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PCI: pci-bridge-emul: Add support for new flag PCI_BRIDGE_EMUL_NO_IO_FORWARD

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Like PCI_BRIDGE_EMUL_NO_PREFMEM_FORWARD, this new flag specifies that
emulated PCI bridge does not support forwarding of IO requests in given
range between primary and secondary buses. This flag should be used as
argument for pci_bridge_emul_init() for hardware setup without IO support.

Setting this flag cause that IO base and limit registers are read-only.

Link: https://lore.kernel.org/r/20220104153529.31647-5-pali@kernel.org
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Rob Herring <robh@kernel.org>
This commit is contained in:
Pali Rohár 2022-01-04 16:35:22 +01:00 committed by Lorenzo Pieralisi
parent d3f332b568
commit 05241c1365
2 changed files with 15 additions and 0 deletions
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9
drivers/pci/pci-bridge-emul.c
View File

@ -382,6 +382,15 @@ int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
bridge->pci_regs_behavior[PCI_PREF_MEMORY_BASE / 4].rw = 0;
}
if (flags & PCI_BRIDGE_EMUL_NO_IO_FORWARD) {
bridge->pci_regs_behavior[PCI_COMMAND / 4].ro |= PCI_COMMAND_IO;
bridge->pci_regs_behavior[PCI_COMMAND / 4].rw &= ~PCI_COMMAND_IO;
bridge->pci_regs_behavior[PCI_IO_BASE / 4].ro |= GENMASK(15, 0);
bridge->pci_regs_behavior[PCI_IO_BASE / 4].rw &= ~GENMASK(15, 0);
bridge->pci_regs_behavior[PCI_IO_BASE_UPPER16 / 4].ro = ~0;
bridge->pci_regs_behavior[PCI_IO_BASE_UPPER16 / 4].rw = 0;
}
return 0;
}
EXPORT_SYMBOL_GPL(pci_bridge_emul_init);

6
drivers/pci/pci-bridge-emul.h
View File

@ -125,6 +125,12 @@ enum {
* requests between primary and secondary buses.
*/
PCI_BRIDGE_EMUL_NO_PREFMEM_FORWARD = BIT(0),
/*
* PCI bridge does not support forwarding of IO requests between
* primary and secondary buses.
*/
PCI_BRIDGE_EMUL_NO_IO_FORWARD = BIT(1),
};
int pci_bridge_emul_init(struct pci_bridge_emul *bridge,