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| author | Vladimir Kondratyev <wulf@FreeBSD.org> | 2022-01-18 20:14:12 +0000 |
|---|---|---|
| committer | Vladimir Kondratyev <wulf@FreeBSD.org> | 2022-01-18 20:14:12 +0000 |
| commit | 02ea6033020e11afec6472bf560b0ddebd0fa97a (patch) | |
| tree | 27ab11801c79a2426941ae695ec9bff8cfe06c10 | |
| parent | a50e92cc203c1e3dd2cca03410b568f76694895c (diff) | |
| download | src-02ea6033020e11afec6472bf560b0ddebd0fa97a.tar.gz src-02ea6033020e11afec6472bf560b0ddebd0fa97a.zip | |
LinuxKPI: Allow spin_lock_irqsave to be called within a critical section
with spinning on spin_trylock. dma-buf part of drm-kmod depends on this
property and absence of it support results in "mi_switch: switch in a
critical section" assertions [1][2].
[1] https://github.com/freebsd/drm-kmod/issues/116
[2] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=261166
MFC after: 1 week
Reviewed by: manu
Differential Revision: https://reviews.freebsd.org/D33887
| -rw-r--r-- | sys/compat/linuxkpi/common/include/linux/spinlock.h | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/sys/compat/linuxkpi/common/include/linux/spinlock.h b/sys/compat/linuxkpi/common/include/linux/spinlock.h index a87cb7180b28..31d47fa73986 100644 --- a/sys/compat/linuxkpi/common/include/linux/spinlock.h +++ b/sys/compat/linuxkpi/common/include/linux/spinlock.h @@ -37,6 +37,7 @@ #include <sys/lock.h> #include <sys/mutex.h> #include <sys/kdb.h> +#include <sys/proc.h> #include <linux/compiler.h> #include <linux/rwlock.h> @@ -117,14 +118,32 @@ typedef struct { local_bh_disable(); \ } while (0) -#define spin_lock_irqsave(_l, flags) do { \ - (flags) = 0; \ - spin_lock(_l); \ +#define __spin_trylock_nested(_l, _n) ({ \ + int __ret; \ + if (SPIN_SKIP()) { \ + __ret = 1; \ + } else { \ + __ret = mtx_trylock_flags(&(_l)->m, MTX_DUPOK); \ + if (likely(__ret != 0)) \ + local_bh_disable(); \ + } \ + __ret; \ +}) + +#define spin_lock_irqsave(_l, flags) do { \ + (flags) = 0; \ + if (unlikely(curthread->td_critnest != 0)) \ + while (!spin_trylock(_l)) {} \ + else \ + spin_lock(_l); \ } while (0) #define spin_lock_irqsave_nested(_l, flags, _n) do { \ (flags) = 0; \ - spin_lock_nested(_l, _n); \ + if (unlikely(curthread->td_critnest != 0)) \ + while (!__spin_trylock_nested(_l, _n)) {} \ + else \ + spin_lock_nested(_l, _n); \ } while (0) #define spin_unlock_irqrestore(_l, flags) do { \ |