prom.c 5.4 KB

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  1. /*
  2. * Copyright (C) 2004 Florian Schirmer <[email protected]>
  3. * Copyright (C) 2007 Aurelien Jarno <[email protected]>
  4. * Copyright (C) 2010-2012 Hauke Mehrtens <[email protected]>
  5. *
  6. * This program is free software; you can redistribute it and/or modify it
  7. * under the terms of the GNU General Public License as published by the
  8. * Free Software Foundation; either version 2 of the License, or (at your
  9. * option) any later version.
  10. *
  11. * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  12. * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  13. * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
  14. * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  15. * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  16. * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  17. * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  18. * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  19. * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  20. * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  21. *
  22. * You should have received a copy of the GNU General Public License along
  23. * with this program; if not, write to the Free Software Foundation, Inc.,
  24. * 675 Mass Ave, Cambridge, MA 02139, USA.
  25. */
  26. #include <linux/init.h>
  27. #include <linux/types.h>
  28. #include <linux/kernel.h>
  29. #include <linux/memblock.h>
  30. #include <linux/spinlock.h>
  31. #include <linux/ssb/ssb_driver_chipcommon.h>
  32. #include <linux/ssb/ssb_regs.h>
  33. #include <linux/smp.h>
  34. #include <asm/bootinfo.h>
  35. #include <bcm47xx.h>
  36. #include <bcm47xx_board.h>
  37. static char bcm47xx_system_type[20] = "Broadcom BCM47XX";
  38. const char *get_system_type(void)
  39. {
  40. return bcm47xx_system_type;
  41. }
  42. __init void bcm47xx_set_system_type(u16 chip_id)
  43. {
  44. snprintf(bcm47xx_system_type, sizeof(bcm47xx_system_type),
  45. (chip_id > 0x9999) ? "Broadcom BCM%d" :
  46. "Broadcom BCM%04X",
  47. chip_id);
  48. }
  49. static unsigned long lowmem __initdata;
  50. static __init void prom_init_mem(void)
  51. {
  52. unsigned long mem;
  53. unsigned long max;
  54. unsigned long off;
  55. struct cpuinfo_mips *c = &current_cpu_data;
  56. /* Figure out memory size by finding aliases.
  57. *
  58. * We should theoretically use the mapping from CFE using cfe_enummem().
  59. * However as the BCM47XX is mostly used on low-memory systems, we
  60. * want to reuse the memory used by CFE (around 4MB). That means cfe_*
  61. * functions stop to work at some point during the boot, we should only
  62. * call them at the beginning of the boot.
  63. *
  64. * BCM47XX uses 128MB for addressing the ram, if the system contains
  65. * less than that amount of ram it remaps the ram more often into the
  66. * available space.
  67. */
  68. /* Physical address, without mapping to any kernel segment */
  69. off = CPHYSADDR((unsigned long)prom_init);
  70. /* Accessing memory after 128 MiB will cause an exception */
  71. max = 128 << 20;
  72. for (mem = 1 << 20; mem < max; mem += 1 << 20) {
  73. /* Loop condition may be not enough, off may be over 1 MiB */
  74. if (off + mem >= max) {
  75. mem = max;
  76. pr_debug("Assume 128MB RAM\n");
  77. break;
  78. }
  79. if (!memcmp((void *)prom_init, (void *)prom_init + mem, 32))
  80. break;
  81. }
  82. lowmem = mem;
  83. /* Ignoring the last page when ddr size is 128M. Cached
  84. * accesses to last page is causing the processor to prefetch
  85. * using address above 128M stepping out of the ddr address
  86. * space.
  87. */
  88. if (c->cputype == CPU_74K && (mem == (128 << 20)))
  89. mem -= 0x1000;
  90. memblock_add(0, mem);
  91. }
  92. /*
  93. * This is the first serial on the chip common core, it is at this position
  94. * for sb (ssb) and ai (bcma) bus.
  95. */
  96. #define BCM47XX_SERIAL_ADDR (SSB_ENUM_BASE + SSB_CHIPCO_UART0_DATA)
  97. void __init prom_init(void)
  98. {
  99. prom_init_mem();
  100. setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
  101. }
  102. #if defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM)
  103. #define EXTVBASE 0xc0000000
  104. #define ENTRYLO(x) ((pte_val(pfn_pte((x) >> _PFN_SHIFT, PAGE_KERNEL_UNCACHED)) >> 6) | 1)
  105. #include <asm/tlbflush.h>
  106. /* Stripped version of tlb_init, with the call to build_tlb_refill_handler
  107. * dropped. Calling it at this stage causes a hang.
  108. */
  109. void early_tlb_init(void)
  110. {
  111. write_c0_pagemask(PM_DEFAULT_MASK);
  112. write_c0_wired(0);
  113. temp_tlb_entry = current_cpu_data.tlbsize - 1;
  114. local_flush_tlb_all();
  115. }
  116. void __init bcm47xx_prom_highmem_init(void)
  117. {
  118. unsigned long off = (unsigned long)prom_init;
  119. unsigned long extmem = 0;
  120. bool highmem_region = false;
  121. if (WARN_ON(bcm47xx_bus_type != BCM47XX_BUS_TYPE_BCMA))
  122. return;
  123. if (bcm47xx_bus.bcma.bus.chipinfo.id == BCMA_CHIP_ID_BCM4706)
  124. highmem_region = true;
  125. if (lowmem != 128 << 20 || !highmem_region)
  126. return;
  127. early_tlb_init();
  128. /* Add one temporary TLB entry to map SDRAM Region 2.
  129. * Physical Virtual
  130. * 0x80000000 0xc0000000 (1st: 256MB)
  131. * 0x90000000 0xd0000000 (2nd: 256MB)
  132. */
  133. add_temporary_entry(ENTRYLO(0x80000000),
  134. ENTRYLO(0x80000000 + (256 << 20)),
  135. EXTVBASE, PM_256M);
  136. off = EXTVBASE + __pa(off);
  137. for (extmem = 128 << 20; extmem < 512 << 20; extmem <<= 1) {
  138. if (!memcmp((void *)prom_init, (void *)(off + extmem), 16))
  139. break;
  140. }
  141. extmem -= lowmem;
  142. early_tlb_init();
  143. if (!extmem)
  144. return;
  145. pr_warn("Found %lu MiB of extra memory, but highmem is unsupported yet!\n",
  146. extmem >> 20);
  147. /* TODO: Register extra memory */
  148. }
  149. #endif /* defined(CONFIG_BCM47XX_BCMA) && defined(CONFIG_HIGHMEM) */