[PATCH 17/19] drm/doc: Add fucntion reference documentation for drm_mm.c
Daniel Vetter
daniel.vetter at ffwll.ch
Thu Jan 23 00:52:42 PST 2014
While at it do a tiny bit of interface cleanup and convert boolean
return values to bool. With this patch all exported functions and inline
helpers which are part of the drm_mm public interface are documented.
Also drop superflous extern function modifiers since most of drm_mm.h
doesn't use them - more consistent that way.
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
Documentation/DocBook/drm.tmpl | 5 ++
drivers/gpu/drm/drm_mm.c | 144 ++++++++++++++++++++++++++++++++------
include/drm/drm_mm.h | 154 +++++++++++++++++++++++++++++++++--------
3 files changed, 251 insertions(+), 52 deletions(-)
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index c6f916989b92..d36e97126f59 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -931,6 +931,11 @@ struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
!Pdrivers/gpu/drm/drm_mm.c lru scan roaster
</sect3>
</sect2>
+ <sect2>
+ <title>DRM MM Range Allocator Function References</title>
+!Edrivers/gpu/drm/drm_mm.c
+!Iinclude/drm/drm_mm.h
+ </sect2>
</sect1>
<!-- Internals: mode setting -->
diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c
index 276a7a27c166..a2d45b748f86 100644
--- a/drivers/gpu/drm/drm_mm.c
+++ b/drivers/gpu/drm/drm_mm.c
@@ -144,6 +144,20 @@ static void drm_mm_insert_helper(struct drm_mm_node *hole_node,
}
}
+/**
+ * drm_mm_reserve_node - insert an pre-initialized node
+ * @mm: drm_mm allocator to insert @node into
+ * @node: drm_mm_node to insert
+ *
+ * This functions inserts an already set-up drm_mm_node into the allocator,
+ * meaning that start, size and color must be set by the caller. This is useful
+ * to initialize the allocator with preallocated objects which must be set-up
+ * before the range allocator can be set-up, e.g. when taking over a firmware
+ * framebuffer.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no hole where @node is.
+ */
int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
{
struct drm_mm_node *hole;
@@ -185,9 +199,18 @@ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node)
EXPORT_SYMBOL(drm_mm_reserve_node);
/**
- * Search for free space and insert a preallocated memory node. Returns
- * -ENOSPC if no suitable free area is available. The preallocated memory node
- * must be cleared.
+ * drm_mm_insert_node_generic - search for space and insert @node
+ * @mm: drm_mm to allocate from
+ * @node: preallocate node to insert
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for this node
+ * @flags: flags to fine-tune the allocation
+ *
+ * The preallocated node must be cleared to 0.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no suitable hole.
*/
int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long size, unsigned alignment,
@@ -259,9 +282,20 @@ static void drm_mm_insert_helper_range(struct drm_mm_node *hole_node,
}
/**
- * Search for free space and insert a preallocated memory node. Returns
- * -ENOSPC if no suitable free area is available. This is for range
- * restricted allocations. The preallocated memory node must be cleared.
+ * drm_mm_insert_node_in_range_generic - ranged search for space and insert @node
+ * @mm: drm_mm to allocate from
+ * @node: preallocate node to insert
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for this node
+ * @start: start of the allowed range for this node
+ * @end: end of the allowed range for this node
+ * @flags: flags to fine-tune the allocation
+ *
+ * The preallocated node must be cleared to 0.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no suitable hole.
*/
int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *node,
unsigned long size, unsigned alignment, unsigned long color,
@@ -284,7 +318,12 @@ int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *n
EXPORT_SYMBOL(drm_mm_insert_node_in_range_generic);
/**
- * Remove a memory node from the allocator.
+ * drm_mm_remove_node - Remove a memory node from the allocator.
+ * @node: drm_mm_node to remove
+ *
+ * This just removes a node from its drm_mm allocator. The node does not need to
+ * be cleared again before it can be re-inserted into this or any other drm_mm
+ * allocator. It is a bug to call this function on a un-allocated node.
*/
void drm_mm_remove_node(struct drm_mm_node *node)
{
@@ -421,7 +460,13 @@ static struct drm_mm_node *drm_mm_search_free_in_range_generic(const struct drm_
}
/**
- * Moves an allocation. To be used with embedded struct drm_mm_node.
+ * drm_mm_replace_node - move an allocation from @old to @new
+ * @old: drm_mm_node to remove from the allocator
+ * @new: drm_mm_node which should inherit @old's allocation
+ *
+ * This is useful for when drivers embed the drm_mm_node structure and hence
+ * can't move allocations by reassigning pointers. It's a combination of remove
+ * and insert with the guarantee that the allocation start will match.
*/
void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new)
{
@@ -467,12 +512,18 @@ EXPORT_SYMBOL(drm_mm_replace_node);
*/
/**
- * Initializa lru scanning.
+ * drm_mm_init_scan - initialize lru scanning
+ * @mm: drm_mm to scan
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for the allocation
*
* This simply sets up the scanning routines with the parameters for the desired
- * hole.
+ * hole. Note that there's no need to specify allocation flags, since they only
+ * change the place a node is allocated from within a suitable hole.
*
- * Warning: As long as the scan list is non-empty, no other operations than
+ * Warning:
+ * As long as the scan list is non-empty, no other operations than
* adding/removing nodes to/from the scan list are allowed.
*/
void drm_mm_init_scan(struct drm_mm *mm,
@@ -492,12 +543,20 @@ void drm_mm_init_scan(struct drm_mm *mm,
EXPORT_SYMBOL(drm_mm_init_scan);
/**
- * Initializa lru scanning.
+ * drm_mm_init_scan - initialize range-restricted lru scanning
+ * @mm: drm_mm to scan
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @color: opaque tag value to use for the allocation
+ * @start: start of the allowed range for the allocation
+ * @end: end of the allowed range for the allocation
*
* This simply sets up the scanning routines with the parameters for the desired
- * hole. This version is for range-restricted scans.
+ * hole. Note that there's no need to specify allocation flags, since they only
+ * change the place a node is allocated from within a suitable hole.
*
- * Warning: As long as the scan list is non-empty, no other operations than
+ * Warning:
+ * As long as the scan list is non-empty, no other operations than
* adding/removing nodes to/from the scan list are allowed.
*/
void drm_mm_init_scan_with_range(struct drm_mm *mm,
@@ -521,12 +580,16 @@ void drm_mm_init_scan_with_range(struct drm_mm *mm,
EXPORT_SYMBOL(drm_mm_init_scan_with_range);
/**
+ * drm_mm_scan_add_block - add a node to the scan list
+ * @node: drm_mm_node to add
+ *
* Add a node to the scan list that might be freed to make space for the desired
* hole.
*
- * Returns non-zero, if a hole has been found, zero otherwise.
+ * Returns:
+ * True if a hole has been found, false otherwise.
*/
-int drm_mm_scan_add_block(struct drm_mm_node *node)
+bool drm_mm_scan_add_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
@@ -566,15 +629,16 @@ int drm_mm_scan_add_block(struct drm_mm_node *node)
mm->scan_size, mm->scan_alignment)) {
mm->scan_hit_start = hole_start;
mm->scan_hit_end = hole_end;
- return 1;
+ return true;
}
- return 0;
+ return false;
}
EXPORT_SYMBOL(drm_mm_scan_add_block);
/**
- * Remove a node from the scan list.
+ * drm_mm_scan_remove_block - remove a node from the scan list
+ * @node: drm_mm_node to remove
*
* Nodes _must_ be removed in the exact same order from the scan list as they
* have been added, otherwise the internal state of the memory manager will be
@@ -584,10 +648,11 @@ EXPORT_SYMBOL(drm_mm_scan_add_block);
* immediately following drm_mm_search_free with !DRM_MM_SEARCH_BEST will then
* return the just freed block (because its at the top of the free_stack list).
*
- * Returns one if this block should be evicted, zero otherwise. Will always
- * return zero when no hole has been found.
+ * Returns:
+ * True if this block should be evicted, false otherwise. Will always
+ * return false when no hole has been found.
*/
-int drm_mm_scan_remove_block(struct drm_mm_node *node)
+bool drm_mm_scan_remove_block(struct drm_mm_node *node)
{
struct drm_mm *mm = node->mm;
struct drm_mm_node *prev_node;
@@ -608,7 +673,15 @@ int drm_mm_scan_remove_block(struct drm_mm_node *node)
}
EXPORT_SYMBOL(drm_mm_scan_remove_block);
-int drm_mm_clean(struct drm_mm * mm)
+/**
+ * drm_mm_clean - checks whether an allocator is clean
+ * @mm: drm_mm allocator to check
+ *
+ * Returns:
+ * True if the allocator is completely free, false if there's still a node
+ * allocated in it.
+ */
+bool drm_mm_clean(struct drm_mm * mm)
{
struct list_head *head = &mm->head_node.node_list;
@@ -616,6 +689,14 @@ int drm_mm_clean(struct drm_mm * mm)
}
EXPORT_SYMBOL(drm_mm_clean);
+/**
+ * drm_mm_init - initialize a drm-mm allocator
+ * @mm: the drm_mm structure to initialize
+ * @start: start of the range managed by @mm
+ * @size: end of the range managed by @mm
+ *
+ * Note that @mm must be cleared to 0 before calling this function.
+ */
void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
{
INIT_LIST_HEAD(&mm->hole_stack);
@@ -637,6 +718,13 @@ void drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
}
EXPORT_SYMBOL(drm_mm_init);
+/**
+ * drm_mm_takedown - clean up a drm_mm allocator
+ * @mm: drm_mm allocator to clean up
+ *
+ * Note that it is a bug to call this function on an allocator which is not
+ * clean.
+ */
void drm_mm_takedown(struct drm_mm * mm)
{
WARN(!list_empty(&mm->head_node.node_list),
@@ -662,6 +750,11 @@ static unsigned long drm_mm_debug_hole(struct drm_mm_node *entry,
return 0;
}
+/**
+ * drm_mm_debug_table - dump allocator state to dmesg
+ * @mm: drm_mm allocator to dump
+ * @prefix: prefix to use for dumping to dmesg
+ */
void drm_mm_debug_table(struct drm_mm *mm, const char *prefix)
{
struct drm_mm_node *entry;
@@ -700,6 +793,11 @@ static unsigned long drm_mm_dump_hole(struct seq_file *m, struct drm_mm_node *en
return 0;
}
+/**
+ * drm_mm_dump_table - dump allocator state to a seq_file
+ * @m: seq_file to dump to
+ * @mm: drm_mm allocator to dump
+ */
int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
{
struct drm_mm_node *entry;
diff --git a/include/drm/drm_mm.h b/include/drm/drm_mm.h
index cba67865d18f..8b6981ab3fcf 100644
--- a/include/drm/drm_mm.h
+++ b/include/drm/drm_mm.h
@@ -85,11 +85,31 @@ struct drm_mm {
unsigned long *start, unsigned long *end);
};
+/**
+ * drm_mm_node_allocated - checks whether a node is allocated
+ * @node: drm_mm_node to check
+ *
+ * Drivers should use this helpers for proper encapusulation of drm_mm
+ * internals.
+ *
+ * Returns:
+ * True if the @node is allocated.
+ */
static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
{
return node->allocated;
}
+/**
+ * drm_mm_initialized - checks whether an allocator is initialized
+ * @mm: drm_mm to check
+ *
+ * Drivers should use this helpers for proper encapusulation of drm_mm
+ * internals.
+ *
+ * Returns:
+ * True if the @mm is initialized.
+ */
static inline bool drm_mm_initialized(struct drm_mm *mm)
{
return mm->hole_stack.next;
@@ -100,6 +120,17 @@ static inline unsigned long __drm_mm_hole_node_start(struct drm_mm_node *hole_no
return hole_node->start + hole_node->size;
}
+/**
+ * drm_mm_hole_node_start - computes the start of the hole following @node
+ * @hole_node: drm_mm_node which implicitly tracks the following hole
+ *
+ * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
+ * inspect holes themselves. Drivers must check first whether a hole indeed
+ * follows by looking at node->hole_follows.
+ *
+ * Returns:
+ * Start of the subsequent hole.
+ */
static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
{
BUG_ON(!hole_node->hole_follows);
@@ -112,18 +143,49 @@ static inline unsigned long __drm_mm_hole_node_end(struct drm_mm_node *hole_node
struct drm_mm_node, node_list)->start;
}
+/**
+ * drm_mm_hole_node_end - computes the end of the hole following @node
+ * @hole_node: drm_mm_node which implicitly tracks the following hole
+ *
+ * This is useful for driver-sepific debug dumpers. Otherwise drivers should not
+ * inspect holes themselves. Drivers must check first whether a hole indeed
+ * follows by looking at node->hole_follows.
+ *
+ * Returns:
+ * End of the subsequent hole.
+ */
static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
{
return __drm_mm_hole_node_end(hole_node);
}
+/**
+ * drm_mm_for_each_node - iterator to walk over all allocated nodes
+ * @entry: drm_mm_node structure to assign to in each iteration step
+ * @mm: drm_mm allocator to walk
+ *
+ * This iterator walks over all nodes in the range allocator. It is implemented
+ * with list_for_each, so not save against removal of elements.
+ */
#define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
&(mm)->head_node.node_list, \
node_list)
-/* Note that we need to unroll list_for_each_entry in order to inline
- * setting hole_start and hole_end on each iteration and keep the
- * macro sane.
+/**
+ * drm_mm_for_each_hole - iterator to walk over all holes
+ * @entry: drm_mm_node used internally to track progress
+ * @mm: drm_mm allocator to walk
+ * @hole_start: ulong variable to assign the hole start to on each iteration
+ * @hole_end: ulong variable to assign the hole end to on each iteration
+ *
+ * This iterator walks over all holes in the range allocator. It is implemented
+ * with list_for_each, so not save against removal of elements. @entry is used
+ * internally and will not reflect a real drm_mm_node for the very first hole.
+ * Hence users of this iterator may not access it.
+ *
+ * Implementation Note:
+ * We need to inline list_for_each_entry in order to be able to set hole_start
+ * and hole_end on each iteration while keeping the macro sane.
*/
#define drm_mm_for_each_hole(entry, mm, hole_start, hole_end) \
for (entry = list_entry((mm)->hole_stack.next, struct drm_mm_node, hole_stack); \
@@ -136,14 +198,30 @@ static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
/*
* Basic range manager support (drm_mm.c)
*/
-extern int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
-
-extern int drm_mm_insert_node_generic(struct drm_mm *mm,
- struct drm_mm_node *node,
- unsigned long size,
- unsigned alignment,
- unsigned long color,
- enum drm_mm_search_flags flags);
+int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node);
+
+int drm_mm_insert_node_generic(struct drm_mm *mm,
+ struct drm_mm_node *node,
+ unsigned long size,
+ unsigned alignment,
+ unsigned long color,
+ enum drm_mm_search_flags flags);
+/**
+ * drm_mm_insert_node - search for space and insert @node
+ * @mm: drm_mm to allocate from
+ * @node: preallocate node to insert
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @flags: flags to fine-tune the allocation
+ *
+ * This is a simplified version of drm_mm_insert_node_generic() with @color set
+ * to 0.
+ *
+ * The preallocated node must be cleared to 0.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no suitable hole.
+ */
static inline int drm_mm_insert_node(struct drm_mm *mm,
struct drm_mm_node *node,
unsigned long size,
@@ -153,14 +231,32 @@ static inline int drm_mm_insert_node(struct drm_mm *mm,
return drm_mm_insert_node_generic(mm, node, size, alignment, 0, flags);
}
-extern int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
- struct drm_mm_node *node,
- unsigned long size,
- unsigned alignment,
- unsigned long color,
- unsigned long start,
- unsigned long end,
- enum drm_mm_search_flags flags);
+int drm_mm_insert_node_in_range_generic(struct drm_mm *mm,
+ struct drm_mm_node *node,
+ unsigned long size,
+ unsigned alignment,
+ unsigned long color,
+ unsigned long start,
+ unsigned long end,
+ enum drm_mm_search_flags flags);
+/**
+ * drm_mm_insert_node_in_range - ranged search for space and insert @node
+ * @mm: drm_mm to allocate from
+ * @node: preallocate node to insert
+ * @size: size of the allocation
+ * @alignment: alignment of the allocation
+ * @start: start of the allowed range for this node
+ * @end: end of the allowed range for this node
+ * @flags: flags to fine-tune the allocation
+ *
+ * This is a simplified version of drm_mm_insert_node_in_range_generic() with
+ * @color set to 0.
+ *
+ * The preallocated node must be cleared to 0.
+ *
+ * Returns:
+ * 0 on success, -ENOSPC if there's no suitable hole.
+ */
static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
struct drm_mm_node *node,
unsigned long size,
@@ -173,13 +269,13 @@ static inline int drm_mm_insert_node_in_range(struct drm_mm *mm,
0, start, end, flags);
}
-extern void drm_mm_remove_node(struct drm_mm_node *node);
-extern void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
-extern void drm_mm_init(struct drm_mm *mm,
- unsigned long start,
- unsigned long size);
-extern void drm_mm_takedown(struct drm_mm *mm);
-extern int drm_mm_clean(struct drm_mm *mm);
+void drm_mm_remove_node(struct drm_mm_node *node);
+void drm_mm_replace_node(struct drm_mm_node *old, struct drm_mm_node *new);
+void drm_mm_init(struct drm_mm *mm,
+ unsigned long start,
+ unsigned long size);
+void drm_mm_takedown(struct drm_mm *mm);
+bool drm_mm_clean(struct drm_mm *mm);
void drm_mm_init_scan(struct drm_mm *mm,
unsigned long size,
@@ -191,10 +287,10 @@ void drm_mm_init_scan_with_range(struct drm_mm *mm,
unsigned long color,
unsigned long start,
unsigned long end);
-int drm_mm_scan_add_block(struct drm_mm_node *node);
-int drm_mm_scan_remove_block(struct drm_mm_node *node);
+bool drm_mm_scan_add_block(struct drm_mm_node *node);
+bool drm_mm_scan_remove_block(struct drm_mm_node *node);
-extern void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
+void drm_mm_debug_table(struct drm_mm *mm, const char *prefix);
#ifdef CONFIG_DEBUG_FS
int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm);
#endif
--
1.8.5.2
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