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Commit ded86d8d authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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msi: Kill msi_lookup_irq 



The function msi_lookup_irq was horrible.  As a side effect of running
it changed dev->irq, and then the callers would need to change it
back.  In addition it does a global scan through all of the irqs,
which seems to be the sole justification of the msi_lock.

To remove the neede for msi_lookup_irq I added first_msi_irq to struct
pci_dev.  Then depending on the context I replaced msi_lookup_irq with
dev->first_msi_irq, dev->msi_enabled, or dev->msix_enabled.

msi_enabled and msix_enabled were already present in pci_dev for other
reasons.

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8fed4b65

drivers/pci/msi.c

+59 −90
Original line number Diff line number Diff line
@@ -272,28 +272,6 @@ void disable_msi_mode(struct pci_dev *dev, int pos, int type) 
	pci_intx(dev, 1);  /* enable intx */

}



static int msi_lookup_irq(struct pci_dev *dev, int type)

{

	int irq;

	unsigned long flags;



	spin_lock_irqsave(&msi_lock, flags);

	for (irq = 0; irq < NR_IRQS; irq++) {

		if (!msi_desc[irq] || msi_desc[irq]->dev != dev ||

			msi_desc[irq]->msi_attrib.type != type ||

			msi_desc[irq]->msi_attrib.default_irq != dev->irq)

			continue;

		spin_unlock_irqrestore(&msi_lock, flags);

		/* This pre-assigned MSI irq for this device

		   already exists. Override dev->irq with this irq */

		dev->irq = irq;

		return 0;

	}

	spin_unlock_irqrestore(&msi_lock, flags);



	return -EACCES;

}



#ifdef CONFIG_PM

static int __pci_save_msi_state(struct pci_dev *dev)

{
@@ -364,11 +342,13 @@ static void __pci_restore_msi_state(struct pci_dev *dev) 
static int __pci_save_msix_state(struct pci_dev *dev)

{

	int pos;

	int temp;

	int irq, head, tail = 0;

	u16 control;

	struct pci_cap_saved_state *save_state;



	if (!dev->msix_enabled)

		return 0;



	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);

	if (pos <= 0 || dev->no_msi)

		return 0;
@@ -386,13 +366,7 @@ static int __pci_save_msix_state(struct pci_dev *dev) 
	*((u16 *)&save_state->data[0]) = control;



	/* save the table */

	temp = dev->irq;

	if (msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {

		kfree(save_state);

		return -EINVAL;

	}



	irq = head = dev->irq;

	irq = head = dev->first_msi_irq;

	while (head != tail) {

		struct msi_desc *entry;
@@ -402,7 +376,6 @@ static int __pci_save_msix_state(struct pci_dev *dev) 
		tail = msi_desc[irq]->link.tail;

		irq = tail;

	}

	dev->irq = temp;



	save_state->cap_nr = PCI_CAP_ID_MSIX;

	pci_add_saved_cap(dev, save_state);
@@ -428,9 +401,11 @@ static void __pci_restore_msix_state(struct pci_dev *dev) 
	int pos;

	int irq, head, tail = 0;

	struct msi_desc *entry;

	int temp;

	struct pci_cap_saved_state *save_state;



	if (!dev->msix_enabled)

		return;



	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSIX);

	if (!save_state)

		return;
@@ -443,10 +418,7 @@ static void __pci_restore_msix_state(struct pci_dev *dev) 
		return;



	/* route the table */

	temp = dev->irq;

	if (msi_lookup_irq(dev, PCI_CAP_ID_MSIX))

		return;

	irq = head = dev->irq;

	irq = head = dev->first_msi_irq;

	while (head != tail) {

		entry = msi_desc[irq];

		write_msi_msg(irq, &entry->msg_save);
@@ -454,7 +426,6 @@ static void __pci_restore_msix_state(struct pci_dev *dev) 
		tail = msi_desc[irq]->link.tail;

		irq = tail;

	}

	dev->irq = temp;



	pci_write_config_word(dev, msi_control_reg(pos), save);

	enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
@@ -524,6 +495,7 @@ static int msi_capability_init(struct pci_dev *dev) 
		return status;

	}



	dev->first_msi_irq = irq;

	attach_msi_entry(entry, irq);

	/* Set MSI enabled bits	 */

	enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
@@ -620,6 +592,7 @@ static int msix_capability_init(struct pci_dev *dev, 
			avail = -EBUSY;

		return avail;

	}

	dev->first_msi_irq = entries[0].vector;

	/* Set MSI-X enabled bits */

	enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
@@ -667,13 +640,11 @@ int pci_msi_supported(struct pci_dev * dev) 
 **/

int pci_enable_msi(struct pci_dev* dev)

{

	int pos, temp, status;

	int pos, status;



	if (pci_msi_supported(dev) < 0)

		return -EINVAL;



	temp = dev->irq;



	status = msi_init();

	if (status < 0)

		return status;
@@ -682,15 +653,14 @@ int pci_enable_msi(struct pci_dev* dev) 
	if (!pos)

		return -EINVAL;



	WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSI));

	WARN_ON(!!dev->msi_enabled);



	/* Check whether driver already requested for MSI-X irqs */

	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);

	if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {

	if (pos > 0 && dev->msix_enabled) {

			printk(KERN_INFO "PCI: %s: Can't enable MSI.  "

			       "Device already has MSI-X irq assigned\n",

			       "Device already has MSI-X enabled\n",

			       pci_name(dev));

			dev->irq = temp;

			return -EINVAL;

	}

	status = msi_capability_init(dev);
@@ -709,6 +679,9 @@ void pci_disable_msi(struct pci_dev* dev) 
	if (!dev)

		return;



	if (!dev->msi_enabled)

		return;



	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);

	if (!pos)

		return;
@@ -717,28 +690,30 @@ void pci_disable_msi(struct pci_dev* dev) 
	if (!(control & PCI_MSI_FLAGS_ENABLE))

		return;





	disable_msi_mode(dev, pos, PCI_CAP_ID_MSI);



	spin_lock_irqsave(&msi_lock, flags);

	entry = msi_desc[dev->irq];

	entry = msi_desc[dev->first_msi_irq];

	if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {

		spin_unlock_irqrestore(&msi_lock, flags);

		return;

	}

	if (irq_has_action(dev->irq)) {

	if (irq_has_action(dev->first_msi_irq)) {

		spin_unlock_irqrestore(&msi_lock, flags);

		printk(KERN_WARNING "PCI: %s: pci_disable_msi() called without "

		       "free_irq() on MSI irq %d\n",

		       pci_name(dev), dev->irq);

		BUG_ON(irq_has_action(dev->irq));

		       pci_name(dev), dev->first_msi_irq);

		BUG_ON(irq_has_action(dev->first_msi_irq));

	} else {

		default_irq = entry->msi_attrib.default_irq;

		spin_unlock_irqrestore(&msi_lock, flags);

		msi_free_irq(dev, dev->irq);

		msi_free_irq(dev, dev->first_msi_irq);



		/* Restore dev->irq to its default pin-assertion irq */

		dev->irq = default_irq;

	}

	dev->first_msi_irq = 0;

}



static int msi_free_irq(struct pci_dev* dev, int irq)
@@ -797,7 +772,7 @@ static int msi_free_irq(struct pci_dev* dev, int irq) 
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)

{

	int status, pos, nr_entries;

	int i, j, temp;

	int i, j;

	u16 control;



	if (!entries || pci_msi_supported(dev) < 0)
@@ -825,16 +800,14 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) 
				return -EINVAL;	/* duplicate entry */

		}

	}

	temp = dev->irq;

	WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSIX));

	WARN_ON(!!dev->msix_enabled);



	/* Check whether driver already requested for MSI irq */

   	if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&

		!msi_lookup_irq(dev, PCI_CAP_ID_MSI)) {

		dev->msi_enabled) {

		printk(KERN_INFO "PCI: %s: Can't enable MSI-X.  "

		       "Device already has an MSI irq assigned\n",

		       pci_name(dev));

		dev->irq = temp;

		return -EINVAL;

	}

	status = msix_capability_init(dev, entries, nvec);
@@ -843,7 +816,9 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) 


void pci_disable_msix(struct pci_dev* dev)

{

	int pos, temp;

	int irq, head, tail = 0, warning = 0;

	unsigned long flags;

	int pos;

	u16 control;



	if (!pci_msi_enable)
@@ -851,6 +826,9 @@ void pci_disable_msix(struct pci_dev* dev) 
	if (!dev)

		return;



	if (!dev->msix_enabled)

		return;



	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);

	if (!pos)

		return;
@@ -861,13 +839,7 @@ void pci_disable_msix(struct pci_dev* dev) 


	disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);



	temp = dev->irq;

	if (!msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {

		int irq, head, tail = 0, warning = 0;

		unsigned long flags;



		irq = head = dev->irq;

		dev->irq = temp;			/* Restore pin IRQ */

	irq = head = dev->first_msi_irq;

	while (head != tail) {

		spin_lock_irqsave(&msi_lock, flags);

		tail = msi_desc[irq]->link.tail;
@@ -885,7 +857,7 @@ void pci_disable_msix(struct pci_dev* dev) 
			pci_name(dev));

		BUG_ON(warning > 0);

	}

	}

	dev->first_msi_irq = 0;

}



/**
@@ -899,30 +871,28 @@ void pci_disable_msix(struct pci_dev* dev) 
 **/

void msi_remove_pci_irq_vectors(struct pci_dev* dev)

{

	int pos, temp;

	int pos;

	unsigned long flags;



	if (!pci_msi_enable || !dev)

 		return;



	temp = dev->irq;		/* Save IOAPIC IRQ */

	pos = pci_find_capability(dev, PCI_CAP_ID_MSI);

	if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSI)) {

		if (irq_has_action(dev->irq)) {

	if (pos > 0 && dev->msi_enabled) {

		if (irq_has_action(dev->first_msi_irq)) {

			printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() "

			       "called without free_irq() on MSI irq %d\n",

			       pci_name(dev), dev->irq);

			BUG_ON(irq_has_action(dev->irq));

			       pci_name(dev), dev->first_msi_irq);

			BUG_ON(irq_has_action(dev->first_msi_irq));

		} else /* Release MSI irq assigned to this device */

			msi_free_irq(dev, dev->irq);

		dev->irq = temp;		/* Restore IOAPIC IRQ */

			msi_free_irq(dev, dev->first_msi_irq);

	}

	pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);

	if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {

	if (pos > 0 && dev->msix_enabled) {

		int irq, head, tail = 0, warning = 0;

		void __iomem *base = NULL;



		irq = head = dev->irq;

		irq = head = dev->first_msi_irq;

		while (head != tail) {

			spin_lock_irqsave(&msi_lock, flags);

			tail = msi_desc[irq]->link.tail;
@@ -942,7 +912,6 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev) 
			       pci_name(dev));

			BUG_ON(warning > 0);

		}

		dev->irq = temp;		/* Restore IOAPIC IRQ */

	}

}

include/linux/pci.h

+3 −0
Original line number Diff line number Diff line
@@ -174,6 +174,9 @@ struct pci_dev { 
	struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */

	int rom_attr_enabled;		/* has display of the rom attribute been enabled? */

	struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */

#ifdef CONFIG_PCI_MSI

	unsigned int first_msi_irq;

#endif

};



#define pci_dev_g(n) list_entry(n, struct pci_dev, global_list)