diff options
Diffstat (limited to 'arch/riscv/kernel')
-rw-r--r-- | arch/riscv/kernel/sys_riscv.c | 32 | ||||
-rw-r--r-- | arch/riscv/kernel/syscall_table.c | 2 | ||||
-rw-r--r-- | arch/riscv/kernel/vdso/Makefile | 1 | ||||
-rw-r--r-- | arch/riscv/kernel/vdso/flush_icache.S | 31 | ||||
-rw-r--r-- | arch/riscv/kernel/vdso/vdso.lds.S | 1 |
5 files changed, 67 insertions, 0 deletions
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 4351be7d0533..c6c037eabaf6 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -16,6 +16,7 @@ #include <linux/syscalls.h> #include <asm/cmpxchg.h> #include <asm/unistd.h> +#include <asm/cacheflush.h> static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -47,3 +48,34 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len, return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12); } #endif /* !CONFIG_64BIT */ + +#ifdef CONFIG_SMP +/* + * 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) +{ + struct mm_struct *mm = current->mm; + bool local = (flags & SYS_RISCV_FLUSH_ICACHE_LOCAL) != 0; + + /* Check the reserved flags. */ + if (unlikely(flags & !SYS_RISCV_FLUSH_ICACHE_ALL)) + return -EINVAL; + + flush_icache_mm(mm, local); + + return 0; +} +#endif diff --git a/arch/riscv/kernel/syscall_table.c b/arch/riscv/kernel/syscall_table.c index 4e30dc5fb593..a5bd6401f95e 100644 --- a/arch/riscv/kernel/syscall_table.c +++ b/arch/riscv/kernel/syscall_table.c @@ -15,6 +15,7 @@ #include <linux/linkage.h> #include <linux/syscalls.h> #include <asm-generic/syscalls.h> +#include <asm/vdso.h> #undef __SYSCALL #define __SYSCALL(nr, call) [nr] = (call), @@ -22,4 +23,5 @@ void *sys_call_table[__NR_syscalls] = { [0 ... __NR_syscalls - 1] = sys_ni_syscall, #include <asm/unistd.h> +#include <asm/vdso-syscalls.h> }; diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile index 2dcc4f3070bc..324568d33921 100644 --- a/arch/riscv/kernel/vdso/Makefile +++ b/arch/riscv/kernel/vdso/Makefile @@ -6,6 +6,7 @@ vdso-syms += gettimeofday vdso-syms += clock_gettime vdso-syms += clock_getres vdso-syms += getcpu +vdso-syms += flush_icache # Files to link into the vdso obj-vdso = $(patsubst %, %.o, $(vdso-syms)) diff --git a/arch/riscv/kernel/vdso/flush_icache.S b/arch/riscv/kernel/vdso/flush_icache.S new file mode 100644 index 000000000000..b0fbad74e873 --- /dev/null +++ b/arch/riscv/kernel/vdso/flush_icache.S @@ -0,0 +1,31 @@ +/* + * 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/linkage.h> +#include <asm/unistd.h> +#include <asm/vdso-syscalls.h> + + .text +/* int __vdso_flush_icache(void *start, void *end, unsigned long flags); */ +ENTRY(__vdso_flush_icache) + .cfi_startproc +#ifdef CONFIG_SMP + li a7, __NR_riscv_flush_icache + ecall +#else + fence.i + li a0, 0 +#endif + ret + .cfi_endproc +ENDPROC(__vdso_flush_icache) diff --git a/arch/riscv/kernel/vdso/vdso.lds.S b/arch/riscv/kernel/vdso/vdso.lds.S index c7543c6a00f9..cd1d47e0724b 100644 --- a/arch/riscv/kernel/vdso/vdso.lds.S +++ b/arch/riscv/kernel/vdso/vdso.lds.S @@ -74,6 +74,7 @@ VERSION __vdso_clock_gettime; __vdso_clock_getres; __vdso_getcpu; + __vdso_flush_icache; local: *; }; } |