arch/mips/mti-malta/malta-dtshim.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2015 Imagination Technologies
   4  * Author: Paul Burton <paul.burton@mips.com>
   5  */
   6
   7 #include <linux/bug.h>
   8 #include <linux/kernel.h>
   9 #include <linux/libfdt.h>
  10 #include <linux/of_fdt.h>
  11 #include <linux/sizes.h>
  12 #include <asm/addrspace.h>
  13 #include <asm/bootinfo.h>
  14 #include <asm/fw/fw.h>
  15 #include <asm/mips-boards/generic.h>
  16 #include <asm/mips-boards/malta.h>
  17 #include <asm/mips-cps.h>
  18 #include <asm/page.h>
  19
  20 #define ROCIT_REG_BASE                  0x1f403000
  21 #define ROCIT_CONFIG_GEN1               (ROCIT_REG_BASE + 0x04)
  22 #define  ROCIT_CONFIG_GEN1_MEMMAP_SHIFT 8
  23 #define  ROCIT_CONFIG_GEN1_MEMMAP_MASK  (0xf << 8)
  24
  25 static unsigned char fdt_buf[16 << 10] __initdata;
  26
  27 /* determined physical memory size, not overridden by command line args  */
  28 extern unsigned long physical_memsize;
  29
  30 enum mem_map {
  31         MEM_MAP_V1 = 0,
  32         MEM_MAP_V2,
  33 };
  34
  35 #define MAX_MEM_ARRAY_ENTRIES 2
  36
  37 static __init int malta_scon(void)
  38 {
  39         int scon = MIPS_REVISION_SCONID;
  40
  41         if (scon != MIPS_REVISION_SCON_OTHER)
  42                 return scon;
  43
  44         switch (MIPS_REVISION_CORID) {
  45         case MIPS_REVISION_CORID_QED_RM5261:
  46         case MIPS_REVISION_CORID_CORE_LV:
  47         case MIPS_REVISION_CORID_CORE_FPGA:
  48         case MIPS_REVISION_CORID_CORE_FPGAR2:
  49                 return MIPS_REVISION_SCON_GT64120;
  50
  51         case MIPS_REVISION_CORID_CORE_EMUL_BON:
  52         case MIPS_REVISION_CORID_BONITO64:
  53         case MIPS_REVISION_CORID_CORE_20K:
  54                 return MIPS_REVISION_SCON_BONITO;
  55
  56         case MIPS_REVISION_CORID_CORE_MSC:
  57         case MIPS_REVISION_CORID_CORE_FPGA2:
  58         case MIPS_REVISION_CORID_CORE_24K:
  59                 return MIPS_REVISION_SCON_SOCIT;
  60
  61         case MIPS_REVISION_CORID_CORE_FPGA3:
  62         case MIPS_REVISION_CORID_CORE_FPGA4:
  63         case MIPS_REVISION_CORID_CORE_FPGA5:
  64         case MIPS_REVISION_CORID_CORE_EMUL_MSC:
  65         default:
  66                 return MIPS_REVISION_SCON_ROCIT;
  67         }
  68 }
  69
  70 static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size,
  71                                          enum mem_map map)
  72 {
  73         unsigned long size_preio;
  74         unsigned entries;
  75
  76         entries = 1;
  77         mem_array[0] = cpu_to_be32(PHYS_OFFSET);
  78         if (IS_ENABLED(CONFIG_EVA)) {
  79                 /*
  80                  * The current Malta EVA configuration is "special" in that it
  81                  * always makes use of addresses in the upper half of the 32 bit
  82                  * physical address map, which gives it a contiguous region of
  83                  * DDR but limits it to 2GB.
  84                  */
  85                 mem_array[1] = cpu_to_be32(size);
  86                 goto done;
  87         }
  88
  89         size_preio = min_t(unsigned long, size, SZ_256M);
  90         mem_array[1] = cpu_to_be32(size_preio);
  91         size -= size_preio;
  92         if (!size)
  93                 goto done;
  94
  95         if (map == MEM_MAP_V2) {
  96                 /*
  97                  * We have a flat 32 bit physical memory map with DDR filling
  98                  * all 4GB of the memory map, apart from the I/O region which
  99                  * obscures 256MB from 0x10000000-0x1fffffff.
 100                  *
 101                  * Therefore we discard the 256MB behind the I/O region.
 102                  */
 103                 if (size <= SZ_256M)
 104                         goto done;
 105                 size -= SZ_256M;
 106
 107                 /* Make use of the memory following the I/O region */
 108                 entries++;
 109                 mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_512M);
 110                 mem_array[3] = cpu_to_be32(size);
 111         } else {
 112                 /*
 113                  * We have a 32 bit physical memory map with a 2GB DDR region
 114                  * aliased in the upper & lower halves of it. The I/O region
 115                  * obscures 256MB from 0x10000000-0x1fffffff in the low alias
 116                  * but the DDR it obscures is accessible via the high alias.
 117                  *
 118                  * Simply access everything beyond the lowest 256MB of DDR using
 119                  * the high alias.
 120                  */
 121                 entries++;
 122                 mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_2G + SZ_256M);
 123                 mem_array[3] = cpu_to_be32(size);
 124         }
 125
 126 done:
 127         BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
 128         return entries;
 129 }
 130
 131 static void __init append_memory(void *fdt, int root_off)
 132 {
 133         __be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
 134         unsigned long memsize;
 135         unsigned mem_entries;
 136         int i, err, mem_off;
 137         enum mem_map mem_map;
 138         u32 config;
 139         char *var, param_name[10], *var_names[] = {
 140                 "ememsize", "memsize",
 141         };
 142
 143         /* if a memory node already exists, leave it alone */
 144         mem_off = fdt_path_offset(fdt, "/memory");
 145         if (mem_off >= 0)
 146                 return;
 147
 148         /* find memory size from the bootloader environment */
 149         for (i = 0; i < ARRAY_SIZE(var_names); i++) {
 150                 var = fw_getenv(var_names[i]);
 151                 if (!var)
 152                         continue;
 153
 154                 err = kstrtoul(var, 0, &physical_memsize);
 155                 if (!err)
 156                         break;
 157
 158                 pr_warn("Failed to read the '%s' env variable '%s'\n",
 159                         var_names[i], var);
 160         }
 161
 162         if (!physical_memsize) {
 163                 pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
 164                 physical_memsize = 32 << 20;
 165         }
 166
 167         if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
 168                 /*
 169                  * SOC-it swaps, or perhaps doesn't swap, when DMA'ing
 170                  * the last word of physical memory.
 171                  */
 172                 physical_memsize -= PAGE_SIZE;
 173         }
 174
 175         /* default to using all available RAM */
 176         memsize = physical_memsize;
 177
 178         /* allow the user to override the usable memory */
 179         for (i = 0; i < ARRAY_SIZE(var_names); i++) {
 180                 snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
 181                 var = strstr(arcs_cmdline, param_name);
 182                 if (!var)
 183                         continue;
 184
 185                 memsize = memparse(var + strlen(param_name), NULL);
 186         }
 187
 188         /* if the user says there's more RAM than we thought, believe them */
 189         physical_memsize = max_t(unsigned long, physical_memsize, memsize);
 190
 191         /* detect the memory map in use */
 192         if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
 193                 /* ROCit has a register indicating the memory map in use */
 194                 config = readl((void __iomem *)CKSEG1ADDR(ROCIT_CONFIG_GEN1));
 195                 mem_map = config & ROCIT_CONFIG_GEN1_MEMMAP_MASK;
 196                 mem_map >>= ROCIT_CONFIG_GEN1_MEMMAP_SHIFT;
 197         } else {
 198                 /* if not using ROCit, presume the v1 memory map */
 199                 mem_map = MEM_MAP_V1;
 200         }
 201         if (mem_map > MEM_MAP_V2)
 202                 panic("Unsupported physical memory map v%u detected",
 203                       (unsigned int)mem_map);
 204
 205         /* append memory to the DT */
 206         mem_off = fdt_add_subnode(fdt, root_off, "memory");
 207         if (mem_off < 0)
 208                 panic("Unable to add memory node to DT: %d", mem_off);
 209
 210         err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
 211         if (err)
 212                 panic("Unable to set memory node device_type: %d", err);
 213
 214         mem_entries = gen_fdt_mem_array(mem_array, physical_memsize, mem_map);
 215         err = fdt_setprop(fdt, mem_off, "reg", mem_array,
 216                           mem_entries * 2 * sizeof(mem_array[0]));
 217         if (err)
 218                 panic("Unable to set memory regs property: %d", err);
 219
 220         mem_entries = gen_fdt_mem_array(mem_array, memsize, mem_map);
 221         err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
 222                           mem_entries * 2 * sizeof(mem_array[0]));
 223         if (err)
 224                 panic("Unable to set linux,usable-memory property: %d", err);
 225 }
 226
 227 static void __init remove_gic(void *fdt)
 228 {
 229         int err, gic_off, i8259_off, cpu_off;
 230         void __iomem *biu_base;
 231         uint32_t cpu_phandle, sc_cfg;
 232
 233         /* if we have a CM which reports a GIC is present, leave the DT alone */
 234         err = mips_cm_probe();
 235         if (!err && (read_gcr_gic_status() & CM_GCR_GIC_STATUS_EX))
 236                 return;
 237
 238         if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
 239                 /*
 240                  * On systems using the RocIT system controller a GIC may be
 241                  * present without a CM. Detect whether that is the case.
 242                  */
 243                 biu_base = ioremap(MSC01_BIU_REG_BASE,
 244                                 MSC01_BIU_ADDRSPACE_SZ);
 245                 sc_cfg = __raw_readl(biu_base + MSC01_SC_CFG_OFS);
 246                 if (sc_cfg & MSC01_SC_CFG_GICPRES_MSK) {
 247                         /* enable the GIC at the system controller level */
 248                         sc_cfg |= BIT(MSC01_SC_CFG_GICENA_SHF);
 249                         __raw_writel(sc_cfg, biu_base + MSC01_SC_CFG_OFS);
 250                         return;
 251                 }
 252         }
 253
 254         gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
 255         if (gic_off < 0) {
 256                 pr_warn("malta-dtshim: unable to find DT GIC node: %d\n",
 257                         gic_off);
 258                 return;
 259         }
 260
 261         err = fdt_nop_node(fdt, gic_off);
 262         if (err)
 263                 pr_warn("malta-dtshim: unable to nop GIC node\n");
 264
 265         i8259_off = fdt_node_offset_by_compatible(fdt, -1, "intel,i8259");
 266         if (i8259_off < 0) {
 267                 pr_warn("malta-dtshim: unable to find DT i8259 node: %d\n",
 268                         i8259_off);
 269                 return;
 270         }
 271
 272         cpu_off = fdt_node_offset_by_compatible(fdt, -1,
 273                         "mti,cpu-interrupt-controller");
 274         if (cpu_off < 0) {
 275                 pr_warn("malta-dtshim: unable to find CPU intc node: %d\n",
 276                         cpu_off);
 277                 return;
 278         }
 279
 280         cpu_phandle = fdt_get_phandle(fdt, cpu_off);
 281         if (!cpu_phandle) {
 282                 pr_warn("malta-dtshim: unable to get CPU intc phandle\n");
 283                 return;
 284         }
 285
 286         err = fdt_setprop_u32(fdt, i8259_off, "interrupt-parent", cpu_phandle);
 287         if (err) {
 288                 pr_warn("malta-dtshim: unable to set i8259 interrupt-parent: %d\n",
 289                         err);
 290                 return;
 291         }
 292
 293         err = fdt_setprop_u32(fdt, i8259_off, "interrupts", 2);
 294         if (err) {
 295                 pr_warn("malta-dtshim: unable to set i8259 interrupts: %d\n",
 296                         err);
 297                 return;
 298         }
 299 }
 300
 301 void __init *malta_dt_shim(void *fdt)
 302 {
 303         int root_off, len, err;
 304         const char *compat;
 305
 306         if (fdt_check_header(fdt))
 307                 panic("Corrupt DT");
 308
 309         err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
 310         if (err)
 311                 panic("Unable to open FDT: %d", err);
 312
 313         root_off = fdt_path_offset(fdt_buf, "/");
 314         if (root_off < 0)
 315                 panic("No / node in DT");
 316
 317         compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
 318         if (!compat)
 319                 panic("No root compatible property in DT: %d", len);
 320
 321         /* if this isn't Malta, leave the DT alone */
 322         if (strncmp(compat, "mti,malta", len))
 323                 return fdt;
 324
 325         append_memory(fdt_buf, root_off);
 326         remove_gic(fdt_buf);
 327
 328         err = fdt_pack(fdt_buf);
 329         if (err)
 330                 panic("Unable to pack FDT: %d\n", err);
 331
 332         return fdt_buf;
 333 }