diff options
author | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-16 17:00:02 -0500 |
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committer | Kent Overstreet <kent.overstreet@linux.dev> | 2024-01-16 17:17:23 -0500 |
commit | b5fd066153c40a70a29caa1ea7987723ab687763 (patch) | |
tree | 6d43a8b0a90d549a54c65565ac96c92b3e84b594 /c_src/include/linux/bit_spinlock.h | |
parent | 06ff8b55b70fda44d91b31b5511fafd1680a8934 (diff) |
Move c_src dirs back to toplevel
We just wanted c sourcefiles out of the top level, not c source
directories.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'c_src/include/linux/bit_spinlock.h')
-rw-r--r-- | c_src/include/linux/bit_spinlock.h | 84 |
1 files changed, 0 insertions, 84 deletions
diff --git a/c_src/include/linux/bit_spinlock.h b/c_src/include/linux/bit_spinlock.h deleted file mode 100644 index 873f08c2..00000000 --- a/c_src/include/linux/bit_spinlock.h +++ /dev/null @@ -1,84 +0,0 @@ -#ifndef __LINUX_BIT_SPINLOCK_H -#define __LINUX_BIT_SPINLOCK_H - -#include <linux/kernel.h> -#include <linux/preempt.h> -#include <linux/futex.h> -#include <urcu/futex.h> - -/* - * The futex wait op wants an explicit 32-bit address and value. If the bitmap - * used for the spinlock is 64-bit, cast down and pass the right 32-bit region - * for the in-kernel checks. The value is the copy that has already been read - * from the atomic op. - * - * The futex wake op interprets the value as the number of waiters to wake (up - * to INT_MAX), so pass that along directly. - */ -static inline void do_futex(int nr, unsigned long *addr, unsigned long v, int futex_flags) -{ - u32 *addr32 = (u32 *) addr; - u32 *v32 = (u32 *) &v; - int shift = 0; - - futex_flags |= FUTEX_PRIVATE_FLAG; - -#if BITS_PER_LONG == 64 -#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ - shift = (nr >= 32) ? 1 : 0; -#else - shift = (nr < 32) ? 1 : 0; -#endif -#endif - if (shift) { - addr32 += shift; - v32 += shift; - } - /* - * The shift to determine the futex address may have cast away a - * literal wake count value. The value is capped to INT_MAX and thus - * always in the low bytes of v regardless of bit nr. Copy in the wake - * count to whatever 32-bit range was selected. - */ - if (futex_flags == FUTEX_WAKE_PRIVATE) - *v32 = (u32) v; - futex(addr32, futex_flags, *v32, NULL, NULL, 0); -} - -static inline void bit_spin_lock(int nr, unsigned long *_addr) -{ - unsigned long mask; - unsigned long *addr = _addr + (nr / BITS_PER_LONG); - unsigned long v; - - nr &= BITS_PER_LONG - 1; - mask = 1UL << nr; - - while (1) { - v = __atomic_fetch_or(addr, mask, __ATOMIC_ACQUIRE); - if (!(v & mask)) - break; - - do_futex(nr, addr, v, FUTEX_WAIT); - } -} - -static inline void bit_spin_wake(int nr, unsigned long *_addr) -{ - do_futex(nr, _addr, INT_MAX, FUTEX_WAKE); -} - -static inline void bit_spin_unlock(int nr, unsigned long *_addr) -{ - unsigned long mask; - unsigned long *addr = _addr + (nr / BITS_PER_LONG); - - nr &= BITS_PER_LONG - 1; - mask = 1UL << nr; - - __atomic_and_fetch(addr, ~mask, __ATOMIC_RELEASE); - do_futex(nr, addr, INT_MAX, FUTEX_WAKE); -} - -#endif /* __LINUX_BIT_SPINLOCK_H */ - |