1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (c) 2023 Ventana Micro Systems In
4 */
5
6 #include <linux/linkage.h>
7 #include <linux/export.h>
8 #include <asm/asm.h>
9 #include <asm/alternative-macros.h>
10 #include <asm/hwcap.h>
11 #include <asm/insn-def.h>
12 #include <asm/page.h>
13
14 #define CBOZ_ALT(order, old, new)
15 ALTERNATIVE(old, new, 0,
16 ((order) << 16) | RISCV_IS
17 CONFIG_RISCV_ISA_ZICBOZ)
18
19 /* void clear_page(void *page) */
20 SYM_FUNC_START(clear_page)
21 li a2, PAGE_SIZE
22
23 /*
24 * If Zicboz isn't present, or somehow
25 * size larger than 4K, then fallback
26 */
27 CBOZ_ALT(12, "j .Lno_zicboz", "nop")
28
29 lw a1, riscv_cboz_block_size
30 add a2, a0, a2
31 .Lzero_loop:
32 CBO_ZERO(a0)
33 add a0, a0, a1
34 CBOZ_ALT(11, "bltu a0, a2, .Lzero_loop
35 CBO_ZERO(a0)
36 add a0, a0, a1
37 CBOZ_ALT(10, "bltu a0, a2, .Lzero_loop
38 CBO_ZERO(a0)
39 add a0, a0, a1
40 CBO_ZERO(a0)
41 add a0, a0, a1
42 CBOZ_ALT(9, "bltu a0, a2, .Lzero_loop;
43 CBO_ZERO(a0)
44 add a0, a0, a1
45 CBO_ZERO(a0)
46 add a0, a0, a1
47 CBO_ZERO(a0)
48 add a0, a0, a1
49 CBO_ZERO(a0)
50 add a0, a0, a1
51 CBOZ_ALT(8, "bltu a0, a2, .Lzero_loop;
52 CBO_ZERO(a0)
53 add a0, a0, a1
54 CBO_ZERO(a0)
55 add a0, a0, a1
56 CBO_ZERO(a0)
57 add a0, a0, a1
58 CBO_ZERO(a0)
59 add a0, a0, a1
60 CBO_ZERO(a0)
61 add a0, a0, a1
62 CBO_ZERO(a0)
63 add a0, a0, a1
64 CBO_ZERO(a0)
65 add a0, a0, a1
66 CBO_ZERO(a0)
67 add a0, a0, a1
68 bltu a0, a2, .Lzero_loop
69 ret
70 .Lno_zicboz:
71 li a1, 0
72 tail __memset
73 SYM_FUNC_END(clear_page)
74 EXPORT_SYMBOL(clear_page)
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