Merge branch 'remotes/lorenzo/pci/bridge-emul'

- Make emulated ROM BAR read-only by default (Pali Rohár)

- Make some emulated legacy PCI bits read-only for PCIe devices (Pali
  Rohár)

- Update reserved bits in emulated PCIe Capability (Pali Rohár)

- Allow drivers to emulate different PCIe Capability versions (Pali Rohár)

- Set emulated Capabilities List bit for all PCIe devices, since they must
  have at least a PCIe Capability (Pali Rohár)

* remotes/lorenzo/pci/bridge-emul:
  PCI: pci-bridge-emul: Set PCI_STATUS_CAP_LIST for PCIe device
  PCI: pci-bridge-emul: Correctly set PCIe capabilities
  PCI: pci-bridge-emul: Fix definitions of reserved bits
  PCI: pci-bridge-emul: Properly mark reserved PCIe bits in PCI config space
  PCI: pci-bridge-emul: Make expansion ROM Base Address register read-only

1 files changed, 54 insertions, 16 deletions

diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index 0d1177e52a43..c994ebec2360 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -139,8 +139,13 @@ struct pci_bridge_reg_behavior pci_regs_behavior[PCI_STD_HEADER_SIZEOF / 4] = {
 		.ro = GENMASK(7, 0),
 	},
 
+	/*
+	 * If expansion ROM is unsupported then ROM Base Address register must
+	 * be implemented as read-only register that return 0 when read, same
+	 * as for unused Base Address registers.
+	 */
 	[PCI_ROM_ADDRESS1 / 4] = {
-		.rw = GENMASK(31, 11) | BIT(0),
+		.ro = ~0,
 	},
 
 	/*
@@ -171,41 +176,55 @@ struct pci_bridge_reg_behavior pcie_cap_regs_behavior[PCI_CAP_PCIE_SIZEOF / 4] =
 	[PCI_CAP_LIST_ID / 4] = {
 		/*
 		 * Capability ID, Next Capability Pointer and
-		 * Capabilities register are all read-only.
+		 * bits [14:0] of Capabilities register are all read-only.
+		 * Bit 15 of Capabilities register is reserved.
 		 */
-		.ro = ~0,
+		.ro = GENMASK(30, 0),
 	},
 
 	[PCI_EXP_DEVCAP / 4] = {
-		.ro = ~0,
+		/*
+		 * Bits [31:29] and [17:16] are reserved.
+		 * Bits [27:18] are reserved for non-upstream ports.
+		 * Bits 28 and [14:6] are reserved for non-endpoint devices.
+		 * Other bits are read-only.
+		 */
+		.ro = BIT(15) | GENMASK(5, 0),
 	},
 
 	[PCI_EXP_DEVCTL / 4] = {
-		/* Device control register is RW */
-		.rw = GENMASK(15, 0),
+		/*
+		 * Device control register is RW, except bit 15 which is
+		 * reserved for non-endpoints or non-PCIe-to-PCI/X bridges.
+		 */
+		.rw = GENMASK(14, 0),
 
 		/*
 		 * Device status register has bits 6 and [3:0] W1C, [5:4] RO,
-		 * the rest is reserved
+		 * the rest is reserved. Also bit 6 is reserved for non-upstream
+		 * ports.
 		 */
-		.w1c = (BIT(6) | GENMASK(3, 0)) << 16,
+		.w1c = GENMASK(3, 0) << 16,
 		.ro = GENMASK(5, 4) << 16,
 	},
 
 	[PCI_EXP_LNKCAP / 4] = {
-		/* All bits are RO, except bit 23 which is reserved */
-		.ro = lower_32_bits(~BIT(23)),
+		/*
+		 * All bits are RO, except bit 23 which is reserved and
+		 * bit 18 which is reserved for non-upstream ports.
+		 */
+		.ro = lower_32_bits(~(BIT(23) | PCI_EXP_LNKCAP_CLKPM)),
 	},
 
 	[PCI_EXP_LNKCTL / 4] = {
 		/*
 		 * Link control has bits [15:14], [11:3] and [1:0] RW, the
-		 * rest is reserved.
+		 * rest is reserved. Bit 8 is reserved for non-upstream ports.
 		 *
 		 * Link status has bits [13:0] RO, and bits [15:14]
 		 * W1C.
 		 */
-		.rw = GENMASK(15, 14) | GENMASK(11, 3) | GENMASK(1, 0),
+		.rw = GENMASK(15, 14) | GENMASK(11, 9) | GENMASK(7, 3) | GENMASK(1, 0),
 		.ro = GENMASK(13, 0) << 16,
 		.w1c = GENMASK(15, 14) << 16,
 	},
@@ -324,11 +343,9 @@ int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
 
 	if (bridge->has_pcie) {
 		bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
+		bridge->conf.status |= cpu_to_le16(PCI_STATUS_CAP_LIST);
 		bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
-		/* Set PCIe v2, root port, slot support */
-		bridge->pcie_conf.cap =
-			cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
-				    PCI_EXP_FLAGS_SLOT);
+		bridge->pcie_conf.cap |= cpu_to_le16(PCI_EXP_TYPE_ROOT_PORT << 4);
 		bridge->pcie_cap_regs_behavior =
 			kmemdup(pcie_cap_regs_behavior,
 				sizeof(pcie_cap_regs_behavior),
@@ -337,6 +354,27 @@ int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
 			kfree(bridge->pci_regs_behavior);
 			return -ENOMEM;
 		}
+		/* These bits are applicable only for PCI and reserved on PCIe */
+		bridge->pci_regs_behavior[PCI_CACHE_LINE_SIZE / 4].ro &=
+			~GENMASK(15, 8);
+		bridge->pci_regs_behavior[PCI_COMMAND / 4].ro &=
+			~((PCI_COMMAND_SPECIAL | PCI_COMMAND_INVALIDATE |
+			   PCI_COMMAND_VGA_PALETTE | PCI_COMMAND_WAIT |
+			   PCI_COMMAND_FAST_BACK) |
+			  (PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK |
+			   PCI_STATUS_DEVSEL_MASK) << 16);
+		bridge->pci_regs_behavior[PCI_PRIMARY_BUS / 4].ro &=
+			~GENMASK(31, 24);
+		bridge->pci_regs_behavior[PCI_IO_BASE / 4].ro &=
+			~((PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK |
+			   PCI_STATUS_DEVSEL_MASK) << 16);
+		bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].rw &=
+			~((PCI_BRIDGE_CTL_MASTER_ABORT |
+			   BIT(8) | BIT(9) | BIT(11)) << 16);
+		bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].ro &=
+			~((PCI_BRIDGE_CTL_FAST_BACK) << 16);
+		bridge->pci_regs_behavior[PCI_INTERRUPT_LINE / 4].w1c &=
+			~(BIT(10) << 16);
 	}
 
 	if (flags & PCI_BRIDGE_EMUL_NO_PREFETCHABLE_BAR) {