davis <afd@xxxxxx> >> * Grzegorz Jaszczyk <grzegorz.jaszczyk@xxxxxxxxxx> for Texas Instruments >> + * Puranjay Mohan <p-mohan@xxxxxx> >> + * Md Danish Anwar <danishanwar@xxxxxx> >> */ >> >> #include <linux/bitops.h> >> @@ -112,6 +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) >> @@ -127,6 +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; >> const char *fw_name; >> unsigned int *mapped_irq; >> struct pru_irq_rsc *pru_interrupt_map; >> @@ -147,6 +153,125 @@ 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); >> + } >> + >> + 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; >> + >> + pru = rproc->priv; >> + dev = &rproc->dev; >> + >> + mutex_lock(&pru->lock); >> + >> + if (pru->client_np) { >> + mutex_unlock(&pru->lock); >> + put_device(dev); > > Is this put_device() to counter balance the get_device() you had earlier? > Is it still needed? >> Did we do the right thing by getting rid of the additional get_device()? > I didn't see a reason for it. > The previous get_device() in __pru_rproc_get() was additional/not required as the same get_device() was called by rproc_get_by_phandle() API before it's completion. So that get_device() is not needed. The put_device() here is to counter the get_device() called by rproc_get_by_phandle() in the API __pru_rproc_get(). So I think, this put_device() is still needed. >> + 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); >> @@ -817,6 +942,8 @@ 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, >> @@ -905,7 +1032,7 @@ 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, >> }, >> @@ -917,5 +1044,7 @@ module_platform_driver(pru_rproc_driver); >> MODULE_AUTHOR("Suman Anna <s-anna@xxxxxx>"); >> MODULE_AUTHOR("Andrew F. Davis <afd@xxxxxx>"); >> MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@xxxxxxxxxx>"); >> +MODULE_AUTHOR("Puranjay Mohan <p-mohan@xxxxxx>"); >> +MODULE_AUTHOR("Md Danish Anwar <danishanwar@xxxxxx>"); >> MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver"); >> MODULE_LICENSE("GPL v2"); >> diff --git a/include/linux/pruss.h b/include/linux/pruss.h >> index fbe4fbb45807..6ea737e995e9 100644 >> --- a/include/linux/pruss.h >> +++ b/include/linux/pruss.h >> @@ -28,5 +28,34 @@ enum pruss_pru_id { >> 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 */ >> \ No newline at end of file > > -- > cheers, > -roger Thanks, Danish
