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 */ 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); 154 155 156 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