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/*
38 * CBR addr doesn't change and we can cache it.
39 * For broken SoC/Bootloader CBR addr might also be provided via DT
40 * with "brcm,bmips-cbr-reg" in the "cpus" node.
41 */
42void __iomem *bmips_cbr_addr __read_mostly;
43
44extern bool bmips_rac_flush_disable;
45
46static const unsigned long kbase = VMLINUX_LOAD_ADDRESS & 0xfff00000;
47
48struct bmips_quirk {
49 const char *compatible;
50 void (*quirk_fn)(void);
51};
52
53static void kbase_setup(void)
54{
55 __raw_writel(val: kbase | RELO_NORMAL_VEC,
56 addr: BMIPS_GET_CBR() + BMIPS_RELO_VECTOR_CONTROL_1);
57 ebase = kbase;
58}
59
60static void bcm3384_viper_quirks(void)
61{
62 /*
63 * Some experimental CM boxes are set up to let CM own the Viper TP0
64 * and let Linux own TP1. This requires moving the kernel
65 * load address to a non-conflicting region (e.g. via
66 * CONFIG_PHYSICAL_START) and supplying an alternate DTB.
67 * If we detect this condition, we need to move the MIPS exception
68 * vectors up to an area that we own.
69 *
70 * This is distinct from the OTHER special case mentioned in
71 * smp-bmips.c (boot on TP1, but enable SMP, then TP0 becomes our
72 * logical CPU#1). For the Viper TP1 case, SMP is off limits.
73 *
74 * Also note that many BMIPS435x CPUs do not have a
75 * BMIPS_RELO_VECTOR_CONTROL_1 register, so it isn't safe to just
76 * write VMLINUX_LOAD_ADDRESS into that register on every SoC.
77 */
78 board_ebase_setup = &kbase_setup;
79 bmips_smp_enabled = 0;
80}
81
82static void bcm63xx_fixup_cpu1(void)
83{
84 /*
85 * The bootloader has set up the CPU1 reset vector at
86 * 0xa000_0200.
87 * This conflicts with the special interrupt vector (IV).
88 * The bootloader has also set up CPU1 to respond to the wrong
89 * IPI interrupt.
90 * Here we will start up CPU1 in the background and ask it to
91 * reconfigure itself then go back to sleep.
92 */
93 memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
94 __sync();
95 set_c0_cause(C_SW0);
96 cpumask_set_cpu(cpu: 1, dstp: &bmips_booted_mask);
97}
98
99static void bcm6328_quirks(void)
100{
101 /* Check CPU1 status in OTP (it is usually disabled) */
102 if (__raw_readl(REG_BCM6328_OTP) & BCM6328_TP1_DISABLED)
103 bmips_smp_enabled = 0;
104 else
105 bcm63xx_fixup_cpu1();
106}
107
108static void bcm6358_quirks(void)
109{
110 /*
111 * BCM3368/BCM6358 need special handling for their shared TLB, so
112 * disable SMP for now
113 */
114 bmips_smp_enabled = 0;
115
116 /*
117 * RAC flush causes kernel panics on BCM6358 when booting from TP1
118 * because the bootloader is not initializing it properly.
119 */
120 bmips_rac_flush_disable = !!(read_c0_brcm_cmt_local() & (1 << 31)) ||
121 !!bmips_cbr_addr;
122}
123
124static void bcm6368_quirks(void)
125{
126 bcm63xx_fixup_cpu1();
127}
128
129static const struct bmips_quirk bmips_quirk_list[] = {
130 { "brcm,bcm3368", &bcm6358_quirks },
131 { "brcm,bcm3384-viper", &bcm3384_viper_quirks },
132 { "brcm,bcm33843-viper", &bcm3384_viper_quirks },
133 { "brcm,bcm6328", &bcm6328_quirks },
134 { "brcm,bcm6358", &bcm6358_quirks },
135 { "brcm,bcm6362", &bcm6368_quirks },
136 { "brcm,bcm6368", &bcm6368_quirks },
137 { "brcm,bcm63168", &bcm6368_quirks },
138 { "brcm,bcm63268", &bcm6368_quirks },
139 { },
140};
141
142static void __init bmips_init_cfe(void)
143{
144 cfe_seal = fw_arg3;
145
146 if (cfe_seal != CFE_EPTSEAL)
147 return;
148
149 cfe_init(fw_arg0, fw_arg2);
150}
151
152void __init prom_init(void)
153{
154 /* Cache CBR addr before CPU/DMA setup */
155 bmips_cbr_addr = BMIPS_GET_CBR();
156 bmips_init_cfe();
157 bmips_cpu_setup();
158 register_bmips_smp_ops();
159}
160
161const char *get_system_type(void)
162{
163 return "Generic BMIPS kernel";
164}
165
166void __init plat_time_init(void)
167{
168 struct device_node *np;
169 u32 freq;
170
171 np = of_find_node_by_name(NULL, name: "cpus");
172 if (!np)
173 panic(fmt: "missing 'cpus' DT node");
174 if (of_property_read_u32(np, propname: "mips-hpt-frequency", out_value: &freq) < 0)
175 panic(fmt: "missing 'mips-hpt-frequency' property");
176 of_node_put(node: np);
177
178 mips_hpt_frequency = freq;
179}
180
181void __init plat_mem_setup(void)
182{
183 void *dtb;
184 const struct bmips_quirk *q;
185
186 set_io_port_base(0);
187 ioport_resource.start = 0;
188 ioport_resource.end = ~0;
189
190 /*
191 * intended to somewhat resemble ARM; see
192 * Documentation/arch/arm/booting.rst
193 */
194 if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
195 dtb = phys_to_virt(address: fw_arg2);
196 else
197 dtb = get_fdt();
198
199 if (!dtb)
200 cfe_die("no dtb found");
201
202 __dt_setup_arch(dtb);
203
204 for (q = bmips_quirk_list; q->quirk_fn; q++) {
205 if (of_flat_dt_is_compatible(node: of_get_flat_dt_root(),
206 name: q->compatible)) {
207 q->quirk_fn();
208 }
209 }
210}
211
212void __init device_tree_init(void)
213{
214 struct device_node *np;
215 u32 addr;
216
217 unflatten_and_copy_device_tree();
218
219 /* Disable SMP boot unless both CPUs are listed in DT and !disabled */
220 np = of_find_node_by_name(NULL, name: "cpus");
221 if (!np)
222 return;
223
224 if (of_get_available_child_count(np) <= 1)
225 bmips_smp_enabled = 0;
226
227 /* Check if DT provide a CBR address */
228 if (of_property_read_u32(np, propname: "brcm,bmips-cbr-reg", out_value: &addr))
229 goto exit;
230
231 /* Make sure CBR address is outside DRAM window */
232 if (addr >= (u32)memblock_start_of_DRAM() &&
233 addr < (u32)memblock_end_of_DRAM()) {
234 WARN(1, "DT CBR %x inside DRAM window. Ignoring DT CBR.\n",
235 addr);
236 goto exit;
237 }
238
239 bmips_cbr_addr = (void __iomem *)addr;
240 /* Since CBR is provided by DT, enable RAC flush */
241 bmips_rac_flush_disable = false;
242
243exit:
244 of_node_put(node: np);
245}
246
247static int __init plat_dev_init(void)
248{
249 of_clk_init(NULL);
250 return 0;
251}
252
253arch_initcall(plat_dev_init);
254

source code of linux/arch/mips/bmips/setup.c