linux/arch/riscv/kernel/vdso
Andrew Waterman 921ebd8f2c RISC-V: Allow userspace to flush the instruction cache
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.

This patch adds both a system call and a VDSO entry.  If possible, we'd
like to avoid having the system call be considered part of the
user-facing ABI and instead restrict that to the VDSO entry -- both just
in general to avoid having additional user-visible ABI to maintain, and
because we'd prefer that users just call the VDSO entry because there
might be a better way to do this in the future (ie, one that doesn't
require entering the kernel).

Signed-off-by: Andrew Waterman <andrew@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-11-30 12:58:29 -08:00
..
.gitignore RISC-V: User-facing API 2017-09-26 15:26:48 -07:00
clock_getres.S RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu 2017-11-27 07:51:39 -08:00
clock_gettime.S RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu 2017-11-27 07:51:39 -08:00
flush_icache.S RISC-V: Allow userspace to flush the instruction cache 2017-11-30 12:58:29 -08:00
getcpu.S RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu 2017-11-27 07:51:39 -08:00
gettimeofday.S RISC-V: Add VDSO entries for clock_get/gettimeofday/getcpu 2017-11-27 07:51:39 -08:00
Makefile RISC-V: Allow userspace to flush the instruction cache 2017-11-30 12:58:29 -08:00
rt_sigreturn.S RISC-V: User-facing API 2017-09-26 15:26:48 -07:00
vdso.lds.S RISC-V: Allow userspace to flush the instruction cache 2017-11-30 12:58:29 -08:00
vdso.S RISC-V: User-facing API 2017-09-26 15:26:48 -07:00