x86, amd-nb: Cleanup AMD northbridge caching code

Support more than just the "Misc Control" part of the northbridges.
Support more flags by turning "gart_supported" into a single bit flag
that is stored in a flags member. Clean up related code by using a set
of functions (amd_nb_num(), amd_nb_has_feature() and node_to_amd_nb())
instead of accessing the NB data structures directly. Reorder the
initialization code and put the GART flush words caching in a separate
function.

Signed-off-by: Hans Rosenfeld <hans.rosenfeld@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

1 files changed, 25 insertions, 9 deletions

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index 35b17a821e34..4d7ec7df7de2 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -3,36 +3,52 @@
 
 #include <linux/pci.h>
 
-extern struct pci_device_id amd_nb_ids[];
+extern struct pci_device_id amd_nb_misc_ids[];
 struct bootnode;
 
 extern int early_is_amd_nb(u32 value);
-extern int cache_amd_northbridges(void);
+extern int amd_cache_northbridges(void);
 extern void amd_flush_garts(void);
 extern int amd_get_nodes(struct bootnode *nodes);
 extern int amd_numa_init(unsigned long start_pfn, unsigned long end_pfn);
 extern int amd_scan_nodes(void);
 
+struct amd_northbridge {
+        struct pci_dev *misc;
+};
+
 struct amd_northbridge_info {
         u16 num;
-        u8 gart_supported;
-        struct pci_dev **nb_misc;
+        u64 flags;
+        struct amd_northbridge *nb;
 };
 extern struct amd_northbridge_info amd_northbridges;
 
+#define AMD_NB_GART                     0x1
+
 #ifdef CONFIG_AMD_NB
 
-static inline struct pci_dev *node_to_amd_nb_misc(int node)
+static inline int amd_nb_num(void)
 {
-        return (node < amd_northbridges.num) ? amd_northbridges.nb_misc[node] : NULL;
+        return amd_northbridges.num;
 }
 
-#else
+static inline int amd_nb_has_feature(int feature)
+{
+        return ((amd_northbridges.flags & feature) == feature);
+}
 
-static inline struct pci_dev *node_to_amd_nb_misc(int node)
+static inline struct amd_northbridge *node_to_amd_nb(int node)
 {
-        return NULL;
+        return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
 }
+
+#else
+
+#define amd_nb_num(x)           0
+#define amd_nb_has_feature(x)   false
+#define node_to_amd_nb(x)       NULL
+
 #endif