[PARISC] Further work for multiple page sizes

More work towards supporing multiple page sizes on 64-bit. Convert
some assumptions that 64bit uses 3 level page tables into testing
PT_NLEVELS. Also some BUG() to BUG_ON() conversions and some cleanups
to assembler.

Signed-off-by: Helge Deller <deller@parisc-linux.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index af88afe..479d9a0 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -55,7 +55,7 @@
 	 * pointers.
 	 */
 
-	.align 4096
+	.align ASM_PAGE_SIZE
 linux_gateway_page:
 
         /* ADDRESS 0x00 to 0xb0 = 176 bytes / 4 bytes per insn = 44 insns */
@@ -632,7 +632,7 @@
 end_compare_and_swap:
 
 	/* Make sure nothing else is placed on this page */
-	.align 4096
+	.align ASM_PAGE_SIZE
 	.export end_linux_gateway_page
 end_linux_gateway_page:
 
@@ -652,7 +652,7 @@
 
 	.section .rodata,"a"
 
-	.align 4096
+	.align ASM_PAGE_SIZE
 	/* Light-weight-syscall table */
 	/* Start of lws table. */
 	.export lws_table
@@ -662,14 +662,14 @@
 	LWS_ENTRY(compare_and_swap64)	/* 1 - ELF64 Atomic compare and swap */
 	/* End of lws table */
 
-	.align 4096
+	.align ASM_PAGE_SIZE
 	.export sys_call_table
 .Lsys_call_table:
 sys_call_table:
 #include "syscall_table.S"
 
 #ifdef CONFIG_64BIT
-	.align 4096
+	.align ASM_PAGE_SIZE
 	.export sys_call_table64
 .Lsys_call_table64:
 sys_call_table64: