[XTENSA] Add support for configurable registers and coprocessors

The Xtensa architecture allows to define custom instructions and
registers. Registers that are bound to a coprocessor are only
accessible if the corresponding enable bit is set, which allows
to implement a 'lazy' context switch mechanism. Other registers
needs to be saved and restore at the time of the context switch
or during interrupt handling.

This patch adds support for these additional states:

- save and restore registers that are used by the compiler upon
  interrupt entry and exit.
- context switch additional registers unbound to any coprocessor
- 'lazy' context switch of registers bound to a coprocessor
- ptrace interface to provide access to additional registers
- update configuration files in include/asm-xtensa/variant-fsf

Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 8 insertions, 8 deletions

diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c
index 6f722f91ba92..c7a021d9f696 100644
--- a/arch/xtensa/kernel/traps.c
+++ b/arch/xtensa/kernel/traps.c
@@ -118,28 +118,28 @@ static dispatch_init_table_t __initdata dispatch_init_table[] = {
 { EXCCAUSE_STORE_CACHE_ATTRIBUTE,       0,         do_page_fault },
 { EXCCAUSE_LOAD_CACHE_ATTRIBUTE,        0,         do_page_fault },
 /* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
-#if (XCHAL_CP_MASK & 1)
+#if XTENSA_HAVE_COPROCESSOR(0)
 COPROCESSOR(0),
 #endif
-#if (XCHAL_CP_MASK & 2)
+#if XTENSA_HAVE_COPROCESSOR(1)
 COPROCESSOR(1),
 #endif
-#if (XCHAL_CP_MASK & 4)
+#if XTENSA_HAVE_COPROCESSOR(2)
 COPROCESSOR(2),
 #endif
-#if (XCHAL_CP_MASK & 8)
+#if XTENSA_HAVE_COPROCESSOR(3)
 COPROCESSOR(3),
 #endif
-#if (XCHAL_CP_MASK & 16)
+#if XTENSA_HAVE_COPROCESSOR(4)
 COPROCESSOR(4),
 #endif
-#if (XCHAL_CP_MASK & 32)
+#if XTENSA_HAVE_COPROCESSOR(5)
 COPROCESSOR(5),
 #endif
-#if (XCHAL_CP_MASK & 64)
+#if XTENSA_HAVE_COPROCESSOR(6)
 COPROCESSOR(6),
 #endif
-#if (XCHAL_CP_MASK & 128)
+#if XTENSA_HAVE_COPROCESSOR(7)
 COPROCESSOR(7),
 #endif
 { EXCCAUSE_MAPPED_DEBUG,                0,              do_debug },