xref: /openbmc/linux/arch/csky/include/asm/processor.h (revision 0eb76ba2)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3 
4 #ifndef __ASM_CSKY_PROCESSOR_H
5 #define __ASM_CSKY_PROCESSOR_H
6 
7 #include <linux/bitops.h>
8 #include <asm/segment.h>
9 #include <asm/ptrace.h>
10 #include <asm/current.h>
11 #include <asm/cache.h>
12 #include <abi/reg_ops.h>
13 #include <abi/regdef.h>
14 #include <abi/switch_context.h>
15 #ifdef CONFIG_CPU_HAS_FPU
16 #include <abi/fpu.h>
17 #endif
18 
19 struct cpuinfo_csky {
20 	unsigned long asid_cache;
21 } __aligned(SMP_CACHE_BYTES);
22 
23 extern struct cpuinfo_csky cpu_data[];
24 
25 /*
26  * User space process size: 2GB. This is hardcoded into a few places,
27  * so don't change it unless you know what you are doing.  TASK_SIZE
28  * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
29  * implementations will "only" be able to use 1TB ...
30  */
31 #define TASK_SIZE       0x7fff8000UL
32 
33 #ifdef __KERNEL__
34 #define STACK_TOP       TASK_SIZE
35 #define STACK_TOP_MAX   STACK_TOP
36 #endif
37 
38 /* This decides where the kernel will search for a free chunk of vm
39  * space during mmap's.
40  */
41 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
42 
43 struct thread_struct {
44 	unsigned long  sp;        /* kernel stack pointer */
45 	unsigned long  trap_no;   /* saved status register */
46 
47 	/* FPU regs */
48 	struct user_fp __aligned(16) user_fp;
49 };
50 
51 #define INIT_THREAD  { \
52 	.sp = sizeof(init_stack) + (unsigned long) &init_stack, \
53 }
54 
55 /*
56  * Do necessary setup to start up a newly executed thread.
57  *
58  * pass the data segment into user programs if it exists,
59  * it can't hurt anything as far as I can tell
60  */
61 #define start_thread(_regs, _pc, _usp)					\
62 do {									\
63 	set_fs(USER_DS); /* reads from user space */			\
64 	(_regs)->pc = (_pc);						\
65 	(_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */	\
66 	(_regs)->regs[2] = 0;						\
67 	(_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */		\
68 	(_regs)->sr &= ~PS_S;						\
69 	(_regs)->usp = (_usp);						\
70 } while (0)
71 
72 /* Forward declaration, a strange C thing */
73 struct task_struct;
74 
75 /* Free all resources held by a thread. */
76 static inline void release_thread(struct task_struct *dead_task)
77 {
78 }
79 
80 /* Prepare to copy thread state - unlazy all lazy status */
81 #define prepare_to_copy(tsk)    do { } while (0)
82 
83 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
84 
85 unsigned long get_wchan(struct task_struct *p);
86 
87 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
88 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->usp)
89 
90 #define task_pt_regs(p) \
91 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
92 
93 #define cpu_relax() barrier()
94 
95 #endif /* __ASM_CSKY_PROCESSOR_H */
96