On Tue, Jul 12, 2022 at 11:59:49AM -0600, Mathieu Poirier wrote: > 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()... ... and in the error path of this function. > > More comments to come tomorrow. I'm especially worried about this API racing > with a remote processor being removed or detached. > Looking at what is done in wkup_m3_ipc_probe(), it should be possible to call rproc_get_by_handle() here and that would make sure the remote processor doesn't go away before the end of the function. More comments to come... > 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 > >
