alpha/kernel/entry.S

1 /* SPDX-License-Identifier: GPL-2.0 */
5  * Kernel entry-points.
8 #include <asm/asm-offsets.h>
34 	.cfi_rel_offset	$18, 40
39 	.size	\func, . - \func
43  * This defines the normal kernel pt-regs layout.
45  * regs 9-15 preserved by C code
46  * regs 16-18 saved by PAL-code
47  * regs 29-30 saved and set up by PAL-code
48  * JRP - Save regs 16-18 in a special area of the stack, so that
49  * the palcode-provided values are available to the signal handler.
79 	stq	$25, 120($sp)
85 	stq	$18, 176($sp)
96 	.cfi_rel_offset	$25, 120
125 	ldq	$25, 120($sp)
145 	.cfi_restore	$25
149 	.cfi_adjust_cfa_offset	-SP_OFF
173 	.cfi_adjust_cfa_offset	-SWITCH_STACK_SIZE
177  * Non-syscall kernel entry points.
194 	mov	$sp, $18
200 /* save $9 - $15 so the inline exception code can manipulate them.  */
238 	.cfi_adjust_cfa_offset	-56
253 	lda	$sp, -256($sp)
264 	bne	$0, entUnaUser	/* yup -> do user-level unaligned fault */
276 	/* 16-18 PAL-saved */
283 	stq	$25, 200($sp)
310 	.cfi_rel_offset	$25, 25*8
335 	/* 16-18 PAL-saved */
342 	ldq	$25, 200($sp)
369 	.cfi_restore	$25
374 	.cfi_adjust_cfa_offset	-256
383 	.cfi_adjust_cfa_offset	-256
385 	lda	$sp, -56($sp)
420 	.cfi_adjust_cfa_offset	-56
441  * Note that a0-a2 are not saved by PALcode as with the other entry points.
464 	stq	$18, SP_OFF+40($sp)
467 	.cfi_rel_offset	$18, SP_OFF+40
487 	cmovne	$26, 0, $18		/* $18 = 0 => non-restartable */
523 	ldq	$18, 0($sp)	/* old syscall nr (zero if success) */
524 	beq	$18, $ret_success
540  *      $18: The old syscall number, or zero if this is not a return
555 	 * restarts for us, so let $18 and $19 burn.
558 	mov	0, $18
591 	ldq	$18, SP_OFF+40($sp)
621 	ldq	$18, 0($sp)	/* old syscall nr (zero if success) */
622 	beq	$18, $strace_success
631 	mov	$18, $9		/* save old syscall number */
634 	mov	$9, $18
643  * Save and restore the switch stack -- aka the balance of the user context.
653 	lda	$sp, -SWITCH_STACK_SIZE($sp)
665 	.size	do_switch_stack, .-do_switch_stack
684 	.size	undo_switch_stack, .-undo_switch_stack
696 	V(16); V(17); V(18); V(19)
698 	V(24); V(25); V(26); V(27)
705 	.size	__save_fpu, .-__save_fpu
719 	V(16); V(17); V(18); V(19)
721 	V(24); V(25); V(26); V(27)
753 	.size	alpha_switch_to, .-alpha_switch_to
769  * ... and new kernel threads - here
823 	lda	$sp, -SWITCH_STACK_SIZE($sp)
845 	   Store a non-zero there - -ENOSYS we need in register
848 	lda	$0, -ENOSYS