path: root/drivers/pci/endpoint/functions/pci-epf-test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Test driver to test endpoint functionality
 *
 * Copyright (C) 2017 Texas Instruments
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <linux/crc32.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci_ids.h>
#include <linux/random.h>

#include <linux/pci-epc.h>
#include <linux/pci-epf.h>
#include <linux/pci_regs.h>

#define IRQ_TYPE_LEGACY			0
#define IRQ_TYPE_MSI			1
#define IRQ_TYPE_MSIX			2

#define COMMAND_RAISE_LEGACY_IRQ	BIT(0)
#define COMMAND_RAISE_MSI_IRQ		BIT(1)
#define COMMAND_RAISE_MSIX_IRQ		BIT(2)
#define COMMAND_READ			BIT(3)
#define COMMAND_WRITE			BIT(4)
#define COMMAND_COPY			BIT(5)

#define STATUS_READ_SUCCESS		BIT(0)
#define STATUS_READ_FAIL		BIT(1)
#define STATUS_WRITE_SUCCESS		BIT(2)
#define STATUS_WRITE_FAIL		BIT(3)
#define STATUS_COPY_SUCCESS		BIT(4)
#define STATUS_COPY_FAIL		BIT(5)
#define STATUS_IRQ_RAISED		BIT(6)
#define STATUS_SRC_ADDR_INVALID		BIT(7)
#define STATUS_DST_ADDR_INVALID		BIT(8)

#define FLAG_USE_DMA			BIT(0)

#define TIMER_RESOLUTION		1

static struct workqueue_struct *kpcitest_workqueue;

struct pci_epf_test {
	void			*reg[PCI_STD_NUM_BARS];
	struct pci_epf		*epf;
	enum pci_barno		test_reg_bar;
	size_t			msix_table_offset;
	struct delayed_work	cmd_handler;
	struct dma_chan		*dma_chan_tx;
	struct dma_chan		*dma_chan_rx;
	struct completion	transfer_complete;
	bool			dma_supported;
	bool			dma_private;
	const struct pci_epc_features *epc_features;
};

struct pci_epf_test_reg {
	u32	magic;
	u32	command;
	u32	status;
	u64	src_addr;
	u64	dst_addr;
	u32	size;
	u32	checksum;
	u32	irq_type;
	u32	irq_number;
	u32	flags;
} __packed;

static struct pci_epf_header test_header = {
	.vendorid	= PCI_ANY_ID,
	.deviceid	= PCI_ANY_ID,
	.baseclass_code = PCI_CLASS_OTHERS,
	.interrupt_pin	= PCI_INTERRUPT_INTA,
};

static size_t bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 };

static void pci_epf_test_dma_callback(void *param)
{
	struct pci_epf_test *epf_test = param;

	complete(&epf_test->transfer_complete);
}

/**
 * pci_epf_test_data_transfer() - Function that uses dmaengine API to transfer
 *				  data between PCIe EP and remote PCIe RC
 * @epf_test: the EPF test device that performs the data transfer operation
 * @dma_dst: The destination address of the data transfer. It can be a physical
 *	     address given by pci_epc_mem_alloc_addr or DMA mapping APIs.
 * @dma_src: The source address of the data transfer. It can be a physical
 *	     address given by pci_epc_mem_alloc_addr or DMA mapping APIs.
 * @len: The size of the data transfer
 * @dma_remote: remote RC physical address
 * @dir: DMA transfer direction
 *
 * Function that uses dmaengine API to transfer data between PCIe EP and remote
 * PCIe RC. The source and destination address can be a physical address given
 * by pci_epc_mem_alloc_addr or the one obtained using DMA mapping APIs.
 *
 * The function returns '0' on success and negative value on failure.
 */
static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test,
				      dma_addr_t dma_dst, dma_addr_t dma_src,
				      size_t len, dma_addr_t dma_remote,
				      enum dma_transfer_direction dir)
{
	struct dma_chan *chan = (dir == DMA_DEV_TO_MEM) ?
				 epf_test->dma_chan_tx : epf_test->dma_chan_rx;
	dma_addr_t dma_local = (dir == DMA_MEM_TO_DEV) ? dma_src : dma_dst;
	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
	struct pci_epf *epf = epf_test->epf;
	struct dma_async_tx_descriptor *tx;
	struct dma_slave_config sconf = {};
	struct device *dev = &epf->dev;
	dma_cookie_t cookie;
	int ret;

	if (IS_ERR_OR_NULL(chan)) {
		dev_err(dev, "Invalid DMA memcpy channel\n");
		return -EINVAL;
	}

	if (epf_test->dma_private) {
		sconf.direction = dir;
		if (dir == DMA_MEM_TO_DEV)
			sconf.dst_addr = dma_remote;
		else
			sconf.src_addr = dma_remote;

		if (dmaengine_slave_config(chan, &sconf)) {
			dev_err(dev, "DMA slave config fail\n");
			return -EIO;
		}
		tx = dmaengine_prep_slave_single(chan, dma_local, len, dir,
						 flags);
	} else {
		tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len,
					       flags);
	}

	if (!tx) {
		dev_err(dev, "Failed to prepare DMA memcpy\n");
		return -EIO;
	}

	tx->callback = pci_epf_test_dma_callback;
	tx->callback_param = epf_test;
	cookie = tx->tx_submit(tx);
	reinit_completion(&epf_test->transfer_complete);

	ret = dma_submit_error(cookie);
	if (ret) {
		dev_err(dev, "Failed to do DMA tx_submit %d\n", cookie);
		return -EIO;
	}

	dma_async_issue_pending(chan);
	ret = wait_for_completion_interruptible(&epf_test->transfer_complete);
	if (ret < 0) {
		dmaengine_terminate_sync(chan);
		dev_err(dev, "DMA wait_for_completion_timeout\n");
		return -ETIMEDOUT;
	}

	return 0;
}

struct epf_dma_filter {
	struct device *dev;
	u32 dma_mask;
};

static bool epf_dma_filter_fn(struct dma_chan *chan, void *node)
{
	struct epf_dma_filter *filter = node;
	struct dma_slave_caps caps;

	memset(&caps, 0, sizeof(caps));
	dma_get_slave_caps(chan, &caps);

	return chan->device->dev == filter->dev
		&& (filter->dma_mask & caps.directions);
}

/**
 * pci_epf_test_init_dma_chan() - Function to initialize EPF test DMA channel
 * @epf_test: the EPF test device that perform