xref: /linux-6.15/arch/riscv/include/asm/processor.h (revision ecd2ada8)
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 #include <linux/prctl.h>
12 
13 #include <vdso/processor.h>
14 
15 #include <asm/ptrace.h>
16 
17 #ifdef CONFIG_64BIT
18 #define DEFAULT_MAP_WINDOW	(UL(1) << (MMAP_VA_BITS - 1))
19 #define STACK_TOP_MAX		TASK_SIZE_64
20 
21 #define arch_get_mmap_end(addr, len, flags)			\
22 ({								\
23 	unsigned long mmap_end;					\
24 	typeof(addr) _addr = (addr);				\
25 	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
26 		mmap_end = STACK_TOP_MAX;			\
27 	else if ((_addr) >= VA_USER_SV57)			\
28 		mmap_end = STACK_TOP_MAX;			\
29 	else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
30 		mmap_end = VA_USER_SV48;			\
31 	else							\
32 		mmap_end = VA_USER_SV39;			\
33 	mmap_end;						\
34 })
35 
36 #define arch_get_mmap_base(addr, base)				\
37 ({								\
38 	unsigned long mmap_base;				\
39 	typeof(addr) _addr = (addr);				\
40 	typeof(base) _base = (base);				\
41 	unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base);	\
42 	if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
43 		mmap_base = (_base);				\
44 	else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
45 		mmap_base = VA_USER_SV57 - rnd_gap;		\
46 	else if ((((_addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \
47 		mmap_base = VA_USER_SV48 - rnd_gap;		\
48 	else							\
49 		mmap_base = VA_USER_SV39 - rnd_gap;		\
50 	mmap_base;						\
51 })
52 
53 #else
54 #define DEFAULT_MAP_WINDOW	TASK_SIZE
55 #define STACK_TOP_MAX		TASK_SIZE
56 #endif
57 #define STACK_ALIGN		16
58 
59 #define STACK_TOP		DEFAULT_MAP_WINDOW
60 
61 /*
62  * This decides where the kernel will search for a free chunk of vm
63  * space during mmap's.
64  */
65 #ifdef CONFIG_64BIT
66 #define TASK_UNMAPPED_BASE	PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
67 #else
68 #define TASK_UNMAPPED_BASE	PAGE_ALIGN(TASK_SIZE / 3)
69 #endif
70 
71 #ifndef __ASSEMBLY__
72 
73 struct task_struct;
74 struct pt_regs;
75 
76 /*
77  * We use a flag to track in-kernel Vector context. Currently the flag has the
78  * following meaning:
79  *
80  *  - bit 0: indicates whether the in-kernel Vector context is active. The
81  *    activation of this state disables the preemption.
82  */
83 #define RISCV_KERNEL_MODE_V	0x1
84 
85 /* CPU-specific state of a task */
86 struct thread_struct {
87 	/* Callee-saved registers */
88 	unsigned long ra;
89 	unsigned long sp;	/* Kernel mode stack */
90 	unsigned long s[12];	/* s[0]: frame pointer */
91 	struct __riscv_d_ext_state fstate;
92 	unsigned long bad_cause;
93 	u32 riscv_v_flags;
94 	u32 vstate_ctrl;
95 	struct __riscv_v_ext_state vstate;
96 	unsigned long align_ctl;
97 };
98 
99 /* Whitelist the fstate from the task_struct for hardened usercopy */
100 static inline void arch_thread_struct_whitelist(unsigned long *offset,
101 						unsigned long *size)
102 {
103 	*offset = offsetof(struct thread_struct, fstate);
104 	*size = sizeof_field(struct thread_struct, fstate);
105 }
106 
107 #define INIT_THREAD {					\
108 	.sp = sizeof(init_stack) + (long)&init_stack,	\
109 	.align_ctl = PR_UNALIGN_NOPRINT,		\
110 }
111 
112 #define task_pt_regs(tsk)						\
113 	((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE		\
114 			    - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
115 
116 #define KSTK_EIP(tsk)		(task_pt_regs(tsk)->epc)
117 #define KSTK_ESP(tsk)		(task_pt_regs(tsk)->sp)
118 
119 
120 /* Do necessary setup to start up a newly executed thread. */
121 extern void start_thread(struct pt_regs *regs,
122 			unsigned long pc, unsigned long sp);
123 
124 extern unsigned long __get_wchan(struct task_struct *p);
125 
126 
127 static inline void wait_for_interrupt(void)
128 {
129 	__asm__ __volatile__ ("wfi");
130 }
131 
132 extern phys_addr_t dma32_phys_limit;
133 
134 struct device_node;
135 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
136 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
137 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
138 
139 extern void riscv_fill_hwcap(void);
140 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
141 
142 extern unsigned long signal_minsigstksz __ro_after_init;
143 
144 #ifdef CONFIG_RISCV_ISA_V
145 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
146 #define RISCV_V_SET_CONTROL(arg)	riscv_v_vstate_ctrl_set_current(arg)
147 #define RISCV_V_GET_CONTROL()		riscv_v_vstate_ctrl_get_current()
148 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
149 extern long riscv_v_vstate_ctrl_get_current(void);
150 #endif /* CONFIG_RISCV_ISA_V */
151 
152 extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr);
153 extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
154 
155 #define GET_UNALIGN_CTL(tsk, addr)	get_unalign_ctl((tsk), (addr))
156 #define SET_UNALIGN_CTL(tsk, val)	set_unalign_ctl((tsk), (val))
157 
158 #endif /* __ASSEMBLY__ */
159 
160 #endif /* _ASM_RISCV_PROCESSOR_H */
161