[RFC PATCH 4/5] x86/amd_nb: Use Hygon DF misc enumeration for Family 0x18

[Lin Wang]

On Hygon Family 0x18 systems, DF devices cannot be enumerated through
the fixed PCI slot layout used by AMD systems.

Use the Hygon node helpers to size the northbridge array and to obtain DF
misc/link devices for NB initialization.

Signed-off-by: Lin Wang <wanglin@xxxxxxxxxxxxxx>
---
 arch/x86/kernel/amd_nb.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index 5d364540673d..77d166a17154 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -16,6 +16,8 @@
 
 #include <asm/amd/nb.h>
 #include <asm/cpuid/api.h>
+#include <asm/hygon/node.h>
+#include <asm/processor.h>
 
 static u32 *flush_words;
 
@@ -60,13 +62,20 @@ EXPORT_SYMBOL_GPL(node_to_amd_nb);
 
 static int amd_cache_northbridges(void)
 {
+	bool is_hygon = (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON);
 	struct amd_northbridge *nb;
 	u16 i;
 
 	if (amd_northbridges.num)
 		return 0;
 
-	amd_northbridges.num = amd_num_nodes();
+	if (is_hygon) {
+		amd_northbridges.num = hygon_node_num();
+		if (!amd_northbridges.num)
+			return -ENODEV;
+	} else {
+		amd_northbridges.num = amd_num_nodes();
+	}
 
 	nb = kzalloc_objs(struct amd_northbridge, amd_northbridges.num);
 	if (!nb)
@@ -75,7 +84,8 @@ static int amd_cache_northbridges(void)
 	amd_northbridges.nb = nb;
 
 	for (i = 0; i < amd_northbridges.num; i++) {
-		node_to_amd_nb(i)->misc = amd_node_get_func(i, 3);
+		node_to_amd_nb(i)->misc = is_hygon ? hygon_node_get_func(i, 3)
+						   : amd_node_get_func(i, 3);
 
 		/*
 		 * Each Northbridge must have a 'misc' device.
@@ -87,7 +97,8 @@ static int amd_cache_northbridges(void)
 			return -ENODEV;
 		}
 
-		node_to_amd_nb(i)->link = amd_node_get_func(i, 4);
+		node_to_amd_nb(i)->link = is_hygon ? hygon_node_get_func(i, 4)
+						   : amd_node_get_func(i, 4);
 	}
 
 	if (amd_gart_present())
-- 
2.43.0