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