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/memblock.h>
  13 #include <linux/ioport.h>
  14 #include <linux/kernel.h>
  15 #include <linux/io.h>
  16 #include <linux/of.h>
  17 #include <linux/of_clk.h>
  18 #include <linux/of_fdt.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/libfdt.h>
  21 #include <linux/smp.h>
  22 #include <asm/addrspace.h>
  23 #include <asm/bmips.h>
  24 #include <asm/bootinfo.h>
  25 #include <asm/cpu-type.h>
  26 #include <asm/mipsregs.h>
  27 #include <asm/prom.h>
  28 #include <asm/smp-ops.h>
  29 #include <asm/time.h>
  30 #include <asm/traps.h>
  31
  32 #define RELO_NORMAL_VEC         BIT(18)
  33
  34 #define REG_BCM6328_OTP         ((void __iomem *)CKSEG1ADDR(0x1000062c))
  35 #define BCM6328_TP1_DISABLED    BIT(9)
  36
  37 static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
  38
  39 struct bmips_quirk {
  40         const char              *compatible;
  41         void                    (*quirk_fn)(void);
  42 };
  43
  44 static void kbase_setup(void)
  45 {
  46         __raw_writel(kbase | RELO_NORMAL_VEC,
  47                      BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
  48         ebase = kbase;
  49 }
  50
  51 static void bcm3384_viper_quirks(void)
  52 {
  53         /*
  54          * Some experimental CM boxes are set up to let CM own the Viper TP0
  55          * and let Linux own TP1.  This requires moving the kernel
  56          * load address to a non-conflicting region (e.g. via
  57          * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
  58          * If we detect this condition, we need to move the MIPS exception
  59          * vectors up to an area that we own.
  60          *
  61          * This is distinct from the OTHER special case mentioned in
  62          * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
  63          * logical CPU#1).  For the Viper TP1 case, SMP is off limits.
  64          *
  65          * Also note that many BMIPS435x CPUs do not have a
  66          * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
  67          * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
  68          */
  69         board_ebase_setup = &kbase_setup;
  70         bmips_smp_enabled = 0;
  71 }
  72
  73 static void bcm63xx_fixup_cpu1(void)
  74 {
  75         /*
  76          * The bootloader has set up the CPU1 reset vector at
  77          * 0xa000_0200.
  78          * This conflicts with the special interrupt vector (IV).
  79          * The bootloader has also set up CPU1 to respond to the wrong
  80          * IPI interrupt.
  81          * Here we will start up CPU1 in the background and ask it to
  82          * reconfigure itself then go back to sleep.
  83          */
  84         memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
  85         __sync();
  86         set_c0_cause(C_SW0);
  87         cpumask_set_cpu(1, &bmips_booted_mask);
  88 }
  89
  90 static void bcm6328_quirks(void)
  91 {
  92         /* Check CPU1 status in OTP (it is usually disabled) */
  93         if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
  94                 bmips_smp_enabled = 0;
  95         else
  96                 bcm63xx_fixup_cpu1();
  97 }
  98
  99 static void bcm6358_quirks(void)
 100 {
 101         /*
 102          * BCM3368/BCM6358 need special handling for their shared TLB, so
 103          * disable SMP for now
 104          */
 105         bmips_smp_enabled = 0;
 106 }
 107
 108 static void bcm6368_quirks(void)
 109 {
 110         bcm63xx_fixup_cpu1();
 111 }
 112
 113 static const struct bmips_quirk bmips_quirk_list[] = {
 114         { "brcm,bcm3368",               &bcm6358_quirks                 },
 115         { "brcm,bcm3384-viper",         &bcm3384_viper_quirks           },
 116         { "brcm,bcm33843-viper",        &bcm3384_viper_quirks           },
 117         { "brcm,bcm6328",               &bcm6328_quirks                 },
 118         { "brcm,bcm6358",               &bcm6358_quirks                 },
 119         { "brcm,bcm6362",               &bcm6368_quirks                 },
 120         { "brcm,bcm6368",               &bcm6368_quirks                 },
 121         { "brcm,bcm63168",              &bcm6368_quirks                 },
 122         { "brcm,bcm63268",              &bcm6368_quirks                 },
 123         { },
 124 };
 125
 126 void __init prom_init(void)
 127 {
 128         bmips_cpu_setup();
 129         register_bmips_smp_ops();
 130 }
 131
 132 void __init prom_free_prom_memory(void)
 133 {
 134 }
 135
 136 const char *get_system_type(void)
 137 {
 138         return "Generic BMIPS kernel";
 139 }
 140
 141 void __init plat_time_init(void)
 142 {
 143         struct device_node *np;
 144         u32 freq;
 145
 146         np = of_find_node_by_name(NULL, "cpus");
 147         if (!np)
 148                 panic("missing 'cpus' DT node");
 149         if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
 150                 panic("missing 'mips-hpt-frequency' property");
 151         of_node_put(np);
 152
 153         mips_hpt_frequency = freq;
 154 }
 155
 156 void __init plat_mem_setup(void)
 157 {
 158         void *dtb;
 159         const struct bmips_quirk *q;
 160
 161         set_io_port_base(0);
 162         ioport_resource.start = 0;
 163         ioport_resource.end = ~0;
 164
 165         /* intended to somewhat resemble ARM; see Documentation/arm/booting.rst */
 166         if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
 167                 dtb = phys_to_virt(fw_arg2);
 168         else if (fw_passed_dtb) /* UHI interface or appended dtb */
 169                 dtb = (void *)fw_passed_dtb;
 170         else if (__dtb_start != __dtb_end)
 171                 dtb = (void *)__dtb_start;
 172         else
 173                 panic("no dtb found");
 174
 175         __dt_setup_arch(dtb);
 176
 177         for (q = bmips_quirk_list; q->quirk_fn; q++) {
 178                 if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
 179                                              q->compatible)) {
 180                         q->quirk_fn();
 181                 }
 182         }
 183 }
 184
 185 void __init device_tree_init(void)
 186 {
 187         struct device_node *np;
 188
 189         unflatten_and_copy_device_tree();
 190
 191         /* Disable SMP boot unless both CPUs are listed in DT and !disabled */
 192         np = of_find_node_by_name(NULL, "cpus");
 193         if (np && of_get_available_child_count(np) <= 1)
 194                 bmips_smp_enabled = 0;
 195         of_node_put(np);
 196 }
 197
 198 static int __init plat_dev_init(void)
 199 {
 200         of_clk_init(NULL);
 201         return 0;
 202 }
 203
 204 device_initcall(plat_dev_init);