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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
4 *
5 * This file implements the EFI boot stub for the arm64 kernel.
6 * Adapted from ARM version by Mark Salter <msalter@redhat.com>
7 */
8
9
10#include <linux/efi.h>
11#include <asm/efi.h>
12#include <asm/image.h>
13#include <asm/memory.h>
14#include <asm/sysreg.h>
15
16#include "efistub.h"
17
18static bool system_needs_vamap(void)
19{
20 const struct efi_smbios_type4_record *record;
21 const u32 __aligned(1) *socid;
22 const u8 *version;
23
24 /*
25 * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
26 * SetVirtualAddressMap() has not been called prior. Most Altra systems
27 * can be identified by the SMCCC soc ID, which is conveniently exposed
28 * via the type 4 SMBIOS records. Otherwise, test the processor version
29 * field. eMAG systems all appear to have the processor version field
30 * set to "eMAG".
31 */
32 record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4);
33 if (!record)
34 return false;
35
36 socid = (u32 *)record->processor_id;
37 switch (*socid & 0xffff000f) {
38 static char const altra[] = "Ampere(TM) Altra(TM) Processor";
39 static char const emag[] = "eMAG";
40
41 default:
42 version = efi_get_smbios_string(&record->header, 4,
43 processor_version);
44 if (!version || (strncmp(version, altra, sizeof(altra) - 1) &&
45 strncmp(version, emag, sizeof(emag) - 1)))
46 break;
47
48 fallthrough;
49
50 case 0x0a160001: // Altra
51 case 0x0a160002: // Altra Max
52 efi_warn("Working around broken SetVirtualAddressMap()\n");
53 return true;
54 }
55
56 return false;
57}
58
59efi_status_t check_platform_features(void)
60{
61 u64 tg;
62
63 /*
64 * If we have 48 bits of VA space for TTBR0 mappings, we can map the
65 * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is
66 * unnecessary.
67 */
68 if (VA_BITS_MIN >= 48 && !system_needs_vamap())
69 efi_novamap = true;
70
71 /* UEFI mandates support for 4 KB granularity, no need to check */
72 if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
73 return EFI_SUCCESS;
74
75 tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf;
76 if (tg < ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MAX) {
77 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
78 efi_err("This 64 KB granular kernel is not supported by your CPU\n");
79 else
80 efi_err("This 16 KB granular kernel is not supported by your CPU\n");
81 return EFI_UNSUPPORTED;
82 }
83 return EFI_SUCCESS;
84}
85
86#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
87#define DCTYPE "civac"
88#else
89#define DCTYPE "cvau"
90#endif
91
92u32 __weak code_size;
93
94void efi_cache_sync_image(unsigned long image_base,
95 unsigned long alloc_size)
96{
97 u32 ctr = read_cpuid_effective_cachetype();
98 u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr,
99 CTR_EL0_DminLine_SHIFT);
100
101 /* only perform the cache maintenance if needed for I/D coherency */
102 if (!(ctr & BIT(CTR_EL0_IDC_SHIFT))) {
103 unsigned long base = image_base;
104 unsigned long size = code_size;
105
106 do {
107 asm("dc " DCTYPE ", %0" :: "r"(base));
108 base += lsize;
109 size -= lsize;
110 } while (size >= lsize);
111 }
112
113 asm("ic ialluis");
114 dsb(ish);
115 isb();
116
117 efi_remap_image(image_base, alloc_size, code_size);
118}
119
120unsigned long __weak primary_entry_offset(void)
121{
122 /*
123 * By default, we can invoke the kernel via the branch instruction in
124 * the image header, so offset #0. This will be overridden by the EFI
125 * stub build that is linked into the core kernel, as in that case, the
126 * image header may not have been loaded into memory, or may be mapped
127 * with non-executable permissions.
128 */
129 return 0;
130}
131
132void __noreturn efi_enter_kernel(unsigned long entrypoint,
133 unsigned long fdt_addr,
134 unsigned long fdt_size)
135{
136 void (* __noreturn enter_kernel)(u64, u64, u64, u64);
137
138 enter_kernel = (void *)entrypoint + primary_entry_offset();
139 enter_kernel(fdt_addr, 0, 0, 0);
140}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
4 *
5 * This file implements the EFI boot stub for the arm64 kernel.
6 * Adapted from ARM version by Mark Salter <msalter@redhat.com>
7 */
8
9
10#include <linux/efi.h>
11#include <asm/efi.h>
12#include <asm/image.h>
13#include <asm/memory.h>
14#include <asm/sysreg.h>
15
16#include "efistub.h"
17
18static bool system_needs_vamap(void)
19{
20 const struct efi_smbios_type4_record *record;
21 const u32 __aligned(1) *socid;
22 const u8 *version;
23
24 /*
25 * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
26 * SetVirtualAddressMap() has not been called prior. Most Altra systems
27 * can be identified by the SMCCC soc ID, which is conveniently exposed
28 * via the type 4 SMBIOS records. Otherwise, test the processor version
29 * field. eMAG systems all appear to have the processor version field
30 * set to "eMAG".
31 */
32 record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4);
33 if (!record)
34 return false;
35
36 socid = (u32 *)record->processor_id;
37 switch (*socid & 0xffff000f) {
38 static char const altra[] = "Ampere(TM) Altra(TM) Processor";
39 static char const emag[] = "eMAG";
40
41 default:
42 version = efi_get_smbios_string(record, processor_version);
43 if (!version || (strncmp(version, altra, sizeof(altra) - 1) &&
44 strncmp(version, emag, sizeof(emag) - 1)))
45 break;
46
47 fallthrough;
48
49 case 0x0a160001: // Altra
50 case 0x0a160002: // Altra Max
51 efi_warn("Working around broken SetVirtualAddressMap()\n");
52 return true;
53 }
54
55 return false;
56}
57
58efi_status_t check_platform_features(void)
59{
60 u64 tg;
61
62 /*
63 * If we have 48 bits of VA space for TTBR0 mappings, we can map the
64 * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is
65 * unnecessary.
66 */
67 if (VA_BITS_MIN >= 48 && !system_needs_vamap())
68 efi_novamap = true;
69
70 /* UEFI mandates support for 4 KB granularity, no need to check */
71 if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
72 return EFI_SUCCESS;
73
74 tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf;
75 if (tg < ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MAX) {
76 if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
77 efi_err("This 64 KB granular kernel is not supported by your CPU\n");
78 else
79 efi_err("This 16 KB granular kernel is not supported by your CPU\n");
80 return EFI_UNSUPPORTED;
81 }
82 return EFI_SUCCESS;
83}
84
85#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
86#define DCTYPE "civac"
87#else
88#define DCTYPE "cvau"
89#endif
90
91u32 __weak code_size;
92
93void efi_cache_sync_image(unsigned long image_base,
94 unsigned long alloc_size)
95{
96 u32 ctr = read_cpuid_effective_cachetype();
97 u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr,
98 CTR_EL0_DminLine_SHIFT);
99
100 /* only perform the cache maintenance if needed for I/D coherency */
101 if (!(ctr & BIT(CTR_EL0_IDC_SHIFT))) {
102 unsigned long base = image_base;
103 unsigned long size = code_size;
104
105 do {
106 asm("dc " DCTYPE ", %0" :: "r"(base));
107 base += lsize;
108 size -= lsize;
109 } while (size >= lsize);
110 }
111
112 asm("ic ialluis");
113 dsb(ish);
114 isb();
115
116 efi_remap_image(image_base, alloc_size, code_size);
117}
118
119unsigned long __weak primary_entry_offset(void)
120{
121 /*
122 * By default, we can invoke the kernel via the branch instruction in
123 * the image header, so offset #0. This will be overridden by the EFI
124 * stub build that is linked into the core kernel, as in that case, the
125 * image header may not have been loaded into memory, or may be mapped
126 * with non-executable permissions.
127 */
128 return 0;
129}
130
131void __noreturn efi_enter_kernel(unsigned long entrypoint,
132 unsigned long fdt_addr,
133 unsigned long fdt_size)
134{
135 void (* __noreturn enter_kernel)(u64, u64, u64, u64);
136
137 enter_kernel = (void *)entrypoint + primary_entry_offset();
138 enter_kernel(fdt_addr, 0, 0, 0);
139}