[coreboot-gerrit] New patch to review for coreboot: 4b2a146 AMD fam10: Fix add_more_links FIXME

[Kyösti Mälkki]

Kyösti Mälkki ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/8555

-gerrit

commit 4b2a1464936dc1f4b748698b311be5df1868f834
Author: Kyösti Mälkki 
Date:   Sat Feb 21 23:56:07 2015 +0200

AMD fam10: Fix add_more_links FIXME

One PCI function may contain upto 4 links, further links must
    be added to PCI function 4 on the same device.

To have support for 8 links starts with HT 3.0 specs?

There is no requirement that in dev->link_list the last element
    would have the highest link->link_num.

Also fix off-by-one error when allocating for more links.

Change-Id: If7ebdd1ad52653d3757b5930bd0a83e2cf2fcac6
    Signed-off-by: Kyösti Mälkki 
---
 src/northbridge/amd/amdfam10/northbridge.c | 56 ++++++++++++++++++------------
 1 file changed, 33 insertions(+), 23 deletions(-)

diff --git a/src/northbridge/amd/amdfam10/northbridge.c b/src/northbridge/amd/amdfam10/northbridge.c
index 5ce7ae6..49a28de 100644
--- a/src/northbridge/amd/amdfam10/northbridge.c
+++ b/src/northbridge/amd/amdfam10/northbridge.c
@@ -172,18 +172,8 @@ static u32 amdfam10_scan_chain(device_t dev, u32 nodeid, struct bus *link, bool
 #endif
    	u32 max_devfn;

-		if (link->link_num > 3) {
-			u32 regpos;
-			u32 reg;
-			regpos = 0x170 + 4 * (link->link_num & 3); // it is only on sublink0
-			reg = pci_read_config32(dev, regpos);
-			if(reg & 1) return max; // already ganged no sblink1
-
-			dev = get_node_pci(nodeid, 4);
-		}
-
    	/* Check for connected link. */
-		link->cap = 0x80 + ((link->link_num & 3) * 0x20);
+		link->cap = 0x80 + (link->link_num * 0x20);
    	if (!is_non_coherent_link(dev, link))
    		return max;

@@ -1017,17 +1007,34 @@ static void sysconf_init(device_t dev) // first node
 #endif
 }

+#if 0
+static void FIXME_add_more_links();
+{
+	if (link->link_num > 3) {
+		u32 regpos;
+		u32 reg;
+		regpos = 0x170 + 4 * (link->link_num & 3); // it is only on sublink0
+		reg = pci_read_config32(dev, regpos);
+		if (reg & 1) return max; // already ganged no sblink1
+
+		dev = get_node_pci(nodeid, 4);
+	}
+}
+#endif
+
 static void add_more_links(device_t dev, unsigned total_links)
 {
    struct bus *link, *last = NULL;
-	int link_num;
+	int link_num = -1;

-	for (link = dev->link_list; link; link = link->next)
+	for (link = dev->link_list; link; link = link->next) {
+		if (link_num < link->link_num)
+			link_num = link->link_num;
    	last = link;
+	}

if (last) {
-		int links = total_links - last->link_num;
-		link_num = last->link_num;
+		int links = total_links - (link_num + 1);
    	if (links > 0) {
    		link = malloc(links*sizeof(*link));
    		if (!link)
@@ -1037,7 +1044,6 @@ static void add_more_links(device_t dev, unsigned total_links)
    	}
    }
    else {
-		link_num = -1;
    	link = malloc(total_links*sizeof(*link));
    	memset(link, 0, total_links*sizeof(*link));
    	dev->link_list = link;
@@ -1179,15 +1185,19 @@ static u32 cpu_bus_scan(device_t dev, u32 max)
    			cdb_dev = pci_probe_dev(NULL, pbus,
    				PCI_DEVFN(devn, fn));
    		}
-			cdb_dev = dev_find_slot(busn, PCI_DEVFN(devn, 0));
-		}
-		if (cdb_dev) {
-			/* Ok, We need to set the links for that device.
-			 * otherwise the device under it will not be scanned
-			 */
-			add_more_links(cdb_dev, 8);
    	}

+		/* Ok, We need to set the links for that device.
+		 * otherwise the device under it will not be scanned
+		 */
+		cdb_dev = dev_find_slot(busn, PCI_DEVFN(devn, 0));
+		if (cdb_dev)
+			add_more_links(cdb_dev, 4);
+
+		cdb_dev = dev_find_slot(busn, PCI_DEVFN(devn, 4));
+		if (cdb_dev)
+			add_more_links(cdb_dev, 4);
+
    	cores_found = 0; // one core
    	cdb_dev = dev_find_slot(busn, PCI_DEVFN(devn, 3));
    	int enable_node = cdb_dev && cdb_dev->enabled;