arch/tile: support multiple huge page sizes dynamically

This change adds support for a new "super" bit in the PTE, using the new
arch_make_huge_pte() method.  The Tilera hypervisor sees the bit set at a
given level of the page table and gangs together 4, 16, or 64 consecutive
pages from that level of the hierarchy to create a larger TLB entry.

One extra "super" page size can be specified at each of the three levels
of the page table hierarchy on tilegx, using the "hugepagesz" argument
on the boot command line.  A new hypervisor API is added to allow Linux
to tell the hypervisor how many PTEs to gang together at each level of
the page table.

To allow pre-allocating huge pages larger than the buddy allocator can
handle, this change modifies the Tilera bootmem support to put all of
memory on tilegx platforms into bootmem.

As part of this change I eliminate the vestigial CONFIG_HIGHPTE support,
which never worked anyway, and eliminate the hv_page_size() API in favor
of the standard vma_kernel_pagesize() API.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c
index c04fbfd..630dd2c 100644
--- a/arch/tile/mm/init.c
+++ b/arch/tile/mm/init.c
@@ -698,6 +698,7 @@
 #endif /* CONFIG_HIGHMEM */
 
 
+#ifndef CONFIG_64BIT
 static void __init init_free_pfn_range(unsigned long start, unsigned long end)
 {
 	unsigned long pfn;
@@ -770,6 +771,7 @@
 		init_free_pfn_range(start, end);
 	}
 }
+#endif
 
 /*
  * paging_init() sets up the page tables - note that all of lowmem is
@@ -858,8 +860,10 @@
 	/* this will put all bootmem onto the freelists */
 	totalram_pages += free_all_bootmem();
 
+#ifndef CONFIG_64BIT
 	/* count all remaining LOWMEM and give all HIGHMEM to page allocator */
 	set_non_bootmem_pages_init();
+#endif
 
 	codesize =  (unsigned long)&_etext - (unsigned long)&_text;
 	datasize =  (unsigned long)&_end - (unsigned long)&_sdata;