1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2012 Regents of the University of California
4 * Copyright (C) 2014 Darius Rad <darius@bluespec.com>
5 * Copyright (C) 2017 SiFive
6 */
7
8#include <linux/syscalls.h>
9#include <asm/cacheflush.h>
10#include <asm-generic/mman-common.h>
11
12static long riscv_sys_mmap(unsigned long addr, unsigned long len,
13			   unsigned long prot, unsigned long flags,
14			   unsigned long fd, off_t offset,
15			   unsigned long page_shift_offset)
16{
17	if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
18		return -EINVAL;
19
20	return ksys_mmap_pgoff(addr, len, prot, flags, fd,
21			       offset >> (PAGE_SHIFT - page_shift_offset));
22}
23
24#ifdef CONFIG_64BIT
25SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
26	unsigned long, prot, unsigned long, flags,
27	unsigned long, fd, off_t, offset)
28{
29	return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
30}
31#endif
32
33#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT)
34SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
35	unsigned long, prot, unsigned long, flags,
36	unsigned long, fd, off_t, offset)
37{
38	/*
39	 * Note that the shift for mmap2 is constant (12),
40	 * regardless of PAGE_SIZE
41	 */
42	return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
43}
44#endif
45
46/*
47 * Allows the instruction cache to be flushed from userspace.  Despite RISC-V
48 * having a direct 'fence.i' instruction available to userspace (which we
49 * can't trap!), that's not actually viable when running on Linux because the
50 * kernel might schedule a process on another hart.  There is no way for
51 * userspace to handle this without invoking the kernel (as it doesn't know the
52 * thread->hart mappings), so we've defined a RISC-V specific system call to
53 * flush the instruction cache.
54 *
55 * sys_riscv_flush_icache() is defined to flush the instruction cache over an
56 * address range, with the flush applying to either all threads or just the
57 * caller.  We don't currently do anything with the address range, that's just
58 * in there for forwards compatibility.
59 */
60SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
61	uintptr_t, flags)
62{
63	/* Check the reserved flags. */
64	if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
65		return -EINVAL;
66
67	flush_icache_mm(current->mm, flags & SYS_RISCV_FLUSH_ICACHE_LOCAL);
68
69	return 0;
70}
71
72/* Not defined using SYSCALL_DEFINE0 to avoid error injection */
73asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *__unused)
74{
75	return -ENOSYS;
76}
77