kernel/arch/arm/mach-keystone/keystone.c

   1 /*
   2  * Keystone2 based boards and SOC related code.
   3  *
   4  * Copyright 2013 Texas Instruments, Inc.
   5  *      Cyril Chemparathy <cyril@ti.com>
   6  *      Santosh Shilimkar <santosh.shillimkar@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2, as published by the Free Software Foundation.
  11  */
  12 #include <linux/io.h>
  13 #include <linux/of.h>
  14 #include <linux/init.h>
  15 #include <linux/of_platform.h>
  16 #include <linux/of_address.h>
  17 #include <linux/memblock.h>
  18
  19 #include <asm/setup.h>
  20 #include <asm/mach/map.h>
  21 #include <asm/mach/arch.h>
  22 #include <asm/mach/time.h>
  23 #include <asm/smp_plat.h>
  24 #include <asm/memory.h>
  25
  26 #include "memory.h"
  27
  28 #include "keystone.h"
  29
  30 static struct notifier_block platform_nb;
  31 static unsigned long keystone_dma_pfn_offset __read_mostly;
  32
  33 static int keystone_platform_notifier(struct notifier_block *nb,
  34                                       unsigned long event, void *data)
  35 {
  36         struct device *dev = data;
  37
  38         if (event != BUS_NOTIFY_ADD_DEVICE)
  39                 return NOTIFY_DONE;
  40
  41         if (!dev)
  42                 return NOTIFY_BAD;
  43
  44         if (!dev->of_node) {
  45                 dev->dma_pfn_offset = keystone_dma_pfn_offset;
  46                 dev_err(dev, "set dma_pfn_offset%08lx\n",
  47                         dev->dma_pfn_offset);
  48         }
  49         return NOTIFY_OK;
  50 }
  51
  52 static void __init keystone_init(void)
  53 {
  54         keystone_pm_runtime_init();
  55         if (platform_nb.notifier_call)
  56                 bus_register_notifier(&platform_bus_type, &platform_nb);
  57         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
  58 }
  59
  60 static phys_addr_t keystone_virt_to_idmap(unsigned long x)
  61 {
  62         return (phys_addr_t)(x) - CONFIG_PAGE_OFFSET + KEYSTONE_LOW_PHYS_START;
  63 }
  64
  65 static void __init keystone_init_meminfo(void)
  66 {
  67         bool lpae = IS_ENABLED(CONFIG_ARM_LPAE);
  68         bool pvpatch = IS_ENABLED(CONFIG_ARM_PATCH_PHYS_VIRT);
  69         phys_addr_t offset = PHYS_OFFSET - KEYSTONE_LOW_PHYS_START;
  70         phys_addr_t mem_start, mem_end;
  71
  72         mem_start = memblock_start_of_DRAM();
  73         mem_end = memblock_end_of_DRAM();
  74
  75         /* nothing to do if we are running out of the <32-bit space */
  76         if (mem_start >= KEYSTONE_LOW_PHYS_START &&
  77             mem_end   <= KEYSTONE_LOW_PHYS_END)
  78                 return;
  79
  80         if (!lpae || !pvpatch) {
  81                 pr_crit("Enable %s%s%s to run outside 32-bit space\n",
  82                       !lpae ? __stringify(CONFIG_ARM_LPAE) : "",
  83                       (!lpae && !pvpatch) ? " and " : "",
  84                       !pvpatch ? __stringify(CONFIG_ARM_PATCH_PHYS_VIRT) : "");
  85         }
  86
  87         if (mem_start < KEYSTONE_HIGH_PHYS_START ||
  88             mem_end   > KEYSTONE_HIGH_PHYS_END) {
  89                 pr_crit("Invalid address space for memory (%08llx-%08llx)\n",
  90                       (u64)mem_start, (u64)mem_end);
  91         }
  92
  93         offset += KEYSTONE_HIGH_PHYS_START;
  94         __pv_phys_pfn_offset = PFN_DOWN(offset);
  95         __pv_offset = (offset - PAGE_OFFSET);
  96
  97         /* Populate the arch idmap hook */
  98         arch_virt_to_idmap = keystone_virt_to_idmap;
  99         platform_nb.notifier_call = keystone_platform_notifier;
 100         keystone_dma_pfn_offset = PFN_DOWN(KEYSTONE_HIGH_PHYS_START -
 101                                                 KEYSTONE_LOW_PHYS_START);
 102
 103         pr_info("Switching to high address space at 0x%llx\n", (u64)offset);
 104 }
 105
 106 static const char *const keystone_match[] __initconst = {
 107         "ti,keystone",
 108         NULL,
 109 };
 110
 111 DT_MACHINE_START(KEYSTONE, "Keystone")
 112 #if defined(CONFIG_ZONE_DMA) && defined(CONFIG_ARM_LPAE)
 113         .dma_zone_size  = SZ_2G,
 114 #endif
 115         .smp            = smp_ops(keystone_smp_ops),
 116         .init_machine   = keystone_init,
 117         .dt_compat      = keystone_match,
 118         .init_meminfo   = keystone_init_meminfo,
 119 MACHINE_END