wii: use both mem1 and mem2 as ram
The Nintendo Wii video game console has two discontiguous RAM regions:
- MEM1: 24MB @ 0x00000000
- MEM2: 64MB @ 0x10000000
Unfortunately, the kernel currently does not support discontiguous RAM
memory regions on 32-bit PowerPC platforms.
This patch adds a series of workarounds to allow the use of the second
memory region (MEM2) as RAM by the kernel.
Basically, a single range of memory from the beginning of MEM1 to the
end of MEM2 is reported to the kernel, and a memory reservation is
created for the hole between MEM1 and MEM2.
With this patch the system is able to use all the available RAM and not
just ~27% of it.
This will no longer be needed when proper discontig memory support
for 32-bit PowerPC is added to the kernel.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index cb96cb2..b55bbe8 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -283,18 +283,18 @@
}
/*
- * Map in a big chunk of physical memory starting at PAGE_OFFSET.
+ * Map in a chunk of physical memory starting at start.
*/
-void __init mapin_ram(void)
+void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
{
unsigned long v, s, f;
phys_addr_t p;
int ktext;
- s = mmu_mapin_ram();
+ s = offset;
v = PAGE_OFFSET + s;
p = memstart_addr + s;
- for (; s < total_lowmem; s += PAGE_SIZE) {
+ for (; s < top; s += PAGE_SIZE) {
ktext = ((char *) v >= _stext && (char *) v < etext);
f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL;
map_page(v, p, f);
@@ -307,6 +307,30 @@
}
}
+void __init mapin_ram(void)
+{
+ unsigned long s, top;
+
+#ifndef CONFIG_WII
+ top = total_lowmem;
+ s = mmu_mapin_ram(top);
+ __mapin_ram_chunk(s, top);
+#else
+ if (!wii_hole_size) {
+ s = mmu_mapin_ram(total_lowmem);
+ __mapin_ram_chunk(s, total_lowmem);
+ } else {
+ top = wii_hole_start;
+ s = mmu_mapin_ram(top);
+ __mapin_ram_chunk(s, top);
+
+ top = lmb_end_of_DRAM();
+ s = wii_mmu_mapin_mem2(top);
+ __mapin_ram_chunk(s, top);
+ }
+#endif
+}
+
/* Scan the real Linux page tables and return a PTE pointer for
* a virtual address in a context.
* Returns true (1) if PTE was found, zero otherwise. The pointer to