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
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. On a non-RT kernel, it
82 * also disable bh.
83 * - bits 8: is used for tracking preemptible kernel-mode Vector, when
84 * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not
85 * disable the preemption if the thread's kernel_vstate.datap is allocated.
86 * Instead, the kernel set this bit field. Then the trap entry/exit code
87 * knows if we are entering/exiting the context that owns preempt_v.
88 * - 0: the task is not using preempt_v
89 * - 1: the task is actively using preempt_v. But whether does the task own
90 * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK.
91 * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine
92 * when preempt_v starts:
93 * - 0: the task is actively using, and own preempt_v context.
94 * - non-zero: the task was using preempt_v, but then took a trap within.
95 * Thus, the task does not own preempt_v. Any use of Vector will have to
96 * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode
97 * Vector.
98 * - bit 30: The in-kernel preempt_v context is saved, and requries to be
99 * restored when returning to the context that owns the preempt_v.
100 * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the
101 * trap entry code. Any context switches out-of current task need to save
102 * it to the task's in-kernel V context. Also, any traps nesting on-top-of
103 * preempt_v requesting to use V needs a save.
104 */
105 #define RISCV_V_CTX_DEPTH_MASK 0x00ff0000
106
107 #define RISCV_V_CTX_UNIT_DEPTH 0x00010000
108 #define RISCV_KERNEL_MODE_V 0x00000001
109 #define RISCV_PREEMPT_V 0x00000100
110 #define RISCV_PREEMPT_V_DIRTY 0x80000000
111 #define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000
112
113 /* CPU-specific state of a task */
114 struct thread_struct {
115 /* Callee-saved registers */
116 unsigned long ra;
117 unsigned long sp; /* Kernel mode stack */
118 unsigned long s[12]; /* s[0]: frame pointer */
119 struct __riscv_d_ext_state fstate;
120 unsigned long bad_cause;
121 u32 riscv_v_flags;
122 u32 vstate_ctrl;
123 struct __riscv_v_ext_state vstate;
124 unsigned long align_ctl;
125 struct __riscv_v_ext_state kernel_vstate;
126 };
127
128 /* Whitelist the fstate from the task_struct for hardened usercopy */
arch_thread_struct_whitelist(unsigned long * offset,unsigned long * size)129 static inline void arch_thread_struct_whitelist(unsigned long *offset,
130 unsigned long *size)
131 {
132 *offset = offsetof(struct thread_struct, fstate);
133 *size = sizeof_field(struct thread_struct, fstate);
134 }
135
136 #define INIT_THREAD { \
137 .sp = sizeof(init_stack) + (long)&init_stack, \
138 .align_ctl = PR_UNALIGN_NOPRINT, \
139 }
140
141 #define task_pt_regs(tsk) \
142 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \
143 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
144
145 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc)
146 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
147
148
149 /* Do necessary setup to start up a newly executed thread. */
150 extern void start_thread(struct pt_regs *regs,
151 unsigned long pc, unsigned long sp);
152
153 extern unsigned long __get_wchan(struct task_struct *p);
154
155
wait_for_interrupt(void)156 static inline void wait_for_interrupt(void)
157 {
158 __asm__ __volatile__ ("wfi");
159 }
160
161 extern phys_addr_t dma32_phys_limit;
162
163 struct device_node;
164 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
165 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
166 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
167
168 extern void riscv_fill_hwcap(void);
169 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
170
171 extern unsigned long signal_minsigstksz __ro_after_init;
172
173 #ifdef CONFIG_RISCV_ISA_V
174 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
175 #define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg)
176 #define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current()
177 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
178 extern long riscv_v_vstate_ctrl_get_current(void);
179 #endif /* CONFIG_RISCV_ISA_V */
180
181 extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr);
182 extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
183
184 #define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr))
185 #define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val))
186
187 #endif /* __ASSEMBLY__ */
188
189 #endif /* _ASM_RISCV_PROCESSOR_H */
190