[PATCH 1/2] PCI: pci-bridge-emul: Create per-bridge copy of register behavior

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

The behavior of the different registers of the PCI-to-PCI bridge is
currently encoded in two global arrays, shared by all instances of
PCI-to-PCI bridge emulation.

However, we will need to tweak the behavior on a per-bridge basis, to
accommodate for different capabilities of the platforms where this
code is used. In preparation for this, this commit creates a
per-bridge copy of the register behavior arrays, so that they can
later be tweaked on a per-bridge basis.

Reported-by: Luís Mendes <luis.p.mendes@gmail.com>
Reported-by: Leigh Brown <leigh@solinno.co.uk>
Cc: Luís Mendes <luis.p.mendes@gmail.com>
Cc: Leigh Brown <leigh@solinno.co.uk>
Fixes: 1f08673eef123 ("PCI: mvebu: Convert to PCI emulated bridge config space")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
 drivers/pci/pci-bridge-emul.c | 80 +++++++++++++++++++++++------------
 drivers/pci/pci-bridge-emul.h |  8 +++-
 2 files changed, 60 insertions(+), 28 deletions(-)

diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index 129738362d90..dd8d8060317e 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -24,29 +24,6 @@
 #define PCI_CAP_PCIE_START	PCI_BRIDGE_CONF_END
 #define PCI_CAP_PCIE_END	(PCI_CAP_PCIE_START + PCI_EXP_SLTSTA2 + 2)
 
-/*
- * Initialize a pci_bridge_emul structure to represent a fake PCI
- * bridge configuration space. The caller needs to have initialized
- * the PCI configuration space with whatever values make sense
- * (typically at least vendor, device, revision), the ->ops pointer,
- * and optionally ->data and ->has_pcie.
- */
-void pci_bridge_emul_init(struct pci_bridge_emul *bridge)
-{
-	bridge->conf.class_revision |= PCI_CLASS_BRIDGE_PCI << 16;
-	bridge->conf.header_type = PCI_HEADER_TYPE_BRIDGE;
-	bridge->conf.cache_line_size = 0x10;
-	bridge->conf.status = PCI_STATUS_CAP_LIST;
-
-	if (bridge->has_pcie) {
-		bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
-		bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
-		/* Set PCIe v2, root port, slot support */
-		bridge->pcie_conf.cap = PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
-			PCI_EXP_FLAGS_SLOT;
-	}
-}
-
 struct pci_bridge_reg_behavior {
 	/* Read-only bits */
 	u32 ro;
@@ -283,6 +260,55 @@ const static struct pci_bridge_reg_behavior pcie_cap_regs_behavior[] = {
 	},
 };
 
+/*
+ * Initialize a pci_bridge_emul structure to represent a fake PCI
+ * bridge configuration space. The caller needs to have initialized
+ * the PCI configuration space with whatever values make sense
+ * (typically at least vendor, device, revision), the ->ops pointer,
+ * and optionally ->data and ->has_pcie.
+ */
+int pci_bridge_emul_init(struct pci_bridge_emul *bridge)
+{
+	bridge->conf.class_revision |= PCI_CLASS_BRIDGE_PCI << 16;
+	bridge->conf.header_type = PCI_HEADER_TYPE_BRIDGE;
+	bridge->conf.cache_line_size = 0x10;
+	bridge->conf.status = PCI_STATUS_CAP_LIST;
+	bridge->pci_regs_behavior = kmemdup(pci_regs_behavior,
+					    sizeof(pci_regs_behavior),
+					    GFP_KERNEL);
+	if (!bridge->pci_regs_behavior)
+		return -ENOMEM;
+
+	if (bridge->has_pcie) {
+		bridge->conf.capabilities_pointer = PCI_CAP_PCIE_START;
+		bridge->pcie_conf.cap_id = PCI_CAP_ID_EXP;
+		/* Set PCIe v2, root port, slot support */
+		bridge->pcie_conf.cap = PCI_EXP_TYPE_ROOT_PORT << 4 | 2 |
+			PCI_EXP_FLAGS_SLOT;
+		bridge->pcie_cap_regs_behavior =
+			kmemdup(pcie_cap_regs_behavior,
+				sizeof(pcie_cap_regs_behavior),
+				GFP_KERNEL);
+		if (!bridge->pcie_cap_regs_behavior) {
+			kfree(bridge->pci_regs_behavior);
+			return -ENOMEM;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Cleanup a pci_bridge_emul structure that was previously initilized
+ * using pci_bridge_emul_init().
+ */
+void pci_bridge_emul_cleanup(struct pci_bridge_emul *bridge)
+{
+	if (bridge->has_pcie)
+		kfree(bridge->pcie_cap_regs_behavior);
+	kfree(bridge->pci_regs_behavior);
+}
+
 /*
  * Should be called by the PCI controller driver when reading the PCI
  * configuration space of the fake bridge. It will call back the
@@ -312,11 +338,11 @@ int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where,
 		reg -= PCI_CAP_PCIE_START;
 		read_op = bridge->ops->read_pcie;
 		cfgspace = (u32 *) &bridge->pcie_conf;
-		behavior = pcie_cap_regs_behavior;
+		behavior = bridge->pcie_cap_regs_behavior;
 	} else {
 		read_op = bridge->ops->read_base;
 		cfgspace = (u32 *) &bridge->conf;
-		behavior = pci_regs_behavior;
+		behavior = bridge->pci_regs_behavior;
 	}
 
 	if (read_op)
@@ -383,11 +409,11 @@ int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where,
 		reg -= PCI_CAP_PCIE_START;
 		write_op = bridge->ops->write_pcie;
 		cfgspace = (u32 *) &bridge->pcie_conf;
-		behavior = pcie_cap_regs_behavior;
+		behavior = bridge->pcie_cap_regs_behavior;
 	} else {
 		write_op = bridge->ops->write_base;
 		cfgspace = (u32 *) &bridge->conf;
-		behavior = pci_regs_behavior;
+		behavior = bridge->pci_regs_behavior;
 	}
 
 	/* Keep all bits, except the RW bits */
diff --git a/drivers/pci/pci-bridge-emul.h b/drivers/pci/pci-bridge-emul.h
index 9d510ccf738b..f04637bb3222 100644
--- a/drivers/pci/pci-bridge-emul.h
+++ b/drivers/pci/pci-bridge-emul.h
@@ -107,15 +107,21 @@ struct pci_bridge_emul_ops {
 			   u32 old, u32 new, u32 mask);
 };
 
+struct pci_bridge_reg_behavior;
+
 struct pci_bridge_emul {
 	struct pci_bridge_emul_conf conf;
 	struct pci_bridge_emul_pcie_conf pcie_conf;
 	struct pci_bridge_emul_ops *ops;
+	struct pci_bridge_reg_behavior *pci_regs_behavior;
+	struct pci_bridge_reg_behavior *pcie_cap_regs_behavior;
 	void *data;
 	bool has_pcie;
 };
 
-void pci_bridge_emul_init(struct pci_bridge_emul *bridge);
+int pci_bridge_emul_init(struct pci_bridge_emul *bridge);
+void pci_bridge_emul_cleanup(struct pci_bridge_emul *bridge);
+
 int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where,
 			      int size, u32 *value);
 int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where,
-- 
2.20.1