+Danish Hi Mathieu, On 14/07/22 22:50, Mathieu Poirier wrote: > On Tue, Jul 12, 2022 at 11:59:49AM -0600, Mathieu Poirier wrote: >> Hi Puranjay, Removed Puranjay (as he is no longer with TI) and adding Danish. Regards, Kishon >> >> 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 >>>
