From a52e2e3513d4beafe8fe8699f1519b021c2d05ba Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Sat, 24 Jan 2009 00:21:14 +0100 Subject: [PATCH] PCI/MSI: Introduce pci_msix_table_size() Introduce new function pci_msix_table_size() returning the size of the MSI-X table of given PCI device or 0 if the device doesn't support MSI-X. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hidetoshi Seto Signed-off-by: Jesse Barnes --- drivers/pci/msi.c | 24 +++++++++++++++++++----- include/linux/pci.h | 5 +++++ 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index baba2eb5367d..08aedd5875b0 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -674,6 +674,23 @@ static int msi_free_irqs(struct pci_dev* dev) return 0; } +/** + * pci_msix_table_size - 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) +{ + int pos; + u16 control; + + pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); + if (!pos) + return 0; + + pci_read_config_word(dev, msi_control_reg(pos), &control); + return multi_msix_capable(control); +} + /** * pci_enable_msix - configure device's MSI-X capability structure * @dev: pointer to the pci_dev data structure of MSI-X device function @@ -691,9 +708,8 @@ static int msi_free_irqs(struct pci_dev* dev) **/ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) { - int status, pos, nr_entries; + int status, nr_entries; int i, j; - u16 control; if (!entries) return -EINVAL; @@ -702,9 +718,7 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) 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); + nr_entries = pci_msix_table_size(dev); if (nvec > nr_entries) return -EINVAL; diff --git a/include/linux/pci.h b/include/linux/pci.h index 7bd624bfdcfd..b5d6d0e0f1cb 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -799,6 +799,10 @@ static inline void pci_msi_shutdown(struct pci_dev *dev) static inline void pci_disable_msi(struct pci_dev *dev) { } +static inline int pci_msix_table_size(struct pci_dev *dev) +{ + return 0; +} static inline int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) { @@ -823,6 +827,7 @@ static inline int pci_msi_enabled(void) extern int pci_enable_msi(struct pci_dev *dev); extern void pci_msi_shutdown(struct pci_dev *dev); extern void pci_disable_msi(struct pci_dev *dev); +extern int pci_msix_table_size(struct pci_dev *dev); extern int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec); extern void pci_msix_shutdown(struct pci_dev *dev); -- 2.20.1