[PATCH 2/7] x86/amd_nb: Add support for northbridges on Aldebaran

[Naveen Krishna Chatradhi]

From: Muralidhara M K <muralimk@xxxxxxx>

On newer heterogeneous systems from AMD, there is a possibility of
having GPU nodes along with CPU nodes with the MCA banks. The GPU
nodes (noncpu nodes) starts enumerating from northbridge index 8.

Aldebaran GPUs have 2 root ports, with 4 misc port for each root.

Signed-off-by: Muralidhara M K <muralimk@xxxxxxx>
Signed-off-by: Naveen Krishna Chatradhi <nchatrad@xxxxxxx>
---
 arch/x86/include/asm/amd_nb.h |  6 ++++
 arch/x86/kernel/amd_nb.c      | 62 ++++++++++++++++++++++++++++++++---
 2 files changed, 63 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index 00d1a400b7a1..e71581cf00e3 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -79,6 +79,12 @@ struct amd_northbridge_info {
 
 #ifdef CONFIG_AMD_NB
 
+/*
+ * On Newer heterogeneous systems from AMD with CPU and GPU nodes connected
+ * via xGMI links, the NON CPU Nodes are enumerated from index 8
+ */
+#define NONCPU_NODE_INDEX	8
+
 u16 amd_nb_num(void);
 bool amd_nb_has_feature(unsigned int feature);
 struct amd_northbridge *node_to_amd_nb(int node);
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 5884dfa619ff..489003e850dd 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -26,6 +26,8 @@
 #define PCI_DEVICE_ID_AMD_17H_M70H_DF_F4 0x1444
 #define PCI_DEVICE_ID_AMD_19H_DF_F4	0x1654
 #define PCI_DEVICE_ID_AMD_19H_M50H_DF_F4 0x166e
+#define PCI_DEVICE_ID_AMD_ALDEBARAN_ROOT	0x14bb
+#define PCI_DEVICE_ID_AMD_ALDEBARAN_DF_F4	0x14d4
 
 /* Protect the PCI config register pairs used for SMN. */
 static DEFINE_MUTEX(smn_mutex);
@@ -94,6 +96,21 @@ static const struct pci_device_id hygon_nb_link_ids[] = {
 	{}
 };
 
+static const struct pci_device_id amd_noncpu_root_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_ALDEBARAN_ROOT) },
+	{}
+};
+
+static const struct pci_device_id amd_noncpu_nb_misc_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_ALDEBARAN_DF_F3) },
+	{}
+};
+
+static const struct pci_device_id amd_noncpu_nb_link_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_ALDEBARAN_DF_F4) },
+	{}
+};
+
 const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
 	{ 0x00, 0x18, 0x20 },
 	{ 0xff, 0x00, 0x20 },
@@ -182,11 +199,16 @@ int amd_cache_northbridges(void)
 	const struct pci_device_id *misc_ids = amd_nb_misc_ids;
 	const struct pci_device_id *link_ids = amd_nb_link_ids;
 	const struct pci_device_id *root_ids = amd_root_ids;
+
+	const struct pci_device_id *noncpu_misc_ids = amd_noncpu_nb_misc_ids;
+	const struct pci_device_id *noncpu_link_ids = amd_noncpu_nb_link_ids;
+	const struct pci_device_id *noncpu_root_ids = amd_noncpu_root_ids;
+
 	struct pci_dev *root, *misc, *link;
 	struct amd_northbridge *nb;
 	u16 roots_per_misc = 0;
-	u16 misc_count = 0;
-	u16 root_count = 0;
+	u16 misc_count = 0, misc_count_noncpu = 0;
+	u16 root_count = 0, root_count_noncpu = 0;
 	u16 i, j;
 
 	if (amd_northbridges.num)
@@ -205,10 +227,16 @@ int amd_cache_northbridges(void)
 	if (!misc_count)
 		return -ENODEV;
 
+	while ((misc = next_northbridge(misc, noncpu_misc_ids)) != NULL)
+		misc_count_noncpu++;
+
 	root = NULL;
 	while ((root = next_northbridge(root, root_ids)) != NULL)
 		root_count++;
 
+	while ((root = next_northbridge(root, noncpu_root_ids)) != NULL)
+		root_count_noncpu++;
+
 	if (root_count) {
 		roots_per_misc = root_count / misc_count;
 
@@ -222,15 +250,27 @@ int amd_cache_northbridges(void)
 		}
 	}
 
-	nb = kcalloc(misc_count, sizeof(struct amd_northbridge), GFP_KERNEL);
+	/*
+	 * The valid amd_northbridges are in between (0 ~ misc_count) and
+	 * (NONCPU_NODE_INDEX ~ NONCPU_NODE_INDEX + misc_count_noncpu)
+	 */
+	if (misc_count_noncpu)
+		/*
+		 * There are NONCPU Nodes with pci root ports starting at index 8
+		 * allocate few extra cells for simplicity in handling the indexes
+		 */
+		amd_northbridges.num = NONCPU_NODE_INDEX + misc_count_noncpu;
+	else
+		amd_northbridges.num = misc_count;
+
+	nb = kcalloc(amd_northbridges.num, sizeof(struct amd_northbridge), GFP_KERNEL);
 	if (!nb)
 		return -ENOMEM;
 
 	amd_northbridges.nb = nb;
-	amd_northbridges.num = misc_count;
 
 	link = misc = root = NULL;
-	for (i = 0; i < amd_northbridges.num; i++) {
+	for (i = 0; i < misc_count; i++) {
 		node_to_amd_nb(i)->root = root =
 			next_northbridge(root, root_ids);
 		node_to_amd_nb(i)->misc = misc =
@@ -251,6 +291,18 @@ int amd_cache_northbridges(void)
 			root = next_northbridge(root, root_ids);
 	}
 
+	link = misc = root = NULL;
+	if (misc_count_noncpu) {
+		for (i = NONCPU_NODE_INDEX; i < NONCPU_NODE_INDEX + misc_count_noncpu; i++) {
+			node_to_amd_nb(i)->root = root =
+				next_northbridge(root, noncpu_root_ids);
+			node_to_amd_nb(i)->misc = misc =
+				next_northbridge(misc, noncpu_misc_ids);
+			node_to_amd_nb(i)->link = link =
+				next_northbridge(link, noncpu_link_ids);
+		}
+	}
+
 	if (amd_gart_present())
 		amd_northbridges.flags |= AMD_NB_GART;
 
-- 
2.25.1