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Commit c9953a73 authored by Michael Ellerman's avatar Michael Ellerman Committed by Greg Kroah-Hartman
Browse files

MSI: Add an arch_msi_check_device() 



Add an arch_check_device(), which gives archs a chance to check the input
to pci_enable_msi/x. The arch might be interested in the value of nvec so
pass it in. Propagate the error value returned from the arch routine out
to the caller.

Signed-off-by: default avatarMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 17bbc12a

drivers/pci/msi.c

+25 −4
Original line number Diff line number Diff line
@@ -459,15 +459,17 @@ static int msix_capability_init(struct pci_dev *dev, 
/**

 * pci_msi_check_device - check whether MSI may be enabled on a device

 * @dev: pointer to the pci_dev data structure of MSI device function

 * @nvec: how many MSIs have been requested ?

 * @type: are we checking for MSI or MSI-X ?

 *

 * Look at global flags, the device itself, and its parent busses

 * to determine if MSI/-X are supported for the device. If MSI/-X is

 * supported return 0, else return an error code.

 **/

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

static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type)

{

	struct pci_bus *bus;

	int ret;



	/* MSI must be globally enabled and supported by the device */

	if (!pci_msi_enable || !dev || dev->no_msi)
@@ -483,6 +485,10 @@ static int pci_msi_check_device(struct pci_dev * dev, int type) 
		if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)

			return -EINVAL;



	ret = arch_msi_check_device(dev, nvec, type);

	if (ret)

		return ret;



	if (!pci_find_capability(dev, type))

		return -EINVAL;
@@ -503,8 +509,9 @@ int pci_enable_msi(struct pci_dev* dev) 
{

	int status;



	if (pci_msi_check_device(dev, PCI_CAP_ID_MSI))

		return -EINVAL;

	status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI);

	if (status)

		return status;



	WARN_ON(!!dev->msi_enabled);
@@ -601,9 +608,13 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) 
	int i, j;

	u16 control;



	if (!entries || pci_msi_check_device(dev, PCI_CAP_ID_MSIX))

	if (!entries)

 		return -EINVAL;



	status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);

	if (status)

		return status;



	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);
@@ -687,3 +698,13 @@ void pci_no_msi(void) 
{

	pci_msi_enable = 0;

}





/* Arch hooks */



int __attribute__ ((weak))

arch_msi_check_device(struct pci_dev* dev, int nvec, int type)

{

	return 0;

}

include/linux/msi.h

+1 −0
Original line number Diff line number Diff line
@@ -41,6 +41,7 @@ struct msi_desc { 
 */

int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc);

void arch_teardown_msi_irq(unsigned int irq);

extern int arch_msi_check_device(struct pci_dev* dev, int nvec, int type);





#endif /* LINUX_MSI_H */