pciehp_ctrl.c

底层驱动开发

 * size must be a power of two.
 */
static struct pci_resource *get_io_resource(struct pci_resource **head, u32 size)
{
	struct pci_resource *prevnode;
	struct pci_resource *node;
	struct pci_resource *split_node = NULL;
	u32 temp_dword;

	if (!(*head))
		return NULL;

	if ( pciehp_resource_sort_and_combine(head) )
		return NULL;

	if ( sort_by_size(head) )
		return NULL;

	for (node = *head; node; node = node->next) {
		if (node->length < size)
			continue;

		if (node->base & (size - 1)) {
			/* this one isn't base aligned properly
			   so we'll make a new entry and split it up */
			temp_dword = (node->base | (size-1)) + 1;

			/*/ Short circuit if adjusted size is too small */
			if ((node->length - (temp_dword - node->base)) < size)
				continue;

			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;

			split_node->base = node->base;
			split_node->length = temp_dword - node->base;
			node->base = temp_dword;
			node->length -= split_node->length;

			/* Put it in the list */
			split_node->next = node->next;
			node->next = split_node;
		} /* End of non-aligned base */

		/* Don't need to check if too small since we already did */
		if (node->length > size) {
			/* this one is longer than we need
			   so we'll make a new entry and split it up */
			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;

			split_node->base = node->base + size;
			split_node->length = node->length - size;
			node->length = size;

			/* Put it in the list */
			split_node->next = node->next;
			node->next = split_node;
		}  /* End of too big on top end */

		/* For IO make sure it's not in the ISA aliasing space */
		if (node->base & 0x300L)
			continue;

		/* If we got here, then it is the right size 
		   Now take it out of the list */
		if (*head == node) {
			*head = node->next;
		} else {
			prevnode = *head;
			while (prevnode->next != node)
				prevnode = prevnode->next;

			prevnode->next = node->next;
		}
		node->next = NULL;
		/* Stop looping */
		break;
	}

	return node;
}


/*
 * get_max_resource
 *
 * Gets the largest node that is at least "size" big from the
 * list pointed to by head.  It aligns the node on top and bottom
 * to "size" alignment before returning it.
 * J.I. modified to put max size limits of; 64M->32M->16M->8M->4M->1M
 *  This is needed to avoid allocating entire ACPI _CRS res to one child bridge/slot.
 */
static struct pci_resource *get_max_resource(struct pci_resource **head, u32 size)
{
	struct pci_resource *max;
	struct pci_resource *temp;
	struct pci_resource *split_node;
	u32 temp_dword;
	u32 max_size[] = { 0x4000000, 0x2000000, 0x1000000, 0x0800000, 0x0400000, 0x0200000, 0x0100000, 0x00 };
	int i;

	if (!(*head))
		return NULL;

	if (pciehp_resource_sort_and_combine(head))
		return NULL;

	if (sort_by_max_size(head))
		return NULL;

	for (max = *head;max; max = max->next) {

		/* If not big enough we could probably just bail, 
		   instead we'll continue to the next. */
		if (max->length < size)
			continue;

		if (max->base & (size - 1)) {
			/* this one isn't base aligned properly
			   so we'll make a new entry and split it up */
			temp_dword = (max->base | (size-1)) + 1;

			/* Short circuit if adjusted size is too small */
			if ((max->length - (temp_dword - max->base)) < size)
				continue;

			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;

			split_node->base = max->base;
			split_node->length = temp_dword - max->base;
			max->base = temp_dword;
			max->length -= split_node->length;

			/* Put it next in the list */
			split_node->next = max->next;
			max->next = split_node;
		}

		if ((max->base + max->length) & (size - 1)) {
			/* this one isn't end aligned properly at the top
			   so we'll make a new entry and split it up */
			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;
			temp_dword = ((max->base + max->length) & ~(size - 1));
			split_node->base = temp_dword;
			split_node->length = max->length + max->base
					     - split_node->base;
			max->length -= split_node->length;

			/* Put it in the list */
			split_node->next = max->next;
			max->next = split_node;
		}

		/* Make sure it didn't shrink too much when we aligned it */
		if (max->length < size)
			continue;

		for ( i = 0; max_size[i] > size; i++) {
			if (max->length > max_size[i]) {
				split_node = kmalloc(sizeof(struct pci_resource),
							GFP_KERNEL);
				if (!split_node)
					break;	/* return NULL; */
				split_node->base = max->base + max_size[i];
				split_node->length = max->length - max_size[i];
				max->length = max_size[i];
				/* Put it next in the list */
				split_node->next = max->next;
				max->next = split_node;
				break;
			}
		}

		/* Now take it out of the list */
		temp = (struct pci_resource*) *head;
		if (temp == max) {
			*head = max->next;
		} else {
			while (temp && temp->next != max) {
				temp = temp->next;
			}

			temp->next = max->next;
		}

		max->next = NULL;
		return max;
	}

	/* If we get here, we couldn't find one */
	return NULL;
}


/*
 * get_resource
 *
 * this function sorts the resource list by size and then
 * returns the first node of "size" length.  If it finds a node
 * larger than "size" it will split it up.
 *
 * size must be a power of two.
 */
static struct pci_resource *get_resource(struct pci_resource **head, u32 size)
{
	struct pci_resource *prevnode;
	struct pci_resource *node;
	struct pci_resource *split_node;
	u32 temp_dword;

	if (!(*head))
		return NULL;

	if ( pciehp_resource_sort_and_combine(head) )
		return NULL;

	if ( sort_by_size(head) )
		return NULL;

	for (node = *head; node; node = node->next) {
		dbg("%s: req_size =0x%x node=%p, base=0x%x, length=0x%x\n",
		    __FUNCTION__, size, node, node->base, node->length);
		if (node->length < size)
			continue;

		if (node->base & (size - 1)) {
			dbg("%s: not aligned\n", __FUNCTION__);
			/* this one isn't base aligned properly
			   so we'll make a new entry and split it up */
			temp_dword = (node->base | (size-1)) + 1;

			/* Short circuit if adjusted size is too small */
			if ((node->length - (temp_dword - node->base)) < size)
				continue;

			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;

			split_node->base = node->base;
			split_node->length = temp_dword - node->base;
			node->base = temp_dword;
			node->length -= split_node->length;

			/* Put it in the list */
			split_node->next = node->next;
			node->next = split_node;
		} /* End of non-aligned base */

		/* Don't need to check if too small since we already did */
		if (node->length > size) {
			dbg("%s: too big\n", __FUNCTION__);
			/* this one is longer than we need
			   so we'll make a new entry and split it up */
			split_node = kmalloc(sizeof(struct pci_resource),
						GFP_KERNEL);

			if (!split_node)
				return NULL;

			split_node->base = node->base + size;
			split_node->length = node->length - size;
			node->length = size;

			/* Put it in the list */
			split_node->next = node->next;
			node->next = split_node;
		}  /* End of too big on top end */

		dbg("%s: got one!!!\n", __FUNCTION__);
		/* If we got here, then it is the right size
		   Now take it out of the list */
		if (*head == node) {
			*head = node->next;
		} else {
			prevnode = *head;
			while (prevnode->next != node)
				prevnode = prevnode->next;

			prevnode->next = node->next;
		}
		node->next = NULL;
		/* Stop looping */
		break;
	}
	return node;
}


/*
 * pciehp_resource_sort_and_combine
 *
 * Sorts all of the nodes in the list in ascending order by
 * their base addresses.  Also does garbage collection by
 * combining adjacent nodes.
 *
 * returns 0 if success
 */
int pciehp_resource_sort_and_combine(struct pci_resource **head)
{
	struct pci_resource *node1;
	struct pci_resource *node2;
	int out_of_order = 1;

	dbg("%s: head = %p, *head = %p\n", __FUNCTION__, head, *head);

	if (!(*head))
		return 1;

	dbg("*head->next = %p\n",(*head)->next);

	if (!(*head)->next)
		return 0;	/* only one item on the list, already sorted! */

	dbg("*head->base = 0x%x\n",(*head)->base);
	dbg("*head->next->base = 0x%x\n",(*head)->next->base);
	while (out_of_order) {
		out_of_order = 0;

		/* Special case for swapping list head */
		if (((*head)->next) &&
		    ((*head)->base > (*head)->next->base)) {
			node1 = *head;
			(*head) = (*head)->next;
			node1->next = (*head)->next;
			(*head)->next = node1;
			out_of_order++;
		}

		node1 = (*head);

		while (node1->next && node1->next->next) {
			if (node1->next->base > node1->next->next->base) {
				out_of_order++;
				node2 = node1->next;
				node1->next = node1->next->next;
				node1 = node1->next;
				node2->next = node1->next;
				node1->next = node2;
			} else
				node1 = node1->next;
		}
	}  /* End of out_of_order loop */

	node1 = *head;

	while (node1 && node1->next) {
		if ((node1->base + node1->length) == node1->next->base) {
			/* Combine */
			dbg("8..\n");
			node1->length += node1->next->length;
			node2 = node1->next;
			node1->next = node1->next->next;
			kfree(node2);
		} else
			node1 = node1->next;
	}

	return 0;
}


/**
 * pciehp_slot_create - Creates a node and adds it to the proper bus.
 * @busnumber - bus where new node is to be located
 *
 * Returns pointer to the new node or NULL if unsuccessful
 */
struct pci_func *pciehp_slot_create(u8 busnumber)
{
	struct pci_func *new_slot;
	struct pci_func *next;
	dbg("%s: busnumber %x\n", __FUNCTION__, busnumber);
	new_slot = kmalloc(sizeof(struct pci_func), GFP_KERNEL);

	if (new_slot == NULL)
		return new_slot;

	memset(new_slot, 0, sizeof(struct pci_func));

	new_slot->next = NULL;
	new_slot->configured = 1;

	if (pciehp_slot_list[busnumber] == NULL) {
		pciehp_slot_list[busnumber] = new_slot;
	} else {
		next = pciehp_slot_list[busnumber];
		while (next->next != NULL)
			next = next->next;
		next->next = new_slot;
	}
	return new_slot;
}


/**
 * slot_remove - Removes a node from the linked list of slots.
 * @old_slot: slot to remove
 *
 * Returns 0 if successful, !0 otherwise.
 */
static int slot_remove(struct pci_func * old_slot)
{
	struct pci_func *next;

	if (old_slot == NULL)
		return 1;

	next = pciehp_slot_list[old_slot->bus];

	if (next == NULL)
		return 1;

	if (next == old_slot) {
		pciehp_slot_list[old_slot->bus] = old_slot->next;
		pciehp_destroy_board_resources(old_slot);
		kfree(old_slot);
		return 0;
	}

	while ((next->next != old_slot) && (next->next != NULL)) {
		next = next->next;
	}

	if (next->next == old_slot) {
		next->next = old_slot->next;
		pciehp_destroy_board_resources(old_slot);
		kfree(old_slot);
		return 0;
	} else
		return 2;
}


/**
 * bridge_slot_remove - Removes a node from the linked list of slots.
 * @bridge: bridge to remove
 *
 * Returns 0 if successful, !0 otherwise.
 */
static int bridge_slot_remove(struct pci_func *bridge)
{
	u8 subordinateBus, secondaryBus;
	u8 tempBus;
	struct pci_func *next;

	if (bridge == NULL)
		return 1;

	secondaryBus = (bridge->config_space[0x06] >> 8) & 0xFF;
	subordinateBus = (bridge->config_space[0x06] >> 16) & 0xFF;

	for (tempBus = secondaryBus; tempBus <= subordinateBus; tempBus++) {
		next = pciehp_slot_list[tempBus];

		while (!slot_remove(next)) {
			next = pciehp_slot_list[tempBus];
		}
	}

	next = pciehp_slot_list[bridge->bus];

	if (next == NULL) {
		return 1;
	}

	if (next == bridge) {
		pciehp_slot_list[bridge->bus] = bridge->next;
		kfree(bridge);
		return 0;
	}

	while ((next->next != bridge) && (next->next != NULL)) {
		next = next->next;
	}

	if (next->next == bridge) {
		next->next = bridge->next;
		kfree(bridge);