1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * ARC CPU startup Code
4 *
5 * Copyright (C) 2004, 2007-2010, 2011-2012 Sy
6 *
7 * Vineetg: Dec 2007
8 * -Check if we are running on Simulator or o
9 * to skip certain things during boot on
10 */
11
12 #include <linux/linkage.h>
13 #include <asm/asm-offsets.h>
14 #include <asm/entry.h>
15 #include <asm/arcregs.h>
16 #include <asm/cache.h>
17 #include <asm/dsp-impl.h>
18 #include <asm/irqflags.h>
19
20 .macro CPU_EARLY_SETUP
21
22 ; Setting up Vectror Table (in case ex
23 sr @_int_vec_base_lds, [AUX_INTR_
24
25 ; Disable I-cache/D-cache if kernel so
26 lr r5, [ARC_REG_IC_BCR]
27 breq r5, 0, 1f ; I$ d
28 lr r5, [ARC_REG_IC_CTRL]
29 #ifdef CONFIG_ARC_HAS_ICACHE
30 bclr r5, r5, 0 ; 0 -
31 #else
32 bset r5, r5, 0 ; I$ e
33 #endif
34 sr r5, [ARC_REG_IC_CTRL]
35
36 1:
37 lr r5, [ARC_REG_DC_BCR]
38 breq r5, 0, 1f ; D$ d
39 lr r5, [ARC_REG_DC_CTRL]
40 bclr r5, r5, 6 ; Inva
41 #ifdef CONFIG_ARC_HAS_DCACHE
42 bclr r5, r5, 0 ; Enab
43 #else
44 bset r5, r5, 0 ; Disa
45 #endif
46 sr r5, [ARC_REG_DC_CTRL]
47
48 1:
49
50 #ifdef CONFIG_ISA_ARCV2
51 ; Unaligned access is disabled at rese
52 ; gcc 7.3.1 (ARC GNU 2018.03) onwards
53 ; by default
54 lr r5, [status32]
55 #ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
56 bset r5, r5, STATUS_AD_BIT
57 #else
58 ; Although disabled at reset, bootload
59 bclr r5, r5, STATUS_AD_BIT
60 #endif
61 kflag r5
62
63 #ifdef CONFIG_ARC_LPB_DISABLE
64 lr r5, [ARC_REG_LPB_BUILD]
65 breq r5, 0, 1f ; LPB
66 mov r5, 1
67 sr r5, [ARC_REG_LPB_CTRL]
68 1:
69 #endif /* CONFIG_ARC_LPB_DISABLE */
70
71 /* On HSDK, CCMs need to remapped supe
72 #ifdef CONFIG_ARC_SOC_HSDK
73 mov r6, 0x60000000
74 lr r5, [ARC_REG_ICCM_BUILD]
75 breq r5, 0, 1f
76 sr r6, [ARC_REG_AUX_ICCM]
77 1:
78 lr r5, [ARC_REG_DCCM_BUILD]
79 breq r5, 0, 2f
80 sr r6, [ARC_REG_AUX_DCCM]
81 2:
82 #endif /* CONFIG_ARC_SOC_HSDK */
83
84 #endif /* CONFIG_ISA_ARCV2 */
85
86 ; Config DSP_CTRL properly, so kernel
87 ; multiply-accumulate, and divide oper
88 DSP_EARLY_INIT
89 .endm
90
91 .section .init.text, "ax",@progbits
92
93 ;---------------------------------------------
94 ; Default Reset Handler (jumped into from Rese
95 ; - Don't clobber r0,r1,r2 as they might have
96 ; - Platforms can override this weak version i
97 ;---------------------------------------------
98 WEAK(res_service)
99 j stext
100 END(res_service)
101
102 ;---------------------------------------------
103 ; Kernel Entry point
104 ;---------------------------------------------
105 ENTRY(stext)
106
107 CPU_EARLY_SETUP
108
109 #ifdef CONFIG_SMP
110 GET_CPU_ID r5
111 cmp r5, 0
112 mov.nz r0, r5
113 bz .Lmaster_proceed
114
115 ; Non-Masters wait for Master to boot
116 ; when they resume, tail-call to entry
117 mov blink, @first_lines_of_seconda
118 j arc_platform_smp_wait_to_boot
119
120 .Lmaster_proceed:
121 #endif
122
123 ; Clear BSS before updating any global
124 ; XXX: use ZOL here
125 mov r5, __bss_start
126 sub r6, __bss_stop, r5
127 lsr.f lp_count, r6, 2
128 lpnz 1f
129 st.ab 0, [r5, 4]
130 1:
131
132 ; Uboot - kernel ABI
133 ; r0 = [0] No uboot interaction, [1
134 ; r1 = magic number (always zero as
135 ; r2 = pointer to uboot provided cm
136 ; These are handled later in handle_ub
137 st r0, [@uboot_tag]
138 st r1, [@uboot_magic]
139 st r2, [@uboot_arg]
140
141 ; setup "current" tsk and optionally c
142 mov r9, @init_task
143 SET_CURR_TASK_ON_CPU r9, r0 ; r9 =
144
145 ; setup stack (fp, sp)
146 mov fp, 0
147
148 ; tsk->thread_info is really a PAGE, w
149 GET_TSK_STACK_BASE r9, sp ; r9 =
150
151 j start_kernel ; "C" entry po
152 END(stext)
153
154 #ifdef CONFIG_SMP
155 ;---------------------------------------------
156 ; First lines of code run by secondary bef
157 ;---------------------------------------------
158 .section .text, "ax",@progbits
159 ENTRY(first_lines_of_secondary)
160
161 ; setup per-cpu idle task as "current"
162 ld r0, [@secondary_idle_tsk]
163 SET_CURR_TASK_ON_CPU r0, r1
164
165 ; setup stack (fp, sp)
166 mov fp, 0
167
168 ; set its stack base to tsk->thread_in
169 GET_TSK_STACK_BASE r0, sp
170
171 j start_kernel_secondary
172 END(first_lines_of_secondary)
173 #endif
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