Merge tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa

Pull xtensa updates from Max Filippov:

 - add support for xtensa cores without windowed registers option

* tag 'xtensa-20211105' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: move section symbols to asm/sections.h
  xtensa: remove unused variable wmask
  xtensa: only build windowed register support code when needed
  xtensa: use register window specific opcodes only when present
  xtensa: implement call0 ABI support in assembly
  xtensa: definitions for call0 ABI
  xtensa: don't use a12 in __xtensa_copy_user in call0 ABI
  xtensa: don't use a12 in strncpy_user
  xtensa: use a14 instead of a15 in inline assembly
  xtensa: move _SimulateUserKernelVectorException out of WindowVectors

1 files changed, 26 insertions, 6 deletions

diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
index ad15fbc57283..37d3e9887fe7 100644
--- a/arch/xtensa/include/asm/processor.h
+++ b/arch/xtensa/include/asm/processor.h
@@ -18,12 +18,6 @@
 #include <asm/types.h>
 #include <asm/regs.h>
 
-/* Assertions. */
-
-#if (XCHAL_HAVE_WINDOWED != 1)
-# error Linux requires the Xtensa Windowed Registers Option.
-#endif
-
 /* Xtensa ABI requires stack alignment to be at least 16 */
 
 #define STACK_ALIGN (XCHAL_DATA_WIDTH > 16 ? XCHAL_DATA_WIDTH : 16)
@@ -105,8 +99,18 @@
 #define WSBITS  (XCHAL_NUM_AREGS / 4)      /* width of WINDOWSTART in bits */
 #define WBBITS  (XCHAL_NUM_AREGS_LOG2 - 2) /* width of WINDOWBASE in bits */
 
+#if defined(__XTENSA_WINDOWED_ABI__)
+#define KERNEL_PS_WOE_MASK PS_WOE_MASK
+#elif defined(__XTENSA_CALL0_ABI__)
+#define KERNEL_PS_WOE_MASK 0
+#else
+#error Unsupported xtensa ABI
+#endif
+
 #ifndef __ASSEMBLY__
 
+#if defined(__XTENSA_WINDOWED_ABI__)
+
 /* Build a valid return address for the specified call winsize.
  * winsize must be 1 (call4), 2 (call8), or 3 (call12)
  */
@@ -117,6 +121,22 @@
  */
 #define MAKE_PC_FROM_RA(ra,sp)    (((ra) & 0x3fffffff) | ((sp) & 0xc0000000))
 
+#elif defined(__XTENSA_CALL0_ABI__)
+
+/* Build a valid return address for the specified call winsize.
+ * winsize must be 1 (call4), 2 (call8), or 3 (call12)
+ */
+#define MAKE_RA_FOR_CALL(ra, ws)   (ra)
+
+/* Convert return address to a valid pc
+ * Note: We assume that the stack pointer is in the same 1GB ranges as the ra
+ */
+#define MAKE_PC_FROM_RA(ra, sp)    (ra)
+
+#else
+#error Unsupported Xtensa ABI
+#endif
+
 /* Spill slot location for the register reg in the spill area under the stack
  * pointer sp. reg must be in the range [0..4).
  */