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 */ 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 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 } 105 106 void plat_rpi_bl31_custom_setup(void) 107 { 108 rpi4_prepare_dtb(); 109 } 110