cmd/qemu_fw_cfg.c

   1 /*
   2  * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <command.h>
   9 #include <errno.h>
  10 #include <malloc.h>
  11 #include <qemu_fw_cfg.h>
  12 #include <asm/io.h>
  13 #include <linux/list.h>
  14
  15 static bool fwcfg_present;
  16 static bool fwcfg_dma_present;
  17
  18 static LIST_HEAD(fw_list);
  19
  20 /* Read configuration item using fw_cfg PIO interface */
  21 static void qemu_fwcfg_read_entry_pio(uint16_t entry,
  22                 uint32_t size, void *address)
  23 {
  24         uint32_t i = 0;
  25         uint8_t *data = address;
  26
  27         /*
  28          * writting FW_CFG_INVALID will cause read operation to resume at
  29          * last offset, otherwise read will start at offset 0
  30          */
  31         if (entry != FW_CFG_INVALID)
  32                 outw(entry, FW_CONTROL_PORT);
  33         while (size--)
  34                 data[i++] = inb(FW_DATA_PORT);
  35 }
  36
  37 /* Read configuration item using fw_cfg DMA interface */
  38 static void qemu_fwcfg_read_entry_dma(uint16_t entry,
  39                 uint32_t size, void *address)
  40 {
  41         struct fw_cfg_dma_access dma;
  42
  43         dma.length = cpu_to_be32(size);
  44         dma.address = cpu_to_be64((uintptr_t)address);
  45         dma.control = cpu_to_be32(FW_CFG_DMA_READ);
  46
  47         /*
  48          * writting FW_CFG_INVALID will cause read operation to resume at
  49          * last offset, otherwise read will start at offset 0
  50          */
  51         if (entry != FW_CFG_INVALID)
  52                 dma.control |= cpu_to_be32(FW_CFG_DMA_SELECT | (entry << 16));
  53
  54         barrier();
  55
  56         debug("qemu_fwcfg_dma_read_entry: addr %p, length %u control 0x%x\n",
  57               address, size, be32_to_cpu(dma.control));
  58
  59         outl(cpu_to_be32((uint32_t)&dma), FW_DMA_PORT_HIGH);
  60
  61         while (be32_to_cpu(dma.control) & ~FW_CFG_DMA_ERROR)
  62                 __asm__ __volatile__ ("pause");
  63 }
  64
  65 static bool qemu_fwcfg_present(void)
  66 {
  67         uint32_t qemu;
  68
  69         qemu_fwcfg_read_entry_pio(FW_CFG_SIGNATURE, 4, &qemu);
  70         return be32_to_cpu(qemu) == QEMU_FW_CFG_SIGNATURE;
  71 }
  72
  73 static bool qemu_fwcfg_dma_present(void)
  74 {
  75         uint8_t dma_enabled;
  76
  77         qemu_fwcfg_read_entry_pio(FW_CFG_ID, 1, &dma_enabled);
  78         if (dma_enabled & FW_CFG_DMA_ENABLED)
  79                 return true;
  80
  81         return false;
  82 }
  83
  84 void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address)
  85 {
  86         if (fwcfg_dma_present)
  87                 qemu_fwcfg_read_entry_dma(entry, length, address);
  88         else
  89                 qemu_fwcfg_read_entry_pio(entry, length, address);
  90 }
  91
  92 int qemu_fwcfg_online_cpus(void)
  93 {
  94         uint16_t nb_cpus;
  95
  96         if (!fwcfg_present)
  97                 return -ENODEV;
  98
  99         qemu_fwcfg_read_entry(FW_CFG_NB_CPUS, 2, &nb_cpus);
 100
 101         return le16_to_cpu(nb_cpus);
 102 }
 103
 104 /*
 105  * This function prepares kernel for zboot. It loads kernel data
 106  * to 'load_addr', initrd to 'initrd_addr' and kernel command
 107  * line using qemu fw_cfg interface.
 108  */
 109 static int qemu_fwcfg_setup_kernel(void *load_addr, void *initrd_addr)
 110 {
 111         char *data_addr;
 112         uint32_t setup_size, kernel_size, cmdline_size, initrd_size;
 113
 114         qemu_fwcfg_read_entry(FW_CFG_SETUP_SIZE, 4, &setup_size);
 115         qemu_fwcfg_read_entry(FW_CFG_KERNEL_SIZE, 4, &kernel_size);
 116
 117         if (setup_size == 0 || kernel_size == 0) {
 118                 printf("warning: no kernel available\n");
 119                 return -1;
 120         }
 121
 122         data_addr = load_addr;
 123         qemu_fwcfg_read_entry(FW_CFG_SETUP_DATA,
 124                               le32_to_cpu(setup_size), data_addr);
 125         data_addr += le32_to_cpu(setup_size);
 126
 127         qemu_fwcfg_read_entry(FW_CFG_KERNEL_DATA,
 128                               le32_to_cpu(kernel_size), data_addr);
 129         data_addr += le32_to_cpu(kernel_size);
 130
 131         data_addr = initrd_addr;
 132         qemu_fwcfg_read_entry(FW_CFG_INITRD_SIZE, 4, &initrd_size);
 133         if (initrd_size == 0) {
 134                 printf("warning: no initrd available\n");
 135         } else {
 136                 qemu_fwcfg_read_entry(FW_CFG_INITRD_DATA,
 137                                       le32_to_cpu(initrd_size), data_addr);
 138                 data_addr += le32_to_cpu(initrd_size);
 139         }
 140
 141         qemu_fwcfg_read_entry(FW_CFG_CMDLINE_SIZE, 4, &cmdline_size);
 142         if (cmdline_size) {
 143                 qemu_fwcfg_read_entry(FW_CFG_CMDLINE_DATA,
 144                                       le32_to_cpu(cmdline_size), data_addr);
 145                 /*
 146                  * if kernel cmdline only contains '\0', (e.g. no -append
 147                  * when invoking qemu), do not update bootargs
 148                  */
 149                 if (*data_addr != '\0') {
 150                         if (setenv("bootargs", data_addr) < 0)
 151                                 printf("warning: unable to change bootargs\n");
 152                 }
 153         }
 154
 155         printf("loading kernel to address %p size %x", load_addr,
 156                le32_to_cpu(kernel_size));
 157         if (initrd_size)
 158                 printf(" initrd %p size %x\n",
 159                        initrd_addr,
 160                        le32_to_cpu(initrd_size));
 161         else
 162                 printf("\n");
 163
 164         return 0;
 165 }
 166
 167 int qemu_fwcfg_read_firmware_list(void)
 168 {
 169         int i;
 170         uint32_t count;
 171         struct fw_file *file;
 172         struct list_head *entry;
 173
 174         /* don't read it twice */
 175         if (!list_empty(&fw_list))
 176                 return 0;
 177
 178         qemu_fwcfg_read_entry(FW_CFG_FILE_DIR, 4, &count);
 179         if (!count)
 180                 return 0;
 181
 182         count = be32_to_cpu(count);
 183         for (i = 0; i < count; i++) {
 184                 file = malloc(sizeof(*file));
 185                 if (!file) {
 186                         printf("error: allocating resource\n");
 187                         goto err;
 188                 }
 189                 qemu_fwcfg_read_entry(FW_CFG_INVALID,
 190                                       sizeof(struct fw_cfg_file), &file->cfg);
 191                 file->addr = 0;
 192                 list_add_tail(&file->list, &fw_list);
 193         }
 194
 195         return 0;
 196
 197 err:
 198         list_for_each(entry, &fw_list) {
 199                 file = list_entry(entry, struct fw_file, list);
 200                 free(file);
 201         }
 202
 203         return -ENOMEM;
 204 }
 205
 206 struct fw_file *qemu_fwcfg_find_file(const char *name)
 207 {
 208         struct list_head *entry;
 209         struct fw_file *file;
 210
 211         list_for_each(entry, &fw_list) {
 212                 file = list_entry(entry, struct fw_file, list);
 213                 if (!strcmp(file->cfg.name, name))
 214                         return file;
 215         }
 216
 217         return NULL;
 218 }
 219
 220 struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter)
 221 {
 222         iter->entry = fw_list.next;
 223         return list_entry(iter->entry, struct fw_file, list);
 224 }
 225
 226 struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter)
 227 {
 228         iter->entry = iter->entry->next;
 229         return list_entry(iter->entry, struct fw_file, list);
 230 }
 231
 232 bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter)
 233 {
 234         return iter->entry == &fw_list;
 235 }
 236
 237 static int qemu_fwcfg_list_firmware(void)
 238 {
 239         int ret;
 240         struct fw_cfg_file_iter iter;
 241         struct fw_file *file;
 242
 243         /* make sure fw_list is loaded */
 244         ret = qemu_fwcfg_read_firmware_list();
 245         if (ret)
 246                 return ret;
 247
 248
 249         for (file = qemu_fwcfg_file_iter_init(&iter);
 250              !qemu_fwcfg_file_iter_end(&iter);
 251              file = qemu_fwcfg_file_iter_next(&iter)) {
 252                 printf("%-56s\n", file->cfg.name);
 253         }
 254
 255         return 0;
 256 }
 257
 258 void qemu_fwcfg_init(void)
 259 {
 260         fwcfg_present = qemu_fwcfg_present();
 261         if (fwcfg_present)
 262                 fwcfg_dma_present = qemu_fwcfg_dma_present();
 263 }
 264
 265 static int qemu_fwcfg_do_list(cmd_tbl_t *cmdtp, int flag,
 266                 int argc, char * const argv[])
 267 {
 268         if (qemu_fwcfg_list_firmware() < 0)
 269                 return CMD_RET_FAILURE;
 270
 271         return 0;
 272 }
 273
 274 static int qemu_fwcfg_do_cpus(cmd_tbl_t *cmdtp, int flag,
 275                 int argc, char * const argv[])
 276 {
 277         int ret = qemu_fwcfg_online_cpus();
 278         if (ret < 0) {
 279                 printf("QEMU fw_cfg interface not found\n");
 280                 return CMD_RET_FAILURE;
 281         }
 282
 283         printf("%d cpu(s) online\n", qemu_fwcfg_online_cpus());
 284
 285         return 0;
 286 }
 287
 288 static int qemu_fwcfg_do_load(cmd_tbl_t *cmdtp, int flag,
 289                 int argc, char * const argv[])
 290 {
 291         char *env;
 292         void *load_addr;
 293         void *initrd_addr;
 294
 295         env = getenv("loadaddr");
 296         load_addr = env ?
 297                 (void *)simple_strtoul(env, NULL, 16) :
 298                 (void *)CONFIG_LOADADDR;
 299
 300         env = getenv("ramdiskaddr");
 301         initrd_addr = env ?
 302                 (void *)simple_strtoul(env, NULL, 16) :
 303                 (void *)CONFIG_RAMDISK_ADDR;
 304
 305         if (argc == 2) {
 306                 load_addr = (void *)simple_strtoul(argv[0], NULL, 16);
 307                 initrd_addr = (void *)simple_strtoul(argv[1], NULL, 16);
 308         } else if (argc == 1) {
 309                 load_addr = (void *)simple_strtoul(argv[0], NULL, 16);
 310         }
 311
 312         return qemu_fwcfg_setup_kernel(load_addr, initrd_addr);
 313 }
 314
 315 static cmd_tbl_t fwcfg_commands[] = {
 316         U_BOOT_CMD_MKENT(list, 0, 1, qemu_fwcfg_do_list, "", ""),
 317         U_BOOT_CMD_MKENT(cpus, 0, 1, qemu_fwcfg_do_cpus, "", ""),
 318         U_BOOT_CMD_MKENT(load, 2, 1, qemu_fwcfg_do_load, "", ""),
 319 };
 320
 321 static int do_qemu_fw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 322 {
 323         int ret;
 324         cmd_tbl_t *fwcfg_cmd;
 325
 326         if (!fwcfg_present) {
 327                 printf("QEMU fw_cfg interface not found\n");
 328                 return CMD_RET_USAGE;
 329         }
 330
 331         fwcfg_cmd = find_cmd_tbl(argv[1], fwcfg_commands,
 332                                  ARRAY_SIZE(fwcfg_commands));
 333         argc -= 2;
 334         argv += 2;
 335         if (!fwcfg_cmd || argc > fwcfg_cmd->maxargs)
 336                 return CMD_RET_USAGE;
 337
 338         ret = fwcfg_cmd->cmd(fwcfg_cmd, flag, argc, argv);
 339
 340         return cmd_process_error(fwcfg_cmd, ret);
 341 }
 342
 343 U_BOOT_CMD(
 344         qfw,    4,      1,      do_qemu_fw,
 345         "QEMU firmware interface",
 346         "<command>\n"
 347         "    - list                             : print firmware(s) currently loaded\n"
 348         "    - cpus                             : print online cpu number\n"
 349         "    - load <kernel addr> <initrd addr> : load kernel and initrd (if any), and setup for zboot\n"
 350 )