[PATCH] powerpc: silence a -Wcast-function-type warning in dawr_write_file_bool

[Mathieu Malaterre <malat@debian.org>]

In commit c1fe190c0672 ("powerpc: Add force enable of DAWR on P9
option") the following piece of code was added:

   smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);

Since GCC 8 this trigger the following warning about incompatible
function types:

  arch/powerpc/kernel/hw_breakpoint.c:408:21: error: cast between incompatible function types from 'int (*)(struct arch_hw_breakpoint *)' to 'void (*)(void *)' [-Werror=cast-function-type]

Cast the function to an intermediate (void*) to make the compiler loose
knowledge about actual type.

Fixes: c1fe190c0672 ("powerpc: Add force enable of DAWR on P9 option")
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
---
 arch/powerpc/kernel/hw_breakpoint.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/hw_breakpoint.c b/arch/powerpc/kernel/hw_breakpoint.c
index f70fb89dbf60..baeb4c58de3b 100644
--- a/arch/powerpc/kernel/hw_breakpoint.c
+++ b/arch/powerpc/kernel/hw_breakpoint.c
@@ -405,7 +405,8 @@ static ssize_t dawr_write_file_bool(struct file *file,
 
 	/* If we are clearing, make sure all CPUs have the DAWR cleared */
 	if (!dawr_force_enable)
-		smp_call_function((smp_call_func_t)set_dawr, &null_brk, 0);
+		smp_call_function((smp_call_func_t)(void *)set_dawr,
+				  &null_brk, 0);
 
 	return rc;
 }
-- 
2.20.1