Commit | Line | Data |
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d9523678 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
138fe4e0 | 2 | /* |
4e639fdf | 3 | * Copyright 2007-2010 Red Hat, Inc. |
138fe4e0 KR |
4 | * by Peter Jones <pjones@redhat.com> |
5 | * Copyright 2007 IBM, Inc. | |
6 | * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com> | |
7 | * Copyright 2008 | |
8 | * by Konrad Rzeszutek <ketuzsezr@darnok.org> | |
9 | * | |
10 | * This code finds the iSCSI Boot Format Table. | |
138fe4e0 KR |
11 | */ |
12 | ||
57c8a661 | 13 | #include <linux/memblock.h> |
138fe4e0 KR |
14 | #include <linux/blkdev.h> |
15 | #include <linux/ctype.h> | |
16 | #include <linux/device.h> | |
4e639fdf | 17 | #include <linux/efi.h> |
138fe4e0 KR |
18 | #include <linux/err.h> |
19 | #include <linux/init.h> | |
20 | #include <linux/limits.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/pci.h> | |
138fe4e0 KR |
23 | #include <linux/stat.h> |
24 | #include <linux/string.h> | |
25 | #include <linux/types.h> | |
4e639fdf PJ |
26 | #include <linux/acpi.h> |
27 | #include <linux/iscsi_ibft.h> | |
138fe4e0 KR |
28 | |
29 | #include <asm/mmzone.h> | |
30 | ||
31 | /* | |
32 | * Physical location of iSCSI Boot Format Table. | |
33 | */ | |
4e639fdf | 34 | struct acpi_table_ibft *ibft_addr; |
138fe4e0 KR |
35 | EXPORT_SYMBOL_GPL(ibft_addr); |
36 | ||
14036350 MC |
37 | static const struct { |
38 | char *sign; | |
39 | } ibft_signs[] = { | |
14036350 MC |
40 | { "iBFT" }, |
41 | { "BIFT" }, /* Broadcom iSCSI Offload */ | |
42 | }; | |
43 | ||
138fe4e0 KR |
44 | #define IBFT_SIGN_LEN 4 |
45 | #define IBFT_START 0x80000 /* 512kB */ | |
46 | #define IBFT_END 0x100000 /* 1MB */ | |
47 | #define VGA_MEM 0xA0000 /* VGA buffer */ | |
48 | #define VGA_SIZE 0x20000 /* 128kB */ | |
49 | ||
1303a35b | 50 | static int __init find_ibft_in_mem(void) |
138fe4e0 KR |
51 | { |
52 | unsigned long pos; | |
53 | unsigned int len = 0; | |
54 | void *virt; | |
14036350 | 55 | int i; |
138fe4e0 | 56 | |
138fe4e0 KR |
57 | for (pos = IBFT_START; pos < IBFT_END; pos += 16) { |
58 | /* The table can't be inside the VGA BIOS reserved space, | |
59 | * so skip that area */ | |
60 | if (pos == VGA_MEM) | |
61 | pos += VGA_SIZE; | |
ed3c6614 | 62 | virt = isa_bus_to_virt(pos); |
14036350 MC |
63 | |
64 | for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) { | |
65 | if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) == | |
66 | 0) { | |
67 | unsigned long *addr = | |
68 | (unsigned long *)isa_bus_to_virt(pos + 4); | |
69 | len = *addr; | |
70 | /* if the length of the table extends past 1M, | |
71 | * the table cannot be valid. */ | |
72 | if (pos + len <= (IBFT_END-1)) { | |
73 | ibft_addr = (struct acpi_table_ibft *)virt; | |
935a9fee | 74 | pr_info("iBFT found at 0x%lx.\n", pos); |
14036350 MC |
75 | goto done; |
76 | } | |
138fe4e0 KR |
77 | } |
78 | } | |
79 | } | |
14036350 | 80 | done: |
1303a35b KRW |
81 | return len; |
82 | } | |
83 | /* | |
84 | * Routine used to find the iSCSI Boot Format Table. The logical | |
85 | * kernel address is set in the ibft_addr global variable. | |
86 | */ | |
87 | unsigned long __init find_ibft_region(unsigned long *sizep) | |
88 | { | |
1303a35b KRW |
89 | ibft_addr = NULL; |
90 | ||
1303a35b KRW |
91 | /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will |
92 | * only use ACPI for this */ | |
93 | ||
83e68189 | 94 | if (!efi_enabled(EFI_BOOT)) |
1303a35b KRW |
95 | find_ibft_in_mem(); |
96 | ||
042be38e | 97 | if (ibft_addr) { |
4e639fdf | 98 | *sizep = PAGE_ALIGN(ibft_addr->header.length); |
8bd04c57 | 99 | return (u64)virt_to_phys(ibft_addr); |
042be38e YL |
100 | } |
101 | ||
102 | *sizep = 0; | |
103 | return 0; | |
138fe4e0 | 104 | } |