1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_PROCESSOR_64_H
3 #define __ASM_SH_PROCESSOR_64_H
4
5 /*
6 * include/asm-sh/processor_64.h
7 *
8 * Copyright (C) 2000, 2001 Paolo Alberelli
9 * Copyright (C) 2003 Paul Mundt
10 * Copyright (C) 2004 Richard Curnow
11 */
12 #ifndef __ASSEMBLY__
13
14 #include <linux/compiler.h>
15 #include <asm/page.h>
16 #include <asm/types.h>
17 #include <cpu/registers.h>
18
19 #endif
20
21 /*
22 * User space process size: 2GB - 4k.
23 */
24 #define TASK_SIZE 0x7ffff000UL
25
26 #define STACK_TOP TASK_SIZE
27 #define STACK_TOP_MAX STACK_TOP
28
29 /* This decides where the kernel will search for a free chunk of vm
30 * space during mmap's.
31 */
32 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
33
34 /*
35 * Bit of SR register
36 *
37 * FD-bit:
38 * When it's set, it means the processor doesn't have right to use FPU,
39 * and it results exception when the floating operation is executed.
40 *
41 * IMASK-bit:
42 * Interrupt level mask
43 *
44 * STEP-bit:
45 * Single step bit
46 *
47 */
48 #if defined(CONFIG_SH64_SR_WATCH)
49 #define SR_MMU 0x84000000
50 #else
51 #define SR_MMU 0x80000000
52 #endif
53
54 #define SR_IMASK 0x000000f0
55 #define SR_FD 0x00008000
56 #define SR_SSTEP 0x08000000
57
58 #ifndef __ASSEMBLY__
59
60 /*
61 * FPU structure and data : require 8-byte alignment as we need to access it
62 with fld.p, fst.p
63 */
64
65 struct sh_fpu_hard_struct {
66 unsigned long fp_regs[64];
67 unsigned int fpscr;
68 /* long status; * software status information */
69 };
70
71 /* Dummy fpu emulator */
72 struct sh_fpu_soft_struct {
73 unsigned long fp_regs[64];
74 unsigned int fpscr;
75 unsigned char lookahead;
76 unsigned long entry_pc;
77 };
78
79 union thread_xstate {
80 struct sh_fpu_hard_struct hardfpu;
81 struct sh_fpu_soft_struct softfpu;
82 /*
83 * The structure definitions only produce 32 bit alignment, yet we need
84 * to access them using 64 bit load/store as well.
85 */
86 unsigned long long alignment_dummy;
87 };
88
89 struct thread_struct {
90 unsigned long sp;
91 unsigned long pc;
92
93 /* Various thread flags, see SH_THREAD_xxx */
94 unsigned long flags;
95
96 /* This stores the address of the pt_regs built during a context
97 switch, or of the register save area built for a kernel mode
98 exception. It is used for backtracing the stack of a sleeping task
99 or one that traps in kernel mode. */
100 struct pt_regs *kregs;
101 /* This stores the address of the pt_regs constructed on entry from
102 user mode. It is a fixed value over the lifetime of a process, or
103 NULL for a kernel thread. */
104 struct pt_regs *uregs;
105
106 unsigned long address;
107 /* Hardware debugging registers may come here */
108
109 /* floating point info */
110 union thread_xstate *xstate;
111
112 /*
113 * fpu_counter contains the number of consecutive context switches
114 * that the FPU is used. If this is over a threshold, the lazy fpu
115 * saving becomes unlazy to save the trap. This is an unsigned char
116 * so that after 256 times the counter wraps and the behavior turns
117 * lazy again; this to deal with bursty apps that only use FPU for
118 * a short time
119 */
120 unsigned char fpu_counter;
121 };
122
123 #define INIT_MMAP \
124 { &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
125
126 #define INIT_THREAD { \
127 .sp = sizeof(init_stack) + \
128 (long) &init_stack, \
129 .pc = 0, \
130 .kregs = &fake_swapper_regs, \
131 .uregs = NULL, \
132 .address = 0, \
133 .flags = 0, \
134 }
135
136 /*
137 * Do necessary setup to start up a newly executed thread.
138 */
139 #define SR_USER (SR_MMU | SR_FD)
140
141 #define start_thread(_regs, new_pc, new_sp) \
142 _regs->sr = SR_USER; /* User mode. */ \
143 _regs->pc = new_pc - 4; /* Compensate syscall exit */ \
144 _regs->pc |= 1; /* Set SHmedia ! */ \
145 _regs->regs[18] = 0; \
146 _regs->regs[15] = new_sp
147
148 /* Forward declaration, a strange C thing */
149 struct task_struct;
150 struct mm_struct;
151
152 /* Free all resources held by a thread. */
153 extern void release_thread(struct task_struct *);
154
155 /*
156 * FPU lazy state save handling.
157 */
158
159 static inline void disable_fpu(void)
160 {
161 unsigned long long __dummy;
162
163 /* Set FD flag in SR */
164 __asm__ __volatile__("getcon " __SR ", %0\n\t"
165 "or %0, %1, %0\n\t"
166 "putcon %0, " __SR "\n\t"
167 : "=&r" (__dummy)
168 : "r" (SR_FD));
169 }
170
171 static inline void enable_fpu(void)
172 {
173 unsigned long long __dummy;
174
175 /* Clear out FD flag in SR */
176 __asm__ __volatile__("getcon " __SR ", %0\n\t"
177 "and %0, %1, %0\n\t"
178 "putcon %0, " __SR "\n\t"
179 : "=&r" (__dummy)
180 : "r" (~SR_FD));
181 }
182
183 /* Round to nearest, no exceptions on inexact, overflow, underflow,
184 zero-divide, invalid. Configure option for whether to flush denorms to
185 zero, or except if a denorm is encountered. */
186 #if defined(CONFIG_SH64_FPU_DENORM_FLUSH)
187 #define FPSCR_INIT 0x00040000
188 #else
189 #define FPSCR_INIT 0x00000000
190 #endif
191
192 #ifdef CONFIG_SH_FPU
193 /* Initialise the FP state of a task */
194 void fpinit(struct sh_fpu_hard_struct *fpregs);
195 #else
196 #define fpinit(fpregs) do { } while (0)
197 #endif
198
199 extern struct task_struct *last_task_used_math;
200
201 /*
202 * Return saved PC of a blocked thread.
203 */
204 #define thread_saved_pc(tsk) (tsk->thread.pc)
205
206 extern unsigned long get_wchan(struct task_struct *p);
207
208 #define KSTK_EIP(tsk) ((tsk)->thread.pc)
209 #define KSTK_ESP(tsk) ((tsk)->thread.sp)
210
211 #endif /* __ASSEMBLY__ */
212 #endif /* __ASM_SH_PROCESSOR_64_H */
213
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