There is currently no way for a PCIe bridge to impose constraints on
devices added to it. For example, the Xilinx PCIe host bridge only
supports 32-bit physical addresses (due to a limitation on the AXI
port's address width). Thus, even devices that claim to support 64-bit
DMA addresses must be restricted to 32-bit addresses when attached to
this host controller.
This patch adds a "add_device" method to struct pci_host_bridge that
allows the host driver to act upon acting adding devices.
Based on an earlier patch from Wesley W. Terpstra <wesley@xxxxxxxxxx>.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/pci/probe.c | 6 ++++++
include/linux/pci.h | 1 +
2 files changed, 7 insertions(+)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ac876e32de4b..452190fb05e7 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2290,6 +2290,7 @@ static void pci_set_msi_domain(struct pci_dev *dev)
void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
{
+ struct pci_host_bridge *host = pci_find_host_bridge(bus);
int ret;
pci_configure_device(dev);
@@ -2328,6 +2329,11 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
ret = pcibios_add_device(dev);
WARN_ON(ret < 0);
+ if (host->add_device) {
+ ret = host->add_device(dev);
+ WARN_ON(ret < 0);
+ }
+
/* Set up MSI IRQ domain */
pci_set_msi_domain(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index abd5d5e17aee..1524adbb30ab 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -485,6 +485,7 @@ struct pci_host_bridge {
resource_size_t start,
resource_size_t size,
resource_size_t align);
+ int (*add_device)(struct pci_dev *dev);
unsigned long private[0] ____cacheline_aligned;
};
--
2.18.0
