powerpc: Force memory size to be a multiple of PAGE_SIZE

Ensure that total memory size is page-aligned, because otherwise
mark_bootmem() gets upset.

This error case was triggered by using 64 KiB pages in the kernel
while arch/powerpc/boot/4xx.c arbitrarily reduced the amount of memory
by 4096 (to work around a chip bug that affects the last 256 bytes of
physical memory).

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index d8266dd..6f73c73 100644 (file)
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -1160,6 +1160,8 @@ static inline void __init phyp_dump_reserve_mem(void) {}
 
 void __init early_init_devtree(void *params)
 {
+       unsigned long limit;
+
        DBG(" -> early_init_devtree(%p)\n", params);
 
        /* Setup flat device-tree pointer */
@@ -1200,7 +1202,19 @@ void __init early_init_devtree(void *params)
        early_reserve_mem();
        phyp_dump_reserve_mem();
 
-       lmb_enforce_memory_limit(memory_limit);
+       limit = memory_limit;
+       if (! limit) {
+               unsigned long memsize;
+
+               /* Ensure that total memory size is page-aligned, because
+                * otherwise mark_bootmem() gets upset. */
+               lmb_analyze();
+               memsize = lmb_phys_mem_size();
+               if ((memsize & PAGE_MASK) != memsize)
+                       limit = memsize & PAGE_MASK;
+       }
+       lmb_enforce_memory_limit(limit);
+
        lmb_analyze();
 
        DBG("Phys. mem: %lx\n", lmb_phys_mem_size());