src/soc/intel/apollolake/car.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2016 Intel Corp.
   5  * Copyright 2016 Google Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <arch/cpu.h>
  19 #include <assert.h>
  20 #include <program_loading.h>
  21 #include <soc/cpu.h>
  22
  23 /*
  24  * This file supports the necessary hoops one needs to jump through since
  25  * early FSP component and early stages are running from cache-as-ram.
  26  */
  27
  28 static void flush_l1d_to_l2(void)
  29 {
  30         msr_t msr = rdmsr(MSR_POWER_MISC);
  31         msr.lo |= (1 << 8);
  32         wrmsr(MSR_POWER_MISC, msr);
  33 }
  34
  35 static inline int is_car_addr(uintptr_t addr)
  36 {
  37         return ((addr >= CONFIG_DCACHE_RAM_BASE) &&
  38                 (addr < (CONFIG_DCACHE_RAM_BASE + CONFIG_DCACHE_RAM_SIZE)));
  39 }
  40
  41 void platform_segment_loaded(uintptr_t start, size_t size, int flags)
  42 {
  43         /* Bail out if this is not the final segment. */
  44         if (!(flags & SEG_FINAL))
  45                 return;
  46
  47         char start_car_check = is_car_addr(start);
  48         char end_car_check = is_car_addr(start + size - 1);
  49
  50         /* Bail out if loaded program segment does not lie in CAR region. */
  51         if (!start_car_check && !end_car_check)
  52                 return;
  53
  54         /* Loaded program segment should lie entirely within CAR region. */
  55         assert (start_car_check && end_car_check);
  56
  57         flush_l1d_to_l2();
  58 }