diff mbox series

[v2,04/11] PCI: pci-bridge-emul: Add support for new flag PCI_BRIDGE_EMUL_NO_IO_FORWARD

Message ID 20220104153529.31647-5-pali@kernel.org (mailing list archive)
State New, archived
Headers show
Series PCI: Small improvements for pci-bridge-emul and mvebu | expand

Commit Message

Pali Rohár Jan. 4, 2022, 3:35 p.m. UTC
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.

Signed-off-by: Pali Rohár <pali@kernel.org>

---
Changes in v2:
* Add comment into code.
---
 drivers/pci/pci-bridge-emul.c | 9 +++++++++
 drivers/pci/pci-bridge-emul.h | 6 ++++++
 2 files changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index 432b1bec2e22..033bbeb99176 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -378,6 +378,15 @@  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);
diff --git a/drivers/pci/pci-bridge-emul.h b/drivers/pci/pci-bridge-emul.h
index 087b5fa01bcf..4953274cac18 100644
--- a/drivers/pci/pci-bridge-emul.h
+++ b/drivers/pci/pci-bridge-emul.h
@@ -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,