Commit 30ff1332 authored by Kumar Kartikeya Dwivedi's avatar Kumar Kartikeya Dwivedi Committed by Alexei Starovoitov
Browse files

rqspinlock: Add rqspinlock.h header 



This header contains the public declarations usable in the rest of the
kernel for rqspinlock.

Let's also type alias qspinlock to rqspinlock_t to ensure consistent use
of the new lock type. We want to remove dependence on the qspinlock type
in later patches as we need to provide a test-and-set fallback, hence
begin abstracting away from now onwards.

Reviewed-by: default avatarBarret Rhoden <brho@google.com>
Signed-off-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250316040541.108729-6-memxor@gmail.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent a8fcf2a3

include/asm-generic/rqspinlock.h

0 → 100644
+19 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-or-later */

/*

 * Resilient Queued Spin Lock

 *

 * (C) Copyright 2024-2025 Meta Platforms, Inc. and affiliates.

 *

 * Authors: Kumar Kartikeya Dwivedi <memxor@gmail.com>

 */

#ifndef __ASM_GENERIC_RQSPINLOCK_H

#define __ASM_GENERIC_RQSPINLOCK_H



#include <linux/types.h>



struct qspinlock;

typedef struct qspinlock rqspinlock_t;



extern void resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val);



#endif /* __ASM_GENERIC_RQSPINLOCK_H */

kernel/bpf/rqspinlock.c

+2 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <asm/byteorder.h>

#include <asm/qspinlock.h>

#include <trace/events/lock.h>

#include <asm/rqspinlock.h>



/*

 * Include queued spinlock definitions and statistics code
@@ -127,7 +128,7 @@ static __always_inline u32 __pv_wait_head_or_lock(struct qspinlock *lock, 
 * contended             :    (*,x,y) +--> (*,0,0) ---> (*,0,1) -'  :

 *   queue               :         ^--'                             :

 */

void __lockfunc resilient_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)

void __lockfunc resilient_queued_spin_lock_slowpath(rqspinlock_t *lock, u32 val)

{

	struct mcs_spinlock *prev, *next, *node;

	u32 old, tail;