nb/intel/haswell: Set up Root Complex topology

System BIOS must program some of the Root Complex Topology Capability
Structure registers located in configuration space, specs say. So do it.

Tested on Asrock B85M Pro4, still boots.

Change-Id: Ia2a61706a127bf2b817004a8ec6a723da9826aad
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43744
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/northbridge/intel/haswell/haswell.h

@@ -20,6 +20,14 @@
 
 #include "registers/host_bridge.h"
 
+/* Device 0:1.0 PCI configuration space (PCIe Graphics) */
+
+#define PEG_DCAP2	0xc4	/* 32bit */
+
+#define PEG_ESD		0x144	/* 32bit */
+#define PEG_LE1D	0x150	/* 32bit */
+#define PEG_LE1A	0x158	/* 64bit */
+
 /* Device 0:2.0 PCI configuration space (Graphics Device) */
 
 #define MSAC		0x62	/* Multi Size Aperture Control */
@@ -59,6 +67,7 @@
 #define EPBAR8(x)  *((volatile u8  *)(DEFAULT_EPBAR + (x)))
 #define EPBAR16(x) *((volatile u16 *)(DEFAULT_EPBAR + (x)))
 #define EPBAR32(x) *((volatile u32 *)(DEFAULT_EPBAR + (x)))
+#define EPBAR64(x) *((volatile u64 *)(DEFAULT_EPBAR + (x)))
 
 #include "registers/epbar.h"
 
@@ -69,6 +78,7 @@
 #define DMIBAR8(x)  *((volatile u8  *)(DEFAULT_DMIBAR + (x)))
 #define DMIBAR16(x) *((volatile u16 *)(DEFAULT_DMIBAR + (x)))
 #define DMIBAR32(x) *((volatile u32 *)(DEFAULT_DMIBAR + (x)))
+#define DMIBAR64(x) *((volatile u64 *)(DEFAULT_DMIBAR + (x)))
 
 #include "registers/dmibar.h"
 

src/northbridge/intel/haswell/northbridge.c

@@ -498,12 +498,77 @@ static void northbridge_dmi_init(void)
 	}
 }
 
+static void northbridge_topology_init(void)
+{
+	const u32 eple_a[3] = { EPLE2A, EPLE3A, EPLE4A };
+	const u32 eple_d[3] = { EPLE2D, EPLE3D, EPLE4D };
+
+	u32 reg32;
+
+	/* Set the CID1 Egress Port 0 Root Topology */
+	reg32 = EPBAR32(EPESD);
+	reg32 &= ~(0xff << 16);
+	reg32 |= 1 << 16;
+	EPBAR32(EPESD) = reg32;
+
+	reg32 = EPBAR32(EPLE1D);
+	reg32 &= ~(0xff << 16);
+	reg32 |= 1 | (1 << 16);
+	EPBAR32(EPLE1D) = reg32;
+	EPBAR64(EPLE1A) = (uintptr_t)DEFAULT_DMIBAR;
+
+	for (unsigned int i = 0; i <= 2; i++) {
+		const struct device *const dev = pcidev_on_root(1, i);
+
+		if (!dev || !dev->enabled)
+			continue;
+
+		EPBAR64(eple_a[i]) = (u64)PCI_DEV(0, 1, i);
+
+		reg32 = EPBAR32(eple_d[i]);
+		reg32 &= ~(0xff << 16);
+		reg32 |= 1 | (1 << 16);
+		EPBAR32(eple_d[i]) = reg32;
+
+		pci_update_config32(dev, PEG_ESD, ~(0xff << 16), (1 << 16));
+		pci_write_config32(dev, PEG_LE1A, (uintptr_t)DEFAULT_EPBAR);
+		pci_write_config32(dev, PEG_LE1A + 4, 0);
+		pci_update_config32(dev, PEG_LE1D, ~(0xff << 16), (1 << 16) | 1);
+
+		/* Read and write to lock register */
+		pci_or_config32(dev, PEG_DCAP2, 0);
+	}
+
+	/* Set the CID1 DMI Port Root Topology */
+	reg32 = DMIBAR32(DMIESD);
+	reg32 &= ~(0xff << 16);
+	reg32 |= 1 << 16;
+	DMIBAR32(DMIESD) = reg32;
+
+	reg32 = DMIBAR32(DMILE1D);
+	reg32 &= ~(0xffff << 16);
+	reg32 |= 1 | (2 << 16);
+	DMIBAR32(DMILE1D) = reg32;
+	DMIBAR64(DMILE1A) = (uintptr_t)DEFAULT_RCBA;
+
+	DMIBAR64(DMILE2A) = (uintptr_t)DEFAULT_EPBAR;
+	reg32 = DMIBAR32(DMILE2D);
+	reg32 &= ~(0xff << 16);
+	reg32 |= 1 | (1 << 16);
+	DMIBAR32(DMILE2D) = reg32;
+
+	/* Program RO and Write-Once Registers */
+	DMIBAR32(DMIPVCCAP1) = DMIBAR32(DMIPVCCAP1);
+	DMIBAR32(DMILCAP)    = DMIBAR32(DMILCAP);
+}
+
 static void northbridge_init(struct device *dev)
 {
 	u8 bios_reset_cpl, pair;
 
 	init_egress();
 	northbridge_dmi_init();
+	northbridge_topology_init();
 
 	/* Enable Power Aware Interrupt Routing. */
 	pair = MCHBAR8(INTRDIRCTL);

src/northbridge/intel/haswell/registers/epbar.h

@@ -20,5 +20,9 @@
 #define EPLE1A		0x058	/* 64bit */
 #define EPLE2D		0x060	/* 32bit */
 #define EPLE2A		0x068	/* 64bit */
+#define EPLE3D		0x070	/* 32bit */
+#define EPLE3A		0x078	/* 64bit */
+#define EPLE4D		0x080	/* 32bit */
+#define EPLE4A		0x088	/* 64bit */
 
 #endif /* __HASWELL_REGISTERS_EPBAR_H__ */