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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * ARC CPU startup Code
4 *
5 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6 *
7 * Vineetg: Dec 2007
8 * -Check if we are running on Simulator or on real hardware
9 * to skip certain things during boot on simulator
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 exception happens in early boot
23 sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
24
25 ; Disable I-cache/D-cache if kernel so configured
26 lr r5, [ARC_REG_IC_BCR]
27 breq r5, 0, 1f ; I$ doesn't exist
28 lr r5, [ARC_REG_IC_CTRL]
29#ifdef CONFIG_ARC_HAS_ICACHE
30 bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
31#else
32 bset r5, r5, 0 ; I$ exists, but is not used
33#endif
34 sr r5, [ARC_REG_IC_CTRL]
35
361:
37 lr r5, [ARC_REG_DC_BCR]
38 breq r5, 0, 1f ; D$ doesn't exist
39 lr r5, [ARC_REG_DC_CTRL]
40 bclr r5, r5, 6 ; Invalidate (discard w/o wback)
41#ifdef CONFIG_ARC_HAS_DCACHE
42 bclr r5, r5, 0 ; Enable (+Inv)
43#else
44 bset r5, r5, 0 ; Disable (+Inv)
45#endif
46 sr r5, [ARC_REG_DC_CTRL]
47
481:
49
50#ifdef CONFIG_ISA_ARCV2
51 ; Unaligned access is disabled at reset, so re-enable early as
52 ; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
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, bootloader might have enabled it
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 doesn't exist
66 mov r5, 1
67 sr r5, [ARC_REG_LPB_CTRL]
681:
69#endif /* CONFIG_ARC_LPB_DISABLE */
70#endif
71 ; Config DSP_CTRL properly, so kernel may use integer multiply,
72 ; multiply-accumulate, and divide operations
73 DSP_EARLY_INIT
74.endm
75
76 .section .init.text, "ax",@progbits
77
78;----------------------------------------------------------------
79; Default Reset Handler (jumped into from Reset vector)
80; - Don't clobber r0,r1,r2 as they might have u-boot provided args
81; - Platforms can override this weak version if needed
82;----------------------------------------------------------------
83WEAK(res_service)
84 j stext
85END(res_service)
86
87;----------------------------------------------------------------
88; Kernel Entry point
89;----------------------------------------------------------------
90ENTRY(stext)
91
92 CPU_EARLY_SETUP
93
94#ifdef CONFIG_SMP
95 GET_CPU_ID r5
96 cmp r5, 0
97 mov.nz r0, r5
98 bz .Lmaster_proceed
99
100 ; Non-Masters wait for Master to boot enough and bring them up
101 ; when they resume, tail-call to entry point
102 mov blink, @first_lines_of_secondary
103 j arc_platform_smp_wait_to_boot
104
105.Lmaster_proceed:
106#endif
107
108 ; Clear BSS before updating any globals
109 ; XXX: use ZOL here
110 mov r5, __bss_start
111 sub r6, __bss_stop, r5
112 lsr.f lp_count, r6, 2
113 lpnz 1f
114 st.ab 0, [r5, 4]
1151:
116
117 ; Uboot - kernel ABI
118 ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
119 ; r1 = magic number (always zero as of now)
120 ; r2 = pointer to uboot provided cmdline or external DTB in mem
121 ; These are handled later in handle_uboot_args()
122 st r0, [@uboot_tag]
123 st r1, [@uboot_magic]
124 st r2, [@uboot_arg]
125
126 ; setup "current" tsk and optionally cache it in dedicated r25
127 mov r9, @init_task
128 SET_CURR_TASK_ON_CPU r9, r0 ; r9 = tsk, r0 = scratch
129
130 ; setup stack (fp, sp)
131 mov fp, 0
132
133 ; tsk->thread_info is really a PAGE, whose bottom hoists stack
134 GET_TSK_STACK_BASE r9, sp ; r9 = tsk, sp = stack base(output)
135
136 j start_kernel ; "C" entry point
137END(stext)
138
139#ifdef CONFIG_SMP
140;----------------------------------------------------------------
141; First lines of code run by secondary before jumping to 'C'
142;----------------------------------------------------------------
143 .section .text, "ax",@progbits
144ENTRY(first_lines_of_secondary)
145
146 ; setup per-cpu idle task as "current" on this CPU
147 ld r0, [@secondary_idle_tsk]
148 SET_CURR_TASK_ON_CPU r0, r1
149
150 ; setup stack (fp, sp)
151 mov fp, 0
152
153 ; set it's stack base to tsk->thread_info bottom
154 GET_TSK_STACK_BASE r0, sp
155
156 j start_kernel_secondary
157END(first_lines_of_secondary)
158#endif
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * ARC CPU startup Code
4 *
5 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6 *
7 * Vineetg: Dec 2007
8 * -Check if we are running on Simulator or on real hardware
9 * to skip certain things during boot on simulator
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/irqflags.h>
18
19.macro CPU_EARLY_SETUP
20
21 ; Setting up Vectror Table (in case exception happens in early boot
22 sr @_int_vec_base_lds, [AUX_INTR_VEC_BASE]
23
24 ; Disable I-cache/D-cache if kernel so configured
25 lr r5, [ARC_REG_IC_BCR]
26 breq r5, 0, 1f ; I$ doesn't exist
27 lr r5, [ARC_REG_IC_CTRL]
28#ifdef CONFIG_ARC_HAS_ICACHE
29 bclr r5, r5, 0 ; 0 - Enable, 1 is Disable
30#else
31 bset r5, r5, 0 ; I$ exists, but is not used
32#endif
33 sr r5, [ARC_REG_IC_CTRL]
34
351:
36 lr r5, [ARC_REG_DC_BCR]
37 breq r5, 0, 1f ; D$ doesn't exist
38 lr r5, [ARC_REG_DC_CTRL]
39 bclr r5, r5, 6 ; Invalidate (discard w/o wback)
40#ifdef CONFIG_ARC_HAS_DCACHE
41 bclr r5, r5, 0 ; Enable (+Inv)
42#else
43 bset r5, r5, 0 ; Disable (+Inv)
44#endif
45 sr r5, [ARC_REG_DC_CTRL]
46
471:
48
49#ifdef CONFIG_ISA_ARCV2
50 ; Unaligned access is disabled at reset, so re-enable early as
51 ; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
52 ; by default
53 lr r5, [status32]
54#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
55 bset r5, r5, STATUS_AD_BIT
56#else
57 ; Although disabled at reset, bootloader might have enabled it
58 bclr r5, r5, STATUS_AD_BIT
59#endif
60 kflag r5
61#endif
62.endm
63
64 .section .init.text, "ax",@progbits
65
66;----------------------------------------------------------------
67; Default Reset Handler (jumped into from Reset vector)
68; - Don't clobber r0,r1,r2 as they might have u-boot provided args
69; - Platforms can override this weak version if needed
70;----------------------------------------------------------------
71WEAK(res_service)
72 j stext
73END(res_service)
74
75;----------------------------------------------------------------
76; Kernel Entry point
77;----------------------------------------------------------------
78ENTRY(stext)
79
80 CPU_EARLY_SETUP
81
82#ifdef CONFIG_SMP
83 GET_CPU_ID r5
84 cmp r5, 0
85 mov.nz r0, r5
86 bz .Lmaster_proceed
87
88 ; Non-Masters wait for Master to boot enough and bring them up
89 ; when they resume, tail-call to entry point
90 mov blink, @first_lines_of_secondary
91 j arc_platform_smp_wait_to_boot
92
93.Lmaster_proceed:
94#endif
95
96 ; Clear BSS before updating any globals
97 ; XXX: use ZOL here
98 mov r5, __bss_start
99 sub r6, __bss_stop, r5
100 lsr.f lp_count, r6, 2
101 lpnz 1f
102 st.ab 0, [r5, 4]
1031:
104
105 ; Uboot - kernel ABI
106 ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
107 ; r1 = magic number (always zero as of now)
108 ; r2 = pointer to uboot provided cmdline or external DTB in mem
109 ; These are handled later in handle_uboot_args()
110 st r0, [@uboot_tag]
111 st r1, [@uboot_magic]
112 st r2, [@uboot_arg]
113
114 ; setup "current" tsk and optionally cache it in dedicated r25
115 mov r9, @init_task
116 SET_CURR_TASK_ON_CPU r9, r0 ; r9 = tsk, r0 = scratch
117
118 ; setup stack (fp, sp)
119 mov fp, 0
120
121 ; tsk->thread_info is really a PAGE, whose bottom hoists stack
122 GET_TSK_STACK_BASE r9, sp ; r9 = tsk, sp = stack base(output)
123
124 j start_kernel ; "C" entry point
125END(stext)
126
127#ifdef CONFIG_SMP
128;----------------------------------------------------------------
129; First lines of code run by secondary before jumping to 'C'
130;----------------------------------------------------------------
131 .section .text, "ax",@progbits
132ENTRY(first_lines_of_secondary)
133
134 ; setup per-cpu idle task as "current" on this CPU
135 ld r0, [@secondary_idle_tsk]
136 SET_CURR_TASK_ON_CPU r0, r1
137
138 ; setup stack (fp, sp)
139 mov fp, 0
140
141 ; set it's stack base to tsk->thread_info bottom
142 GET_TSK_STACK_BASE r0, sp
143
144 j start_kernel_secondary
145END(first_lines_of_secondary)
146#endif