1 /*
2 * Copyright (c) 2016-2024, Arm Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <assert.h>
8 #include <inttypes.h>
9 #include <stdint.h>
10
11 #include <arch_helpers.h>
12 #include <common/fdt_fixup.h>
13 #include <common/fdt_wrappers.h>
14
15 #include <rpi_shared.h>
16
17 /*
18 * Remove the FDT /memreserve/ entry that covers the region at the very
19 * beginning of memory (if that exists). This is where the secondaries
20 * originally spin, but we pull them out there.
21 * Having overlapping /reserved-memory and /memreserve/ regions confuses
22 * the Linux kernel, so we need to get rid of this one.
23 */
remove_spintable_memreserve(void * dtb)24 static void remove_spintable_memreserve(void *dtb)
25 {
26 uint64_t addr, size;
27 int regions = fdt_num_mem_rsv(dtb);
28 int i;
29
30 for (i = 0; i < regions; i++) {
31 if (fdt_get_mem_rsv(dtb, i, &addr, &size) != 0) {
32 return;
33 }
34 if (size == 0U) {
35 return;
36 }
37 /* We only look for the region at the beginning of DRAM. */
38 if (addr != 0U) {
39 continue;
40 }
41 /*
42 * Currently the region in the existing DTs is exactly 4K
43 * in size. Should this value ever change, there is probably
44 * a reason for that, so inform the user about this.
45 */
46 if (size == 4096U) {
47 fdt_del_mem_rsv(dtb, i);
48 return;
49 }
50 WARN("Keeping unknown /memreserve/ region at 0, size: %" PRId64 "\n",
51 size);
52 }
53 }
54
rpi4_prepare_dtb(void)55 static void rpi4_prepare_dtb(void)
56 {
57 void *dtb = (void *)rpi4_get_dtb_address();
58 uint32_t gic_int_prop[3];
59 int ret, offs;
60
61 /* Return if no device tree is detected */
62 if (fdt_check_header(dtb) != 0)
63 return;
64
65 ret = fdt_open_into(dtb, dtb, 0x100000);
66 if (ret < 0) {
67 ERROR("Invalid Device Tree at %p: error %d\n", dtb, ret);
68 return;
69 }
70
71 if (dt_add_psci_node(dtb)) {
72 ERROR("Failed to add PSCI Device Tree node\n");
73 return;
74 }
75
76 if (dt_add_psci_cpu_enable_methods(dtb)) {
77 ERROR("Failed to add PSCI cpu enable methods in Device Tree\n");
78 return;
79 }
80
81 /*
82 * Remove the original reserved region (used for the spintable), and
83 * replace it with a region describing the whole of Trusted Firmware.
84 */
85 remove_spintable_memreserve(dtb);
86 if (fdt_add_reserved_memory(dtb, "atf@0", 0, 0x80000))
87 WARN("Failed to add reserved memory nodes to DT.\n");
88
89 offs = fdt_node_offset_by_compatible(dtb, 0, "arm,gic-400");
90 gic_int_prop[0] = cpu_to_fdt32(1); // PPI
91 gic_int_prop[1] = cpu_to_fdt32(9); // PPI #9
92 gic_int_prop[2] = cpu_to_fdt32(0x0f04); // all cores, level high
93 fdt_setprop(dtb, offs, "interrupts", gic_int_prop, 12);
94
95 offs = fdt_path_offset(dtb, "/chosen");
96 fdt_setprop_string(dtb, offs, "stdout-path", "serial0");
97
98 ret = fdt_pack(dtb);
99 if (ret < 0)
100 ERROR("Failed to pack Device Tree at %p: error %d\n", dtb, ret);
101
102 clean_dcache_range((uintptr_t)dtb, fdt_blob_size(dtb));
103 INFO("Changed device tree to advertise PSCI.\n");
104 }
105
plat_rpi_bl31_custom_setup(void)106 void plat_rpi_bl31_custom_setup(void)
107 {
108 rpi4_prepare_dtb();
109 }
110