powerpc: Make early memory scan more resilient to out of order nodes

We keep track of the size of the lowest block of memory and call
setup_initial_memory_limit() only after we've parsed them all

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Milton Miller <miltonm@bga.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 5f5e6aed2b70..5311a26dcf46 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -68,6 +68,7 @@ int __initdata iommu_force_on;
 unsigned long tce_alloc_start, tce_alloc_end;
 u64 ppc64_rma_size;
 #endif
+static phys_addr_t first_memblock_size;
 
 static int __init early_parse_mem(char *p)
 {
@@ -505,11 +506,14 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
                         size = 0x80000000ul - base;
         }
 #endif
-
-        /* First MEMBLOCK added, do some special initializations */
-        if (memstart_addr == ~(phys_addr_t)0)
-                setup_initial_memory_limit(base, size);
-        memstart_addr = min((u64)memstart_addr, base);
+        /* Keep track of the beginning of memory -and- the size of
+         * the very first block in the device-tree as it represents
+         * the RMA on ppc64 server
+         */
+        if (base < memstart_addr) {
+                memstart_addr = base;
+                first_memblock_size = size;
+        }
 
         /* Add the chunk to the MEMBLOCK list */
         memblock_add(base, size);
@@ -694,6 +698,7 @@ void __init early_init_devtree(void *params)
 
         of_scan_flat_dt(early_init_dt_scan_root, NULL);
         of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
+        setup_initial_memory_limit(memstart_addr, first_memblock_size);
 
         /* Save command line for /proc/cmdline and then parse parameters */
         strlcpy(boot_command_line, cmd_line, COMMAND_LINE_SIZE);