[PATCH v2 2/6] remoteproc/pru: Add a PRU remoteproc driver
Mathieu Poirier
mathieu.poirier at linaro.org
Wed Dec 2 15:53:36 EST 2020
On Tue, Dec 01, 2020 at 03:54:36PM -0700, Mathieu Poirier wrote:
> Hi Grzeg,
>
> I have started to review this set - comments will come over the next few days.
>
> See below for a start.
>
> On Thu, Nov 19, 2020 at 03:08:46PM +0100, Grzegorz Jaszczyk wrote:
> > From: Suman Anna <s-anna at ti.com>
> >
> > The Programmable Real-Time Unit Subsystem (PRUSS) consists of
> > dual 32-bit RISC cores (Programmable Real-Time Units, or PRUs)
> > for program execution. This patch adds a remoteproc platform
> > driver for managing the individual PRU RISC cores life cycle.
> >
> > The PRUs do not have a unified address space (have an Instruction
> > RAM and a primary Data RAM at both 0x0). The PRU remoteproc driver
> > therefore uses a custom remoteproc core ELF loader ops. The added
> > .da_to_va ops is only used to provide translations for the PRU
> > Data RAMs. This remoteproc driver does not have support for error
> > recovery and system suspend/resume features. Different compatibles
> > are used to allow providing scalability for instance-specific device
> > data if needed. The driver uses a default firmware-name retrieved
> > from device-tree for each PRU core, and the firmwares are expected
> > to be present in the standard Linux firmware search paths. They can
> > also be adjusted by userspace if required through the sysfs interface
> > provided by the remoteproc core.
> >
> > The PRU remoteproc driver uses a client-driven boot methodology: it
> > does _not_ support auto-boot so that the PRU load and boot is dictated
> > by the corresponding client drivers for achieving various usecases.
> > This allows flexibility for the client drivers or applications to set
> > a firmware name (if needed) based on their desired functionality and
> > boot the PRU. The sysfs bind and unbind attributes have also been
> > suppressed so that the PRU devices cannot be unbound and thereby
> > shutdown a PRU from underneath a PRU client driver.
> >
> > The driver currently supports the AM335x, AM437x, AM57xx and 66AK2G
> > SoCs, and support for other TI SoCs will be added in subsequent
> > patches.
> >
> > Co-developed-by: Andrew F. Davis <afd at ti.com>
> > Signed-off-by: Andrew F. Davis <afd at ti.com>
> > Signed-off-by: Suman Anna <s-anna at ti.com>
> > Co-developed-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> > Signed-off-by: Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>
> > ---
> > v1->v2:
> > - Use PRU_IRAM_ADDR_MASK definition instead of raw 0x3ffff.
> > - Convert 'len' argument from int to size_t type in all *da_to_va.
> > - Return 0 in case of missing .resource_table for pru_rproc_parse_fw()
> > (move the logic from patch #3 where it was corrected).
> > ---
> > drivers/remoteproc/Kconfig | 12 +
> > drivers/remoteproc/Makefile | 1 +
> > drivers/remoteproc/pru_rproc.c | 435 +++++++++++++++++++++++++++++++++
> > 3 files changed, 448 insertions(+)
> > create mode 100644 drivers/remoteproc/pru_rproc.c
> >
> > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> > index d99548fb5dde..3e3865a7cd78 100644
> > --- a/drivers/remoteproc/Kconfig
> > +++ b/drivers/remoteproc/Kconfig
> > @@ -125,6 +125,18 @@ config KEYSTONE_REMOTEPROC
> > It's safe to say N here if you're not interested in the Keystone
> > DSPs or just want to use a bare minimum kernel.
> >
> > +config PRU_REMOTEPROC
> > + tristate "TI PRU remoteproc support"
> > + depends on TI_PRUSS
> > + default TI_PRUSS
> > + help
> > + Support for TI PRU remote processors present within a PRU-ICSS
> > + subsystem via the remote processor framework.
> > +
> > + Say Y or M here to support the Programmable Realtime Unit (PRU)
> > + processors on various TI SoCs. It's safe to say N here if you're
> > + not interested in the PRU or if you are unsure.
> > +
> > config QCOM_PIL_INFO
> > tristate
> >
> > diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> > index da2ace4ec86c..bb26c9e4ef9c 100644
> > --- a/drivers/remoteproc/Makefile
> > +++ b/drivers/remoteproc/Makefile
> > @@ -18,6 +18,7 @@ obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o
> > obj-$(CONFIG_WKUP_M3_RPROC) += wkup_m3_rproc.o
> > obj-$(CONFIG_DA8XX_REMOTEPROC) += da8xx_remoteproc.o
> > obj-$(CONFIG_KEYSTONE_REMOTEPROC) += keystone_remoteproc.o
> > +obj-$(CONFIG_PRU_REMOTEPROC) += pru_rproc.o
> > obj-$(CONFIG_QCOM_PIL_INFO) += qcom_pil_info.o
> > obj-$(CONFIG_QCOM_RPROC_COMMON) += qcom_common.o
> > obj-$(CONFIG_QCOM_Q6V5_COMMON) += qcom_q6v5.o
> > diff --git a/drivers/remoteproc/pru_rproc.c b/drivers/remoteproc/pru_rproc.c
> > new file mode 100644
> > index 000000000000..b686f19f9b1a
> > --- /dev/null
> > +++ b/drivers/remoteproc/pru_rproc.c
> > @@ -0,0 +1,435 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * PRU-ICSS remoteproc driver for various TI SoCs
> > + *
> > + * Copyright (C) 2014-2020 Texas Instruments Incorporated - https://www.ti.com/
> > + *
> > + * Author(s):
> > + * Suman Anna <s-anna at ti.com>
> > + * Andrew F. Davis <afd at ti.com>
> > + * Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org> for Texas Instruments
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/pruss_driver.h>
> > +#include <linux/remoteproc.h>
> > +
> > +#include "remoteproc_internal.h"
> > +#include "remoteproc_elf_helpers.h"
> > +
> > +/* PRU_ICSS_PRU_CTRL registers */
> > +#define PRU_CTRL_CTRL 0x0000
> > +#define PRU_CTRL_STS 0x0004
> > +
> > +/* CTRL register bit-fields */
> > +#define CTRL_CTRL_SOFT_RST_N BIT(0)
> > +#define CTRL_CTRL_EN BIT(1)
> > +#define CTRL_CTRL_SLEEPING BIT(2)
> > +#define CTRL_CTRL_CTR_EN BIT(3)
> > +#define CTRL_CTRL_SINGLE_STEP BIT(8)
> > +#define CTRL_CTRL_RUNSTATE BIT(15)
> > +
> > +/* PRU Core IRAM address masks */
> > +#define PRU_IRAM_ADDR_MASK 0x3ffff
> > +#define PRU0_IRAM_ADDR_MASK 0x34000
> > +#define PRU1_IRAM_ADDR_MASK 0x38000
> > +
> > +/* PRU device addresses for various type of PRU RAMs */
> > +#define PRU_IRAM_DA 0 /* Instruction RAM */
> > +#define PRU_PDRAM_DA 0 /* Primary Data RAM */
> > +#define PRU_SDRAM_DA 0x2000 /* Secondary Data RAM */
> > +#define PRU_SHRDRAM_DA 0x10000 /* Shared Data RAM */
> > +
> > +/**
> > + * enum pru_iomem - PRU core memory/register range identifiers
> > + *
> > + * @PRU_IOMEM_IRAM: PRU Instruction RAM range
> > + * @PRU_IOMEM_CTRL: PRU Control register range
> > + * @PRU_IOMEM_DEBUG: PRU Debug register range
> > + * @PRU_IOMEM_MAX: just keep this one at the end
> > + */
> > +enum pru_iomem {
> > + PRU_IOMEM_IRAM = 0,
> > + PRU_IOMEM_CTRL,
> > + PRU_IOMEM_DEBUG,
> > + PRU_IOMEM_MAX,
> > +};
> > +
> > +/**
> > + * struct pru_rproc - PRU remoteproc structure
> > + * @id: id of the PRU core within the PRUSS
> > + * @dev: PRU core device pointer
> > + * @pruss: back-reference to parent PRUSS structure
> > + * @rproc: remoteproc pointer for this PRU core
> > + * @mem_regions: data for each of the PRU memory regions
> > + * @fw_name: name of firmware image used during loading
> > + */
> > +struct pru_rproc {
> > + int id;
> > + struct device *dev;
> > + struct pruss *pruss;
> > + struct rproc *rproc;
> > + struct pruss_mem_region mem_regions[PRU_IOMEM_MAX];
> > + const char *fw_name;
> > +};
> > +
> > +static inline u32 pru_control_read_reg(struct pru_rproc *pru, unsigned int reg)
> > +{
> > + return readl_relaxed(pru->mem_regions[PRU_IOMEM_CTRL].va + reg);
> > +}
> > +
> > +static inline
> > +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 int pru_rproc_start(struct rproc *rproc)
> > +{
> > + struct device *dev = &rproc->dev;
> > + struct pru_rproc *pru = rproc->priv;
> > + u32 val;
> > +
> > + dev_dbg(dev, "starting PRU%d: entry-point = 0x%llx\n",
> > + pru->id, (rproc->bootaddr >> 2));
> > +
> > + val = CTRL_CTRL_EN | ((rproc->bootaddr >> 2) << 16);
> > + pru_control_write_reg(pru, PRU_CTRL_CTRL, val);
> > +
> > + return 0;
> > +}
> > +
> > +static int pru_rproc_stop(struct rproc *rproc)
> > +{
> > + struct device *dev = &rproc->dev;
> > + struct pru_rproc *pru = rproc->priv;
> > + u32 val;
> > +
> > + dev_dbg(dev, "stopping PRU%d\n", pru->id);
> > +
> > + val = pru_control_read_reg(pru, PRU_CTRL_CTRL);
> > + val &= ~CTRL_CTRL_EN;
> > + pru_control_write_reg(pru, PRU_CTRL_CTRL, val);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Convert PRU device address (data spaces only) to kernel virtual address.
> > + *
> > + * Each PRU has access to all data memories within the PRUSS, accessible at
> > + * different ranges. So, look through both its primary and secondary Data
> > + * RAMs as well as any shared Data RAM to convert a PRU device address to
> > + * kernel virtual address. Data RAM0 is primary Data RAM for PRU0 and Data
> > + * RAM1 is primary Data RAM for PRU1.
> > + */
> > +static void *pru_d_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
> > +{
> > + struct pruss_mem_region dram0, dram1, shrd_ram;
> > + struct pruss *pruss = pru->pruss;
> > + u32 offset;
> > + void *va = NULL;
> > +
> > + if (len == 0)
> > + return NULL;
> > +
> > + 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)
> > + swap(dram0, dram1);
> > + shrd_ram = pruss->mem_regions[PRUSS_MEM_SHRD_RAM2];
> > +
> > + if (da >= PRU_PDRAM_DA && da + len <= PRU_PDRAM_DA + dram0.size) {
> > + offset = da - PRU_PDRAM_DA;
> > + va = (__force void *)(dram0.va + offset);
> > + } else if (da >= PRU_SDRAM_DA &&
> > + da + len <= PRU_SDRAM_DA + dram1.size) {
> > + offset = da - PRU_SDRAM_DA;
> > + va = (__force void *)(dram1.va + offset);
> > + } else if (da >= PRU_SHRDRAM_DA &&
> > + da + len <= PRU_SHRDRAM_DA + shrd_ram.size) {
> > + offset = da - PRU_SHRDRAM_DA;
> > + va = (__force void *)(shrd_ram.va + offset);
> > + }
> > +
> > + return va;
> > +}
> > +
> > +/*
> > + * Convert PRU device address (instruction space) to kernel virtual address.
> > + *
> > + * A PRU does not have an unified address space. Each PRU has its very own
> > + * private Instruction RAM, and its device address is identical to that of
> > + * its primary Data RAM device address.
> > + */
> > +static void *pru_i_da_to_va(struct pru_rproc *pru, u32 da, size_t len)
> > +{
> > + u32 offset;
> > + void *va = NULL;
> > +
> > + if (len == 0)
> > + return NULL;
> > +
> > + if (da >= PRU_IRAM_DA &&
> > + da + len <= PRU_IRAM_DA + pru->mem_regions[PRU_IOMEM_IRAM].size) {
> > + offset = da - PRU_IRAM_DA;
> > + va = (__force void *)(pru->mem_regions[PRU_IOMEM_IRAM].va +
> > + offset);
> > + }
> > +
> > + return va;
> > +}
> > +
> > +/*
> > + * Provide address translations for only PRU Data RAMs through the remoteproc
> > + * core for any PRU client drivers. The PRU Instruction RAM access is restricted
> > + * only to the PRU loader code.
> > + */
> > +static void *pru_rproc_da_to_va(struct rproc *rproc, u64 da, size_t len)
> > +{
> > + struct pru_rproc *pru = rproc->priv;
> > +
> > + return pru_d_da_to_va(pru, da, len);
> > +}
> > +
> > +/* PRU-specific address translator used by PRU loader. */
> > +static void *pru_da_to_va(struct rproc *rproc, u64 da, size_t len, bool is_iram)
> > +{
> > + struct pru_rproc *pru = rproc->priv;
> > + void *va;
> > +
> > + if (is_iram)
> > + va = pru_i_da_to_va(pru, da, len);
> > + else
> > + va = pru_d_da_to_va(pru, da, len);
> > +
> > + return va;
> > +}
> > +
> > +static struct rproc_ops pru_rproc_ops = {
> > + .start = pru_rproc_start,
> > + .stop = pru_rproc_stop,
> > + .da_to_va = pru_rproc_da_to_va,
> > +};
> > +
> > +static int
> > +pru_rproc_load_elf_segments(struct rproc *rproc, const struct firmware *fw)
> > +{
> > + struct device *dev = &rproc->dev;
> > + struct elf32_hdr *ehdr;
> > + struct elf32_phdr *phdr;
> > + int i, ret = 0;
> > + const u8 *elf_data = fw->data;
> > +
> > + ehdr = (struct elf32_hdr *)elf_data;
> > + phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
> > +
> > + /* go through the available ELF segments */
> > + for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
> > + u32 da = phdr->p_paddr;
> > + u32 memsz = phdr->p_memsz;
> > + u32 filesz = phdr->p_filesz;
> > + u32 offset = phdr->p_offset;
> > + bool is_iram;
> > + void *ptr;
> > +
> > + if (phdr->p_type != PT_LOAD)
> > + continue;
> > +
> > + dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
> > + phdr->p_type, da, memsz, filesz);
> > +
> > + if (filesz > memsz) {
> > + dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
> > + filesz, memsz);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + if (offset + filesz > fw->size) {
> > + dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
> > + offset + filesz, fw->size);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + /* grab the kernel address for this device address */
> > + is_iram = phdr->p_flags & PF_X;
> > + ptr = pru_da_to_va(rproc, da, memsz, is_iram);
> > + if (!ptr) {
> > + dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
> > + ret = -EINVAL;
> > + break;
> > + }
> > +
> > + /* skip the memzero logic performed by remoteproc ELF loader */
> > + if (!phdr->p_filesz)
> > + continue;
>
> I don't see the need to do all this if phdr->p_filesz is not valid. I would move
> this below the check for PT_LOAD above. Otherwise people are looking for some
> kind of hidden logic when there isn't any. The comment should probably go
> after the memcpy().
... and thinking futher on this, it would be nice to know why the memory isn't
zero'ed out when a discrepency exists between the segment size in memory and the
segment size in the image. Right now all we know is that it isn't done.
>
> I am running out of time for today and will continue tomorrow.
>
> > +
> > + memcpy(ptr, elf_data + phdr->p_offset, filesz);
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +/*
> > + * Use a custom parse_fw callback function for dealing with PRU firmware
> > + * specific sections.
> > + */
> > +static int pru_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
> > +{
> > + int ret;
> > +
> > + /* load optional rsc table */
> > + ret = rproc_elf_load_rsc_table(rproc, fw);
> > + if (ret == -EINVAL)
> > + dev_dbg(&rproc->dev, "no resource table found for this fw\n");
> > + else if (ret)
> > + return ret;
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Compute PRU id based on the IRAM addresses. The PRU IRAMs are
> > + * always at a particular offset within the PRUSS address space.
> > + */
> > +static int pru_rproc_set_id(struct pru_rproc *pru)
> > +{
> > + int ret = 0;
> > +
> > + switch (pru->mem_regions[PRU_IOMEM_IRAM].pa & PRU_IRAM_ADDR_MASK) {
> > + case PRU0_IRAM_ADDR_MASK:
> > + pru->id = 0;
> > + break;
> > + case PRU1_IRAM_ADDR_MASK:
> > + pru->id = 1;
> > + break;
> > + default:
> > + ret = -EINVAL;
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int pru_rproc_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct device_node *np = dev->of_node;
> > + struct platform_device *ppdev = to_platform_device(dev->parent);
> > + struct pru_rproc *pru;
> > + const char *fw_name;
> > + struct rproc *rproc = NULL;
> > + struct resource *res;
> > + int i, ret;
> > + const char *mem_names[PRU_IOMEM_MAX] = { "iram", "control", "debug" };
> > +
> > + ret = of_property_read_string(np, "firmware-name", &fw_name);
> > + if (ret) {
> > + dev_err(dev, "unable to retrieve firmware-name %d\n", ret);
> > + return ret;
> > + }
> > +
> > + rproc = devm_rproc_alloc(dev, pdev->name, &pru_rproc_ops, fw_name,
> > + sizeof(*pru));
> > + if (!rproc) {
> > + dev_err(dev, "rproc_alloc failed\n");
> > + return -ENOMEM;
> > + }
> > + /* use a custom load function to deal with PRU-specific quirks */
> > + rproc->ops->load = pru_rproc_load_elf_segments;
> > +
> > + /* use a custom parse function to deal with PRU-specific resources */
> > + rproc->ops->parse_fw = pru_rproc_parse_fw;
> > +
> > + /* error recovery is not supported for PRUs */
> > + rproc->recovery_disabled = true;
> > +
> > + /*
> > + * rproc_add will auto-boot the processor normally, but this is not
> > + * desired with PRU client driven boot-flow methodology. A PRU
> > + * application/client driver will boot the corresponding PRU
> > + * remote-processor as part of its state machine either through the
> > + * remoteproc sysfs interface or through the equivalent kernel API.
> > + */
> > + rproc->auto_boot = false;
> > +
> > + pru = rproc->priv;
> > + pru->dev = dev;
> > + pru->pruss = platform_get_drvdata(ppdev);
> > + pru->rproc = rproc;
> > + pru->fw_name = fw_name;
> > +
> > + for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
> > + res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> > + mem_names[i]);
> > + pru->mem_regions[i].va = devm_ioremap_resource(dev, res);
> > + if (IS_ERR(pru->mem_regions[i].va)) {
> > + dev_err(dev, "failed to parse and map memory resource %d %s\n",
> > + i, mem_names[i]);
> > + ret = PTR_ERR(pru->mem_regions[i].va);
> > + return ret;
> > + }
> > + pru->mem_regions[i].pa = res->start;
> > + pru->mem_regions[i].size = resource_size(res);
> > +
> > + dev_dbg(dev, "memory %8s: pa %pa size 0x%zx va %pK\n",
> > + mem_names[i], &pru->mem_regions[i].pa,
> > + pru->mem_regions[i].size, pru->mem_regions[i].va);
> > + }
> > +
> > + ret = pru_rproc_set_id(pru);
> > + if (ret < 0)
> > + return ret;
> > +
> > + platform_set_drvdata(pdev, rproc);
> > +
> > + ret = devm_rproc_add(dev, pru->rproc);
> > + if (ret) {
> > + dev_err(dev, "rproc_add failed: %d\n", ret);
> > + return ret;
> > + }
> > +
> > + dev_dbg(dev, "PRU rproc node %pOF probed successfully\n", np);
> > +
> > + return 0;
> > +}
> > +
> > +static int pru_rproc_remove(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct rproc *rproc = platform_get_drvdata(pdev);
> > +
> > + dev_dbg(dev, "%s: removing rproc %s\n", __func__, rproc->name);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct of_device_id pru_rproc_match[] = {
> > + { .compatible = "ti,am3356-pru", },
> > + { .compatible = "ti,am4376-pru", },
> > + { .compatible = "ti,am5728-pru", },
> > + { .compatible = "ti,k2g-pru", },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, pru_rproc_match);
> > +
> > +static struct platform_driver pru_rproc_driver = {
> > + .driver = {
> > + .name = "pru-rproc",
> > + .of_match_table = pru_rproc_match,
> > + .suppress_bind_attrs = true,
> > + },
> > + .probe = pru_rproc_probe,
> > + .remove = pru_rproc_remove,
> > +};
> > +module_platform_driver(pru_rproc_driver);
> > +
> > +MODULE_AUTHOR("Suman Anna <s-anna at ti.com>");
> > +MODULE_AUTHOR("Andrew F. Davis <afd at ti.com>");
> > +MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk at linaro.org>");
> > +MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.29.0
> >
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