[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>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 19f911c5dd58..910fb3afc0b5 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -138,6 +138,37 @@ config 64BIT
           enable this option otherwise. The 64bit kernel is significantly bigger
           and slower than the 32bit one.
 
+choice
+        prompt "Kernel page size"
+        default PARISC_PAGE_SIZE_4KB  if !64BIT
+        default PARISC_PAGE_SIZE_4KB  if 64BIT
+#       default PARISC_PAGE_SIZE_16KB if 64BIT
+
+config PARISC_PAGE_SIZE_4KB
+        bool "4KB"
+        help
+          This lets you select the page size of the kernel.  For best
+          performance, a page size of 16KB is recommended.  For best
+          compatibility with 32bit applications, a page size of 4KB should be
+          selected (the vast majority of 32bit binaries work perfectly fine
+          with a larger page size).
+
+          4KB                For best 32bit compatibility
+          16KB               For best performance
+          64KB               For best performance, might give more overhead.
+
+          If you don't know what to do, choose 4KB.
+
+config PARISC_PAGE_SIZE_16KB
+        bool "16KB (EXPERIMENTAL)"
+        depends on PA8X00 && EXPERIMENTAL
+
+config PARISC_PAGE_SIZE_64KB
+        bool "64KB (EXPERIMENTAL)"
+        depends on PA8X00 && EXPERIMENTAL
+
+endchoice
+
 config SMP
         bool "Symmetric multi-processing support"
         ---help---