powerpc/47x: allow kernel to be loaded in higher physical memory

The 44x code (which is shared by 47x) assumes the available physical memory
begins at 0x00000000.  This is not necessarily the case in an AMP
environment.

Support CONFIG_RELOCATABLE for 476 in order to allow the kernel to be
loaded into a higher memory range.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
index 024acab588fd..f60e006d90c3 100644
--- a/arch/powerpc/mm/44x_mmu.c
+++ b/arch/powerpc/mm/44x_mmu.c
@@ -186,10 +186,11 @@ void __init MMU_init_hw(void)
 unsigned long __init mmu_mapin_ram(unsigned long top)
 {
         unsigned long addr;
+        unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
 
         /* Pin in enough TLBs to cover any lowmem not covered by the
          * initial 256M mapping established in head_44x.S */
-        for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
+        for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
              addr += PPC_PIN_SIZE) {
                 if (mmu_has_feature(MMU_FTR_TYPE_47x))
                         ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);
@@ -218,19 +219,25 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
                                 phys_addr_t first_memblock_size)
 {
+        u64 size;
+
+#ifndef CONFIG_RELOCATABLE
         /* We don't currently support the first MEMBLOCK not mapping 0
          * physical on those processors
          */
         BUG_ON(first_memblock_base != 0);
+#endif
 
         /* 44x has a 256M TLB entry pinned at boot */
-        memblock_set_current_limit(min_t(u64, first_memblock_size, PPC_PIN_SIZE));
+        size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
+        memblock_set_current_limit(first_memblock_base + size);
 }
 
 #ifdef CONFIG_SMP
 void __cpuinit mmu_init_secondary(int cpu)
 {
         unsigned long addr;
+        unsigned long memstart = memstart_addr & ~(PPC_PIN_SIZE - 1);
 
         /* Pin in enough TLBs to cover any lowmem not covered by the
          * initial 256M mapping established in head_44x.S
@@ -241,7 +248,7 @@ void __cpuinit mmu_init_secondary(int cpu)
          * stack. current (r2) isn't initialized, smp_processor_id()
          * will not work, current thread info isn't accessible, ...
          */
-        for (addr = PPC_PIN_SIZE; addr < lowmem_end_addr;
+        for (addr = memstart + PPC_PIN_SIZE; addr < lowmem_end_addr;
              addr += PPC_PIN_SIZE) {
                 if (mmu_has_feature(MMU_FTR_TYPE_47x))
                         ppc47x_pin_tlb(addr + PAGE_OFFSET, addr);