uapi: simplify __ARCH_FLOCK{,64}_PAD a little

Don't bother to define the symbols empty, just don't use them.
That makes the intent a little more clear.

Remove the unused HAVE_ARCH_STRUCT_FLOCK64 define and merge the
32-bit mips struct flock into the generic one.

Add a new __ARCH_FLOCK_EXTRA_SYSID macro following the style of
__ARCH_FLOCK_PAD to avoid having a separate definition just for
one architecture.

Signed-off-by: Christoph Hellwig <[e-mail]>
Signed-off-by: Guo Ren <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Tested-by: Heiko Stuebner <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Palmer Dabbelt <[e-mail]>

arch/mips/include/uapi/asm/fcntl.h

···
 #define F_SETLKW64	35
 #endif
 
-/*
- * The flavours of struct flock.  "struct flock" is the ABI compliant
- * variant.  Finally struct flock64 is the LFS variant of struct flock.	 As
- * a historic accident and inconsistence with the ABI definition it doesn't
- * contain all the same fields as struct flock.
- */
-
 #if _MIPS_SIM != _MIPS_SIM_ABI64
-
-#include <linux/types.h>
-
-struct flock {
-	short	l_type;
-	short	l_whence;
-	__kernel_off_t	l_start;
-	__kernel_off_t	l_len;
-	long	l_sysid;
-	__kernel_pid_t l_pid;
-	long	pad[4];
-};
-
-#define HAVE_ARCH_STRUCT_FLOCK
-
-#endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
+#define __ARCH_FLOCK_EXTRA_SYSID	long l_sysid;
+#define __ARCH_FLOCK_PAD		long pad[4];
+#endif
 
 #include <asm-generic/fcntl.h>
 

include/uapi/asm-generic/fcntl.h

···
 
 #define F_LINUX_SPECIFIC_BASE	1024
 
-#ifndef HAVE_ARCH_STRUCT_FLOCK
-#ifndef __ARCH_FLOCK_PAD
-#define __ARCH_FLOCK_PAD
-#endif
-
 struct flock {
 	short	l_type;
 	short	l_whence;
 	__kernel_off_t	l_start;
 	__kernel_off_t	l_len;
 	__kernel_pid_t	l_pid;
+#ifdef	__ARCH_FLOCK_EXTRA_SYSID
+	__ARCH_FLOCK_EXTRA_SYSID
+#endif
+#ifdef	__ARCH_FLOCK_PAD
 	__ARCH_FLOCK_PAD
+#endif
 };
-#endif
-
-#ifndef HAVE_ARCH_STRUCT_FLOCK64
-#ifndef __ARCH_FLOCK64_PAD
-#define __ARCH_FLOCK64_PAD
-#endif
 
 struct flock64 {
 	short  l_type;
···
 	__kernel_loff_t l_start;
 	__kernel_loff_t l_len;
 	__kernel_pid_t  l_pid;
+#ifdef	__ARCH_FLOCK64_PAD
 	__ARCH_FLOCK64_PAD
-};
 #endif
+};
 
 #endif /* _ASM_GENERIC_FCNTL_H */

tools/include/uapi/asm-generic/fcntl.h

···
 
 #define F_LINUX_SPECIFIC_BASE	1024
 
-#ifndef HAVE_ARCH_STRUCT_FLOCK
-#ifndef __ARCH_FLOCK_PAD
-#define __ARCH_FLOCK_PAD
-#endif
-
 struct flock {
 	short	l_type;
 	short	l_whence;
 	__kernel_off_t	l_start;
 	__kernel_off_t	l_len;
 	__kernel_pid_t	l_pid;
+#ifdef	__ARCH_FLOCK_EXTRA_SYSID
+	__ARCH_FLOCK_EXTRA_SYSID
+#endif
+#ifdef	__ARCH_FLOCK_PAD
 	__ARCH_FLOCK_PAD
+#endif
 };
-#endif
-
-#ifndef HAVE_ARCH_STRUCT_FLOCK64
-#ifndef __ARCH_FLOCK64_PAD
-#define __ARCH_FLOCK64_PAD
-#endif
 
 struct flock64 {
 	short  l_type;
···
 	__kernel_loff_t l_start;
 	__kernel_loff_t l_len;
 	__kernel_pid_t  l_pid;
+#ifdef	__ARCH_FLOCK64_PAD
 	__ARCH_FLOCK64_PAD
-};
 #endif
+};
 
 #endif /* _ASM_GENERIC_FCNTL_H */