arch/mips/bmips/setup.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
   7  * Copyright (C) 2014 Kevin Cernekee <cernekee@gmail.com>
   8  */
   9
  10 #include <linux/init.h>
  11 #include <linux/bitops.h>
  12 #include <linux/bootmem.h>
  13 #include <linux/clk-provider.h>
  14 #include <linux/ioport.h>
  15 #include <linux/kernel.h>
  16 #include <linux/io.h>
  17 #include <linux/of.h>
  18 #include <linux/of_fdt.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/smp.h>
  21 #include <asm/addrspace.h>
  22 #include <asm/bmips.h>
  23 #include <asm/bootinfo.h>
  24 #include <asm/cpu-type.h>
  25 #include <asm/mipsregs.h>
  26 #include <asm/prom.h>
  27 #include <asm/smp-ops.h>
  28 #include <asm/time.h>
  29 #include <asm/traps.h>
  30
  31 #define RELO_NORMAL_VEC         BIT(18)
  32
  33 #define REG_BCM6328_OTP         ((void __iomem *)CKSEG1ADDR(0x1000062c))
  34 #define BCM6328_TP1_DISABLED    BIT(9)
  35
  36 static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
  37
  38 struct bmips_quirk {
  39         const char              *compatible;
  40         void                    (*quirk_fn)(void);
  41 };
  42
  43 static void kbase_setup(void)
  44 {
  45         __raw_writel(kbase | RELO_NORMAL_VEC,
  46                      BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
  47         ebase = kbase;
  48 }
  49
  50 static void bcm3384_viper_quirks(void)
  51 {
  52         /*
  53          * Some experimental CM boxes are set up to let CM own the Viper TP0
  54          * and let Linux own TP1.  This requires moving the kernel
  55          * load address to a non-conflicting region (e.g. via
  56          * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
  57          * If we detect this condition, we need to move the MIPS exception
  58          * vectors up to an area that we own.
  59          *
  60          * This is distinct from the OTHER special case mentioned in
  61          * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
  62          * logical CPU#1).  For the Viper TP1 case, SMP is off limits.
  63          *
  64          * Also note that many BMIPS435x CPUs do not have a
  65          * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
  66          * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
  67          */
  68         board_ebase_setup = &kbase_setup;
  69         bmips_smp_enabled = 0;
  70 }
  71
  72 static void bcm63xx_fixup_cpu1(void)
  73 {
  74         /*
  75          * The bootloader has set up the CPU1 reset vector at
  76          * 0xa000_0200.
  77          * This conflicts with the special interrupt vector (IV).
  78          * The bootloader has also set up CPU1 to respond to the wrong
  79          * IPI interrupt.
  80          * Here we will start up CPU1 in the background and ask it to
  81          * reconfigure itself then go back to sleep.
  82          */
  83         memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
  84         __sync();
  85         set_c0_cause(C_SW0);
  86         cpumask_set_cpu(1, &bmips_booted_mask);
  87 }
  88
  89 static void bcm6328_quirks(void)
  90 {
  91         /* Check CPU1 status in OTP (it is usually disabled) */
  92         if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
  93                 bmips_smp_enabled = 0;
  94         else
  95                 bcm63xx_fixup_cpu1();
  96 }
  97
  98 static void bcm6368_quirks(void)
  99 {
 100         bcm63xx_fixup_cpu1();
 101 }
 102
 103 static const struct bmips_quirk bmips_quirk_list[] = {
 104         { "brcm,bcm3384-viper",         &bcm3384_viper_quirks           },
 105         { "brcm,bcm33843-viper",        &bcm3384_viper_quirks           },
 106         { "brcm,bcm6328",               &bcm6328_quirks                 },
 107         { "brcm,bcm6368",               &bcm6368_quirks                 },
 108         { "brcm,bcm63168",              &bcm6368_quirks                 },
 109         { },
 110 };
 111
 112 void __init prom_init(void)
 113 {
 114         register_bmips_smp_ops();
 115 }
 116
 117 void __init prom_free_prom_memory(void)
 118 {
 119 }
 120
 121 const char *get_system_type(void)
 122 {
 123         return "Generic BMIPS kernel";
 124 }
 125
 126 void __init plat_time_init(void)
 127 {
 128         struct device_node *np;
 129         u32 freq;
 130
 131         np = of_find_node_by_name(NULL, "cpus");
 132         if (!np)
 133                 panic("missing 'cpus' DT node");
 134         if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
 135                 panic("missing 'mips-hpt-frequency' property");
 136         of_node_put(np);
 137
 138         mips_hpt_frequency = freq;
 139 }
 140
 141 void __init plat_mem_setup(void)
 142 {
 143         void *dtb;
 144         const struct bmips_quirk *q;
 145
 146         set_io_port_base(0);
 147         ioport_resource.start = 0;
 148         ioport_resource.end = ~0;
 149
 150         /* intended to somewhat resemble ARM; see Documentation/arm/Booting */
 151         if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
 152                 dtb = phys_to_virt(fw_arg2);
 153         else if (fw_arg0 == -2) /* UHI interface */
 154                 dtb = (void *)fw_arg1;
 155         else if (__dtb_start != __dtb_end)
 156                 dtb = (void *)__dtb_start;
 157         else
 158                 panic("no dtb found");
 159
 160         __dt_setup_arch(dtb);
 161
 162         for (q = bmips_quirk_list; q->quirk_fn; q++) {
 163                 if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
 164                                              q->compatible)) {
 165                         q->quirk_fn();
 166                 }
 167         }
 168 }
 169
 170 void __init device_tree_init(void)
 171 {
 172         struct device_node *np;
 173
 174         unflatten_and_copy_device_tree();
 175
 176         /* Disable SMP boot unless both CPUs are listed in DT and !disabled */
 177         np = of_find_node_by_name(NULL, "cpus");
 178         if (np && of_get_available_child_count(np) <= 1)
 179                 bmips_smp_enabled = 0;
 180         of_node_put(np);
 181 }
 182
 183 int __init plat_of_setup(void)
 184 {
 185         return __dt_register_buses("simple-bus", NULL);
 186 }
 187
 188 arch_initcall(plat_of_setup);
 189
 190 static int __init plat_dev_init(void)
 191 {
 192         of_clk_init(NULL);
 193         return 0;
 194 }
 195
 196 device_initcall(plat_dev_init);