summaryrefslogtreecommitdiffstats
path: root/arch/sparc64/kernel/tsb.S
blob: 76f2c0b01f36c996f892c994a3fdca3c3c5a2c83 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/* tsb.S: Sparc64 TSB table handling.
 *
 * Copyright (C) 2006 David S. Miller <davem@davemloft.net>
 */

#include <asm/tsb.h>

	.text
	.align	32

	/* Invoked from TLB miss handler, we are in the
	 * MMU global registers and they are setup like
	 * this:
	 *
	 * %g1: TSB entry pointer
	 * %g2:	available temporary
	 * %g3:	FAULT_CODE_{D,I}TLB
	 * %g4:	available temporary
	 * %g5:	available temporary
	 * %g6: TAG TARGET
	 * %g7:	physical address base of the linux page
	 *      tables for the current address space
	 */
	.globl		tsb_miss_dtlb
tsb_miss_dtlb:
	mov		TLB_TAG_ACCESS, %g4
	ldxa		[%g4] ASI_DMMU, %g4
	ba,pt		%xcc, tsb_miss_page_table_walk
	 nop

	.globl		tsb_miss_itlb
tsb_miss_itlb:
	mov		TLB_TAG_ACCESS, %g4
	ldxa		[%g4] ASI_IMMU, %g4
	ba,pt		%xcc, tsb_miss_page_table_walk
	 nop

tsb_miss_page_table_walk:
	/* This clobbers %g1 and %g6, preserve them... */
	mov		%g1, %g5
	mov		%g6, %g2

	TRAP_LOAD_PGD_PHYS

	mov		%g2, %g6
	mov		%g5, %g1

	USER_PGTABLE_WALK_TL1(%g4, %g7, %g5, %g2, tsb_do_fault)

tsb_reload:
	TSB_LOCK_TAG(%g1, %g2, %g4)

	/* Load and check PTE.  */
	ldxa		[%g5] ASI_PHYS_USE_EC, %g5
	brgez,a,pn	%g5, tsb_do_fault
	 stx		%g0, [%g1]

	/* If it is larger than the base page size, don't
	 * bother putting it into the TSB.
	 */
	srlx		%g5, 32, %g2
	sethi		%hi(_PAGE_ALL_SZ_BITS >> 32), %g4
	sethi		%hi(_PAGE_SZBITS >> 32), %g7
	and		%g2, %g4, %g2
	cmp		%g2, %g7
	bne,a,pn	%xcc, tsb_tlb_reload
	 stx		%g0, [%g1]

	TSB_WRITE(%g1, %g5, %g6)

	/* Finally, load TLB and return from trap.  */
tsb_tlb_reload:
	cmp		%g3, FAULT_CODE_DTLB
	bne,pn		%xcc, tsb_itlb_load
	 nop

tsb_dtlb_load:
	stxa		%g5, [%g0] ASI_DTLB_DATA_IN
	retry

tsb_itlb_load:
	stxa		%g5, [%g0] ASI_ITLB_DATA_IN
	retry

	/* No valid entry in the page tables, do full fault
	 * processing.
	 */

	.globl		tsb_do_fault
tsb_do_fault:
	cmp		%g3, FAULT_CODE_DTLB
	rdpr		%pstate, %g5
	bne,pn		%xcc, tsb_do_itlb_fault
	 wrpr		%g5, PSTATE_AG | PSTATE_MG, %pstate

tsb_do_dtlb_fault:
	rdpr	%tl, %g4
	cmp	%g4, 1
	mov	TLB_TAG_ACCESS, %g4
	ldxa	[%g4] ASI_DMMU, %g5
	be,pt	%xcc, sparc64_realfault_common
	 mov	FAULT_CODE_DTLB, %g4
	ba,pt	%xcc, winfix_trampoline
	 nop

tsb_do_itlb_fault:
	rdpr	%tpc, %g5
	ba,pt	%xcc, sparc64_realfault_common
	 mov	FAULT_CODE_ITLB, %g4

	.globl	sparc64_realfault_common
sparc64_realfault_common:
	stb	%g4, [%g6 + TI_FAULT_CODE]	! Save fault code
	stx	%g5, [%g6 + TI_FAULT_ADDR]	! Save fault address
	ba,pt	%xcc, etrap			! Save trap state
1:	 rd	%pc, %g7			! ...
	call	do_sparc64_fault		! Call fault handler
	 add	%sp, PTREGS_OFF, %o0		! Compute pt_regs arg
	ba,pt	%xcc, rtrap_clr_l6		! Restore cpu state
	 nop					! Delay slot (fill me)

	.globl	winfix_trampoline
winfix_trampoline:
	rdpr	%tpc, %g3			! Prepare winfixup TNPC
	or	%g3, 0x7c, %g3			! Compute branch offset
	wrpr	%g3, %tnpc			! Write it into TNPC
	done					! Trap return

	/* Reload MMU related context switch state at
	 * schedule() time.
	 *
	 * %o0: page table physical address
	 * %o1:	TSB address
	 */
	.align	32
	.globl	tsb_context_switch
tsb_context_switch:
	rdpr	%pstate, %o5
	wrpr	%o5, PSTATE_IE, %pstate

	ldub	[%g6 + TI_CPU], %o3
	sethi	%hi(trap_block), %o4
	sllx	%o3, TRAP_BLOCK_SZ_SHIFT, %o3
	or	%o4, %lo(trap_block), %o4
	add	%o4, %o3, %o4
	stx	%o0, [%o4 + TRAP_PER_CPU_PGD_PADDR]

	brgez	%o1, 9f
	 nop

	/* Lock TSB into D-TLB.  */
	sethi		%hi(PAGE_SIZE), %o3
	and		%o3, %o1, %o3
	sethi		%hi(TSBMAP_BASE), %o2
	add		%o2, %o3, %o2

	/* XXX handle PAGE_SIZE != 8K correctly...  */
	mov	TSB_REG, %g1
	stxa	%o2, [%g1] ASI_DMMU
	membar	#Sync

	stxa	%o2, [%g1] ASI_IMMU
	membar	#Sync

#define KERN_HIGHBITS	((_PAGE_VALID|_PAGE_SZBITS)^0xfffff80000000000)
#define KERN_LOWBITS	(_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W | _PAGE_L)
	sethi		%uhi(KERN_HIGHBITS), %g2
	or		%g2, %ulo(KERN_HIGHBITS), %g2
	sllx		%g2, 32, %g2
	or		%g2, KERN_LOWBITS, %g2
#undef KERN_HIGHBITS
#undef KERN_LOWBITS

	xor		%o1, %g2, %o1	

	/* We use entry 61 for this locked entry.  This is the spitfire
	 * TLB entry number, and luckily cheetah masks the value with
	 * 15 ending us up with entry 13 which is what we want in that
	 * case too.
	 *
	 * XXX Interactions with prom_world()...
	 */
	mov		TLB_TAG_ACCESS, %g1
	stxa		%o2, [%g1] ASI_DMMU
	membar		#Sync
	mov		(61 << 3), %g1
	stxa		%o1, [%g1] ASI_DTLB_DATA_ACCESS
	membar		#Sync

9:
	wrpr	%o5, %pstate

	retl
	 mov	%o2, %o0
OpenPOWER on IntegriCloud