summaryrefslogtreecommitdiffstats
path: root/kernel/include/linux/types.h
diff options
context:
space:
mode:
authorJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-11 10:41:07 +0300
committerJosé Pekkarinen <jose.pekkarinen@nokia.com>2016-04-13 08:17:18 +0300
commite09b41010ba33a20a87472ee821fa407a5b8da36 (patch)
treed10dc367189862e7ca5c592f033dc3726e1df4e3 /kernel/include/linux/types.h
parentf93b97fd65072de626c074dbe099a1fff05ce060 (diff)
These changes are the raw update to linux-4.4.6-rt14. Kernel sources
are taken from kernel.org, and rt patch from the rt wiki download page. During the rebasing, the following patch collided: Force tick interrupt and get rid of softirq magic(I70131fb85). Collisions have been removed because its logic was found on the source already. Change-Id: I7f57a4081d9deaa0d9ccfc41a6c8daccdee3b769 Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>
Diffstat (limited to 'kernel/include/linux/types.h')
-rw-r--r--kernel/include/linux/types.h21
1 files changed, 19 insertions, 2 deletions
diff --git a/kernel/include/linux/types.h b/kernel/include/linux/types.h
index 8715287c3..70dd3dfde 100644
--- a/kernel/include/linux/types.h
+++ b/kernel/include/linux/types.h
@@ -35,7 +35,7 @@ typedef __kernel_gid16_t gid16_t;
typedef unsigned long uintptr_t;
-#ifdef CONFIG_UID16
+#ifdef CONFIG_HAVE_UID16
/* This is defined by include/asm-{arch}/posix_types.h */
typedef __kernel_old_uid_t old_uid_t;
typedef __kernel_old_gid_t old_gid_t;
@@ -205,13 +205,30 @@ struct ustat {
* struct callback_head - callback structure for use with RCU and task_work
* @next: next update requests in a list
* @func: actual update function to call after the grace period.
+ *
+ * The struct is aligned to size of pointer. On most architectures it happens
+ * naturally due ABI requirements, but some architectures (like CRIS) have
+ * weird ABI and we need to ask it explicitly.
+ *
+ * The alignment is required to guarantee that bits 0 and 1 of @next will be
+ * clear under normal conditions -- as long as we use call_rcu(),
+ * call_rcu_bh(), call_rcu_sched(), or call_srcu() to queue callback.
+ *
+ * This guarantee is important for few reasons:
+ * - future call_rcu_lazy() will make use of lower bits in the pointer;
+ * - the structure shares storage spacer in struct page with @compound_head,
+ * which encode PageTail() in bit 0. The guarantee is needed to avoid
+ * false-positive PageTail().
*/
struct callback_head {
struct callback_head *next;
void (*func)(struct callback_head *head);
-};
+} __attribute__((aligned(sizeof(void *))));
#define rcu_head callback_head
+typedef void (*rcu_callback_t)(struct rcu_head *head);
+typedef void (*call_rcu_func_t)(struct rcu_head *head, rcu_callback_t func);
+
/* clocksource cycle base type */
typedef u64 cycle_t;