xtensa: nommu support

Add support for !CONFIG_MMU setups.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

5 files changed, 17 insertions, 2 deletions

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index a51d36a27389..80d24c485fd3 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1463,6 +1463,7 @@ ENTRY(_spill_registers)
         callx0  a0              # should not return
 1:      j       1b
 
+#ifdef CONFIG_MMU
 /*
  * We should never get here. Bail out!
  */
@@ -1775,7 +1776,7 @@ ENTRY(fast_store_prohibited)
         bbsi.l  a2, PS_UM_BIT, 1f
         j       _kernel_exception
 1:      j       _user_exception
-
+#endif /* CONFIG_MMU */
 
 /*
  * System Calls.
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 67e69139520b..d092c225d5b7 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -235,8 +235,9 @@ should_never_return:
  */
         
 .section ".bss.page_aligned", "w"
+#ifdef CONFIG_MMU
 ENTRY(swapper_pg_dir)
         .fill   PAGE_SIZE, 1, 0
+#endif
 ENTRY(empty_zero_page)
         .fill   PAGE_SIZE, 1, 0
-
diff --git a/arch/xtensa/kernel/setup.c b/arch/xtensa/kernel/setup.c
index 4ec1633c2941..1e5a034fe011 100644
--- a/arch/xtensa/kernel/setup.c
+++ b/arch/xtensa/kernel/setup.c
@@ -84,7 +84,13 @@ sysmem_info_t __initdata sysmem;
 int initrd_is_mapped;
 #endif
 
+#ifdef CONFIG_MMU
 extern void init_mmu(void);
+#else
+static inline void init_mmu(void) { }
+#endif
+
+extern void zones_init(void);
 
 /*
  * Boot parameter parsing.
@@ -286,6 +292,7 @@ void __init setup_arch(char **cmdline_p)
 
 
         paging_init();
+        zones_init();
 
 #ifdef CONFIG_VT
 # if defined(CONFIG_VGA_CONSOLE)
diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 6b4a9d79e7be..9f0b71189e94 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -104,6 +104,7 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
 #endif
 { EXCCAUSE_UNALIGNED,           KRNL,      fast_unaligned },
 #endif
+#ifdef CONFIG_MMU
 { EXCCAUSE_ITLB_MISS,           0,         do_page_fault },
 { EXCCAUSE_ITLB_MISS,           USER|KRNL, fast_second_level_miss},
 { EXCCAUSE_ITLB_MULTIHIT,               0,         do_multihit },
@@ -118,6 +119,7 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
 { EXCCAUSE_STORE_CACHE_ATTRIBUTE,       USER|KRNL, fast_store_prohibited },
 { EXCCAUSE_STORE_CACHE_ATTRIBUTE,       0,         do_page_fault },
 { EXCCAUSE_LOAD_CACHE_ATTRIBUTE,        0,         do_page_fault },
+#endif /* CONFIG_MMU */
 /* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
 #if XTENSA_HAVE_COPROCESSOR(0)
 COPROCESSOR(0),
diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S
index eb2d7bb69ee0..74a7518faf16 100644
--- a/arch/xtensa/kernel/vectors.S
+++ b/arch/xtensa/kernel/vectors.S
@@ -309,6 +309,7 @@ ENTRY(_DoubleExceptionVector)
          * All other exceptions are unexpected and thus unrecoverable!
          */
 
+#ifdef CONFIG_MMU
         .extern fast_second_level_miss_double_kernel
 
 .Lksp:  /* a0: a0, a1: a1, a2: a2, a3: trashed, depc: depc, excsave: a3 */
@@ -319,6 +320,9 @@ ENTRY(_DoubleExceptionVector)
         bnez    a3, .Lunrecoverable
 1:      movi    a3, fast_second_level_miss_double_kernel
         jx      a3
+#else
+.equ    .Lksp,  .Lunrecoverable
+#endif
 
         /* Critical! We can't handle this situation. PANIC! */