Blackfin: add new cacheflush syscall

Flushing caches sometimes requires anomaly workarounds which require
supervisor-only insns.  Normally we don't need to flush caches from
userspace so this isn't a problem, but when gcc generates trampolines
on the stack, we do.

So add a new syscall for gcc to use modeled after the mips version.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/sys_bfin.c b/arch/blackfin/kernel/sys_bfin.c
index bdc1e2f0da32..89448ed7065d 100644
--- a/arch/blackfin/kernel/sys_bfin.c
+++ b/arch/blackfin/kernel/sys_bfin.c
@@ -21,6 +21,8 @@
 
 #include <asm/cacheflush.h>
 #include <asm/dma.h>
+#include <asm/cachectl.h>
+#include <asm/ptrace.h>
 
 asmlinkage void *sys_sram_alloc(size_t size, unsigned long flags)
 {
@@ -70,3 +72,16 @@ asmlinkage int sys_bfin_spinlock(int *p)
 
         return ret;
 }
+
+SYSCALL_DEFINE3(cacheflush, unsigned long, addr, unsigned long, len, int, op)
+{
+        if (is_user_addr_valid(current, addr, len) != 0)
+                return -EINVAL;
+
+        if (op & DCACHE)
+                blackfin_dcache_flush_range(addr, addr + len);
+        if (op & ICACHE)
+                blackfin_icache_flush_range(addr, addr + len);
+
+        return 0;
+}