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