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/libfdt.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 #include <asm/fw/cfe/cfe_api.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 extern bool bmips_rac_flush_disable;
38
39 static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
40
41 struct bmips_quirk {
42 const char *compatible;
43 void (*quirk_fn)(void);
44 };
45
kbase_setup(void)46 static void kbase_setup(void)
47 {
48 __raw_writel(kbase | RELO_NORMAL_VEC,
49 BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
50 ebase = kbase;
51 }
52
bcm3384_viper_quirks(void)53 static void bcm3384_viper_quirks(void)
54 {
55 /*
56 * Some experimental CM boxes are set up to let CM own the Viper TP0
57 * and let Linux own TP1. This requires moving the kernel
58 * load address to a non-conflicting region (e.g. via
59 * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
60 * If we detect this condition, we need to move the MIPS exception
61 * vectors up to an area that we own.
62 *
63 * This is distinct from the OTHER special case mentioned in
64 * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
65 * logical CPU#1). For the Viper TP1 case, SMP is off limits.
66 *
67 * Also note that many BMIPS435x CPUs do not have a
68 * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
69 * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
70 */
71 board_ebase_setup = &kbase_setup;
72 bmips_smp_enabled = 0;
73 }
74
bcm63xx_fixup_cpu1(void)75 static void bcm63xx_fixup_cpu1(void)
76 {
77 /*
78 * The bootloader has set up the CPU1 reset vector at
79 * 0xa000_0200.
80 * This conflicts with the special interrupt vector (IV).
81 * The bootloader has also set up CPU1 to respond to the wrong
82 * IPI interrupt.
83 * Here we will start up CPU1 in the background and ask it to
84 * reconfigure itself then go back to sleep.
85 */
86 memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
87 __sync();
88 set_c0_cause(C_SW0);
89 cpumask_set_cpu(1, &bmips_booted_mask);
90 }
91
bcm6328_quirks(void)92 static void bcm6328_quirks(void)
93 {
94 /* Check CPU1 status in OTP (it is usually disabled) */
95 if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
96 bmips_smp_enabled = 0;
97 else
98 bcm63xx_fixup_cpu1();
99 }
100
bcm6358_quirks(void)101 static void bcm6358_quirks(void)
102 {
103 /*
104 * BCM3368/BCM6358 need special handling for their shared TLB, so
105 * disable SMP for now
106 */
107 bmips_smp_enabled = 0;
108
109 /*
110 * RAC flush causes kernel panics on BCM6358 when booting from TP1
111 * because the bootloader is not initializing it properly.
112 */
113 bmips_rac_flush_disable = !!(read_c0_brcm_cmt_local() & (1 << 31)) ||
114 !!BMIPS_GET_CBR();
115 }
116
bcm6368_quirks(void)117 static void bcm6368_quirks(void)
118 {
119 bcm63xx_fixup_cpu1();
120 }
121
122 static const struct bmips_quirk bmips_quirk_list[] = {
123 { "brcm,bcm3368", &bcm6358_quirks },
124 { "brcm,bcm3384-viper", &bcm3384_viper_quirks },
125 { "brcm,bcm33843-viper", &bcm3384_viper_quirks },
126 { "brcm,bcm6328", &bcm6328_quirks },
127 { "brcm,bcm6358", &bcm6358_quirks },
128 { "brcm,bcm6362", &bcm6368_quirks },
129 { "brcm,bcm6368", &bcm6368_quirks },
130 { "brcm,bcm63168", &bcm6368_quirks },
131 { "brcm,bcm63268", &bcm6368_quirks },
132 { },
133 };
134
bmips_init_cfe(void)135 static void __init bmips_init_cfe(void)
136 {
137 cfe_seal = fw_arg3;
138
139 if (cfe_seal != CFE_EPTSEAL)
140 return;
141
142 cfe_init(fw_arg0, fw_arg2);
143 }
144
prom_init(void)145 void __init prom_init(void)
146 {
147 bmips_init_cfe();
148 bmips_cpu_setup();
149 register_bmips_smp_ops();
150 }
151
get_system_type(void)152 const char *get_system_type(void)
153 {
154 return "Generic BMIPS kernel";
155 }
156
plat_time_init(void)157 void __init plat_time_init(void)
158 {
159 struct device_node *np;
160 u32 freq;
161
162 np = of_find_node_by_name(NULL, "cpus");
163 if (!np)
164 panic("missing 'cpus' DT node");
165 if (of_property_read_u32(np, "mips-hpt-frequency", &freq) < 0)
166 panic("missing 'mips-hpt-frequency' property");
167 of_node_put(np);
168
169 mips_hpt_frequency = freq;
170 }
171
plat_mem_setup(void)172 void __init plat_mem_setup(void)
173 {
174 void *dtb;
175 const struct bmips_quirk *q;
176
177 set_io_port_base(0);
178 ioport_resource.start = 0;
179 ioport_resource.end = ~0;
180
181 /*
182 * intended to somewhat resemble ARM; see
183 * Documentation/arch/arm/booting.rst
184 */
185 if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
186 dtb = phys_to_virt(fw_arg2);
187 else
188 dtb = get_fdt();
189
190 if (!dtb)
191 cfe_die("no dtb found");
192
193 __dt_setup_arch(dtb);
194
195 for (q = bmips_quirk_list; q->quirk_fn; q++) {
196 if (of_flat_dt_is_compatible(of_get_flat_dt_root(),
197 q->compatible)) {
198 q->quirk_fn();
199 }
200 }
201 }
202
device_tree_init(void)203 void __init device_tree_init(void)
204 {
205 struct device_node *np;
206
207 unflatten_and_copy_device_tree();
208
209 /* Disable SMP boot unless both CPUs are listed in DT and !disabled */
210 np = of_find_node_by_name(NULL, "cpus");
211 if (np && of_get_available_child_count(np) <= 1)
212 bmips_smp_enabled = 0;
213 of_node_put(np);
214 }
215
plat_dev_init(void)216 static int __init plat_dev_init(void)
217 {
218 of_clk_init(NULL);
219 return 0;
220 }
221
222 arch_initcall(plat_dev_init);
223