parisc: Add Huge Page and HUGETLBFS support

This patch adds huge page support to allow userspace to allocate huge
pages and to use hugetlbfs filesystem on 32- and 64-bit Linux kernels.
A later patch will add kernel support to map kernel text and data on
huge pages.

The only requirement is, that the kernel needs to be compiled for a
PA8X00 CPU (PA2.0 architecture). Older PA1.X CPUs do not support
variable page sizes. 64bit Kernels are compiled for PA2.0 by default.

Technically on parisc multiple physical huge pages may be needed to
emulate standard 2MB huge pages.

Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/setup.c

@@ -130,7 +130,16 @@ void __init setup_arch(char **cmdline_p)
 	printk(KERN_INFO "The 32-bit Kernel has started...\n");
 #endif
 
-	printk(KERN_INFO "Default page size is %dKB.\n", (int)(PAGE_SIZE / 1024));
+	printk(KERN_INFO "Kernel default page size is %d KB. Huge pages ",
+		(int)(PAGE_SIZE / 1024));
+#ifdef CONFIG_HUGETLB_PAGE
+	printk(KERN_CONT "enabled with %d MB physical and %d MB virtual size",
+		 1 << (REAL_HPAGE_SHIFT - 20), 1 << (HPAGE_SHIFT - 20));
+#else
+	printk(KERN_CONT "disabled");
+#endif
+	printk(KERN_CONT ".\n");
+
 
 	pdc_console_init();