xref: /openbmc/linux/arch/csky/include/asm/processor.h (revision 47010c04)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #ifndef __ASM_CSKY_PROCESSOR_H
4 #define __ASM_CSKY_PROCESSOR_H
5 
6 #include <linux/bitops.h>
7 #include <asm/ptrace.h>
8 #include <asm/current.h>
9 #include <asm/cache.h>
10 #include <abi/reg_ops.h>
11 #include <abi/regdef.h>
12 #include <abi/switch_context.h>
13 #ifdef CONFIG_CPU_HAS_FPU
14 #include <abi/fpu.h>
15 #endif
16 
17 struct cpuinfo_csky {
18 	unsigned long asid_cache;
19 } __aligned(SMP_CACHE_BYTES);
20 
21 extern struct cpuinfo_csky cpu_data[];
22 
23 /*
24  * User space process size: 2GB. This is hardcoded into a few places,
25  * so don't change it unless you know what you are doing.  TASK_SIZE
26  * for a 64 bit kernel expandable to 8192EB, of which the current CSKY
27  * implementations will "only" be able to use 1TB ...
28  */
29 #define TASK_SIZE	(PAGE_OFFSET - (PAGE_SIZE * 8))
30 
31 #ifdef __KERNEL__
32 #define STACK_TOP       TASK_SIZE
33 #define STACK_TOP_MAX   STACK_TOP
34 #endif
35 
36 /* This decides where the kernel will search for a free chunk of vm
37  * space during mmap's.
38  */
39 #define TASK_UNMAPPED_BASE      (TASK_SIZE / 3)
40 
41 struct thread_struct {
42 	unsigned long  sp;        /* kernel stack pointer */
43 	unsigned long  trap_no;   /* saved status register */
44 
45 	/* FPU regs */
46 	struct user_fp __aligned(16) user_fp;
47 };
48 
49 #define INIT_THREAD  { \
50 	.sp = sizeof(init_stack) + (unsigned long) &init_stack, \
51 }
52 
53 /*
54  * Do necessary setup to start up a newly executed thread.
55  *
56  * pass the data segment into user programs if it exists,
57  * it can't hurt anything as far as I can tell
58  */
59 #define start_thread(_regs, _pc, _usp)					\
60 do {									\
61 	(_regs)->pc = (_pc);						\
62 	(_regs)->regs[1] = 0; /* ABIV1 is R7, uClibc_main rtdl arg */	\
63 	(_regs)->regs[2] = 0;						\
64 	(_regs)->regs[3] = 0; /* ABIV2 is R7, use it? */		\
65 	(_regs)->sr &= ~PS_S;						\
66 	(_regs)->usp = (_usp);						\
67 } while (0)
68 
69 /* Forward declaration, a strange C thing */
70 struct task_struct;
71 
72 /* Free all resources held by a thread. */
73 static inline void release_thread(struct task_struct *dead_task)
74 {
75 }
76 
77 /* Prepare to copy thread state - unlazy all lazy status */
78 #define prepare_to_copy(tsk)    do { } while (0)
79 
80 extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
81 
82 unsigned long __get_wchan(struct task_struct *p);
83 
84 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
85 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->usp)
86 
87 #define task_pt_regs(p) \
88 	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
89 
90 #define cpu_relax() barrier()
91 
92 #endif /* __ASM_CSKY_PROCESSOR_H */
93