diff options
Diffstat (limited to 'drivers/pci/msi.c')
| -rw-r--r-- | drivers/pci/msi.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 5099636a6e5..00cc78c7aa0 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -845,6 +845,32 @@ int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec) } EXPORT_SYMBOL(pci_enable_msi_block); +int pci_enable_msi_block_auto(struct pci_dev *dev, unsigned int *maxvec) +{ + int ret, pos, nvec; + u16 msgctl; + + pos = pci_find_capability(dev, PCI_CAP_ID_MSI); + if (!pos) + return -EINVAL; + + pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl); + ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1); + + if (maxvec) + *maxvec = ret; + + do { + nvec = ret; + ret = pci_enable_msi_block(dev, nvec); + } while (ret > 0); + + if (ret < 0) + return ret; + return nvec; +} +EXPORT_SYMBOL(pci_enable_msi_block_auto); + void pci_msi_shutdown(struct pci_dev *dev) { struct msi_desc *desc; |