diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/dtl.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/dtl.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/pseries/dtl.c b/arch/powerpc/platforms/pseries/dtl.c index fb05804adb2f..ae4fb2a68758 100644 --- a/arch/powerpc/platforms/pseries/dtl.c +++ b/arch/powerpc/platforms/pseries/dtl.c @@ -193,11 +193,16 @@ static int dtl_enable(struct dtl *dtl) if (dtl->buf) return -EBUSY; + /* ensure there are no other conflicting dtl users */ + if (!read_trylock(&dtl_access_lock)) + return -EBUSY; + n_entries = dtl_buf_entries; buf = kmem_cache_alloc_node(dtl_cache, GFP_KERNEL, cpu_to_node(dtl->cpu)); if (!buf) { printk(KERN_WARNING "%s: buffer alloc failed for cpu %d\n", __func__, dtl->cpu); + read_unlock(&dtl_access_lock); return -ENOMEM; } @@ -214,8 +219,11 @@ static int dtl_enable(struct dtl *dtl) } spin_unlock(&dtl->lock); - if (rc) + if (rc) { + read_unlock(&dtl_access_lock); kmem_cache_free(dtl_cache, buf); + } + return rc; } @@ -227,6 +235,7 @@ static void dtl_disable(struct dtl *dtl) dtl->buf = NULL; dtl->buf_entries = 0; spin_unlock(&dtl->lock); + read_unlock(&dtl_access_lock); } /* file interface */ |