Commit 5cce39b6 authored by Max Filippov's avatar Max Filippov
Browse files

xtensa: definitions for call0 ABI 



Add assembly macros for calls, call arguments, preserved registers,
function entry and return for windowed and call0 ABIs.

Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 61a6b912

arch/xtensa/include/asm/asmmacro.h

+65 −0
Original line number Diff line number Diff line
@@ -194,6 +194,12 @@ 
#define XTENSA_STACK_ALIGNMENT		16



#if defined(__XTENSA_WINDOWED_ABI__)



/* Assembly instructions for windowed kernel ABI. */

#define KABI_W

/* Assembly instructions for call0 kernel ABI (will be ignored). */

#define KABI_C0 #



#define XTENSA_FRAME_SIZE_RESERVE	16

#define XTENSA_SPILL_STACK_RESERVE	32
@@ -206,8 +212,34 @@ 
#define abi_ret(frame_size) retw

#define abi_ret_default retw



	/* direct call */

#define abi_call call4

	/* indirect call */

#define abi_callx callx4

	/* outgoing call argument registers */

#define abi_arg0 a6

#define abi_arg1 a7

#define abi_arg2 a8

#define abi_arg3 a9

#define abi_arg4 a10

#define abi_arg5 a11

	/* return value */

#define abi_rv a6

	/* registers preserved across call */

#define abi_saved0 a2

#define abi_saved1 a3



	/* none of the above */

#define abi_tmp0 a4

#define abi_tmp1 a5



#elif defined(__XTENSA_CALL0_ABI__)



/* Assembly instructions for windowed kernel ABI (will be ignored). */

#define KABI_W #

/* Assembly instructions for call0 kernel ABI. */

#define KABI_C0



#define XTENSA_SPILL_STACK_RESERVE	0



#define abi_entry(frame_size) __abi_entry (frame_size)
@@ -233,10 +265,43 @@ 


#define abi_ret_default ret



	/* direct call */

#define abi_call call0

	/* indirect call */

#define abi_callx callx0

	/* outgoing call argument registers */

#define abi_arg0 a2

#define abi_arg1 a3

#define abi_arg2 a4

#define abi_arg3 a5

#define abi_arg4 a6

#define abi_arg5 a7

	/* return value */

#define abi_rv a2

	/* registers preserved across call */

#define abi_saved0 a12

#define abi_saved1 a13



	/* none of the above */

#define abi_tmp0 a8

#define abi_tmp1 a9



#else

#error Unsupported Xtensa ABI

#endif



#if defined(USER_SUPPORT_WINDOWED)

/* Assembly instructions for windowed user ABI. */

#define UABI_W

/* Assembly instructions for call0 user ABI (will be ignored). */

#define UABI_C0 #

#else

/* Assembly instructions for windowed user ABI (will be ignored). */

#define UABI_W #

/* Assembly instructions for call0 user ABI. */

#define UABI_C0

#endif



#define __XTENSA_HANDLER	.section ".exception.text", "ax"



#endif /* _XTENSA_ASMMACRO_H */

arch/xtensa/include/asm/core.h

+11 −0
Original line number Diff line number Diff line
@@ -26,4 +26,15 @@ 
#define XCHAL_SPANNING_WAY 0

#endif



#if XCHAL_HAVE_WINDOWED

#if defined(CONFIG_USER_ABI_DEFAULT) || defined(CONFIG_USER_ABI_CALL0_PROBE)

/* Whether windowed ABI is supported in userspace. */

#define USER_SUPPORT_WINDOWED

#endif

#if defined(__XTENSA_WINDOWED_ABI__) || defined(USER_SUPPORT_WINDOWED)

/* Whether windowed ABI is supported either in userspace or in the kernel. */

#define SUPPORT_WINDOWED

#endif

#endif



#endif

arch/xtensa/include/asm/processor.h

+26 −6
Original line number Diff line number Diff line
@@ -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).

 */