diff options
| author | Alexandre Ghiti <alexghiti@rivosinc.com> | 2024-11-03 15:51:53 +0100 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-11-11 07:33:20 -0800 |
| commit | ab83647fadae2f1f723119dc066b39a461d6d288 (patch) | |
| tree | 7f07ef18ee81fa7666f9500f87c4989368f71639 /include/asm-generic | |
| parent | 447b2afbcde16be43c9459507f48f5c602c121c0 (diff) | |
riscv: Add qspinlock support
In order to produce a generic kernel, a user can select
CONFIG_COMBO_SPINLOCKS which will fallback at runtime to the ticket
spinlock implementation if Zabha or Ziccrse are not present.
Note that we can't use alternatives here because the discovery of
extensions is done too late and we need to start with the qspinlock
implementation because the ticket spinlock implementation would pollute
the spinlock value, so let's use static keys.
This is largely based on Guo's work and Leonardo reviews at [1].
Link: https://lore.kernel.org/linux-riscv/20231225125847.2778638-1-guoren@kernel.org/ [1]
Signed-off-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrea Parri <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20241103145153.105097-14-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'include/asm-generic')
| -rw-r--r-- | include/asm-generic/qspinlock.h | 2 | ||||
| -rw-r--r-- | include/asm-generic/ticket_spinlock.h | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/include/asm-generic/qspinlock.h b/include/asm-generic/qspinlock.h index 0655aa5b57b2..bf47cca2c375 100644 --- a/include/asm-generic/qspinlock.h +++ b/include/asm-generic/qspinlock.h @@ -136,6 +136,7 @@ static __always_inline bool virt_spin_lock(struct qspinlock *lock) } #endif +#ifndef __no_arch_spinlock_redefine /* * Remapping spinlock architecture specific functions to the corresponding * queued spinlock functions. @@ -146,5 +147,6 @@ static __always_inline bool virt_spin_lock(struct qspinlock *lock) #define arch_spin_lock(l) queued_spin_lock(l) #define arch_spin_trylock(l) queued_spin_trylock(l) #define arch_spin_unlock(l) queued_spin_unlock(l) +#endif #endif /* __ASM_GENERIC_QSPINLOCK_H */ diff --git a/include/asm-generic/ticket_spinlock.h b/include/asm-generic/ticket_spinlock.h index cfcff22b37b3..325779970d8a 100644 --- a/include/asm-generic/ticket_spinlock.h +++ b/include/asm-generic/ticket_spinlock.h @@ -89,6 +89,7 @@ static __always_inline int ticket_spin_is_contended(arch_spinlock_t *lock) return (s16)((val >> 16) - (val & 0xffff)) > 1; } +#ifndef __no_arch_spinlock_redefine /* * Remapping spinlock architecture specific functions to the corresponding * ticket spinlock functions. @@ -99,5 +100,6 @@ static __always_inline int ticket_spin_is_contended(arch_spinlock_t *lock) #define arch_spin_lock(l) ticket_spin_lock(l) #define arch_spin_trylock(l) ticket_spin_trylock(l) #define arch_spin_unlock(l) ticket_spin_unlock(l) +#endif #endif /* __ASM_GENERIC_TICKET_SPINLOCK_H */ |