Danish, On 09/12/2022 06:55, Md Danish Anwar wrote: > 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. But at the end of this function we are calling rproc_put() which also does a put_device(), right? > >>> + 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); <snip> cheers, -roger
