1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * dtlb_prot.S: DTLB protection trap strategy.
4 *              This is included directly into the trap table.
5 *
6 * Copyright (C) 1996,1998 David S. Miller (davem@redhat.com)
7 * Copyright (C) 1997,1998 Jakub Jelinek   (jj@ultra.linux.cz)
8 */
9
10/* Ways we can get here:
11 *
12 * [TL == 0] 1) User stores to readonly pages.
13 * [TL == 0] 2) Nucleus stores to user readonly pages.
14 * [TL >  0] 3) Nucleus stores to user readonly stack frame.
15 */
16
17/* PROT ** ICACHE line 1: User DTLB protection trap	*/
18	mov		TLB_SFSR, %g1
19	stxa		%g0, [%g1] ASI_DMMU		! Clear FaultValid bit
20	membar		#Sync				! Synchronize stores
21	rdpr		%pstate, %g5			! Move into alt-globals
22	wrpr		%g5, PSTATE_AG|PSTATE_MG, %pstate
23	rdpr		%tl, %g1			! Need a winfixup?
24	cmp		%g1, 1				! Trap level >1?
25	mov		TLB_TAG_ACCESS, %g4		! For reload of vaddr
26
27/* PROT ** ICACHE line 2: More real fault processing */
28	ldxa		[%g4] ASI_DMMU, %g5		! Put tagaccess in %g5
29	srlx		%g5, PAGE_SHIFT, %g5
30	sllx		%g5, PAGE_SHIFT, %g5		! Clear context ID bits
31	bgu,pn		%xcc, winfix_trampoline		! Yes, perform winfixup
32	 mov		FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4
33	ba,pt		%xcc, sparc64_realfault_common	! Nope, normal fault
34	 nop
35	nop
36
37/* PROT ** ICACHE line 3: Unused...	*/
38	nop
39	nop
40	nop
41	nop
42	nop
43	nop
44	nop
45	nop
46
47/* PROT ** ICACHE line 4: Unused...	*/
48	nop
49	nop
50	nop
51	nop
52	nop
53	nop
54	nop
55	nop
56