| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2016 IBM Corporation. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | */ |
| 9 | |
| 10 | #include "ops.h" |
| 11 | #include "stdio.h" |
| 12 | #include "io.h" |
| 13 | #include <libfdt.h> |
| 14 | #include "../include/asm/opal-api.h" |
| 15 | |
| 16 | /* Global OPAL struct used by opal-call.S */ |
| 17 | struct opal { |
| 18 | u64 base; |
| 19 | u64 entry; |
| 20 | } opal; |
| 21 | |
| 22 | static u32 opal_con_id; |
| 23 | |
| 24 | /* see opal-wrappers.S */ |
| 25 | int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer); |
| 26 | int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer); |
| 27 | int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length); |
| 28 | int64_t opal_console_flush(uint64_t term_number); |
| 29 | int64_t opal_poll_events(uint64_t *outstanding_event_mask); |
| 30 | |
| 31 | void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr); |
| 32 | |
| 33 | static int opal_con_open(void) |
| 34 | { |
| 35 | /* |
| 36 | * When OPAL loads the boot kernel it stashes the OPAL base and entry |
| 37 | * address in r8 and r9 so the kernel can use the OPAL console |
| 38 | * before unflattening the devicetree. While executing the wrapper will |
| 39 | * probably trash r8 and r9 so this kentry hook restores them before |
| 40 | * entering the decompressed kernel. |
| 41 | */ |
| 42 | platform_ops.kentry = opal_kentry; |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | static void opal_con_putc(unsigned char c) |
| 47 | { |
| 48 | int64_t rc; |
| 49 | uint64_t olen, len; |
| 50 | |
| 51 | do { |
| 52 | rc = opal_console_write_buffer_space(opal_con_id, &olen); |
| 53 | len = be64_to_cpu(olen); |
| 54 | if (rc) |
| 55 | return; |
| 56 | opal_poll_events(NULL); |
| 57 | } while (len < 1); |
| 58 | |
| 59 | |
| 60 | olen = cpu_to_be64(1); |
| 61 | opal_console_write(opal_con_id, &olen, &c); |
| 62 | } |
| 63 | |
| 64 | static void opal_con_close(void) |
| 65 | { |
| 66 | opal_console_flush(opal_con_id); |
| 67 | } |
| 68 | |
| 69 | static void opal_init(void) |
| 70 | { |
| 71 | void *opal_node; |
| 72 | |
| 73 | opal_node = finddevice("/ibm,opal"); |
| 74 | if (!opal_node) |
| 75 | return; |
| 76 | if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0) |
| 77 | return; |
| 78 | opal.base = be64_to_cpu(opal.base); |
| 79 | if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0) |
| 80 | return; |
| 81 | opal.entry = be64_to_cpu(opal.entry); |
| 82 | } |
| 83 | |
| 84 | int opal_console_init(void *devp, struct serial_console_data *scdp) |
| 85 | { |
| 86 | opal_init(); |
| 87 | |
| 88 | if (devp) { |
| 89 | int n = getprop(devp, "reg", &opal_con_id, sizeof(u32)); |
| 90 | if (n != sizeof(u32)) |
| 91 | return -1; |
| 92 | opal_con_id = be32_to_cpu(opal_con_id); |
| 93 | } else |
| 94 | opal_con_id = 0; |
| 95 | |
| 96 | scdp->open = opal_con_open; |
| 97 | scdp->putc = opal_con_putc; |
| 98 | scdp->close = opal_con_close; |
| 99 | |
| 100 | return 0; |
| 101 | } |