| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
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| 2 | /* |
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| 3 | * Copyright (c) 2016 IBM Corporation. |
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| 4 | */ |
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| 5 | |
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| 6 | #include "ops.h" |
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| 7 | #include "stdio.h" |
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| 8 | #include "io.h" |
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| 9 | #include <libfdt.h> |
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| 10 | #include "../include/asm/opal-api.h" |
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| 11 | |
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| 12 | /* Global OPAL struct used by opal-call.S */ |
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| 13 | struct opal { |
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| 14 | u64 base; |
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| 15 | u64 entry; |
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| 16 | } opal; |
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| 17 | |
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| 18 | static u32 opal_con_id; |
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| 19 | |
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| 20 | /* see opal-wrappers.S */ |
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| 21 | int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer); |
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| 22 | int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer); |
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| 23 | int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length); |
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| 24 | int64_t opal_console_flush(uint64_t term_number); |
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| 25 | int64_t opal_poll_events(uint64_t *outstanding_event_mask); |
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| 26 | |
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| 27 | void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr); |
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| 28 | |
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| 29 | static int opal_con_open(void) |
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| 30 | { |
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| 31 | /* |
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| 32 | * When OPAL loads the boot kernel it stashes the OPAL base and entry |
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| 33 | * address in r8 and r9 so the kernel can use the OPAL console |
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| 34 | * before unflattening the devicetree. While executing the wrapper will |
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| 35 | * probably trash r8 and r9 so this kentry hook restores them before |
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| 36 | * entering the decompressed kernel. |
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| 37 | */ |
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| 38 | platform_ops.kentry = opal_kentry; |
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| 39 | return 0; |
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| 40 | } |
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| 41 | |
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| 42 | static void opal_con_putc(unsigned char c) |
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| 43 | { |
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| 44 | int64_t rc; |
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| 45 | uint64_t olen, len; |
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| 46 | |
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| 47 | do { |
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| 48 | rc = opal_console_write_buffer_space(term_number: opal_con_id, length: &olen); |
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| 49 | len = be64_to_cpu(olen); |
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| 50 | if (rc) |
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| 51 | return; |
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| 52 | opal_poll_events(NULL); |
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| 53 | } while (len < 1); |
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| 54 | |
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| 55 | |
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| 56 | olen = cpu_to_be64(1); |
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| 57 | opal_console_write(term_number: opal_con_id, length: &olen, buffer: &c); |
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| 58 | } |
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| 59 | |
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| 60 | static void opal_con_close(void) |
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| 61 | { |
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| 62 | opal_console_flush(term_number: opal_con_id); |
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| 63 | } |
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| 64 | |
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| 65 | static void opal_init(void) |
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| 66 | { |
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| 67 | void *opal_node; |
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| 68 | |
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| 69 | opal_node = finddevice(name: "/ibm,opal" ); |
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| 70 | if (!opal_node) |
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| 71 | return; |
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| 72 | if (getprop(devp: opal_node, name: "opal-base-address" , buf: &opal.base, buflen: sizeof(u64)) < 0) |
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| 73 | return; |
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| 74 | opal.base = be64_to_cpu(opal.base); |
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| 75 | if (getprop(devp: opal_node, name: "opal-entry-address" , buf: &opal.entry, buflen: sizeof(u64)) < 0) |
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| 76 | return; |
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| 77 | opal.entry = be64_to_cpu(opal.entry); |
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| 78 | } |
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| 79 | |
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| 80 | int opal_console_init(void *devp, struct serial_console_data *scdp) |
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| 81 | { |
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| 82 | opal_init(); |
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| 83 | |
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| 84 | if (devp) { |
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| 85 | int n = getprop(devp, name: "reg" , buf: &opal_con_id, buflen: sizeof(u32)); |
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| 86 | if (n != sizeof(u32)) |
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| 87 | return -1; |
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| 88 | opal_con_id = be32_to_cpu(opal_con_id); |
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| 89 | } else |
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| 90 | opal_con_id = 0; |
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| 91 | |
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| 92 | scdp->open = opal_con_open; |
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| 93 | scdp->putc = opal_con_putc; |
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| 94 | scdp->close = opal_con_close; |
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| 95 | |
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| 96 | return 0; |
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| 97 | } |
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| 98 | |
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