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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
4 */
5#include <linux/efi.h>
6#include <asm/efi.h>
7
8#include "efistub.h"
9
10static efi_guid_t cpu_state_guid = LINUX_EFI_ARM_CPU_STATE_TABLE_GUID;
11
12struct efi_arm_entry_state *efi_entry_state;
13
14static void get_cpu_state(u32 *cpsr, u32 *sctlr)
15{
16 asm("mrs %0, cpsr" : "=r"(*cpsr));
17 if ((*cpsr & MODE_MASK) == HYP_MODE)
18 asm("mrc p15, 4, %0, c1, c0, 0" : "=r"(*sctlr));
19 else
20 asm("mrc p15, 0, %0, c1, c0, 0" : "=r"(*sctlr));
21}
22
23efi_status_t check_platform_features(void)
24{
25 efi_status_t status;
26 u32 cpsr, sctlr;
27 int block;
28
29 get_cpu_state(&cpsr, &sctlr);
30
31 efi_info("Entering in %s mode with MMU %sabled\n",
32 ((cpsr & MODE_MASK) == HYP_MODE) ? "HYP" : "SVC",
33 (sctlr & 1) ? "en" : "dis");
34
35 status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
36 sizeof(*efi_entry_state),
37 (void **)&efi_entry_state);
38 if (status != EFI_SUCCESS) {
39 efi_err("allocate_pool() failed\n");
40 return status;
41 }
42
43 efi_entry_state->cpsr_before_ebs = cpsr;
44 efi_entry_state->sctlr_before_ebs = sctlr;
45
46 status = efi_bs_call(install_configuration_table, &cpu_state_guid,
47 efi_entry_state);
48 if (status != EFI_SUCCESS) {
49 efi_err("install_configuration_table() failed\n");
50 goto free_state;
51 }
52
53 /* non-LPAE kernels can run anywhere */
54 if (!IS_ENABLED(CONFIG_ARM_LPAE))
55 return EFI_SUCCESS;
56
57 /* LPAE kernels need compatible hardware */
58 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
59 if (block < 5) {
60 efi_err("This LPAE kernel is not supported by your CPU\n");
61 status = EFI_UNSUPPORTED;
62 goto drop_table;
63 }
64 return EFI_SUCCESS;
65
66drop_table:
67 efi_bs_call(install_configuration_table, &cpu_state_guid, NULL);
68free_state:
69 efi_bs_call(free_pool, efi_entry_state);
70 return status;
71}
72
73void efi_handle_post_ebs_state(void)
74{
75 get_cpu_state(&efi_entry_state->cpsr_after_ebs,
76 &efi_entry_state->sctlr_after_ebs);
77}
78
79efi_status_t handle_kernel_image(unsigned long *image_addr,
80 unsigned long *image_size,
81 unsigned long *reserve_addr,
82 unsigned long *reserve_size,
83 efi_loaded_image_t *image,
84 efi_handle_t image_handle)
85{
86 const int slack = TEXT_OFFSET - 5 * PAGE_SIZE;
87 int alloc_size = MAX_UNCOMP_KERNEL_SIZE + EFI_PHYS_ALIGN;
88 unsigned long alloc_base, kernel_base;
89 efi_status_t status;
90
91 /*
92 * Allocate space for the decompressed kernel as low as possible.
93 * The region should be 16 MiB aligned, but the first 'slack' bytes
94 * are not used by Linux, so we allow those to be occupied by the
95 * firmware.
96 */
97 status = efi_low_alloc_above(alloc_size, EFI_PAGE_SIZE, &alloc_base, 0x0);
98 if (status != EFI_SUCCESS) {
99 efi_err("Unable to allocate memory for uncompressed kernel.\n");
100 return status;
101 }
102
103 if ((alloc_base % EFI_PHYS_ALIGN) > slack) {
104 /*
105 * More than 'slack' bytes are already occupied at the base of
106 * the allocation, so we need to advance to the next 16 MiB block.
107 */
108 kernel_base = round_up(alloc_base, EFI_PHYS_ALIGN);
109 efi_info("Free memory starts at 0x%lx, setting kernel_base to 0x%lx\n",
110 alloc_base, kernel_base);
111 } else {
112 kernel_base = round_down(alloc_base, EFI_PHYS_ALIGN);
113 }
114
115 *reserve_addr = kernel_base + slack;
116 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
117
118 /* now free the parts that we will not use */
119 if (*reserve_addr > alloc_base) {
120 efi_bs_call(free_pages, alloc_base,
121 (*reserve_addr - alloc_base) / EFI_PAGE_SIZE);
122 alloc_size -= *reserve_addr - alloc_base;
123 }
124 efi_bs_call(free_pages, *reserve_addr + MAX_UNCOMP_KERNEL_SIZE,
125 (alloc_size - MAX_UNCOMP_KERNEL_SIZE) / EFI_PAGE_SIZE);
126
127 *image_addr = kernel_base + TEXT_OFFSET;
128 *image_size = 0;
129
130 efi_debug("image addr == 0x%lx, reserve_addr == 0x%lx\n",
131 *image_addr, *reserve_addr);
132
133 return EFI_SUCCESS;
134}
1/*
2 * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 */
9#include <linux/efi.h>
10#include <asm/efi.h>
11
12efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
13{
14 int block;
15
16 /* non-LPAE kernels can run anywhere */
17 if (!IS_ENABLED(CONFIG_ARM_LPAE))
18 return EFI_SUCCESS;
19
20 /* LPAE kernels need compatible hardware */
21 block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
22 if (block < 5) {
23 pr_efi_err(sys_table_arg, "This LPAE kernel is not supported by your CPU\n");
24 return EFI_UNSUPPORTED;
25 }
26 return EFI_SUCCESS;
27}
28
29efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
30 unsigned long *image_addr,
31 unsigned long *image_size,
32 unsigned long *reserve_addr,
33 unsigned long *reserve_size,
34 unsigned long dram_base,
35 efi_loaded_image_t *image)
36{
37 unsigned long nr_pages;
38 efi_status_t status;
39 /* Use alloc_addr to tranlsate between types */
40 efi_physical_addr_t alloc_addr;
41
42 /*
43 * Verify that the DRAM base address is compatible with the ARM
44 * boot protocol, which determines the base of DRAM by masking
45 * off the low 27 bits of the address at which the zImage is
46 * loaded. These assumptions are made by the decompressor,
47 * before any memory map is available.
48 */
49 dram_base = round_up(dram_base, SZ_128M);
50
51 /*
52 * Reserve memory for the uncompressed kernel image. This is
53 * all that prevents any future allocations from conflicting
54 * with the kernel. Since we can't tell from the compressed
55 * image how much DRAM the kernel actually uses (due to BSS
56 * size uncertainty) we allocate the maximum possible size.
57 * Do this very early, as prints can cause memory allocations
58 * that may conflict with this.
59 */
60 alloc_addr = dram_base;
61 *reserve_size = MAX_UNCOMP_KERNEL_SIZE;
62 nr_pages = round_up(*reserve_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
63 status = sys_table->boottime->allocate_pages(EFI_ALLOCATE_ADDRESS,
64 EFI_LOADER_DATA,
65 nr_pages, &alloc_addr);
66 if (status != EFI_SUCCESS) {
67 *reserve_size = 0;
68 pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n");
69 return status;
70 }
71 *reserve_addr = alloc_addr;
72
73 /*
74 * Relocate the zImage, so that it appears in the lowest 128 MB
75 * memory window.
76 */
77 *image_size = image->image_size;
78 status = efi_relocate_kernel(sys_table, image_addr, *image_size,
79 *image_size,
80 dram_base + MAX_UNCOMP_KERNEL_SIZE, 0);
81 if (status != EFI_SUCCESS) {
82 pr_efi_err(sys_table, "Failed to relocate kernel.\n");
83 efi_free(sys_table, *reserve_size, *reserve_addr);
84 *reserve_size = 0;
85 return status;
86 }
87
88 /*
89 * Check to see if we were able to allocate memory low enough
90 * in memory. The kernel determines the base of DRAM from the
91 * address at which the zImage is loaded.
92 */
93 if (*image_addr + *image_size > dram_base + ZIMAGE_OFFSET_LIMIT) {
94 pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n");
95 efi_free(sys_table, *reserve_size, *reserve_addr);
96 *reserve_size = 0;
97 efi_free(sys_table, *image_size, *image_addr);
98 *image_size = 0;
99 return EFI_LOAD_ERROR;
100 }
101 return EFI_SUCCESS;
102}