Immediate Values - PowerPC Optimization - kerneldoc
Add kerneldoc to Immediate Values (PowerPC Optimization) API.
Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
CC: [EMAIL PROTECTED]
---
include/asm-powerpc/immediate.h | 51 ++++++++++++++++++++++++++++------------
1 file changed, 36 insertions(+), 15 deletions(-)
Index: linux-2.6-lttng/include/asm-powerpc/immediate.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-powerpc/immediate.h 2007-07-14
20:54:47.000000000 -0400
+++ linux-2.6-lttng/include/asm-powerpc/immediate.h 2007-07-14
20:56:50.000000000 -0400
@@ -24,14 +24,18 @@ struct __immediate {
long size; /* Type size. */
};
-/*
+/**
+ * immediate_read - read immediate variable
+ * @var: pointer of type immediate_*_t
+ *
+ * Reads the value of @var.
* Optimized version of the immediate.
- * Make sure the 2 bytes update will be atomic by aligning the immediate
- * value.
- * Use a normal memory read for the 4 bytes immediate because there is no way
to
- * atomically update it without using a seqlock read side, which would cost
more
- * in term of total i-cache and d-cache space than a simple memory read.
* Do not use in __init and __exit functions. Use _immediate_read() instead.
+ * Makes sure the 2 bytes update will be atomic by aligning the immediate
+ * value. Use a normal memory read for the 4 bytes immediate because there is
no
+ * way to atomically update it without using a seqlock read side, which would
+ * cost more in term of total i-cache and d-cache space than a simple memory
+ * read.
*/
#define immediate_read(var) \
({ \
@@ -65,37 +69,54 @@ struct __immediate {
value; \
})
-/*
- * Update immediate value, can take module mutex.
+/**
+ * immediate_set - set immediate variable (with locking)
+ * @var: pointer of type immediate_*_t
+ * @i: required value
+ *
+ * Sets the value of @var, taking the module_mutex if required by
+ * the architecture.
*/
#define immediate_set(var, i) \
(var)->value = (i); \
immediate_update(1);
-/*
- * Update immediate value. Module mutex must already be taken.
+/**
+ * _immediate_set - set immediate variable (without locking)
+ * @var: pointer of type immediate_*_t
+ * @i: required value
+ *
+ * Sets the value of @var. Must be called with module_mutex held.
*/
#define _immediate_set(var, i) \
(var)->value = (i); \
immediate_update(0);
-/*
- * Update immediate value at early boot.
+/**
+ * immediate_set_early - set immediate variable at early boot
+ * @var: pointer of type immediate_*_t
+ * @i: required value
+ *
+ * Sets the value of @var. Should be used for early boot updates.
*/
#define immediate_set_early(var, i) \
(var)->value = (i); \
immediate_update_early();
-/*
+/**
+ * immediate_if - if () statement depending on an immediate value
+ * @var: pointer of type immediate_*_t
+ *
+ * Use as an if () statement depending on an immediate value.
+ * Do not use in __init and __exit functions. Use _immediate_if() instead.
* Branch depending on an immediate value. Could eventually be optimized
further
* by improving gcc to give the ability to patch a jump instruction instead of
* the value it depends on.
- * Do not use in __init and __exit functions. Use _immediate_if() instead.
*/
#define immediate_if(var) if (unlikely(immediate_read(var)))
/*
- * Used internally.
+ * Internal update functions.
*/
extern void immediate_update(int lock);
extern void module_immediate_setup(struct module *mod);
--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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