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/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2014 Darius Rad <darius@bluespec.com>
* Copyright (C) 2017 SiFive
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/syscalls.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm-generic/mman-common.h>
static long 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)
{
if (unlikely(offset & (~PAGE_MASK >> page_shift_offset)))
return -EINVAL;
if ((prot & PROT_WRITE) && (prot & PROT_EXEC))
if (unlikely(!(prot & PROT_READ)))
return -EINVAL;
return ksys_mmap_pgoff(addr, len, prot, flags, fd,
offset >> (PAGE_SHIFT - page_shift_offset));
}
#ifdef CONFIG_64BIT
SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
{
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
}
#else
SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
unsigned long, prot, unsigned long, flags,
unsigned long, fd, off_t, offset)
{
/*
* Note that the shift for mmap2 is constant (12),
* regardless of PAGE_SIZE
*/
return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
}
#endif /* !CONFIG_64BIT */
/*
* Allows the instruction cache to be flushed from userspace. Despite RISC-V
* having a direct 'fence.i' instruction available to userspace (which we
* can't trap!), that's not actually viable when running on Linux because the
* kernel might schedule a process on another hart. There is no way for
* userspace to handle this without invoking the kernel (as it doesn't know the
* thread->hart mappings), so we've defined a RISC-V specific system call to
* flush the instruction cache.
*
* sys_riscv_flush_icache() is defined to flush the instruction cache over an
* address range, with the flush applying to either all threads or just the
* caller. We don't currently do anything with the address range, that's just
* in there for forwards compatibility.
*/
SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end,
uintptr_t, flags)
{
/* Check the reserved flags. */
if (unlikely(flags & ~SYS_RISCV_FLUSH_ICACHE_ALL))
return -EINVAL;
flush_icache_mm(current->mm, flags & SYS_RISCV_FLUSH_ICACHE_LOCAL);
return 0;
}
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