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 bcm6358_quirks(void) 99 { 100 /* 101 * BCM6358 needs special handling for its shared TLB, so 102 * disable SMP for now 103 */ 104 bmips_smp_enabled = 0; 105 } 106 107 static void bcm6368_quirks(void) 108 { 109 bcm63xx_fixup_cpu1(); 110 } 111 112 static const struct bmips_quirk bmips_quirk_list[] = { 113 { "brcm,bcm3384-viper", &bcm3384_viper_quirks }, 114 { "brcm,bcm33843-viper", &bcm3384_viper_quirks }, 115 { "brcm,bcm6328", &bcm6328_quirks }, 116 { "brcm,bcm6358", &bcm6358_quirks }, 117 { "brcm,bcm6368", &bcm6368_quirks }, 118 { "brcm,bcm63168", &bcm6368_quirks }, 119 { "brcm,bcm63268", &bcm6368_quirks }, 120 { }, 121 }; 122 123 void __init prom_init(void) 124 { 125 bmips_cpu_setup(); 126 register_bmips_smp_ops(); 127 } 128 129 void __init prom_free_prom_memory(void) 130 { 131 } 132 133 const char *get_system_type(void) 134 { 135 return "Generic BMIPS kernel"; 136 } 137 138 void __init plat_time_init(void) 139 { 140 struct device_node *np; 141 u32 freq; 142 143 np = of_find_node_by_name(NULL, "cpus"); 144 if (!np) 145 panic("missing 'cpus' DT node"); 146 if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0) 147 panic("missing 'mips-hpt-frequency' property"); 148 of_node_put(np); 149 150 mips_hpt_frequency = freq; 151 } 152 153 void __init plat_mem_setup(void) 154 { 155 void *dtb; 156 const struct bmips_quirk *q; 157 158 set_io_port_base(0); 159 ioport_resource.start = 0; 160 ioport_resource.end = ~0; 161 162 /* intended to somewhat resemble ARM; see Documentation/arm/Booting */ 163 if (fw_arg0 == 0 && fw_arg1 == 0xffffffff) 164 dtb = phys_to_virt(fw_arg2); 165 else if (fw_arg0 == -2) /* UHI interface */ 166 dtb = (void *)fw_arg1; 167 else if (__dtb_start != __dtb_end) 168 dtb = (void *)__dtb_start; 169 else 170 panic("no dtb found"); 171 172 __dt_setup_arch(dtb); 173 174 for (q = bmips_quirk_list; q->quirk_fn; q++) { 175 if (of_flat_dt_is_compatible(of_get_flat_dt_root(), 176 q->compatible)) { 177 q->quirk_fn(); 178 } 179 } 180 } 181 182 void __init device_tree_init(void) 183 { 184 struct device_node *np; 185 186 unflatten_and_copy_device_tree(); 187 188 /* Disable SMP boot unless both CPUs are listed in DT and !disabled */ 189 np = of_find_node_by_name(NULL, "cpus"); 190 if (np && of_get_available_child_count(np) <= 1) 191 bmips_smp_enabled = 0; 192 of_node_put(np); 193 } 194 195 int __init plat_of_setup(void) 196 { 197 return __dt_register_buses("simple-bus", NULL); 198 } 199 200 arch_initcall(plat_of_setup); 201 202 static int __init plat_dev_init(void) 203 { 204 of_clk_init(NULL); 205 return 0; 206 } 207 208 device_initcall(plat_dev_init); 209