Merge tag 'asm-generic-cleanup-5.11' of git://git.kernel.org/pub/scm/…

…linux/kernel/git/arnd/asm-generic

Pull asm-generic cleanups from Arnd Bergmann:
 "These are a couple of compiler warning fixes to make 'make W=2' less
  noisy, as well as some fixes to code comments in asm-generic"

* tag 'asm-generic-cleanup-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  syscalls: Fix file comments for syscalls implemented in kernel/sys.c
  ctype.h: remove duplicate isdigit() helper
  qspinlock: use signed temporaries for cmpxchg
  asm-generic: fix ffs -Wshadow warning
  asm-generic: percpu: avoid Wshadow warning
  asm-generic/sembuf: Update architecture related information in comment

include/asm-generic/bitops/builtin-ffs.h

@@ -10,9 +10,6 @@
  * the libc and compiler builtin ffs routines, therefore
  * differs in spirit from the above ffz (man ffs).
  */
-static __always_inline int ffs(int x)
-{
-	return __builtin_ffs(x);
-}
+#define ffs(x) __builtin_ffs(x)
 
 #endif

include/asm-generic/qrwlock.h

@@ -37,7 +37,7 @@ extern void queued_write_lock_slowpath(struct qrwlock *lock);
  */
 static inline int queued_read_trylock(struct qrwlock *lock)
 {
-	u32 cnts;
+	int cnts;
 
 	cnts = atomic_read(&lock->cnts);
 	if (likely(!(cnts & _QW_WMASK))) {
@@ -56,7 +56,7 @@ static inline int queued_read_trylock(struct qrwlock *lock)
  */
 static inline int queued_write_trylock(struct qrwlock *lock)
 {
-	u32 cnts;
+	int cnts;
 
 	cnts = atomic_read(&lock->cnts);
 	if (unlikely(cnts))
@@ -71,7 +71,7 @@ static inline int queued_write_trylock(struct qrwlock *lock)
  */
 static inline void queued_read_lock(struct qrwlock *lock)
 {
-	u32 cnts;
+	int cnts;
 
 	cnts = atomic_add_return_acquire(_QR_BIAS, &lock->cnts);
 	if (likely(!(cnts & _QW_WMASK)))
@@ -87,7 +87,7 @@ static inline void queued_read_lock(struct qrwlock *lock)
  */
 static inline void queued_write_lock(struct qrwlock *lock)
 {
-	u32 cnts = 0;
+	int cnts = 0;
 	/* Optimize for the unfair lock case where the fair flag is 0. */
 	if (likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts, _QW_LOCKED)))
 		return;

include/asm-generic/qspinlock.h

@@ -60,7 +60,7 @@ static __always_inline int queued_spin_is_contended(struct qspinlock *lock)
  */
 static __always_inline int queued_spin_trylock(struct qspinlock *lock)
 {
-	u32 val = atomic_read(&lock->val);
+	int val = atomic_read(&lock->val);
 
 	if (unlikely(val))
 		return 0;
@@ -77,7 +77,7 @@ extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
  */
 static __always_inline void queued_spin_lock(struct qspinlock *lock)
 {
-	u32 val = 0;
+	int val = 0;
 
 	if (likely(atomic_try_cmpxchg_acquire(&lock->val, &val, _Q_LOCKED_VAL)))
 		return;

include/linux/compiler_types.h

@@ -64,6 +64,17 @@ static inline void __chk_io_ptr(const volatile void __iomem *ptr) { }
 /* Attributes */
 #include <linux/compiler_attributes.h>
 
+/* Builtins */
+
+/*
+ * __has_builtin is supported on gcc >= 10, clang >= 3 and icc >= 21.
+ * In the meantime, to support gcc < 10, we implement __has_builtin
+ * by hand.
+ */
+#ifndef __has_builtin
+#define __has_builtin(x) (0)
+#endif
+
 /* Compiler specific macros. */
 #ifdef __clang__
 #include <linux/compiler-clang.h>

include/linux/ctype.h

@@ -2,6 +2,8 @@
 #ifndef _LINUX_CTYPE_H
 #define _LINUX_CTYPE_H
 
+#include <linux/compiler.h>
+
 /*
  * NOTE! This ctype does not handle EOF like the standard C
  * library is required to.
@@ -23,10 +25,6 @@ extern const unsigned char _ctype[];
 #define isalnum(c)	((__ismask(c)&(_U|_L|_D)) != 0)
 #define isalpha(c)	((__ismask(c)&(_U|_L)) != 0)
 #define iscntrl(c)	((__ismask(c)&(_C)) != 0)
-static inline int isdigit(int c)
-{
-	return '0' <= c && c <= '9';
-}
 #define isgraph(c)	((__ismask(c)&(_P|_U|_L|_D)) != 0)
 #define islower(c)	((__ismask(c)&(_L)) != 0)
 #define isprint(c)	((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0)
@@ -39,6 +37,15 @@ static inline int isdigit(int c)
 #define isascii(c) (((unsigned char)(c))<=0x7f)
 #define toascii(c) (((unsigned char)(c))&0x7f)
 
+#if __has_builtin(__builtin_isdigit)
+#define  isdigit(c) __builtin_isdigit(c)
+#else
+static inline int isdigit(int c)
+{
+	return '0' <= c && c <= '9';
+}
+#endif
+
 static inline unsigned char __tolower(unsigned char c)
 {
 	if (isupper(c))

include/linux/syscalls.h

@@ -744,7 +744,7 @@ asmlinkage long sys_settimeofday(struct __kernel_old_timeval __user *tv,
 asmlinkage long sys_adjtimex(struct __kernel_timex __user *txc_p);
 asmlinkage long sys_adjtimex_time32(struct old_timex32 __user *txc_p);
 
-/* kernel/timer.c */
+/* kernel/sys.c */
 asmlinkage long sys_getpid(void);
 asmlinkage long sys_getppid(void);
 asmlinkage long sys_getuid(void);

include/uapi/asm-generic/sembuf.h

@@ -6,9 +6,9 @@
 #include <asm/ipcbuf.h>
 
 /*
- * The semid64_ds structure for x86 architecture.
- * Note extra padding because this structure is passed back and forth
- * between kernel and user space.
+ * The semid64_ds structure for most architectures (though it came from x86_32
+ * originally). Note extra padding because this structure is passed back and
+ * forth between kernel and user space.
  *
  * semid64_ds was originally meant to be architecture specific, but
  * everyone just ended up making identical copies without specific

include/uapi/asm-generic/unistd.h

@@ -517,7 +517,7 @@ __SC_COMP(__NR_settimeofday, sys_settimeofday, compat_sys_settimeofday)
 __SC_3264(__NR_adjtimex, sys_adjtimex_time32, sys_adjtimex)
 #endif
 
-/* kernel/timer.c */
+/* kernel/sys.c */
 #define __NR_getpid 172
 __SYSCALL(__NR_getpid, sys_getpid)
 #define __NR_getppid 173