linux/drivers/remoteproc/pru_rproc.c

// 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@ti.com>
 *	Andrew F. Davis <afd@ti.com>
 *	Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org> for Texas Instruments
 */

#include <linux/bitops.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/pruss_driver.h>
#include <linux/remoteproc.h>

#include "remoteproc_internal.h"
#include "remoteproc_elf_helpers.h"
#include "pru_rproc.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 */

#define MAX_PRU_SYS_EVENTS 160

/**
 * 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
 * @mapped_irq: virtual interrupt numbers of created fw specific mapping
 * @pru_interrupt_map: pointer to interrupt mapping description (firmware)
 * @pru_interrupt_map_sz: pru_interrupt_map size
 * @evt_count: number of mapped events
 */
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;
	unsigned int *mapped_irq;
	struct pru_irq_rsc *pru_interrupt_map;
	size_t pru_interrupt_map_sz;
	u8 evt_count;
};

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 void pru_dispose_irq_mapping(struct pru_rproc *pru)
{
	while (pru->evt_count--) {
		if (pru->mapped_irq[pru->evt_count] > 0)
			irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);
	}

	kfree(pru->mapped_irq);
}

/*
 * Parse the custom PRU interrupt map resource and configure the INTC
 * appropriately.
 */
static int pru_handle_intrmap(struct rproc *rproc)
{
	struct device *dev = rproc->dev.parent;
	struct pru_rproc *pru = rproc->priv;
	struct pru_irq_rsc *rsc = pru->pru_interrupt_map;
	struct irq_fwspec fwspec;
	struct device_node *irq_parent;
	int i, ret = 0;

	/* not having pru_interrupt_map is not an error */
	if (!rsc)
		return 0;

	/* currently supporting only type 0 */
	if (rsc->type != 0) {
		dev_err(dev, "unsupported rsc type: %d\n", rsc->type);
		return -EINVAL;
	}

	if (rsc->num_evts > MAX_PRU_SYS_EVENTS)
		return -EINVAL;

	if (sizeof(*rsc) + rsc->num_evts * sizeof(struct pruss_int_map) !=
	    pru->pru_interrupt_map_sz)
		return -EINVAL;

	pru->evt_count = rsc->num_evts;
	pru->mapped_irq = kcalloc(pru->evt_count, sizeof(unsigned int),
				  GFP_KERNEL);
	if (!pru->mapped_irq)
		return -ENOMEM;

	/*
	 * parse and fill in system event to interrupt channel and
	 * channel-to-host mapping
	 */
	irq_parent = of_irq_find_parent(pru->dev->of_node);
	if (!irq_parent) {
		kfree(pru->mapped_irq);
		return -ENODEV;
	}

	fwspec.fwnode = of_node_to_fwnode(irq_parent);
	fwspec.param_count = 3;
	for (i = 0; i < pru->evt_count; i++) {
		fwspec.param[0] = rsc->pru_intc_map[i].event;
		fwspec.param[1] = rsc->pru_intc_map[i].chnl;
		fwspec.param[2] = rsc->pru_intc_map[i].host;

		dev_dbg(dev, "mapping%d: event %d, chnl %d, host %d\n",
			i, fwspec.param[0], fwspec.param[1], fwspec.param[2]);

		pru->mapped_irq[i] = irq_create_fwspec_mapping(&fwspec);
		if (!pru->mapped_irq[i]) {
			dev_err(dev, "failed to get virq\n");
			ret = pru->mapped_irq[i];
			goto map_fail;
		}
	}

	return ret;

map_fail:
	pru_dispose_irq_mapping(pru);

	return ret;
}

static int pru_rproc_start(struct rproc *rproc)
{
	struct device *dev = &rproc->dev;
	struct pru_rproc *pru = rproc->priv;
	u32 val;
	int ret;

	dev_dbg(dev, "starting PRU%d: entry-point = 0x%llx\n",
		pru->id, (rproc->bootaddr >> 2));

	ret = pru_handle_intrmap(rproc);
	/*
	 * reset references to pru interrupt map - they will stop being valid
	 * after rproc_start returns
	 */
	pru->pru_interrupt_map = NULL;
	pru->pru_interrupt_map_sz = 0;
	if (ret)
		return ret;

	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);

	/* dispose irq mapping - new firmware can provide new mapping */
	if (pru->mapped_irq)
		pru_dispose_irq_mapping(pru);

	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 || !filesz)
			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;
		}

		memcpy(ptr, elf_data + phdr->p_offset, filesz);

		/* skip the memzero logic performed by remoteproc ELF loader */
	}

	return ret;
}

static const void *
pru_rproc_find_interrupt_map(struct device *dev, const struct firmware *fw)
{
	struct elf32_shdr *shdr, *name_table_shdr;
	const char *name_table;
	const u8 *elf_data = fw->data;
	struct elf32_hdr *ehdr = (struct elf32_hdr *)elf_data;
	u16 shnum = ehdr->e_shnum;
	u16 shstrndx = ehdr->e_shstrndx;
	int i;

	/* first, get the section header */
	shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
	/* compute name table section header entry in shdr array */
	name_table_shdr = shdr + shstrndx;
	/* finally, compute the name table section address in elf */
	name_table = elf_data + name_table_shdr->sh_offset;

	for (i = 0; i < shnum; i++, shdr++) {
		u32 size = shdr->sh_size;
		u32 offset = shdr->sh_offset;
		u32 name = shdr->sh_name;

		if (strcmp(name_table + name, ".pru_irq_map"))
			continue;

		/* make sure we have the entire irq map */
		if (offset + size > fw->size || offset + size < size) {
			dev_err(dev, ".pru_irq_map section truncated\n");
			return ERR_PTR(-EINVAL);
		}

		/* make sure irq map has at least the header */
		if (sizeof(struct pru_irq_rsc) > size) {
			dev_err(dev, "header-less .pru_irq_map section\n");
			return ERR_PTR(-EINVAL);
		}

		return shdr;
	}

	dev_dbg(dev, "no .pru_irq_map section found for this fw\n");

	return NULL;
}

/*
 * Use a custom parse_fw callback function for dealing with PRU firmware
 * specific sections.
 *
 * The firmware blob can contain optional ELF sections: .resource_table section
 * and .pru_irq_map one. The second one contains the PRUSS interrupt mapping
 * description, which needs to be setup before powering on the PRU core. To
 * avoid RAM wastage this ELF section is not mapped to any ELF segment (by the
 * firmware linker) and therefore is not loaded to PRU memory.
 */
static int pru_rproc_parse_fw(struct rproc *rproc, const struct firmware *fw)
{
	struct device *dev = &rproc->dev;
	struct pru_rproc *pru = rproc->priv;
	const u8 *elf_data = fw->data;
	const void *shdr;
	u8 class = fw_elf_get_class(fw);
	u64 sh_offset;
	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;

	/* find .pru_interrupt_map section, not having it is not an error */
	shdr = pru_rproc_find_interrupt_map(dev, fw);
	if (IS_ERR(shdr))
		return PTR_ERR(shdr);

	if (!shdr)
		return 0;

	/* preserve pointer to PRU interrupt map together with it size */
	sh_offset = elf_shdr_get_sh_offset(class, shdr);
	pru->pru_interrupt_map = (struct pru_irq_rsc *)(elf_data + sh_offset);
	pru->pru_interrupt_map_sz = elf_shdr_get_sh_size(class, shdr);

	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@ti.com>");
MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
MODULE_AUTHOR("Grzegorz Jaszczyk <grzegorz.jaszczyk@linaro.org>");
MODULE_DESCRIPTION("PRU-ICSS Remote Processor Driver");
MODULE_LICENSE("GPL v2");