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
riscv_sys_mmap(unsigned long addr,unsigned long len,unsigned long prot,unsigned long flags,unsigned long fd,off_t offset,unsigned long page_shift_offset)13 static 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 if ((prot & PROT_WRITE) && (prot & PROT_EXEC))
22 if (unlikely(!(prot & PROT_READ)))
23 return -EINVAL;
24
25 return ksys_mmap_pgoff(addr, len, prot, flags, fd,
26 offset >> (PAGE_SHIFT - page_shift_offset));
27 }
28
29 #ifdef CONFIG_64BIT
SYSCALL_DEFINE6(mmap,unsigned long,addr,unsigned long,len,unsigned long,prot,unsigned long,flags,unsigned long,fd,off_t,offset)30 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
31 unsigned long, prot, unsigned long, flags,
32 unsigned long, fd, off_t, offset)
33 {
34 return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
35 }
36 #else
SYSCALL_DEFINE6(mmap2,unsigned long,addr,unsigned long,len,unsigned long,prot,unsigned long,flags,unsigned long,fd,off_t,offset)37 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
38 unsigned long, prot, unsigned long, flags,
39 unsigned long, fd, off_t, offset)
40 {
41 /*
42 * Note that the shift for mmap2 is constant (12),
43 * regardless of PAGE_SIZE
44 */
45 return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
46 }
47 #endif /* !CONFIG_64BIT */
48
49 /*
50 * Allows the instruction cache to be flushed from userspace. Despite RISC-V
51 * having a direct 'fence.i' instruction available to userspace (which we
52 * can't trap!), that's not actually viable when running on Linux because the
53 * kernel might schedule a process on another hart. There is no way for
54 * userspace to handle this without invoking the kernel (as it doesn't know the
55 * thread->hart mappings), so we've defined a RISC-V specific system call to
56 * flush the instruction cache.
57 *
58 * sys_riscv_flush_icache() is defined to flush the instruction cache over an
59 * address range, with the flush applying to either all threads or just the
60 * caller. We don't currently do anything with the address range, that's just
61 * in there for forwards compatibility.
62 */
SYSCALL_DEFINE3(riscv_flush_icache,uintptr_t,start,uintptr_t,end,uintptr_t,flags)63 SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
64 uintptr_t, flags)
65 {
66 /* Check the reserved flags. */
67 if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
68 return -EINVAL;
69
70 flush_icache_mm(current->mm, flags & SYS_RISCV_FLUSH_ICACHE_LOCAL);
71
72 return 0;
73 }
74