1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* clear_page.S: UltraSparc optimized clear pa 2 /* clear_page.S: UltraSparc optimized clear page.
3 * 3 *
4 * Copyright (C) 1996, 1998, 1999, 2000, 2004 4 * Copyright (C) 1996, 1998, 1999, 2000, 2004 David S. Miller (davem@redhat.com)
5 * Copyright (C) 1997 Jakub Jelinek (jakub@red 5 * Copyright (C) 1997 Jakub Jelinek (jakub@redhat.com)
6 */ 6 */
7 7
8 #include <linux/export.h> 8 #include <linux/export.h>
9 #include <linux/pgtable.h> 9 #include <linux/pgtable.h>
10 #include <asm/visasm.h> 10 #include <asm/visasm.h>
11 #include <asm/thread_info.h> 11 #include <asm/thread_info.h>
12 #include <asm/page.h> 12 #include <asm/page.h>
13 #include <asm/spitfire.h> 13 #include <asm/spitfire.h>
14 #include <asm/head.h> 14 #include <asm/head.h>
15 15
16 /* What we used to do was lock a TLB e 16 /* What we used to do was lock a TLB entry into a specific
17 * TLB slot, clear the page with inter 17 * TLB slot, clear the page with interrupts disabled, then
18 * restore the original TLB entry. Th 18 * restore the original TLB entry. This was great for
19 * disturbing the TLB as little as pos 19 * disturbing the TLB as little as possible, but it meant
20 * we had to keep interrupts disabled 20 * we had to keep interrupts disabled for a long time.
21 * 21 *
22 * Now, we simply use the normal TLB l 22 * Now, we simply use the normal TLB loading mechanism,
23 * and this makes the cpu choose a slo 23 * and this makes the cpu choose a slot all by itself.
24 * Then we do a normal TLB flush on ex 24 * Then we do a normal TLB flush on exit. We need only
25 * disable preemption during the clear 25 * disable preemption during the clear.
26 */ 26 */
27 27
28 .text 28 .text
29 29
30 .globl _clear_page 30 .globl _clear_page
31 EXPORT_SYMBOL(_clear_page) 31 EXPORT_SYMBOL(_clear_page)
32 _clear_page: /* %o0=dest */ 32 _clear_page: /* %o0=dest */
33 ba,pt %xcc, clear_page_commo 33 ba,pt %xcc, clear_page_common
34 clr %o4 34 clr %o4
35 35
36 /* This thing is pretty important, it 36 /* This thing is pretty important, it shows up
37 * on the profiles via do_anonymous_pa 37 * on the profiles via do_anonymous_page().
38 */ 38 */
39 .align 32 39 .align 32
40 .globl clear_user_page 40 .globl clear_user_page
41 EXPORT_SYMBOL(clear_user_page) 41 EXPORT_SYMBOL(clear_user_page)
42 clear_user_page: /* %o0=dest, %o1=vaddr 42 clear_user_page: /* %o0=dest, %o1=vaddr */
43 lduw [%g6 + TI_PRE_COUNT], 43 lduw [%g6 + TI_PRE_COUNT], %o2
44 sethi %hi(PAGE_OFFSET), %g2 44 sethi %hi(PAGE_OFFSET), %g2
45 sethi %hi(PAGE_SIZE), %o4 45 sethi %hi(PAGE_SIZE), %o4
46 46
47 ldx [%g2 + %lo(PAGE_OFFSET 47 ldx [%g2 + %lo(PAGE_OFFSET)], %g2
48 sethi %hi(PAGE_KERNEL_LOCKED 48 sethi %hi(PAGE_KERNEL_LOCKED), %g3
49 49
50 ldx [%g3 + %lo(PAGE_KERNEL 50 ldx [%g3 + %lo(PAGE_KERNEL_LOCKED)], %g3
51 sub %o0, %g2, %g1 51 sub %o0, %g2, %g1 ! paddr
52 52
53 and %o1, %o4, %o0 53 and %o1, %o4, %o0 ! vaddr D-cache alias bit
54 54
55 or %g1, %g3, %g1 55 or %g1, %g3, %g1 ! TTE data
56 sethi %hi(TLBTEMP_BASE), %o3 56 sethi %hi(TLBTEMP_BASE), %o3
57 57
58 add %o2, 1, %o4 58 add %o2, 1, %o4
59 add %o0, %o3, %o0 59 add %o0, %o3, %o0 ! TTE vaddr
60 60
61 /* Disable preemption. */ 61 /* Disable preemption. */
62 mov TLB_TAG_ACCESS, %g3 62 mov TLB_TAG_ACCESS, %g3
63 stw %o4, [%g6 + TI_PRE_COU 63 stw %o4, [%g6 + TI_PRE_COUNT]
64 64
65 /* Load TLB entry. */ 65 /* Load TLB entry. */
66 rdpr %pstate, %o4 66 rdpr %pstate, %o4
67 wrpr %o4, PSTATE_IE, %pstat 67 wrpr %o4, PSTATE_IE, %pstate
68 stxa %o0, [%g3] ASI_DMMU 68 stxa %o0, [%g3] ASI_DMMU
69 stxa %g1, [%g0] ASI_DTLB_DA 69 stxa %g1, [%g0] ASI_DTLB_DATA_IN
70 sethi %hi(KERNBASE), %g1 70 sethi %hi(KERNBASE), %g1
71 flush %g1 71 flush %g1
72 wrpr %o4, 0x0, %pstate 72 wrpr %o4, 0x0, %pstate
73 73
74 mov 1, %o4 74 mov 1, %o4
75 75
76 clear_page_common: 76 clear_page_common:
77 VISEntryHalf 77 VISEntryHalf
78 membar #StoreLoad | #StoreSto 78 membar #StoreLoad | #StoreStore | #LoadStore
79 fzero %f0 79 fzero %f0
80 sethi %hi(PAGE_SIZE/64), %o1 80 sethi %hi(PAGE_SIZE/64), %o1
81 mov %o0, %g1 81 mov %o0, %g1 ! remember vaddr for tlbflush
82 fzero %f2 82 fzero %f2
83 or %o1, %lo(PAGE_SIZE/64) 83 or %o1, %lo(PAGE_SIZE/64), %o1
84 faddd %f0, %f2, %f4 84 faddd %f0, %f2, %f4
85 fmuld %f0, %f2, %f6 85 fmuld %f0, %f2, %f6
86 faddd %f0, %f2, %f8 86 faddd %f0, %f2, %f8
87 fmuld %f0, %f2, %f10 87 fmuld %f0, %f2, %f10
88 88
89 faddd %f0, %f2, %f12 89 faddd %f0, %f2, %f12
90 fmuld %f0, %f2, %f14 90 fmuld %f0, %f2, %f14
91 1: stda %f0, [%o0 + %g0] ASI_B 91 1: stda %f0, [%o0 + %g0] ASI_BLK_P
92 subcc %o1, 1, %o1 92 subcc %o1, 1, %o1
93 bne,pt %icc, 1b 93 bne,pt %icc, 1b
94 add %o0, 0x40, %o0 94 add %o0, 0x40, %o0
95 membar #Sync 95 membar #Sync
96 VISExitHalf 96 VISExitHalf
97 97
98 brz,pn %o4, out 98 brz,pn %o4, out
99 nop 99 nop
100 100
101 stxa %g0, [%g1] ASI_DMMU_DE 101 stxa %g0, [%g1] ASI_DMMU_DEMAP
102 membar #Sync 102 membar #Sync
103 stw %o2, [%g6 + TI_PRE_COU 103 stw %o2, [%g6 + TI_PRE_COUNT]
104 104
105 out: retl 105 out: retl
106 nop 106 nop
107 107
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