nb/intel/i945: Fix ich7_setup_root_complex_topology

Element Self Description register (ESD) [23:16] is R/WO, so let
write the ESD.CID when we start ich7_setup_root_complex_topology.
This value is also used to program the R/WO 'Target Component ID'
registers of RPxD and HHD.
Once it is done, no need to rewrite on them as they become RO.
(For more information, please see ICH7 datasheet page 271.)

Tested done on 945G-M4 using printk before and after writing.
Before this change, writing on those registers had no effect:
ESD:  0x0104: 0x00000802
ULD:  0x0110: 0x00000001
ULBA: 0x0118: 0x00000000
RP1D: 0x0120: 0x01000003
RP2D: 0x0130: 0x02000003
RP3D: 0x0140: 0x03000002
RP4D: 0x0150: 0x04000002
HDD:  0x0160: 0x0f000002
RP5D: 0x0170: 0x05000002
RP6D: 0x0180: 0x06000002

Using this patche, those R/WO get the "right" values.
i.e., We can see RCBA32(ULBA) is now equal to (uintptr_t)DEFAULT_DMIBAR.
ESD:  0x0104: 0x00020802
ULD:  0x0110: 0x01010001
ULBA: 0x0118: 0xfed18000
RP1D: 0x0120: 0x01020003
RP2D: 0x0130: 0x02020003
RP3D: 0x0140: 0x03020002
RP4D: 0x0150: 0x04020002
HDD:  0x0160: 0x0f020002
RP5D: 0x0170: 0x05020002
RP6D: 0x0180: 0x06020002

Change-Id: I3f2199d6da22ce9995496c2a81363710edde81f3
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/30993
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 15 insertions, 25 deletions

diff --git a/src/northbridge/intel/i945/early_init.c b/src/northbridge/intel/i945/early_init.c
index 08dd6752d6..0c92c4bd7d 100644
--- a/src/northbridge/intel/i945/early_init.c
+++ b/src/northbridge/intel/i945/early_init.c
@@ -341,13 +341,6 @@ static void ich7_setup_dmi_rcrb(void)
 
 	RCBA32(V0CTL) = 0x80000001;
 	RCBA32(V1CAP) = 0x03128010;
-	RCBA32(ESD) = 0x00000810;
-	RCBA32(RP1D) = 0x01000003;
-	RCBA32(RP2D) = 0x02000002;
-	RCBA32(RP3D) = 0x03000002;
-	RCBA32(RP4D) = 0x04000002;
-	RCBA32(HDD) = 0x0f000003;
-	RCBA32(RP5D) = 0x05000002;
 
 	pci_write_config16(PCI_DEV(0, 0x1c, 0), 0x42, 0x0141);
 	pci_write_config16(PCI_DEV(0, 0x1c, 4), 0x42, 0x0141);
@@ -361,20 +354,6 @@ static void ich7_setup_dmi_rcrb(void)
 	reg32 |= (0x40 << 1) | (4 << 17) | (1 << 24) | (1 << 31);
 	RCBA32(V1CTL) = reg32;
 
-	RCBA32(ESD) |= (2 << 16);
-
-	RCBA32(ULD) |= (1 << 24) | (1 << 16);
-
-	RCBA32(ULBA) = (uintptr_t)DEFAULT_DMIBAR;
-
-	RCBA32(RP1D) |= (2 << 16);
-	RCBA32(RP2D) |= (2 << 16);
-	RCBA32(RP3D) |= (2 << 16);
-	RCBA32(RP4D) |= (2 << 16);
-	RCBA32(HDD)  |= (2 << 16);
-	RCBA32(RP5D) |= (2 << 16);
-	RCBA32(RP6D) |= (2 << 16);
-
 	RCBA32(LCAP) |= (3 << 10);
 }
 
@@ -871,10 +850,21 @@ static void i945_setup_root_complex_topology(void)
 
 static void ich7_setup_root_complex_topology(void)
 {
-	RCBA32(0x104) = 0x00000802;
-	RCBA32(0x110) = 0x00000001;
-	RCBA32(0x114) = 0x00000000;
-	RCBA32(0x118) = 0x00000000;
+	/* Write the R/WO registers */
+
+	RCBA32(ESD) |= (2 << 16);
+
+	RCBA32(ULD) |= (1 << 24) | (1 << 16);
+
+	RCBA32(ULBA) = (uintptr_t)DEFAULT_DMIBAR;
+	/* Write ESD.CID to TCID */
+	RCBA32(RP1D) |= (2 << 16);
+	RCBA32(RP2D) |= (2 << 16);
+	RCBA32(RP3D) |= (2 << 16);
+	RCBA32(RP4D) |= (2 << 16);
+	RCBA32(HDD)  |= (2 << 16);
+	RCBA32(RP5D) |= (2 << 16);
+	RCBA32(RP6D) |= (2 << 16);
 }
 
 static void ich7_setup_pci_express(void)