[PATCH v2 16/53] MIPS: SGI-IP27: lay out node memory in 1GB banks on Bedrock hubs

[Imre Kaloz <kaloz@kernel.org>]

Hub describes a node's memory as 128MB slots, four slots to a
klconfig bank entry. Bedrock gives each bank entry a 1GB slot of its
own and sizes it in megabytes. Take the slot shift, the slot count and
the bank size from the hub generation.

Signed-off-by: Imre Kaloz <kaloz@kernel.org>
---
 arch/mips/sgi-ip27/ip27-memory.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
index 4317f5ae1fd1..0204dc8bb1bb 100644
--- a/arch/mips/sgi-ip27/ip27-memory.c
+++ b/arch/mips/sgi-ip27/ip27-memory.c
@@ -31,9 +31,16 @@
 
 #include "ip27-common.h"
 
-#define SLOT_PFNSHIFT		(SLOT_SHIFT - PAGE_SHIFT)
 #define PFN_NASIDSHFT		(NASID_SHFT - PAGE_SHIFT)
 
+/* A Bedrock node's memory comes in 1GB banks. */
+#define BEDROCK_SLOT_SHIFT	30
+
+static unsigned int __init slot_shift(void)
+{
+	return system_is_ip35 ? BEDROCK_SLOT_SHIFT : SLOT_SHIFT;
+}
+
 struct node_data *__node_data[MAX_NUMNODES];
 EXPORT_SYMBOL(__node_data);
 
@@ -230,7 +237,8 @@ static void __init dump_topology(void)
 
 static unsigned long __init slot_getbasepfn(nasid_t nasid, int slot)
 {
-	return ((unsigned long)nasid << PFN_NASIDSHFT) | (slot << SLOT_PFNSHIFT);
+	return ((unsigned long)nasid << PFN_NASIDSHFT) |
+	       ((unsigned long)slot << (slot_shift() - PAGE_SHIFT));
 }
 
 static unsigned long __init slot_psize_compute(nasid_t nasid, int slot)
@@ -249,6 +257,12 @@ static unsigned long __init slot_psize_compute(nasid_t nasid, int slot)
 	if (!banks)
 		return 0;
 
+	/* Bedrock bank entry N sizes the 1GB slot N, in megabytes. */
+	if (system_is_ip35) {
+		size = (unsigned long)banks->membnk_bnksz[slot];
+		return (size << 20) >> PAGE_SHIFT;
+	}
+
 	/* Size in _Megabytes_ */
 	size = (unsigned long)banks->membnk_bnksz[slot/4];
 
@@ -315,12 +329,13 @@ static void __init mlreset(void)
 static void __init szmem(void)
 {
 	unsigned long slot_psize, slot0sz = 0, nodebytes;	/* Hack to detect problem configs */
+	int slots = system_is_ip35 ? MD_MEM_BANKS : MAX_MEM_SLOTS;
 	int slot;
 	nasid_t node;
 
 	for_each_online_node(node) {
 		nodebytes = 0;
-		for (slot = 0; slot < MAX_MEM_SLOTS; slot++) {
+		for (slot = 0; slot < slots; slot++) {
 			slot_psize = slot_psize_compute(node, slot);
 			if (slot == 0)
 				slot0sz = slot_psize;
@@ -328,7 +343,7 @@ static void __init szmem(void)
 			 * We need to refine the hack when we have replicated
 			 * kernel text.
 			 */
-			nodebytes += (1LL << SLOT_SHIFT);
+			nodebytes += (1LL << slot_shift());
 
 			if (!slot_psize)
 				continue;
@@ -337,7 +352,7 @@ static void __init szmem(void)
 						(slot0sz << PAGE_SHIFT)) {
 				pr_info("Ignoring slot %d onwards on node %d\n",
 								slot, node);
-				slot = MAX_MEM_SLOTS;
+				slot = slots;
 				continue;
 			}
 			memblock_add_node(PFN_PHYS(slot_getbasepfn(node, slot)),
-- 
2.47.3