Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 553 insertions, 0 deletions

diff --git a/drivers/cdx/cdx.c b/drivers/cdx/cdx.c
new file mode 100644
index 0000000000..d2cad4c670
--- /dev/null
+++ b/drivers/cdx/cdx.c
@@ -0,0 +1,553 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CDX bus driver.
+ *
+ * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
+ */
+
+/*
+ * Architecture Overview
+ * =====================
+ * CDX is a Hardware Architecture designed for AMD FPGA devices. It
+ * consists of sophisticated mechanism for interaction between FPGA,
+ * Firmware and the APUs (Application CPUs).
+ *
+ * Firmware resides on RPU (Realtime CPUs) which interacts with
+ * the FPGA program manager and the APUs. The RPU provides memory-mapped
+ * interface (RPU if) which is used to communicate with APUs.
+ *
+ * The diagram below shows an overview of the CDX architecture:
+ *
+ *          +--------------------------------------+
+ *          |    Application CPUs (APU)            |
+ *          |                                      |
+ *          |                    CDX device drivers|
+ *          |     Linux OS                |        |
+ *          |                        CDX bus       |
+ *          |                             |        |
+ *          |                     CDX controller   |
+ *          |                             |        |
+ *          +-----------------------------|--------+
+ *                                        | (discover, config,
+ *                                        |  reset, rescan)
+ *                                        |
+ *          +------------------------| RPU if |----+
+ *          |                             |        |
+ *          |                             V        |
+ *          |          Realtime CPUs (RPU)         |
+ *          |                                      |
+ *          +--------------------------------------+
+ *                                |
+ *          +---------------------|----------------+
+ *          |  FPGA               |                |
+ *          |      +-----------------------+       |
+ *          |      |           |           |       |
+ *          | +-------+    +-------+   +-------+   |
+ *          | | dev 1 |    | dev 2 |   | dev 3 |   |
+ *          | +-------+    +-------+   +-------+   |
+ *          +--------------------------------------+
+ *
+ * The RPU firmware extracts the device information from the loaded FPGA
+ * image and implements a mechanism that allows the APU drivers to
+ * enumerate such devices (device personality and resource details) via
+ * a dedicated communication channel. RPU mediates operations such as
+ * discover, reset and rescan of the FPGA devices for the APU. This is
+ * done using memory mapped interface provided by the RPU to APU.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/xarray.h>
+#include <linux/cdx/cdx_bus.h>
+#include <linux/iommu.h>
+#include <linux/dma-map-ops.h>
+#include "cdx.h"
+
+/* Default DMA mask for devices on a CDX bus */
+#define CDX_DEFAULT_DMA_MASK	(~0ULL)
+#define MAX_CDX_CONTROLLERS 16
+
+/* CDX controllers registered with the CDX bus */
+static DEFINE_XARRAY_ALLOC(cdx_controllers);
+
+/**
+ * cdx_dev_reset - Reset a CDX device
+ * @dev: CDX device
+ *
+ * Return: -errno on failure, 0 on success.
+ */
+int cdx_dev_reset(struct device *dev)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_controller *cdx = cdx_dev->cdx;
+	struct cdx_device_config dev_config = {0};
+	struct cdx_driver *cdx_drv;
+	int ret;
+
+	cdx_drv = to_cdx_driver(dev->driver);
+	/* Notify driver that device is being reset */
+	if (cdx_drv && cdx_drv->reset_prepare)
+		cdx_drv->reset_prepare(cdx_dev);
+
+	dev_config.type = CDX_DEV_RESET_CONF;
+	ret = cdx->ops->dev_configure(cdx, cdx_dev->bus_num,
+				      cdx_dev->dev_num, &dev_config);
+	if (ret)
+		dev_err(dev, "cdx device reset failed\n");
+
+	/* Notify driver that device reset is complete */
+	if (cdx_drv && cdx_drv->reset_done)
+		cdx_drv->reset_done(cdx_dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_dev_reset);
+
+/**
+ * cdx_unregister_device - Unregister a CDX device
+ * @dev: CDX device
+ * @data: This is always passed as NULL, and is not used in this API,
+ *	  but is required here as the bus_for_each_dev() API expects
+ *	  the passed function (cdx_unregister_device) to have this
+ *	  as an argument.
+ *
+ * Return: 0 on success.
+ */
+static int cdx_unregister_device(struct device *dev,
+				 void *data)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	kfree(cdx_dev->driver_override);
+	cdx_dev->driver_override = NULL;
+	/*
+	 * Do not free cdx_dev here as it would be freed in
+	 * cdx_device_release() called from within put_device().
+	 */
+	device_del(&cdx_dev->dev);
+	put_device(&cdx_dev->dev);
+
+	return 0;
+}
+
+static void cdx_unregister_devices(struct bus_type *bus)
+{
+	/* Reset all the devices attached to cdx bus */
+	bus_for_each_dev(bus, NULL, NULL, cdx_unregister_device);
+}
+
+/**
+ * cdx_match_one_device - Tell if a CDX device structure has a matching
+ *			  CDX device id structure
+ * @id: single CDX device id structure to match
+ * @dev: the CDX device structure to match against
+ *
+ * Return: matching cdx_device_id structure or NULL if there is no match.
+ */
+static inline const struct cdx_device_id *
+cdx_match_one_device(const struct cdx_device_id *id,
+		     const struct cdx_device *dev)
+{
+	/* Use vendor ID and device ID for matching */
+	if ((id->vendor == CDX_ANY_ID || id->vendor == dev->vendor) &&
+	    (id->device == CDX_ANY_ID || id->device == dev->device))
+		return id;
+	return NULL;
+}
+
+/**
+ * cdx_match_id - See if a CDX device matches a given cdx_id table
+ * @ids: array of CDX device ID structures to search in
+ * @dev: the CDX device structure to match against.
+ *
+ * Used by a driver to check whether a CDX device is in its list of
+ * supported devices. Returns the matching cdx_device_id structure or
+ * NULL if there is no match.
+ *
+ * Return: matching cdx_device_id structure or NULL if there is no match.
+ */
+static inline const struct cdx_device_id *
+cdx_match_id(const struct cdx_device_id *ids, struct cdx_device *dev)
+{
+	if (ids) {
+		while (ids->vendor || ids->device) {
+			if (cdx_match_one_device(ids, dev))
+				return ids;
+			ids++;
+		}
+	}
+	return NULL;
+}
+
+/**
+ * cdx_bus_match - device to driver matching callback
+ * @dev: the cdx device to match against
+ * @drv: the device driver to search for matching cdx device
+ * structures
+ *
+ * Return: true on success, false otherwise.
+ */
+static int cdx_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	struct cdx_driver *cdx_drv = to_cdx_driver(drv);
+	const struct cdx_device_id *found_id = NULL;
+	const struct cdx_device_id *ids;
+
+	ids = cdx_drv->match_id_table;
+
+	/* When driver_override is set, only bind to the matching driver */
+	if (cdx_dev->driver_override && strcmp(cdx_dev->driver_override, drv->name))
+		return false;
+
+	found_id = cdx_match_id(ids, cdx_dev);
+	if (!found_id)
+		return false;
+
+	do {
+		/*
+		 * In case override_only was set, enforce driver_override
+		 * matching.
+		 */
+		if (!found_id->override_only)
+			return true;
+		if (cdx_dev->driver_override)
+			return true;
+
+		ids = found_id + 1;
+		found_id = cdx_match_id(ids, cdx_dev);
+	} while (found_id);
+
+	return false;
+}
+
+static int cdx_probe(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	int error;
+
+	error = cdx_drv->probe(cdx_dev);
+	if (error) {
+		dev_err_probe(dev, error, "%s failed\n", __func__);
+		return error;
+	}
+
+	return 0;
+}
+
+static void cdx_remove(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	if (cdx_drv && cdx_drv->remove)
+		cdx_drv->remove(cdx_dev);
+}
+
+static void cdx_shutdown(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	if (cdx_drv && cdx_drv->shutdown)
+		cdx_drv->shutdown(cdx_dev);
+}
+
+static int cdx_dma_configure(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	u32 input_id = cdx_dev->req_id;
+	int ret;
+
+	ret = of_dma_configure_id(dev, dev->parent->of_node, 0, &input_id);
+	if (ret && ret != -EPROBE_DEFER) {
+		dev_err(dev, "of_dma_configure_id() failed\n");
+		return ret;
+	}
+
+	if (!ret && !cdx_drv->driver_managed_dma) {
+		ret = iommu_device_use_default_domain(dev);
+		if (ret)
+			arch_teardown_dma_ops(dev);
+	}
+
+	return 0;
+}
+
+static void cdx_dma_cleanup(struct device *dev)
+{
+	struct cdx_driver *cdx_drv = to_cdx_driver(dev->driver);
+
+	if (!cdx_drv->driver_managed_dma)
+		iommu_device_unuse_default_domain(dev);
+}
+
+/* show configuration fields */
+#define cdx_config_attr(field, format_string)	\
+static ssize_t	\
+field##_show(struct device *dev, struct device_attribute *attr, char *buf)	\
+{	\
+	struct cdx_device *cdx_dev = to_cdx_device(dev);	\
+	return sysfs_emit(buf, format_string, cdx_dev->field);	\
+}	\
+static DEVICE_ATTR_RO(field)
+
+cdx_config_attr(vendor, "0x%04x\n");
+cdx_config_attr(device, "0x%04x\n");
+
+static ssize_t remove_store(struct device *dev,
+			    struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	bool val;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	if (device_remove_file_self(dev, attr)) {
+		int ret;
+
+		ret = cdx_unregister_device(dev, NULL);
+		if (ret)
+			return ret;
+	}
+
+	return count;
+}
+static DEVICE_ATTR_WO(remove);
+
+static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	bool val;
+	int ret;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	ret = cdx_dev_reset(dev);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_WO(reset);
+
+static ssize_t driver_override_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+	int ret;
+
+	if (WARN_ON(dev->bus != &cdx_bus_type))
+		return -EINVAL;
+
+	ret = driver_set_override(dev, &cdx_dev->driver_override, buf, count);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t driver_override_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	return sysfs_emit(buf, "%s\n", cdx_dev->driver_override);
+}
+static DEVICE_ATTR_RW(driver_override);
+
+static struct attribute *cdx_dev_attrs[] = {
+	&dev_attr_remove.attr,
+	&dev_attr_reset.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_device.attr,
+	&dev_attr_driver_override.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cdx_dev);
+
+static ssize_t rescan_store(const struct bus_type *bus,
+			    const char *buf, size_t count)
+{
+	struct cdx_controller *cdx;
+	unsigned long index;
+	bool val;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	if (!val)
+		return -EINVAL;
+
+	/* Unregister all the devices on the bus */
+	cdx_unregister_devices(&cdx_bus_type);
+
+	/* Rescan all the devices */
+	xa_for_each(&cdx_controllers, index, cdx) {
+		int ret;
+
+		ret = cdx->ops->scan(cdx);
+		if (ret)
+			dev_err(cdx->dev, "cdx bus scanning failed\n");
+	}
+
+	return count;
+}
+static BUS_ATTR_WO(rescan);
+
+static struct attribute *cdx_bus_attrs[] = {
+	&bus_attr_rescan.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cdx_bus);
+
+struct bus_type cdx_bus_type = {
+	.name		= "cdx",
+	.match		= cdx_bus_match,
+	.probe		= cdx_probe,
+	.remove		= cdx_remove,
+	.shutdown	= cdx_shutdown,
+	.dma_configure	= cdx_dma_configure,
+	.dma_cleanup	= cdx_dma_cleanup,
+	.bus_groups	= cdx_bus_groups,
+	.dev_groups	= cdx_dev_groups,
+};
+EXPORT_SYMBOL_GPL(cdx_bus_type);
+
+int __cdx_driver_register(struct cdx_driver *cdx_driver,
+			  struct module *owner)
+{
+	int error;
+
+	cdx_driver->driver.owner = owner;
+	cdx_driver->driver.bus = &cdx_bus_type;
+
+	error = driver_register(&cdx_driver->driver);
+	if (error) {
+		pr_err("driver_register() failed for %s: %d\n",
+		       cdx_driver->driver.name, error);
+		return error;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__cdx_driver_register);
+
+void cdx_driver_unregister(struct cdx_driver *cdx_driver)
+{
+	driver_unregister(&cdx_driver->driver);
+}
+EXPORT_SYMBOL_GPL(cdx_driver_unregister);
+
+static void cdx_device_release(struct device *dev)
+{
+	struct cdx_device *cdx_dev = to_cdx_device(dev);
+
+	kfree(cdx_dev);
+}
+
+int cdx_device_add(struct cdx_dev_params *dev_params)
+{
+	struct cdx_controller *cdx = dev_params->cdx;
+	struct device *parent = cdx->dev;
+	struct cdx_device *cdx_dev;
+	int ret;
+
+	cdx_dev = kzalloc(sizeof(*cdx_dev), GFP_KERNEL);
+	if (!cdx_dev)
+		return -ENOMEM;
+
+	/* Populate resource */
+	memcpy(cdx_dev->res, dev_params->res, sizeof(struct resource) *
+		dev_params->res_count);
+	cdx_dev->res_count = dev_params->res_count;
+
+	/* Populate CDX dev params */
+	cdx_dev->req_id = dev_params->req_id;
+	cdx_dev->vendor = dev_params->vendor;
+	cdx_dev->device = dev_params->device;
+	cdx_dev->bus_num = dev_params->bus_num;
+	cdx_dev->dev_num = dev_params->dev_num;
+	cdx_dev->cdx = dev_params->cdx;
+	cdx_dev->dma_mask = CDX_DEFAULT_DMA_MASK;
+
+	/* Initialize generic device */
+	device_initialize(&cdx_dev->dev);
+	cdx_dev->dev.parent = parent;
+	cdx_dev->dev.bus = &cdx_bus_type;
+	cdx_dev->dev.dma_mask = &cdx_dev->dma_mask;
+	cdx_dev->dev.release = cdx_device_release;
+
+	/* Set Name */
+	dev_set_name(&cdx_dev->dev, "cdx-%02x:%02x",
+		     ((cdx->id << CDX_CONTROLLER_ID_SHIFT) | (cdx_dev->bus_num & CDX_BUS_NUM_MASK)),
+		     cdx_dev->dev_num);
+
+	ret = device_add(&cdx_dev->dev);
+	if (ret) {
+		dev_err(&cdx_dev->dev,
+			"cdx device add failed: %d", ret);
+		goto fail;
+	}
+
+	return 0;
+fail:
+	/*
+	 * Do not free cdx_dev here as it would be freed in
+	 * cdx_device_release() called from put_device().
+	 */
+	put_device(&cdx_dev->dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cdx_device_add);
+
+int cdx_register_controller(struct cdx_controller *cdx)
+{
+	int ret;
+
+	ret = xa_alloc(&cdx_controllers, &cdx->id, cdx,
+		       XA_LIMIT(0, MAX_CDX_CONTROLLERS - 1), GFP_KERNEL);
+	if (ret) {
+		dev_err(cdx->dev,
+			"No free index available. Maximum controllers already registered\n");
+		cdx->id = (u8)MAX_CDX_CONTROLLERS;
+		return ret;
+	}
+
+	/* Scan all the devices */
+	cdx->ops->scan(cdx);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdx_register_controller);
+
+void cdx_unregister_controller(struct cdx_controller *cdx)
+{
+	if (cdx->id >= MAX_CDX_CONTROLLERS)
+		return;
+
+	device_for_each_child(cdx->dev, NULL, cdx_unregister_device);
+	xa_erase(&cdx_controllers, cdx->id);
+}
+EXPORT_SYMBOL_GPL(cdx_unregister_controller);
+
+static int __init cdx_bus_init(void)
+{
+	return bus_register(&cdx_bus_type);
+}
+postcore_initcall(cdx_bus_init);