diff options
| author | Alexander Gordeev <agordeev@redhat.com> | 2013-12-30 08:28:15 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2014-01-03 17:17:55 -0700 |
| commit | ff1aa430a2fa43189e89c7ddd559f0bee2298288 (patch) | |
| tree | 731237d3f796f92aa31b41a8fda7f0e38c707fbb /drivers/pci/msi.c | |
| parent | 7b92b4f61ec49cb1a5813298f35258bd7ecd3667 (diff) | |
PCI/MSI: Add pci_msix_vec_count()
This creates an MSI-X counterpart for pci_msi_vec_count(). Device drivers
can use this function to obtain maximum number of MSI-X interrupts the
device supports and use that number in a subsequent call to
pci_enable_msix().
pci_msix_vec_count() supersedes pci_msix_table_size() and returns a
negative errno if device does not support MSI-X interrupts. After this
update, callers must always check the returned value.
The only user of pci_msix_table_size() was the PCI-Express port driver,
which is also updated by this change.
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers/pci/msi.c')
| -rw-r--r-- | drivers/pci/msi.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 76507ab13beb..bd18ecf74c55 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -948,19 +948,25 @@ void pci_disable_msi(struct pci_dev *dev) EXPORT_SYMBOL(pci_disable_msi); /** - * pci_msix_table_size - return the number of device's MSI-X table entries + * pci_msix_vec_count - return the number of device's MSI-X table entries * @dev: pointer to the pci_dev data structure of MSI-X device function - */ -int pci_msix_table_size(struct pci_dev *dev) + + * This function returns the number of device's MSI-X table entries and + * therefore the number of MSI-X vectors device is capable of sending. + * It returns a negative errno if the device is not capable of sending MSI-X + * interrupts. + **/ +int pci_msix_vec_count(struct pci_dev *dev) { u16 control; if (!dev->msix_cap) - return 0; + return -EINVAL; pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); return msix_table_size(control); } +EXPORT_SYMBOL(pci_msix_vec_count); /** * pci_enable_msix - configure device's MSI-X capability structure @@ -989,7 +995,9 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) if (status) return status; - nr_entries = pci_msix_table_size(dev); + nr_entries = pci_msix_vec_count(dev); + if (nr_entries < 0) + return nr_entries; if (nvec > nr_entries) return nr_entries; |