Hi Puranjay, On Tue, Jun 07, 2022 at 10:26:46AM +0530, Puranjay Mohan wrote: > From: Tero Kristo <t-kristo@xxxxxx> > > 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@xxxxxx> > Signed-off-by: Suman Anna <s-anna@xxxxxx> > Signed-off-by: Tero Kristo <t-kristo@xxxxxx> > Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@xxxxxxxxxx> > Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk@xxxxxxxxxx> > Co-developed-by: Puranjay Mohan <p-mohan@xxxxxx> > Signed-off-by: Puranjay Mohan <p-mohan@xxxxxx> > --- > drivers/remoteproc/pru_rproc.c | 138 +++++++++++++++++++++++++++++++-- > include/linux/pruss.h | 56 +++++++++++++ > 2 files changed, 189 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 1777a01fa84e..7a35b400287a 100644 > --- a/drivers/remoteproc/pru_rproc.c > +++ b/drivers/remoteproc/pru_rproc.c > @@ -2,12 +2,13 @@ > /* > * 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> > */ > > #include <linux/bitops.h> > @@ -16,6 +17,7 @@ > #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 +113,8 @@ 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 +130,8 @@ 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 +152,125 @@ 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 device_node *rproc_np = NULL; > + struct platform_device *pdev; > + struct rproc *rproc; > + > + rproc_np = of_parse_phandle(np, "ti,prus", index); > + if (!rproc_np || !of_device_is_available(rproc_np)) > + return ERR_PTR(-ENODEV); > + > + pdev = of_find_device_by_node(rproc_np); > + of_node_put(rproc_np); > + > + if (!pdev || !(&pdev->dev) || !((&pdev->dev)->driver)) > + /* probably PRU not yet probed */ > + return ERR_PTR(-EPROBE_DEFER); > + > + /* make sure it is PRU rproc */ > + if (!is_pru_rproc(&pdev->dev)) { > + put_device(&pdev->dev); > + return ERR_PTR(-ENODEV); > + } > + > + rproc = platform_get_drvdata(pdev); > + put_device(&pdev->dev); > + if (!rproc) > + return ERR_PTR(-EPROBE_DEFER); > + > + get_device(&rproc->dev); > + > + return rproc; > +} > + > +/** > + * 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; > + > + try_module_get(THIS_MODULE); There should be a module_put() in pru_rproc_put()... More comments to come tomorrow. I'm especially worried about this API racing with a remote processor being removed or detached. Thanks, Mathieu > + > + 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); > + return ERR_PTR(-EBUSY); > + } > + > + pru->client_np = np; > + > + mutex_unlock(&pru->lock); > + > + if (pru_id) > + *pru_id = pru->id; > + > + return rproc; > +} > +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); > + > + put_device(&rproc->dev); > +} > +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 +563,7 @@ 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) > swap(dram0, dram1); > shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2]; > > @@ -747,14 +872,14 @@ 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 +941,8 @@ 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, > @@ -903,7 +1030,7 @@ 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, > }, > @@ -915,5 +1042,6 @@ 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_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@xxxxxx> > + */ > + > +#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 */ > -- > 2.17.1 >
