[Qemu-ppc] [PULL 16/52] spapr: Split memory nodes to power-of-two blocks

[Alexander Graf]

From: Alexey Kardashevskiy <address@hidden>

Linux kernel expects nodes to have power-of-two size and
does WARN_ON if this is not the case:
[    0.041456] WARNING: at drivers/base/memory.c:115
which is:

===
        /* Validate blk_sz is a power of 2 and not less than section size */
        if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) {
                WARN_ON(1);
                block_sz = MIN_MEMORY_BLOCK_SIZE;
        }
===

This splits memory nodes into set of smaller blocks with
a size which is a power of two. This makes sure the start
address of every node is aligned to the node size.

Signed-off-by: Alexey Kardashevskiy <address@hidden>
Signed-off-by: Alexander Graf <address@hidden>
---
 hw/ppc/spapr.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 718a201..075806f 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -691,8 +691,18 @@ static int spapr_populate_memory(sPAPREnvironment *spapr, 
void *fdt)
             mem_start += spapr->rma_size;
             node_size -= spapr->rma_size;
         }
-        spapr_populate_memory_node(fdt, i, mem_start, node_size);
-        mem_start += node_size;
+        for ( ; node_size; ) {
+            hwaddr sizetmp = pow2floor(node_size);
+
+            /* mem_start != 0 here */
+            if (ffsl(mem_start) < ffsl(sizetmp)) {
+                sizetmp = 1ULL << (ffsl(mem_start) - 1);
+            }
+
+            spapr_populate_memory_node(fdt, i, mem_start, sizetmp);
+            node_size -= sizetmp;
+            mem_start += sizetmp;
+        }
     }
 
     return 0;
-- 
1.8.1.4