// SPDX-License-Identifier: GPL-2.0

  /*
   * manager.c - Resource Management, Conflict Resolution, Activation and Disabling of Devices
   *

   * based on isapnp.c resource management (c) Jaroslav Kysela <perex@perex.cz>

   * Copyright 2003 Adam Belay <ambx1@neo.rr.com>

   * Copyright (C) 2008 Hewlett-Packard Development Company, L.P.
   *	Bjorn Helgaas <bjorn.helgaas@hp.com>

   */

  #include <linux/errno.h>
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/kernel.h>

  #include <linux/pnp.h>

  #include <linux/bitmap.h>

  #include <linux/mutex.h>

  #include "base.h"

  DEFINE_MUTEX(pnp_res_mutex);

  static struct resource *pnp_find_resource(struct pnp_dev *dev,
  					  unsigned char rule,
  					  unsigned long type,
  					  unsigned int bar)
  {
  	struct resource *res = pnp_get_resource(dev, type, bar);
  
  	/* when the resource already exists, set its resource bits from rule */
  	if (res) {
  		res->flags &= ~IORESOURCE_BITS;
  		res->flags |= rule & IORESOURCE_BITS;
  	}
  
  	return res;
  }

  static int pnp_assign_port(struct pnp_dev *dev, struct pnp_port *rule, int idx)
  {

  	struct resource *res, local_res;

  	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IO, idx);

  	if (res) {

  		pnp_dbg(&dev->dev, "  io %d already set to %#llx-%#llx "

  			"flags %#lx
  ", idx, (unsigned long long) res->start,
  			(unsigned long long) res->end, res->flags);

  		return 0;

  	}

  	res = &local_res;
  	res->flags = rule->flags | IORESOURCE_AUTO;
  	res->start = 0;
  	res->end = 0;

  
  	if (!rule->size) {

  		res->flags |= IORESOURCE_DISABLED;

  		pnp_dbg(&dev->dev, "  io %d disabled
  ", idx);

  		goto __add;

  	}

  	res->start = rule->min;
  	res->end = res->start + rule->size - 1;

  	while (!pnp_check_port(dev, res)) {

  		res->start += rule->align;
  		res->end = res->start + rule->size - 1;
  		if (res->start > rule->max || !rule->align) {

  			pnp_dbg(&dev->dev, "  couldn't assign io %d "

  				"(min %#llx max %#llx)
  ", idx,
  				(unsigned long long) rule->min,
  				(unsigned long long) rule->max);

  			return -EBUSY;

  		}

  	}

  
  __add:
  	pnp_add_io_resource(dev, res->start, res->end, res->flags);

  	return 0;

  }
  
  static int pnp_assign_mem(struct pnp_dev *dev, struct pnp_mem *rule, int idx)
  {

  	struct resource *res, local_res;

  	res = pnp_find_resource(dev, rule->flags, IORESOURCE_MEM, idx);

  	if (res) {

  		pnp_dbg(&dev->dev, "  mem %d already set to %#llx-%#llx "

  			"flags %#lx
  ", idx, (unsigned long long) res->start,
  			(unsigned long long) res->end, res->flags);

  		return 0;

  	}

  	res = &local_res;
  	res->flags = rule->flags | IORESOURCE_AUTO;
  	res->start = 0;
  	res->end = 0;

  	/* ??? rule->flags restricted to 8 bits, all tests bogus ??? */

  	if (!(rule->flags & IORESOURCE_MEM_WRITEABLE))

  		res->flags |= IORESOURCE_READONLY;

  	if (rule->flags & IORESOURCE_MEM_RANGELENGTH)

  		res->flags |= IORESOURCE_RANGELENGTH;

  	if (rule->flags & IORESOURCE_MEM_SHADOWABLE)

  		res->flags |= IORESOURCE_SHADOWABLE;

  
  	if (!rule->size) {

  		res->flags |= IORESOURCE_DISABLED;

  		pnp_dbg(&dev->dev, "  mem %d disabled
  ", idx);

  		goto __add;

  	}

  	res->start = rule->min;
  	res->end = res->start + rule->size - 1;

  	while (!pnp_check_mem(dev, res)) {

  		res->start += rule->align;
  		res->end = res->start + rule->size - 1;
  		if (res->start > rule->max || !rule->align) {

  			pnp_dbg(&dev->dev, "  couldn't assign mem %d "

  				"(min %#llx max %#llx)
  ", idx,
  				(unsigned long long) rule->min,
  				(unsigned long long) rule->max);

  			return -EBUSY;

  		}

  	}

  
  __add:
  	pnp_add_mem_resource(dev, res->start, res->end, res->flags);

  	return 0;

  }

  static int pnp_assign_irq(struct pnp_dev *dev, struct pnp_irq *rule, int idx)

  {

  	struct resource *res, local_res;

  	int i;
  
  	/* IRQ priority: this table is good for i386 */
  	static unsigned short xtab[16] = {
  		5, 10, 11, 12, 9, 14, 15, 7, 3, 4, 13, 0, 1, 6, 8, 2
  	};

  	res = pnp_find_resource(dev, rule->flags, IORESOURCE_IRQ, idx);

  	if (res) {

  		pnp_dbg(&dev->dev, "  irq %d already set to %d flags %#lx
  ",

  			idx, (int) res->start, res->flags);

  		return 0;

  	}

  	res = &local_res;
  	res->flags = rule->flags | IORESOURCE_AUTO;
  	res->start = -1;
  	res->end = -1;

  	if (bitmap_empty(rule->map.bits, PNP_IRQ_NR)) {

  		res->flags |= IORESOURCE_DISABLED;

  		pnp_dbg(&dev->dev, "  irq %d disabled
  ", idx);

  		goto __add;

  	}
  
  	/* TBD: need check for >16 IRQ */

  	res->start = find_next_bit(rule->map.bits, PNP_IRQ_NR, 16);

  	if (res->start < PNP_IRQ_NR) {
  		res->end = res->start;

  		goto __add;

  	}
  	for (i = 0; i < 16; i++) {

  		if (test_bit(xtab[i], rule->map.bits)) {

  			res->start = res->end = xtab[i];

  			if (pnp_check_irq(dev, res))
  				goto __add;

  		}
  	}

  
  	if (rule->flags & IORESOURCE_IRQ_OPTIONAL) {
  		res->start = -1;
  		res->end = -1;
  		res->flags |= IORESOURCE_DISABLED;

  		pnp_dbg(&dev->dev, "  irq %d disabled (optional)
  ", idx);

  		goto __add;
  	}

  	pnp_dbg(&dev->dev, "  couldn't assign irq %d
  ", idx);

  	return -EBUSY;

  
  __add:
  	pnp_add_irq_resource(dev, res->start, res->flags);

  	return 0;

  }

  #ifdef CONFIG_ISA_DMA_API

  static int pnp_assign_dma(struct pnp_dev *dev, struct pnp_dma *rule, int idx)

  {

  	struct resource *res, local_res;

  	int i;
  
  	/* DMA priority: this table is good for i386 */
  	static unsigned short xtab[8] = {
  		1, 3, 5, 6, 7, 0, 2, 4
  	};

  	res = pnp_find_resource(dev, rule->flags, IORESOURCE_DMA, idx);

  	if (res) {

  		pnp_dbg(&dev->dev, "  dma %d already set to %d flags %#lx
  ",

  			idx, (int) res->start, res->flags);

  		return 0;

  	}

  	res = &local_res;
  	res->flags = rule->flags | IORESOURCE_AUTO;
  	res->start = -1;
  	res->end = -1;

  	if (!rule->map) {
  		res->flags |= IORESOURCE_DISABLED;
  		pnp_dbg(&dev->dev, "  dma %d disabled
  ", idx);
  		goto __add;
  	}

  	for (i = 0; i < 8; i++) {

  		if (rule->map & (1 << xtab[i])) {

  			res->start = res->end = xtab[i];

  			if (pnp_check_dma(dev, res))
  				goto __add;

  		}
  	}

  
  	pnp_dbg(&dev->dev, "  couldn't assign dma %d
  ", idx);
  	return -EBUSY;

  __add:
  	pnp_add_dma_resource(dev, res->start, res->flags);

  	return 0;

  }

  #endif /* CONFIG_ISA_DMA_API */

  void pnp_init_resources(struct pnp_dev *dev)

  {

  	pnp_free_resources(dev);

  }

  static void pnp_clean_resource_table(struct pnp_dev *dev)

  {

  	struct pnp_resource *pnp_res, *tmp;
  
  	list_for_each_entry_safe(pnp_res, tmp, &dev->resources, list) {
  		if (pnp_res->res.flags & IORESOURCE_AUTO)
  			pnp_free_resource(pnp_res);

  	}
  }
  
  /**
   * pnp_assign_resources - assigns resources to the device based on the specified dependent number
   * @dev: pointer to the desired device

   * @set: the dependent function number

   */

  static int pnp_assign_resources(struct pnp_dev *dev, int set)

  {

  	struct pnp_option *option;

  	int nport = 0, nmem = 0, nirq = 0;
  	int ndma __maybe_unused = 0;

  	int ret = 0;

  	pnp_dbg(&dev->dev, "pnp_assign_resources, try dependent set %d
  ", set);

  	mutex_lock(&pnp_res_mutex);

  	pnp_clean_resource_table(dev);

  	list_for_each_entry(option, &dev->options, list) {
  		if (pnp_option_is_dependent(option) &&
  		    pnp_option_set(option) != set)
  				continue;
  
  		switch (option->type) {
  		case IORESOURCE_IO:
  			ret = pnp_assign_port(dev, &option->u.port, nport++);
  			break;
  		case IORESOURCE_MEM:
  			ret = pnp_assign_mem(dev, &option->u.mem, nmem++);
  			break;
  		case IORESOURCE_IRQ:
  			ret = pnp_assign_irq(dev, &option->u.irq, nirq++);
  			break;

  #ifdef CONFIG_ISA_DMA_API

  		case IORESOURCE_DMA:
  			ret = pnp_assign_dma(dev, &option->u.dma, ndma++);
  			break;

  #endif

  		default:
  			ret = -EINVAL;
  			break;

  		}

  		if (ret < 0)
  			break;
  	}

  	mutex_unlock(&pnp_res_mutex);

  	if (ret < 0) {

  		pnp_dbg(&dev->dev, "pnp_assign_resources failed (%d)
  ", ret);

  		pnp_clean_resource_table(dev);
  	} else
  		dbg_pnp_show_resources(dev, "pnp_assign_resources succeeded");
  	return ret;

  }
  
  /**

   * pnp_auto_config_dev - automatically assigns resources to a device
   * @dev: pointer to the desired device

   */
  int pnp_auto_config_dev(struct pnp_dev *dev)
  {

  	int i, ret;

  	if (!pnp_can_configure(dev)) {

  		pnp_dbg(&dev->dev, "configuration not supported
  ");

  		return -ENODEV;
  	}

  	ret = pnp_assign_resources(dev, 0);
  	if (ret == 0)
  		return 0;
  
  	for (i = 1; i < dev->num_dependent_sets; i++) {
  		ret = pnp_assign_resources(dev, i);
  		if (ret == 0)

  			return 0;

  	}

  	dev_err(&dev->dev, "unable to assign resources
  ");

  	return ret;

  }
  
  /**

   * pnp_start_dev - low-level start of the PnP device
   * @dev: pointer to the desired device
   *

   * assumes that resources have already been allocated

   */

  int pnp_start_dev(struct pnp_dev *dev)
  {
  	if (!pnp_can_write(dev)) {

  		pnp_dbg(&dev->dev, "activation not supported
  ");

  		return -EINVAL;
  	}

  	dbg_pnp_show_resources(dev, "pnp_start_dev");

  	if (dev->protocol->set(dev) < 0) {

  		dev_err(&dev->dev, "activation failed
  ");

  		return -EIO;
  	}

  	dev_info(&dev->dev, "activated
  ");

  	return 0;
  }
  
  /**
   * pnp_stop_dev - low-level disable of the PnP device
   * @dev: pointer to the desired device
   *
   * does not free resources
   */

  int pnp_stop_dev(struct pnp_dev *dev)
  {
  	if (!pnp_can_disable(dev)) {

  		pnp_dbg(&dev->dev, "disabling not supported
  ");

  		return -EINVAL;
  	}

  	if (dev->protocol->disable(dev) < 0) {

  		dev_err(&dev->dev, "disable failed
  ");

  		return -EIO;
  	}

  	dev_info(&dev->dev, "disabled
  ");

  	return 0;
  }
  
  /**

   * pnp_activate_dev - activates a PnP device for use
   * @dev: pointer to the desired device
   *
   * does not validate or set resources so be careful.
   */
  int pnp_activate_dev(struct pnp_dev *dev)
  {

  	int error;

  	if (dev->active)

  		return 0;

  
  	/* ensure resources are allocated */
  	if (pnp_auto_config_dev(dev))
  		return -EBUSY;

  	error = pnp_start_dev(dev);
  	if (error)
  		return error;

  
  	dev->active = 1;

  	return 0;

  }
  
  /**
   * pnp_disable_dev - disables device
   * @dev: pointer to the desired device
   *
   * inform the correct pnp protocol so that resources can be used by other devices
   */
  int pnp_disable_dev(struct pnp_dev *dev)
  {

  	int error;

  	if (!dev->active)

  		return 0;

  	error = pnp_stop_dev(dev);
  	if (error)
  		return error;

  
  	dev->active = 0;

  
  	/* release the resources so that other devices can use them */

  	mutex_lock(&pnp_res_mutex);

  	pnp_clean_resource_table(dev);

  	mutex_unlock(&pnp_res_mutex);

  	return 0;

  }

  EXPORT_SYMBOL(pnp_start_dev);
  EXPORT_SYMBOL(pnp_stop_dev);

  EXPORT_SYMBOL(pnp_activate_dev);
  EXPORT_SYMBOL(pnp_disable_dev);