alpha/kernel/entry.S

1 /* SPDX-License-Identifier: GPL-2.0 */
5  * Kernel entry-points.
8 #include <asm/asm-offsets.h>
30 	.cfi_rel_offset	$18, 40
35 	.size	\func, . - \func
39  * This defines the normal kernel pt-regs layout.
41  * regs 9-15 preserved by C code
42  * regs 16-18 saved by PAL-code
43  * regs 29-30 saved and set up by PAL-code
44  * JRP - Save regs 16-18 in a special area of the stack, so that
45  * the palcode-provided values are available to the signal handler.
75 	stq	$25, 120($sp)
81 	stq	$18, 176($sp)
92 	.cfi_rel_offset	$25, 120
121 	ldq	$25, 120($sp)
141 	.cfi_restore	$25
145 	.cfi_adjust_cfa_offset	-SP_OFF
169 	.cfi_adjust_cfa_offset	-SWITCH_STACK_SIZE
173  * Non-syscall kernel entry points.
190 	mov	$sp, $18
196 /* save $9 - $15 so the inline exception code can manipulate them.  */
234 	.cfi_adjust_cfa_offset	-64
249 	lda	$sp, -256($sp)
260 	bne	$0, entUnaUser	/* yup -> do user-level unaligned fault */
272 	/* 16-18 PAL-saved */
279 	stq	$25, 200($sp)
306 	.cfi_rel_offset	$25, 25*8
331 	/* 16-18 PAL-saved */
338 	ldq	$25, 200($sp)
365 	.cfi_restore	$25
370 	.cfi_adjust_cfa_offset	-256
379 	.cfi_adjust_cfa_offset	-256
381 	lda	$sp, -64($sp)
416 	.cfi_adjust_cfa_offset	-64
437  * Note that a0-a2 are not saved by PALcode as with the other entry points.
460 	stq	$18, SP_OFF+40($sp)
463 	.cfi_rel_offset	$18, SP_OFF+40
483 	cmovne	$26, 0, $18		/* $18 = 0 => non-restartable */
519 	ldq	$18, 0($sp)	/* old syscall nr (zero if success) */
520 	beq	$18, $ret_success
536  *      $18: The old syscall number, or zero if this is not a return
551 	 * restarts for us, so let $18 and $19 burn.
554 	mov	0, $18
587 	ldq	$18, SP_OFF+40($sp)
617 	ldq	$18, 0($sp)	/* old syscall nr (zero if success) */
618 	beq	$18, $strace_success
627 	mov	$18, $9		/* save old syscall number */
630 	mov	$9, $18
639  * Save and restore the switch stack -- aka the balance of the user context.
649 	lda	$sp, -SWITCH_STACK_SIZE($sp)
661 	.size	do_switch_stack, .-do_switch_stack
680 	.size	undo_switch_stack, .-undo_switch_stack
692 	V(16); V(17); V(18); V(19)
694 	V(24); V(25); V(26); V(27)
701 	.size	__save_fpu, .-__save_fpu
715 	V(16); V(17); V(18); V(19)
717 	V(24); V(25); V(26); V(27)
749 	.size	alpha_switch_to, .-alpha_switch_to
765  * ... and new kernel threads - here
820 	lda	$sp, -SWITCH_STACK_SIZE($sp)
842 	   Store a non-zero there - -ENOSYS we need in register
845 	lda	$0, -ENOSYS