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