xref: /openbmc/linux/arch/riscv/include/asm/processor.h (revision 6db6b729)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  */
5 
6 #ifndef _ASM_RISCV_PROCESSOR_H
7 #define _ASM_RISCV_PROCESSOR_H
8 
9 #include <linux/const.h>
10 #include <linux/cache.h>
11 
12 #include <vdso/processor.h>
13 
14 #include <asm/ptrace.h>
15 
16 #ifdef CONFIG_64BIT
17 #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
18 #define STACK_TOP_MAX		TASK_SIZE_64
19 
20 #define arch_get_mmap_end(addr, len, flags)			\
21 ({								\
22 	unsigned long mmap_end;					\
23 	typeof(addr) _addr = (addr);				\
24 	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
25 		mmap_end = STACK_TOP_MAX;			\
26 	else if ((_addr) >= VA_USER_SV57)			\
27 		mmap_end = STACK_TOP_MAX;			\
28 	else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
29 		mmap_end = VA_USER_SV48;			\
30 	else							\
31 		mmap_end = VA_USER_SV39;			\
32 	mmap_end;						\
33 })
34 
35 #define arch_get_mmap_base(addr, base)				\
36 ({								\
37 	unsigned long mmap_base;				\
38 	typeof(addr) _addr = (addr);				\
39 	typeof(base) _base = (base);				\
40 	unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);	\
41 	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
42 		mmap_base = (_base);				\
43 	else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
44 		mmap_base = VA_USER_SV57 - rnd_gap;		\
45 	else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
46 		mmap_base = VA_USER_SV48 - rnd_gap;		\
47 	else							\
48 		mmap_base = VA_USER_SV39 - rnd_gap;		\
49 	mmap_base;						\
50 })
51 
52 #else
53 #define DEFAULT_MAP_WINDOW	TASK_SIZE
54 #define STACK_TOP_MAX		TASK_SIZE
55 #endif
56 #define STACK_ALIGN		16
57 
58 #define STACK_TOP		DEFAULT_MAP_WINDOW
59 
60 /*
61  * This decides where the kernel will search for a free chunk of vm
62  * space during mmap's.
63  */
64 #ifdef CONFIG_64BIT
65 #define TASK_UNMAPPED_BASE	PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
66 #else
67 #define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
68 #endif
69 
70 #ifndef __ASSEMBLY__
71 
72 struct task_struct;
73 struct pt_regs;
74 
75 /* CPU-specific state of a task */
76 struct thread_struct {
77 	/* Callee-saved registers */
78 	unsigned long ra;
79 	unsigned long sp;	/* Kernel mode stack */
80 	unsigned long s[12];	/* s[0]: frame pointer */
81 	struct __riscv_d_ext_state fstate;
82 	unsigned long bad_cause;
83 	unsigned long vstate_ctrl;
84 	struct __riscv_v_ext_state vstate;
85 };
86 
87 /* Whitelist the fstate from the task_struct for hardened usercopy */
88 static inline void arch_thread_struct_whitelist(unsigned long *offset,
89 						unsigned long *size)
90 {
91 	*offset = offsetof(struct thread_struct, fstate);
92 	*size = sizeof_field(struct thread_struct, fstate);
93 }
94 
95 #define INIT_THREAD {					\
96 	.sp = sizeof(init_stack) + (long)&init_stack,	\
97 }
98 
99 #define task_pt_regs(tsk)						\
100 	((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE		\
101 			    - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
102 
103 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->epc)
104 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->sp)
105 
106 
107 /* Do necessary setup to start up a newly executed thread. */
108 extern void start_thread(struct pt_regs *regs,
109 			unsigned long pc, unsigned long sp);
110 
111 extern unsigned long __get_wchan(struct task_struct *p);
112 
113 
114 static inline void wait_for_interrupt(void)
115 {
116 	__asm__ __volatile__ ("wfi");
117 }
118 
119 struct device_node;
120 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
121 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
122 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
123 
124 extern void riscv_fill_hwcap(void);
125 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
126 
127 extern unsigned long signal_minsigstksz __ro_after_init;
128 
129 #ifdef CONFIG_RISCV_ISA_V
130 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
131 #define RISCV_V_SET_CONTROL(arg)	riscv_v_vstate_ctrl_set_current(arg)
132 #define RISCV_V_GET_CONTROL()		riscv_v_vstate_ctrl_get_current()
133 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
134 extern long riscv_v_vstate_ctrl_get_current(void);
135 #endif /* CONFIG_RISCV_ISA_V */
136 
137 #endif /* __ASSEMBLY__ */
138 
139 #endif /* _ASM_RISCV_PROCESSOR_H */
140