SMP: allow compilation with clang

Change-Id: Iec57820d150f2436cb3b7c543f662d3313197a4c

minix/drivers/bus/pci/pci.c

@@ -1959,7 +1959,7 @@ do_pcibridge(int busind)
  *				pci_intel_init				     *
  *===========================================================================*/
 static void
-pci_intel_init()
+pci_intel_init(void)
 {
 	/* Try to detect a know PCI controller. Read the Vendor ID and
 	 * the Device ID for function 0 of device 0.

minix/include/minix/bitmap.h

@@ -19,6 +19,10 @@
 
 #if defined(CONFIG_SMP) && defined(__GNUC__)
 #ifndef __ASSEMBLY__
+
+#include <limits.h>
+#include <sys/types.h>
+
 static inline void bits_fill(bitchunk_t * chunks, unsigned bits)
 {
 	unsigned c, cnt;

minix/kernel/arch/i386/Makefile.inc

@@ -84,6 +84,8 @@ OBJS.kernel+=	${UNPAGED_OBJS}
 
 .ifdef CONFIG_SMP
 SRCS += arch_smp.c trampoline.S
+# trampoline.S uses .code16, which is unsupported by clang.
+AFLAGS.trampoline.S= ${${ACTIVE_CC} == "clang":?-no-integrated-as:}
 .endif
 
 .if ${USE_ACPI} != "no"

minix/kernel/spinlock.h

@@ -19,9 +19,9 @@ typedef struct spinlock {
 #else
 
 /* SMP */
-#define SPINLOCK_DEFINE(name)	spinlock_t name;
+#define SPINLOCK_DEFINE(name)	spinlock_t name = { .val = 0 };
 #define PRIVATE_SPINLOCK_DEFINE(name)	PRIVATE SPINLOCK_DEFINE(name)
-#define SPINLOCK_DECLARE(name)	extern SPINLOCK_DEFINE(name)
+#define SPINLOCK_DECLARE(name)	extern spinlock_t name;
 #define spinlock_init(sl) do { (sl)->val = 0; } while (0)
 
 #if CONFIG_MAX_CPUS == 1