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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
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2 | /* |
3 | * Copyright (c) 2016 IBM Corporation. | |
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4 | */ |
5 | ||
6 | #include "ops.h" | |
7 | #include "stdio.h" | |
8 | #include "io.h" | |
9 | #include <libfdt.h> | |
10 | #include "../include/asm/opal-api.h" | |
11 | ||
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12 | /* Global OPAL struct used by opal-call.S */ |
13 | struct opal { | |
14 | u64 base; | |
15 | u64 entry; | |
16 | } opal; | |
17 | ||
18 | static u32 opal_con_id; | |
19 | ||
a1ff5741 | 20 | /* see opal-wrappers.S */ |
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21 | int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer); |
22 | int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer); | |
23 | int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length); | |
24 | int64_t opal_console_flush(uint64_t term_number); | |
25 | int64_t opal_poll_events(uint64_t *outstanding_event_mask); | |
26 | ||
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27 | void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr); |
28 | ||
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29 | static int opal_con_open(void) |
30 | { | |
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31 | /* |
32 | * When OPAL loads the boot kernel it stashes the OPAL base and entry | |
33 | * address in r8 and r9 so the kernel can use the OPAL console | |
34 | * before unflattening the devicetree. While executing the wrapper will | |
35 | * probably trash r8 and r9 so this kentry hook restores them before | |
36 | * entering the decompressed kernel. | |
37 | */ | |
38 | platform_ops.kentry = opal_kentry; | |
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39 | return 0; |
40 | } | |
41 | ||
42 | static void opal_con_putc(unsigned char c) | |
43 | { | |
44 | int64_t rc; | |
45 | uint64_t olen, len; | |
46 | ||
47 | do { | |
48 | rc = opal_console_write_buffer_space(opal_con_id, &olen); | |
49 | len = be64_to_cpu(olen); | |
50 | if (rc) | |
51 | return; | |
52 | opal_poll_events(NULL); | |
53 | } while (len < 1); | |
54 | ||
55 | ||
56 | olen = cpu_to_be64(1); | |
57 | opal_console_write(opal_con_id, &olen, &c); | |
58 | } | |
59 | ||
60 | static void opal_con_close(void) | |
61 | { | |
62 | opal_console_flush(opal_con_id); | |
63 | } | |
64 | ||
65 | static void opal_init(void) | |
66 | { | |
67 | void *opal_node; | |
68 | ||
69 | opal_node = finddevice("/ibm,opal"); | |
70 | if (!opal_node) | |
71 | return; | |
72 | if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0) | |
73 | return; | |
74 | opal.base = be64_to_cpu(opal.base); | |
75 | if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0) | |
76 | return; | |
77 | opal.entry = be64_to_cpu(opal.entry); | |
78 | } | |
79 | ||
80 | int opal_console_init(void *devp, struct serial_console_data *scdp) | |
81 | { | |
82 | opal_init(); | |
83 | ||
84 | if (devp) { | |
85 | int n = getprop(devp, "reg", &opal_con_id, sizeof(u32)); | |
86 | if (n != sizeof(u32)) | |
87 | return -1; | |
88 | opal_con_id = be32_to_cpu(opal_con_id); | |
89 | } else | |
90 | opal_con_id = 0; | |
91 | ||
92 | scdp->open = opal_con_open; | |
93 | scdp->putc = opal_con_putc; | |
94 | scdp->close = opal_con_close; | |
95 | ||
96 | return 0; | |
97 | } |