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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 | // SPDX-License-Identifier: GPL-2.0+ /* * Copyright (c) 2024, Linaro Limited */ #include <fdt_support.h> #include <fdtdec.h> #include <memtop.h> #include <asm/types.h> #define MEM_RGN_COUNT 16 struct region { phys_addr_t base; phys_size_t size; }; struct mem_region { struct region rgn[MEM_RGN_COUNT]; uint count; }; static void add_mem_region(struct mem_region *mem_rgn, phys_addr_t base, phys_size_t size) { long i; for (i = mem_rgn->count; i >= 0; i--) { if (i && base < mem_rgn->rgn[i - 1].base) { mem_rgn->rgn[i] = mem_rgn->rgn[i - 1]; } else { mem_rgn->rgn[i].base = base; mem_rgn->rgn[i].size = size; break; } } mem_rgn->count++; } static void mem_regions_init(struct mem_region *mem) { uint i; mem->count = 0; for (i = 0; i < MEM_RGN_COUNT; i++) { mem->rgn[i].base = 0; mem->rgn[i].size = 0; } } static int fdt_add_reserved_regions(struct mem_region *free_mem, struct mem_region *reserved_mem, void *fdt_blob) { u64 addr, size; int i, total, ret; int nodeoffset, subnode; struct fdt_resource res; if (fdt_check_header(fdt_blob) != 0) return -1; /* process memreserve sections */ total = fdt_num_mem_rsv(fdt_blob); assert_noisy(total < MEM_RGN_COUNT); for (i = 0; i < total; i++) { if (fdt_get_mem_rsv(fdt_blob, i, &addr, &size) != 0) continue; add_mem_region(reserved_mem, addr, size); } i = 0; /* process reserved-memory */ nodeoffset = fdt_subnode_offset(fdt_blob, 0, "reserved-memory"); if (nodeoffset >= 0) { subnode = fdt_first_subnode(fdt_blob, nodeoffset); while (subnode >= 0) { /* check if this subnode has a reg property */ ret = fdt_get_resource(fdt_blob, subnode, "reg", 0, &res); if (!ret && fdtdec_get_is_enabled(fdt_blob, subnode)) { addr = res.start; size = res.end - res.start + 1; assert_noisy(i < MEM_RGN_COUNT); add_mem_region(reserved_mem, addr, size); } subnode = fdt_next_subnode(fdt_blob, subnode); ++i; } } return 0; } static long addrs_overlap(phys_addr_t base1, phys_size_t size1, phys_addr_t base2, phys_size_t size2) { const phys_addr_t base1_end = base1 + size1 - 1; const phys_addr_t base2_end = base2 + size2 - 1; return ((base1 <= base2_end) && (base2 <= base1_end)); } static long region_overlap_check(struct mem_region *mem_rgn, phys_addr_t base, phys_size_t size) { unsigned long i; struct region *rgn = mem_rgn->rgn; for (i = 0; i < mem_rgn->count; i++) { phys_addr_t rgnbase = rgn[i].base; phys_size_t rgnsize = rgn[i].size; if (addrs_overlap(base, size, rgnbase, rgnsize)) break; } return (i < mem_rgn->count) ? i : -1; } static phys_addr_t find_ram_top(struct mem_region *free_mem, struct mem_region *reserved_mem, phys_size_t size) { long i, rgn; phys_addr_t base = 0; phys_addr_t res_base; for (i = free_mem->count - 1; i >= 0; i--) { phys_addr_t rgnbase = free_mem->rgn[i].base; phys_size_t rgnsize = free_mem->rgn[i].size; if (rgnsize < size) continue; base = rgnbase + rgnsize - size; while (base && rgnbase <= base) { rgn = region_overlap_check(reserved_mem, base, size); if (rgn < 0) return base; res_base = reserved_mem->rgn[rgn].base; if (res_base < size) break; base = res_base - size; } } return 0; } phys_addr_t get_mem_top(phys_addr_t ram_start, phys_size_t ram_size, phys_size_t size, void *fdt) { int i; struct mem_region free_mem; struct mem_region reserved_mem; mem_regions_init(&free_mem); mem_regions_init(&reserved_mem); add_mem_region(&free_mem, ram_start, ram_size); i = fdt_add_reserved_regions(&free_mem, &reserved_mem, fdt); if (i < 0) return 0; return find_ram_top(&free_mem, &reserved_mem, size); } |