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 #include <asm/insn-def.h> 17 #include <asm/alternative-macros.h> 18 #include <asm/hwcap.h> 19 #include <asm/usercfi.h> 20 21 #define arch_get_mmap_end(addr, len, flags) \ 22 ({ \ 23 STACK_TOP_MAX; \ 24 }) 25 26 #define arch_get_mmap_base(addr, base) \ 27 ({ \ 28 base; \ 29 }) 30 31 #ifdef CONFIG_64BIT 32 #define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1)) 33 #define STACK_TOP_MAX TASK_SIZE_64 34 #else 35 #define DEFAULT_MAP_WINDOW TASK_SIZE 36 #define STACK_TOP_MAX TASK_SIZE 37 #endif 38 #define STACK_ALIGN 16 39 40 #define STACK_TOP DEFAULT_MAP_WINDOW 41 42 #ifdef CONFIG_MMU 43 #define user_max_virt_addr() arch_get_mmap_end(ULONG_MAX, 0, 0) 44 #else 45 #define user_max_virt_addr() 0 46 #endif /* CONFIG_MMU */ 47 48 /* 49 * This decides where the kernel will search for a free chunk of vm 50 * space during mmap's. 51 */ 52 #ifdef CONFIG_64BIT 53 #define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3) 54 #else 55 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) 56 #endif 57 58 #ifndef __ASSEMBLER__ 59 60 struct task_struct; 61 struct pt_regs; 62 63 /* 64 * We use a flag to track in-kernel Vector context. Currently the flag has the 65 * following meaning: 66 * 67 * - bit 0: indicates whether the in-kernel Vector context is active. The 68 * activation of this state disables the preemption. On a non-RT kernel, it 69 * also disable bh. 70 * - bit 1: tells kvm that the vcpu process has guest context saved in vcpu's 71 * context memory and need to be restore upon returing back to the guest. 72 * - bit 2: represents that the vector context has now loaded and belongs to 73 * the guest kernel. Any non-scheduler context saving routing needs to save 74 * the register file to vcpu's context memory. The bit is set upon returing 75 * back to the guest and cleared after loading the host's vector context. 76 * - bits 8: is used for tracking preemptible kernel-mode Vector, when 77 * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not 78 * disable the preemption if the thread's kernel_vstate.datap is allocated. 79 * Instead, the kernel set this bit field. Then the trap entry/exit code 80 * knows if we are entering/exiting the context that owns preempt_v. 81 * - 0: the task is not using preempt_v 82 * - 1: the task is actively using preempt_v. But whether does the task own 83 * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK. 84 * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine 85 * when preempt_v starts: 86 * - 0: the task is actively using, and own preempt_v context. 87 * - non-zero: the task was using preempt_v, but then took a trap within. 88 * Thus, the task does not own preempt_v. Any use of Vector will have to 89 * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode 90 * Vector. 91 * - bit 29: The thread voluntarily calls schedule() while holding an active 92 * preempt_v. All preempt_v context should be dropped in such case because 93 * V-regs are caller-saved. Only sstatus.VS=ON is persisted across a 94 * schedule() call. 95 * - bit 30: The in-kernel preempt_v context is saved, and is required to be 96 * restored when returning to the context that owns the preempt_v. 97 * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the 98 * trap entry code. Any context switches out-of current task need to save 99 * it to the task's in-kernel V context. Also, any traps nesting on-top-of 100 * preempt_v requesting to use V needs a save. 101 */ 102 #define RISCV_V_CTX_DEPTH_MASK 0x00ff0000 103 104 #define RISCV_V_CTX_UNIT_DEPTH 0x00010000 105 #define RISCV_KERNEL_MODE_V 0x00000001 106 #define RISCV_V_VCPU_NEED_RESTORE 0x00000002 107 #define RISCV_V_VCPU_CTX 0x00000004 108 #define RISCV_PREEMPT_V 0x00000100 109 #define RISCV_PREEMPT_V_DIRTY 0x80000000 110 #define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000 111 #define RISCV_PREEMPT_V_IN_SCHEDULE 0x20000000 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 unsigned long envcfg; 122 unsigned long sum; 123 u32 riscv_v_flags; 124 u32 vstate_ctrl; 125 struct __riscv_v_ext_state vstate; 126 unsigned long align_ctl; 127 struct __riscv_v_ext_state kernel_vstate; 128 #ifdef CONFIG_SMP 129 /* Flush the icache on migration */ 130 bool force_icache_flush; 131 /* A forced icache flush is not needed if migrating to the previous cpu. */ 132 unsigned int prev_cpu; 133 #endif 134 }; 135 136 /* Whitelist the fstate from the task_struct for hardened usercopy */ 137 static inline void arch_thread_struct_whitelist(unsigned long *offset, 138 unsigned long *size) 139 { 140 *offset = offsetof(struct thread_struct, fstate); 141 *size = sizeof_field(struct thread_struct, fstate); 142 } 143 144 #define INIT_THREAD { \ 145 .sp = sizeof(init_stack) + (long)&init_stack, \ 146 .align_ctl = PR_UNALIGN_NOPRINT, \ 147 } 148 149 #define task_pt_regs(tsk) \ 150 ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \ 151 - ALIGN(sizeof(struct pt_regs), STACK_ALIGN))) 152 153 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc) 154 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp) 155 156 #define PREFETCH_ASM(x) \ 157 ALTERNATIVE(__nops(1), PREFETCH_R(x, 0), 0, \ 158 RISCV_ISA_EXT_ZICBOP, CONFIG_RISCV_ISA_ZICBOP) 159 160 #define PREFETCHW_ASM(x) \ 161 ALTERNATIVE(__nops(1), PREFETCH_W(x, 0), 0, \ 162 RISCV_ISA_EXT_ZICBOP, CONFIG_RISCV_ISA_ZICBOP) 163 164 #ifdef CONFIG_RISCV_ISA_ZICBOP 165 #define ARCH_HAS_PREFETCH 166 static inline void prefetch(const void *x) 167 { 168 __asm__ __volatile__(PREFETCH_ASM(%0) : : "r" (x) : "memory"); 169 } 170 171 #define ARCH_HAS_PREFETCHW 172 static inline void prefetchw(const void *x) 173 { 174 __asm__ __volatile__(PREFETCHW_ASM(%0) : : "r" (x) : "memory"); 175 } 176 #endif /* CONFIG_RISCV_ISA_ZICBOP */ 177 178 /* Do necessary setup to start up a newly executed thread. */ 179 extern void start_thread(struct pt_regs *regs, 180 unsigned long pc, unsigned long sp); 181 182 extern unsigned long __get_wchan(struct task_struct *p); 183 184 185 static inline void wait_for_interrupt(void) 186 { 187 __asm__ __volatile__ ("wfi"); 188 } 189 190 extern phys_addr_t dma32_phys_limit; 191 192 struct device_node; 193 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid); 194 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid); 195 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid); 196 197 extern void riscv_fill_hwcap(void); 198 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); 199 200 extern unsigned long signal_minsigstksz __ro_after_init; 201 202 #ifdef CONFIG_RISCV_ISA_V 203 /* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */ 204 #define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg) 205 #define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current() 206 extern long riscv_v_vstate_ctrl_set_current(unsigned long arg); 207 extern long riscv_v_vstate_ctrl_get_current(void); 208 #endif /* CONFIG_RISCV_ISA_V */ 209 210 extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr); 211 extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val); 212 213 #define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr)) 214 #define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val)) 215 216 #define RISCV_SET_ICACHE_FLUSH_CTX(arg1, arg2) riscv_set_icache_flush_ctx(arg1, arg2) 217 extern int riscv_set_icache_flush_ctx(unsigned long ctx, unsigned long per_thread); 218 219 #ifdef CONFIG_RISCV_ISA_SUPM 220 /* PR_{SET,GET}_TAGGED_ADDR_CTRL prctl */ 221 long set_tagged_addr_ctrl(struct task_struct *task, unsigned long arg); 222 long get_tagged_addr_ctrl(struct task_struct *task); 223 #define SET_TAGGED_ADDR_CTRL(arg) set_tagged_addr_ctrl(current, arg) 224 #define GET_TAGGED_ADDR_CTRL() get_tagged_addr_ctrl(current) 225 #endif 226 227 #endif /* __ASSEMBLER__ */ 228 229 #endif /* _ASM_RISCV_PROCESSOR_H */ 230