1 /* SPDX-License-Identifier: GPL-2.0-only */
3 * Copyright (C) 2012 Regents of the University of California
6 #ifndef _ASM_RISCV_PROCESSOR_H
7 #define _ASM_RISCV_PROCESSOR_H
9 #include <linux/const.h>
10 #include <linux/cache.h>
11 #include <linux/prctl.h>
13 #include <vdso/processor.h>
15 #include <asm/ptrace.h>
17 #define arch_get_mmap_end(addr, len, flags) \
19 unsigned long mmap_end; \
20 typeof(addr) _addr = (addr); \
22 (IS_ENABLED(CONFIG_COMPAT) && is_compat_task()) || \
23 ((_addr + len) > BIT(VA_BITS - 1))) \
24 mmap_end = STACK_TOP_MAX; \
26 mmap_end = (_addr + len); \
30 #define arch_get_mmap_base(addr, base) \
32 unsigned long mmap_base; \
33 typeof(addr) _addr = (addr); \
34 typeof(base) _base = (base); \
35 unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
37 (IS_ENABLED(CONFIG_COMPAT) && is_compat_task()) || \
38 ((_addr + len) > BIT(VA_BITS - 1))) \
39 mmap_base = (_base); \
41 mmap_base = (_addr + len) - rnd_gap; \
46 #define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1))
47 #define STACK_TOP_MAX TASK_SIZE_64
49 #define DEFAULT_MAP_WINDOW TASK_SIZE
50 #define STACK_TOP_MAX TASK_SIZE
52 #define STACK_ALIGN 16
54 #define STACK_TOP DEFAULT_MAP_WINDOW
57 * This decides where the kernel will search for a free chunk of vm
58 * space during mmap's.
61 #define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
63 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
72 * We use a flag to track in-kernel Vector context. Currently the flag has the
75 * - bit 0: indicates whether the in-kernel Vector context is active. The
76 * activation of this state disables the preemption. On a non-RT kernel, it
78 * - bits 8: is used for tracking preemptible kernel-mode Vector, when
79 * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not
80 * disable the preemption if the thread's kernel_vstate.datap is allocated.
81 * Instead, the kernel set this bit field. Then the trap entry/exit code
82 * knows if we are entering/exiting the context that owns preempt_v.
83 * - 0: the task is not using preempt_v
84 * - 1: the task is actively using preempt_v. But whether does the task own
85 * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK.
86 * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine
87 * when preempt_v starts:
88 * - 0: the task is actively using, and own preempt_v context.
89 * - non-zero: the task was using preempt_v, but then took a trap within.
90 * Thus, the task does not own preempt_v. Any use of Vector will have to
91 * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode
93 * - bit 30: The in-kernel preempt_v context is saved, and requries to be
94 * restored when returning to the context that owns the preempt_v.
95 * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the
96 * trap entry code. Any context switches out-of current task need to save
97 * it to the task's in-kernel V context. Also, any traps nesting on-top-of
98 * preempt_v requesting to use V needs a save.
100 #define RISCV_V_CTX_DEPTH_MASK 0x00ff0000
102 #define RISCV_V_CTX_UNIT_DEPTH 0x00010000
103 #define RISCV_KERNEL_MODE_V 0x00000001
104 #define RISCV_PREEMPT_V 0x00000100
105 #define RISCV_PREEMPT_V_DIRTY 0x80000000
106 #define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000
108 /* CPU-specific state of a task */
109 struct thread_struct {
110 /* Callee-saved registers */
112 unsigned long sp; /* Kernel mode stack */
113 unsigned long s[12]; /* s[0]: frame pointer */
114 struct __riscv_d_ext_state fstate;
115 unsigned long bad_cause;
118 struct __riscv_v_ext_state vstate;
119 unsigned long align_ctl;
120 struct __riscv_v_ext_state kernel_vstate;
123 /* Whitelist the fstate from the task_struct for hardened usercopy */
124 static inline void arch_thread_struct_whitelist(unsigned long *offset,
127 *offset = offsetof(struct thread_struct, fstate);
128 *size = sizeof_field(struct thread_struct, fstate);
131 #define INIT_THREAD { \
132 .sp = sizeof(init_stack) + (long)&init_stack, \
133 .align_ctl = PR_UNALIGN_NOPRINT, \
136 #define task_pt_regs(tsk) \
137 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \
138 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
140 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc)
141 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
144 /* Do necessary setup to start up a newly executed thread. */
145 extern void start_thread(struct pt_regs *regs,
146 unsigned long pc, unsigned long sp);
148 extern unsigned long __get_wchan(struct task_struct *p);
151 static inline void wait_for_interrupt(void)
153 __asm__ __volatile__ ("wfi");
156 extern phys_addr_t dma32_phys_limit;
159 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
160 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
161 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
163 extern void riscv_fill_hwcap(void);
164 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
166 extern unsigned long signal_minsigstksz __ro_after_init;
168 #ifdef CONFIG_RISCV_ISA_V
169 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
170 #define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg)
171 #define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current()
172 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
173 extern long riscv_v_vstate_ctrl_get_current(void);
174 #endif /* CONFIG_RISCV_ISA_V */
176 extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr);
177 extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
179 #define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr))
180 #define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val))
182 #endif /* __ASSEMBLY__ */
184 #endif /* _ASM_RISCV_PROCESSOR_H */