[PATCH v1 05/21] PCI/MSI: Introduce weak arch_find_msi_chip() to find MSI chip
From: l.stach@pengutronix.de (Lucas Stach)
Date: 2014-09-15 14:42:34
Also in:
linux-arch, linux-iommu, linux-mips, linux-pci, linux-s390, linuxppc-dev, sparclinux
Am Freitag, den 05.09.2014, 18:09 +0800 schrieb Yijing Wang:
Introduce weak arch_find_msi_chip() to find the match msi_chip. Currently, MSI chip associates pci bus to msi_chip. Because in ARM platform, there may be more than one MSI controller in system. Associate pci bus to msi_chip help pci device to find the match msi_chip and setup MSI/MSI-X irq correctly. But in other platform, like in x86. we only need one MSI chip, because all device use the same MSI address/data and irq etc. So it's no need to associate pci bus to MSI chip, just use a arch function, arch_find_msi_chip() to return the MSI chip for simplicity. The default weak arch_find_msi_chip() used in ARM platform, find the MSI chip by pci bus.
Hm, while one weak function sounds much better than the plethora we have now, I wonder how much work it would be to associate the msi_chip with the pci bus on other arches the same way as done on ARM. This way we could kill this calling into arch specific functions which would make things a bit clearer to follow I think. Regards, Lucas
quoted hunk ↗ jump to hunk
Signed-off-by: Yijing Wang <redacted> --- drivers/pci/msi.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-)diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index a77e7f7..539c11d 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c@@ -29,9 +29,14 @@ static int pci_msi_enable = 1; /* Arch hooks */ +struct msi_chip * __weak arch_find_msi_chip(struct pci_dev *dev) +{ + return dev->bus->msi; +} + int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc) { - struct msi_chip *chip = dev->bus->msi; + struct msi_chip *chip = arch_find_msi_chip(dev); int err; if (!chip || !chip->setup_irq)
-- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ |