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>

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 5f5e6aed2b70b50f7d116c6e266cadb6687de4de..5311a26dcf4610b61ee97d5fff4371e38af169a1 100644 (file)
--- 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);