msi.c

来自「Linux Kernel 2.6.9 for OMAP1710」· C语言 代码 · 共 1,148 行 · 第 1/3 页

		return;

	spin_lock_irqsave(&msi_lock, flags);
	entry = msi_desc[dev->irq];
	if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
		spin_unlock_irqrestore(&msi_lock, flags);
		return;
	}
	if (entry->msi_attrib.state) {
		spin_unlock_irqrestore(&msi_lock, flags);
		printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on vector->%d\n",
		dev->bus->number, PCI_SLOT(dev->devfn),	PCI_FUNC(dev->devfn),
		dev->irq);
		BUG_ON(entry->msi_attrib.state > 0);
	} else {
		vector_irq[dev->irq] = 0; /* free it */
		nr_released_vectors++;
		default_vector = entry->msi_attrib.default_vector;
		spin_unlock_irqrestore(&msi_lock, flags);
		/* Restore dev->irq to its default pin-assertion vector */
		dev->irq = default_vector;
		disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
					PCI_CAP_ID_MSI);
	}
}

static void release_msi(unsigned int vector)
{
	struct msi_desc *entry;
	unsigned long flags;

	spin_lock_irqsave(&msi_lock, flags);
	entry = msi_desc[vector];
	if (entry && entry->dev)
		entry->msi_attrib.state = 0;	/* Mark it not active */
	spin_unlock_irqrestore(&msi_lock, flags);
}

static int msi_free_vector(struct pci_dev* dev, int vector, int reassign)
{
	struct msi_desc *entry;
	int head, entry_nr, type;
	unsigned long base = 0L;
	unsigned long flags;

	spin_lock_irqsave(&msi_lock, flags);
	entry = msi_desc[vector];
	if (!entry || entry->dev != dev) {
		spin_unlock_irqrestore(&msi_lock, flags);
		return -EINVAL;
	}
	type = entry->msi_attrib.type;
	entry_nr = entry->msi_attrib.entry_nr;
	head = entry->link.head;
	base = entry->mask_base;
	msi_desc[entry->link.head]->link.tail = entry->link.tail;
	msi_desc[entry->link.tail]->link.head = entry->link.head;
	entry->dev = NULL;
	if (!reassign) {
		vector_irq[vector] = 0;
		nr_released_vectors++;
	}
	msi_desc[vector] = NULL;
	spin_unlock_irqrestore(&msi_lock, flags);

	kmem_cache_free(msi_cachep, entry);

	if (type == PCI_CAP_ID_MSIX) {
		if (!reassign)
			writel(1, base +
				entry_nr * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);

		if (head == vector) {
			/*
			 * Detect last MSI-X vector to be released.
			 * Release the MSI-X memory-mapped table.
			 */
			int pos, nr_entries;
			u32 phys_addr, table_offset;
			u16 control;
			u8 bir;

   			pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
			pci_read_config_word(dev, msi_control_reg(pos),
				&control);
			nr_entries = multi_msix_capable(control);
			pci_read_config_dword(dev, msix_table_offset_reg(pos),
				&table_offset);
			bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
			phys_addr = pci_resource_start (dev, bir);
			phys_addr += (u32)(table_offset &
				~PCI_MSIX_FLAGS_BIRMASK);
			iounmap((void*)base);
			release_mem_region(phys_addr,
				nr_entries * PCI_MSIX_ENTRY_SIZE);
		}
	}

	return 0;
}

static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
{
	int vector = head, tail = 0;
	int i = 0, j = 0, nr_entries = 0;
	unsigned long base = 0L;
	unsigned long flags;

	spin_lock_irqsave(&msi_lock, flags);
	while (head != tail) {
		nr_entries++;
		tail = msi_desc[vector]->link.tail;
		if (entries[0].entry == msi_desc[vector]->msi_attrib.entry_nr)
			j = vector;
		vector = tail;
	}
	if (*nvec > nr_entries) {
		spin_unlock_irqrestore(&msi_lock, flags);
		*nvec = nr_entries;
		return -EINVAL;
	}
	vector = ((j > 0) ? j : head);
	for (i = 0; i < *nvec; i++) {
		j = msi_desc[vector]->msi_attrib.entry_nr;
		msi_desc[vector]->msi_attrib.state = 0;	/* Mark it not active */
		vector_irq[vector] = -1;		/* Mark it busy */
		nr_released_vectors--;
		entries[i].vector = vector;
		if (j != (entries + i)->entry) {
			base = msi_desc[vector]->mask_base;
			msi_desc[vector]->msi_attrib.entry_nr =
				(entries + i)->entry;
			writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET), base +
				(entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
			writel(	readl(base + j * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET), base +
				(entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
			writel( (readl(base + j * PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_DATA_OFFSET) & 0xff00) | vector,
				base + (entries+i)->entry*PCI_MSIX_ENTRY_SIZE +
				PCI_MSIX_ENTRY_DATA_OFFSET);
		}
		vector = msi_desc[vector]->link.tail;
	}
	spin_unlock_irqrestore(&msi_lock, flags);

	return 0;
}

/**
 * pci_enable_msix - configure device's MSI-X capability structure
 * @dev: pointer to the pci_dev data structure of MSI-X device function
 * @data: pointer to an array of MSI-X entries
 * @nvec: number of MSI-X vectors requested for allocation by device driver
 *
 * Setup the MSI-X capability structure of device function with the number
 * of requested vectors upon its software driver call to request for
 * MSI-X mode enabled on its hardware device function. A return of zero
 * indicates the successful configuration of MSI-X capability structure
 * with new allocated MSI-X vectors. A return of < 0 indicates a failure.
 * Or a return of > 0 indicates that driver request is exceeding the number
 * of vectors available. Driver should use the returned value to re-send
 * its request.
 **/
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
	int status, pos, nr_entries, free_vectors;
	int i, j, temp;
	u16 control;
	unsigned long flags;

	if (!pci_msi_enable || !dev || !entries)
 		return -EINVAL;

	if ((status = msi_init()) < 0)
		return status;

   	if (!(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
 		return -EINVAL;

	pci_read_config_word(dev, msi_control_reg(pos), &control);
	if (control & PCI_MSIX_FLAGS_ENABLE)
		return -EINVAL;			/* Already in MSI-X mode */

	nr_entries = multi_msix_capable(control);
	if (nvec > nr_entries)
		return -EINVAL;

	/* Check for any invalid entries */
	for (i = 0; i < nvec; i++) {
		if (entries[i].entry >= nr_entries)
			return -EINVAL;		/* invalid entry */
		for (j = i + 1; j < nvec; j++) {
			if (entries[i].entry == entries[j].entry)
				return -EINVAL;	/* duplicate entry */
		}
	}
	temp = dev->irq;
	if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
		/* Lookup Sucess */
		nr_entries = nvec;
		/* Reroute MSI-X table */
		if (reroute_msix_table(dev->irq, entries, &nr_entries)) {
			/* #requested > #previous-assigned */
			dev->irq = temp;
			return nr_entries;
		}
		dev->irq = temp;
		enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
		return 0;
	}
	/* Check whether driver already requested for MSI vector */
   	if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&
		!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
		printk(KERN_INFO "Can't enable MSI-X. Device already had MSI vector assigned\n");
		dev->irq = temp;
		return -EINVAL;
	}

	spin_lock_irqsave(&msi_lock, flags);
	/*
	 * msi_lock is provided to ensure that enough vectors resources are
	 * available before granting.
	 */
	free_vectors = pci_vector_resources(last_alloc_vector,
				nr_released_vectors);
	/* Ensure that each MSI/MSI-X device has one vector reserved by
	   default to avoid any MSI-X driver to take all available
 	   resources */
	free_vectors -= nr_reserved_vectors;
	/* Find the average of free vectors among MSI-X devices */
	if (nr_msix_devices > 0)
		free_vectors /= nr_msix_devices;
	spin_unlock_irqrestore(&msi_lock, flags);

	if (nvec > free_vectors) {
		if (free_vectors > 0)
			return free_vectors;
		else
			return -EBUSY;
	}

	status = msix_capability_init(dev, entries, nvec);
	if (!status && nr_msix_devices > 0)
		nr_msix_devices--;

	return status;
}

void pci_disable_msix(struct pci_dev* dev)
{
	int pos, temp;
	u16 control;

   	if (!dev || !(pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)))
		return;

	pci_read_config_word(dev, msi_control_reg(pos), &control);
	if (!(control & PCI_MSIX_FLAGS_ENABLE))
		return;

	temp = dev->irq;
	if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
		int state, vector, head, tail = 0, warning = 0;
		unsigned long flags;

		vector = head = dev->irq;
		spin_lock_irqsave(&msi_lock, flags);
		while (head != tail) {
			state = msi_desc[vector]->msi_attrib.state;
			if (state)
				warning = 1;
			else {
				vector_irq[vector] = 0; /* free it */
				nr_released_vectors++;
			}
			tail = msi_desc[vector]->link.tail;
			vector = tail;
		}
		spin_unlock_irqrestore(&msi_lock, flags);
		if (warning) {
			dev->irq = temp;
			printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on all vectors\n",
			dev->bus->number, PCI_SLOT(dev->devfn),
			PCI_FUNC(dev->devfn));
			BUG_ON(warning > 0);
		} else {
			dev->irq = temp;
			disable_msi_mode(dev,
				pci_find_capability(dev, PCI_CAP_ID_MSIX),
				PCI_CAP_ID_MSIX);

		}
	}
}

/**
 * msi_remove_pci_irq_vectors - reclaim MSI(X) vectors to unused state
 * @dev: pointer to the pci_dev data structure of MSI(X) device function
 *
 * Being called during hotplug remove, from which the device funciton
 * is hot-removed. All previous assigned MSI/MSI-X vectors, if
 * allocated for this device function, are reclaimed to unused state,
 * which may be used later on.
 **/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
	int state, pos, temp;
	unsigned long flags;

	if (!pci_msi_enable || !dev)
 		return;

	temp = dev->irq;		/* Save IOAPIC IRQ */
   	if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSI)) > 0 &&
		!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
		spin_lock_irqsave(&msi_lock, flags);
		state = msi_desc[dev->irq]->msi_attrib.state;
		spin_unlock_irqrestore(&msi_lock, flags);
		if (state) {
			printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on vector->%d\n",
			dev->bus->number, PCI_SLOT(dev->devfn),
			PCI_FUNC(dev->devfn), dev->irq);
			BUG_ON(state > 0);
		} else /* Release MSI vector assigned to this device */
			msi_free_vector(dev, dev->irq, 0);
		dev->irq = temp;		/* Restore IOAPIC IRQ */
	}
   	if ((pos = pci_find_capability(dev, PCI_CAP_ID_MSIX)) > 0 &&
		!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
		int vector, head, tail = 0, warning = 0;
		unsigned long base = 0L;

		vector = head = dev->irq;
		while (head != tail) {
			spin_lock_irqsave(&msi_lock, flags);
			state = msi_desc[vector]->msi_attrib.state;
			tail = msi_desc[vector]->link.tail;
			base = msi_desc[vector]->mask_base;
			spin_unlock_irqrestore(&msi_lock, flags);
			if (state)
				warning = 1;
			else if (vector != head) /* Release MSI-X vector */
				msi_free_vector(dev, vector, 0);
			vector = tail;
		}
		msi_free_vector(dev, vector, 0);
		if (warning) {
			/* Force to release the MSI-X memory-mapped table */
			u32 phys_addr, table_offset;
			u16 control;
			u8 bir;

			pci_read_config_word(dev, msi_control_reg(pos),
				&control);
			pci_read_config_dword(dev, msix_table_offset_reg(pos),
				&table_offset);
			bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
			phys_addr = pci_resource_start (dev, bir);
			phys_addr += (u32)(table_offset &
				~PCI_MSIX_FLAGS_BIRMASK);
			iounmap((void*)base);
			release_mem_region(phys_addr, PCI_MSIX_ENTRY_SIZE *
				multi_msix_capable(control));
			printk(KERN_DEBUG "Driver[%d:%d:%d] unloaded wo doing free_irq on all vectors\n",
				dev->bus->number, PCI_SLOT(dev->devfn),
				PCI_FUNC(dev->devfn));
			BUG_ON(warning > 0);
		}
		dev->irq = temp;		/* Restore IOAPIC IRQ */
	}
}

EXPORT_SYMBOL(pci_enable_msi);
EXPORT_SYMBOL(pci_disable_msi);
EXPORT_SYMBOL(pci_enable_msix);
EXPORT_SYMBOL(pci_disable_msix);