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