Hi Mathieu, On 15/07/22 11:52, Kishon Vijay Abraham I wrote:
+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, KishonOn 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...
It is possible to call rproc_get_by_handle() here instead of __pru_get_proc(), but that would not provide multiple functionality.
The API rproc_get_by_handle() returns rproc handle on success, and NULL on failure where as __pru_get_proc() returns ERR_PTR on failure which provides multiple functionality and opportunity for us to distinguish between multiple errors.
So we have these three options.1. If we're using the API rproc_get_by_handle() and we want the multiple ERR_PTR on failure then we will need to change the API rproc_get_by_handle() and also all the functions that uses rproc_get_by_handle().
2. Keep the API rproc_get_by_handle() as it is. That will restrict us from using multiple ERR_PTR on different kinds of error.
3. Instead of using rproc_get_by_handle(), keep using __pru_get_proc(). This will make sure we have the proper ERR_PTR to retrun for different kinds of errors.
Please let me know which option to continue with. Thanks, Danish
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
