parisc: Prepare for Block-TLB support on 32-bit kernel

Change HUGEPAGE_SIZE to become 4 MB on 32-bit kernels, which leads
that kernel code and kernel data will start on 4 MB boundaries.

Although a 32-bit kernel does not support huge pages, most
machines have support for Block-TLBs (BTLB) which allow to
configure the system to use large pages (block TLBs) to minimize
the TLB contention. This is done through calls to PDC and the
32-bit kernel can then call BTLB PDC functions to tell
the machine to optimize the TLBs.
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/asm-offsets.c

@@ -275,6 +275,8 @@ int main(void)
 	 * and kernel data on physical huge pages */
 #ifdef CONFIG_HUGETLB_PAGE
 	DEFINE(HUGEPAGE_SIZE, 1UL << REAL_HPAGE_SHIFT);
+#elif !defined(CONFIG_64BIT)
+	DEFINE(HUGEPAGE_SIZE, 4*1024*1024);
 #else
 	DEFINE(HUGEPAGE_SIZE, PAGE_SIZE);
 #endif