From 23a5fba4d9411787c8e86ff5808e7d8e41bf3935 Mon Sep 17 00:00:00 2001 From: Thomas Petazzoni Date: Thu, 18 Oct 2018 17:37:16 +0200 Subject: PCI: Introduce PCI bridge emulated config space common logic Some PCI host controllers do not expose a configuration space for the root port PCI bridge. Due to this, the Marvell Armada 370/38x/XP PCI controller driver (pci-mvebu) emulates a root port PCI bridge configuration space, and uses that to (among other things) dynamically create the memory windows that correspond to the PCI MEM and I/O regions. Since we now need to add a very similar logic for the Marvell Armada 37xx PCI controller driver (pci-aardvark), instead of duplicating the code, we create in this commit a common logic called pci-bridge-emul. The idea of this logic is to emulate a root port PCI bridge configuration space by providing configuration space read/write operations, and faking behind the scenes the configuration space of a PCI bridge. A PCI host controller driver simply has to call pci_bridge_emul_conf_read() and pci_bridge_emul_conf_write() to read/write the configuration space of the bridge. By default, the PCI bridge configuration space is simply emulated by a chunk of memory, but the PCI host controller can override the behavior of the read and write operations on a per-register basis to do additional actions if needed. We take care of complying with the behavior of the PCI configuration space registers in terms of bits that are read-write, read-only, reserved and write-1-to-clear. Signed-off-by: Thomas Petazzoni Signed-off-by: Lorenzo Pieralisi Acked-by: Bjorn Helgaas Reviewed-by: Russell King --- drivers/pci/Kconfig | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/pci/Kconfig') diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 56ff8f6d31fc..4a28e07d4c0e 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -98,6 +98,9 @@ config PCI_ECAM config PCI_LOCKLESS_CONFIG bool +config PCI_BRIDGE_EMUL + bool + config PCI_IOV bool "PCI IOV support" depends on PCI -- cgit v1.2.1