/*
 * IBM PowerPC Virtual I/O Infrastructure Support.
 *
 *    Copyright (c) 2003 IBM Corp.
 *     Dave Engebretsen engebret@us.ibm.com
 *     Santiago Leon santil@us.ibm.com
 *     Hollis Blanchard <hollisb@us.ibm.com>
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/init.h>
#include <linux/console.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/mm.h>
#include <linux/dma-mapping.h>
#include <asm/rtas.h>
#include <asm/iommu.h>
#include <asm/dma.h>
#include <asm/ppcdebug.h>
#include <asm/vio.h>
#include <asm/hvcall.h>
#include <asm/iSeries/vio.h>
#include <asm/iSeries/HvCallXm.h>

#define DBGENTER() pr_debug("%s entered\n", __FUNCTION__)

extern struct subsystem devices_subsys; /* needed for vio_find_name() */

struct iommu_table *vio_build_iommu_table(struct vio_dev *dev);

#ifdef CONFIG_PPC_PSERIES
static int vio_num_address_cells;
#endif
static struct vio_dev *vio_bus_device; /* fake "parent" device */

#ifdef CONFIG_PPC_ISERIES
static struct iommu_table veth_iommu_table;
static struct iommu_table vio_iommu_table;

static struct vio_dev _veth_dev = {
	.iommu_table = &veth_iommu_table,
	.dev.bus = &vio_bus_type
};
static struct vio_dev _vio_dev  = {
	.iommu_table = &vio_iommu_table,
	.dev.bus = &vio_bus_type
};

struct vio_dev *iSeries_veth_dev = &_veth_dev;
struct device *iSeries_vio_dev = &_vio_dev.dev;

EXPORT_SYMBOL(iSeries_veth_dev);
EXPORT_SYMBOL(iSeries_vio_dev);
#endif

/* convert from struct device to struct vio_dev and pass to driver.
 * dev->driver has already been set by generic code because vio_bus_match
 * succeeded. */
static int vio_bus_probe(struct device *dev)
{
	struct vio_dev *viodev = to_vio_dev(dev);
	struct vio_driver *viodrv = to_vio_driver(dev->driver);
	const struct vio_device_id *id;
	int error = -ENODEV;

	DBGENTER();

	if (!viodrv->probe)
		return error;

	id = vio_match_device(viodrv->id_table, viodev);
	if (id) {
		error = viodrv->probe(viodev, id);
	}

	return error;
}

/* convert from struct device to struct vio_dev and pass to driver. */
static int vio_bus_remove(struct device *dev)
{
	struct vio_dev *viodev = to_vio_dev(dev);
	struct vio_driver *viodrv = to_vio_driver(dev->driver);

	DBGENTER();

	if (viodrv->remove) {
		return viodrv->remove(viodev);
	}

	/* driver can't remove */
	return 1;
}

/**
 * vio_register_driver: - Register a new vio driver
 * @drv:	The vio_driver structure to be registered.
 */
int vio_register_driver(struct vio_driver *viodrv)
{
	printk(KERN_DEBUG "%s: driver %s registering\n", __FUNCTION__,
		viodrv->name);

	/* fill in 'struct driver' fields */
	viodrv->driver.name = viodrv->name;
	viodrv->driver.bus = &vio_bus_type;
	viodrv->driver.probe = vio_bus_probe;
	viodrv->driver.remove = vio_bus_remove;

	return driver_register(&viodrv->driver);
}
EXPORT_SYMBOL(vio_register_driver);

/**
 * vio_unregister_driver - Remove registration of vio driver.
 * @driver:	The vio_driver struct to be removed form registration
 */
void vio_unregister_driver(struct vio_driver *viodrv)
{
	driver_unregister(&viodrv->driver);
}
EXPORT_SYMBOL(vio_unregister_driver);

/**
 * vio_match_device: - Tell if a VIO device has a matching VIO device id structure.
 * @ids: 	array of VIO device id structures to search in
 * @dev: 	the VIO device structure to match against
 *
 * Used by a driver to check whether a VIO device present in the
 * system is in its list of supported devices. Returns the matching
 * vio_device_id structure or NULL if there is no match.
 */
const struct vio_device_id * vio_match_device(const struct vio_device_id *ids,
	const struct vio_dev *dev)
{
	DBGENTER();

#ifdef CONFIG_PPC_PSERIES
	while (ids->type) {
		if ((strncmp(dev->archdata->type, ids->type, strlen(ids->type)) == 0) &&
			device_is_compatible((struct device_node*)dev->archdata, ids->compat))
			return ids;
		ids++;
	}
#endif
	return NULL;
}

#ifdef CONFIG_PPC_ISERIES
void __init iommu_vio_init(void)
{
	struct iommu_table *t;
	struct iommu_table_cb cb;
	unsigned long cbp;

	cb.itc_busno = 255;    /* Bus 255 is the virtual bus */
	cb.itc_virtbus = 0xff; /* Ask for virtual bus */

	cbp = virt_to_abs(&cb);
	HvCallXm_getTceTableParms(cbp);

	veth_iommu_table.it_size        = cb.itc_size / 2;
	veth_iommu_table.it_busno       = cb.itc_busno;
	veth_iommu_table.it_offset      = cb.itc_offset;
	veth_iommu_table.it_index       = cb.itc_index;
	veth_iommu_table.it_type        = TCE_VB;
	veth_iommu_table.it_entrysize	= sizeof(union tce_entry);
	veth_iommu_table.it_blocksize	= 1;

	t = iommu_init_table(&veth_iommu_table);

	if (!t)
		printk("Virtual Bus VETH TCE table failed.\n");

	vio_iommu_table.it_size         = cb.itc_size - veth_iommu_table.it_size;
	vio_iommu_table.it_busno        = cb.itc_busno;
	vio_iommu_table.it_offset       = cb.itc_offset +
		veth_iommu_table.it_size * (PAGE_SIZE/sizeof(union tce_entry));
	vio_iommu_table.it_index        = cb.itc_index;
	vio_iommu_table.it_type         = TCE_VB;
	vio_iommu_table.it_entrysize	= sizeof(union tce_entry);
	vio_iommu_table.it_blocksize	= 1;

	t = iommu_init_table(&vio_iommu_table);

	if (!t)
		printk("Virtual Bus VIO TCE table failed.\n");
}
#endif

/**
 * vio_bus_init: - Initialize the virtual IO bus
 */
static int __init vio_bus_init(void)
{
#ifdef CONFIG_PPC_PSERIES
	struct device_node *node_vroot, *of_node;
#endif
	int err;

	err = bus_register(&vio_bus_type);
	if (err) {
		printk(KERN_ERR "failed to register VIO bus\n");
		return err;
	}

	/* the fake parent of all vio devices, just to give us a nice directory */
	vio_bus_device = kmalloc(sizeof(struct vio_dev), GFP_KERNEL);
	if (!vio_bus_device) {
		return 1;
	}
	memset(vio_bus_device, 0, sizeof(struct vio_dev));
	strcpy(vio_bus_device->dev.bus_id, "vio");

	err = device_register(&vio_bus_device->dev);
	if (err) {
		printk(KERN_WARNING "%s: device_register returned %i\n", __FUNCTION__,
			err);
		kfree(vio_bus_device);
		return err;
	}

#ifdef CONFIG_PPC_PSERIES
	node_vroot = find_devices("vdevice");
	if ((node_vroot == NULL) || (node_vroot->child == NULL)) {
		/* this machine doesn't do virtual IO, and that's ok */
		return 0;
	}

	vio_num_address_cells = prom_n_addr_cells(node_vroot->child);

	/*
	 * Create struct vio_devices for each virtual device in the device tree.
	 * Drivers will associate with them later.
	 */
	for (of_node = node_vroot->child;
			of_node != NULL;
			of_node = of_node->sibling) {
		printk(KERN_DEBUG "%s: processing %p\n", __FUNCTION__, of_node);

		vio_register_device(of_node);
	}
#endif

	return 0;
}

__initcall(vio_bus_init);


#ifdef CONFIG_PPC_PSERIES
/* vio_dev refcount hit 0 */
static void __devinit vio_dev_release(struct device *dev)
{
	struct vio_dev *viodev = to_vio_dev(dev);

	DBGENTER();

	/* XXX free TCE table */
	of_node_put(viodev->archdata);
	kfree(viodev);
}

static ssize_t viodev_show_name(struct device *dev, char *buf)
{
	struct vio_dev *viodev = to_vio_dev(dev);
	struct device_node *of_node = viodev->archdata;

	return sprintf(buf, "%s\n", of_node->name);
}
DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, viodev_show_name, NULL);

/**
 * vio_register_device: - Register a new vio device.
 * @of_node:	The OF node for this device.
 *
 * Creates and initializes a vio_dev structure from the data in
 * of_node (archdata) and adds it to the list of virtual devices.
 * Returns a pointer to the created vio_dev or NULL if node has
 * NULL device_type or compatible fields.
 */
struct vio_dev * __devinit vio_register_device(struct device_node *of_node)
{
	struct vio_dev *viodev;
	unsigned int *unit_address;
	unsigned int *irq_p;

	DBGENTER();

	/* we need the 'device_type' property, in order to match with drivers */
	if ((NULL == of_node->type)) {
		printk(KERN_WARNING
			"%s: node %s missing 'device_type'\n", __FUNCTION__,
			of_node->name ? of_node->name : "<unknown>");
		return NULL;
	}

	unit_address = (unsigned int *)get_property(of_node, "reg", NULL);
	if (!unit_address) {
		printk(KERN_WARNING "%s: node %s missing 'reg'\n", __FUNCTION__,
			of_node->name ? of_node->name : "<unknown>");
		return NULL;
	}

	/* allocate a vio_dev for this node */
	viodev = kmalloc(sizeof(struct vio_dev), GFP_KERNEL);
	if (!viodev) {
		return NULL;
	}
	memset(viodev, 0, sizeof(struct vio_dev));

	viodev->archdata = (void *)of_node_get(of_node);
	viodev->unit_address = *unit_address;
	viodev->iommu_table = vio_build_iommu_table(viodev);

	viodev->irq = NO_IRQ;
	irq_p = (unsigned int *)get_property(of_node, "interrupts", 0);
	if (irq_p) {
		int virq = virt_irq_create_mapping(*irq_p);
		if (virq == NO_IRQ) {
			printk(KERN_ERR "Unable to allocate interrupt "
			       "number for %s\n", of_node->full_name);
		} else
			viodev->irq = irq_offset_up(virq);
	}

	/* init generic 'struct device' fields: */
	viodev->dev.parent = &vio_bus_device->dev;
	viodev->dev.bus = &vio_bus_type;
	snprintf(viodev->dev.bus_id, BUS_ID_SIZE, "%x", viodev->unit_address);
	viodev->dev.release = vio_dev_release;

	/* register with generic device framework */
	if (device_register(&viodev->dev)) {
		printk(KERN_ERR "%s: failed to register device %s\n", __FUNCTION__,
			viodev->dev.bus_id);
		/* XXX free TCE table */
		kfree(viodev);
		return NULL;
	}
	device_create_file(&viodev->dev, &dev_attr_name);

	return viodev;
}
EXPORT_SYMBOL(vio_register_device);

void __devinit vio_unregister_device(struct vio_dev *viodev)
{
	DBGENTER();
	device_unregister(&viodev->dev);
}
EXPORT_SYMBOL(vio_unregister_device);

/**
 * vio_get_attribute: - get attribute for virtual device
 * @vdev:	The vio device to get property.
 * @which:	The property/attribute to be extracted.
 * @length:	Pointer to length of returned data size (unused if NULL).
 *
 * Calls prom.c's get_property() to return the value of the
 * attribute specified by the preprocessor constant @which
*/
const void * vio_get_attribute(struct vio_dev *vdev, void* which, int* length)
{
	return get_property((struct device_node *)vdev->archdata, (char*)which, length);
}
EXPORT_SYMBOL(vio_get_attribute);

/* vio_find_name() - internal because only vio.c knows how we formatted the
 * kobject name
 * XXX once vio_bus_type.devices is actually used as a kset in
 * drivers/base/bus.c, this function should be removed in favor of
 * "device_find(kobj_name, &vio_bus_type)"
 */
static struct vio_dev *vio_find_name(const char *kobj_name)
{
	struct kobject *found;

	found = kset_find_obj(&devices_subsys.kset, kobj_name);
	if (!found)
		return NULL;

	return to_vio_dev(container_of(found, struct device, kobj));
}

/**
 * vio_find_node - find an already-registered vio_dev
 * @vnode: device_node of the virtual device we're looking for
 */
struct vio_dev *vio_find_node(struct device_node *vnode)
{
	uint32_t *unit_address;
	char kobj_name[BUS_ID_SIZE];

	/* construct the kobject name from the device node */
	unit_address = (uint32_t *)get_property(vnode, "reg", NULL);
	if (!unit_address)
		return NULL;
	snprintf(kobj_name, BUS_ID_SIZE, "%x", *unit_address);

	return vio_find_name(kobj_name);
}
EXPORT_SYMBOL(vio_find_node);

/**
 * vio_build_iommu_table: - gets the dma information from OF and builds the TCE tree.
 * @dev: the virtual device.
 *
 * Returns a pointer to the built tce tree, or NULL if it can't
 * find property.
*/
struct iommu_table * vio_build_iommu_table(struct vio_dev *dev)
{
	unsigned int *dma_window;
	struct iommu_table *newTceTable;
	unsigned long offset;
	unsigned long size;
	int dma_window_property_size;

	dma_window = (unsigned int *) get_property((struct device_node *)dev->archdata, "ibm,my-dma-window", &dma_window_property_size);
	if(!dma_window) {
		return NULL;
	}

	newTceTable = (struct iommu_table *) kmalloc(sizeof(struct iommu_table), GFP_KERNEL);

	/* RPA docs say that #address-cells is always 1 for virtual
		devices, but some older boxes' OF returns 2.  This should
		be removed by GA, unless there is legacy OFs that still
		have 2 for #address-cells */
	size = ((dma_window[1+vio_num_address_cells] >> PAGE_SHIFT) << 3)
		>> PAGE_SHIFT;

	/* This is just an ugly kludge. Remove as soon as the OF for all
	machines actually follow the spec and encodes the offset field
	as phys-encode (that is, #address-cells wide)*/
	if (dma_window_property_size == 12) {
		size = ((dma_window[1] >> PAGE_SHIFT) << 3) >> PAGE_SHIFT;
	} else if (dma_window_property_size == 20) {
		size = ((dma_window[4] >> PAGE_SHIFT) << 3) >> PAGE_SHIFT;
	} else {
		printk(KERN_WARNING "vio_build_iommu_table: Invalid size of ibm,my-dma-window=%i, using 0x80 for size\n", dma_window_property_size);
		size = 0x80;
	}

	/*  There should be some code to extract the phys-encoded offset
		using prom_n_addr_cells(). However, according to a comment
		on earlier versions, it's always zero, so we don't bother */
	offset = dma_window[1] >>  PAGE_SHIFT;

	/* TCE table size - measured in units of pages of tce table */
	newTceTable->it_size		= size;
	/* offset for VIO should always be 0 */
	newTceTable->it_offset		= offset;
	newTceTable->it_busno		= 0;
	newTceTable->it_index		= (unsigned long)dma_window[0];
	newTceTable->it_type		= TCE_VB;
	newTceTable->it_entrysize	= sizeof(union tce_entry);

	return iommu_init_table(newTceTable);
}

int vio_enable_interrupts(struct vio_dev *dev)
{
	int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
	if (rc != H_Success) {
		printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
	}
	return rc;
}
EXPORT_SYMBOL(vio_enable_interrupts);

int vio_disable_interrupts(struct vio_dev *dev)
{
	int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
	if (rc != H_Success) {
		printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
	}
	return rc;
}
EXPORT_SYMBOL(vio_disable_interrupts);
#endif

dma_addr_t vio_map_single(struct vio_dev *dev, void *vaddr,
			  size_t size, enum dma_data_direction direction)
{
	return iommu_map_single(dev->iommu_table, vaddr, size, direction);
}
EXPORT_SYMBOL(vio_map_single);

void vio_unmap_single(struct vio_dev *dev, dma_addr_t dma_handle,
		      size_t size, enum dma_data_direction direction)
{
	iommu_unmap_single(dev->iommu_table, dma_handle, size, direction);
}
EXPORT_SYMBOL(vio_unmap_single);

int vio_map_sg(struct vio_dev *vdev, struct scatterlist *sglist, int nelems,
	       enum dma_data_direction direction)
{
	return iommu_map_sg(&vdev->dev, vdev->iommu_table, sglist,
			nelems, direction);
}
EXPORT_SYMBOL(vio_map_sg);

void vio_unmap_sg(struct vio_dev *vdev, struct scatterlist *sglist, int nelems,
		  enum dma_data_direction direction)
{
	iommu_unmap_sg(vdev->iommu_table, sglist, nelems, direction);
}
EXPORT_SYMBOL(vio_unmap_sg);

void *vio_alloc_consistent(struct vio_dev *dev, size_t size,
			   dma_addr_t *dma_handle)
{
	return iommu_alloc_consistent(dev->iommu_table, size, dma_handle);
}
EXPORT_SYMBOL(vio_alloc_consistent);

void vio_free_consistent(struct vio_dev *dev, size_t size,
			 void *vaddr, dma_addr_t dma_handle)
{
	iommu_free_consistent(dev->iommu_table, size, vaddr, dma_handle);
}
EXPORT_SYMBOL(vio_free_consistent);

static int vio_bus_match(struct device *dev, struct device_driver *drv)
{
	const struct vio_dev *vio_dev = to_vio_dev(dev);
	struct vio_driver *vio_drv = to_vio_driver(drv);
	const struct vio_device_id *ids = vio_drv->id_table;
	const struct vio_device_id *found_id;

	DBGENTER();

	if (!ids)
		return 0;

	found_id = vio_match_device(ids, vio_dev);
	if (found_id)
		return 1;

	return 0;
}

struct bus_type vio_bus_type = {
	.name = "vio",
	.match = vio_bus_match,
};

EXPORT_SYMBOL(vio_bus_type);
