linux/include/drm/drm_mm.h
Dave Airlie 735dc0d1e2 Merge branch 'drm-kms-locking' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
The aim of this locking rework is that ioctls which a compositor should be
might call for every frame (set_cursor, page_flip, addfb, rmfb and
getfb/create_handle) should not be able to block on kms background
activities like output detection. And since each EDID read takes about
25ms (in the best case), that always means we'll drop at least one frame.

The solution is to add per-crtc locking for these ioctls, and restrict
background activities to only use the global lock. Change-the-world type
of events (modeset, dpms, ...) need to grab all locks.

Two tricky parts arose in the conversion:
- A lot of current code assumes that a kms fb object can't disappear while
  holding the global lock, since the current code serializes fb
  destruction with it. Hence proper lifetime management using the already
  created refcounting for fbs need to be instantiated for all ioctls and
  interfaces/users.

- The rmfb ioctl removes the to-be-deleted fb from all active users. But
  unconditionally taking the global kms lock to do so introduces an
  unacceptable potential stall point. And obviously changing the userspace
  abi isn't on the table, either. Hence this conversion opportunistically
  checks whether the rmfb ioctl holds the very last reference, which
  guarantees that the fb isn't in active use on any crtc or plane (thanks
  to the conversion to the new lifetime rules using proper refcounting).
  Only if this is not the case will the code go through the slowpath and
  grab all modeset locks. Sane compositors will never hit this path and so
  avoid the stall, but userspace relying on these semantics will also not
  break.

All these cases are exercised by the newly added subtests for the i-g-t
kms_flip, tested on a machine where a full detect cycle takes around 100
ms.  It works, and no frames are dropped any more with these patches
applied.  kms_flip also contains a special case to exercise the
above-describe rmfb slowpath.

* 'drm-kms-locking' of git://people.freedesktop.org/~danvet/drm-intel: (335 commits)
  drm/fb_helper: check whether fbcon is bound
  drm/doc: updates for new framebuffer lifetime rules
  drm: don't hold crtc mutexes for connector ->detect callbacks
  drm: only grab the crtc lock for pageflips
  drm: optimize drm_framebuffer_remove
  drm/vmwgfx: add proper framebuffer refcounting
  drm/i915: dump refcount into framebuffer debugfs file
  drm: refcounting for crtc framebuffers
  drm: refcounting for sprite framebuffers
  drm: fb refcounting for dirtyfb_ioctl
  drm: don't take modeset locks in getfb ioctl
  drm: push modeset_lock_all into ->fb_create driver callbacks
  drm: nest modeset locks within fpriv->fbs_lock
  drm: reference framebuffers which are on the idr
  drm: revamp framebuffer cleanup interfaces
  drm: create drm_framebuffer_lookup
  drm: revamp locking around fb creation/destruction
  drm: only take the crtc lock for ->cursor_move
  drm: only take the crtc lock for ->cursor_set
  drm: add per-crtc locks
  ...
2013-01-21 07:44:58 +10:00

309 lines
9.9 KiB
C

/**************************************************************************
*
* Copyright 2006-2008 Tungsten Graphics, Inc., Cedar Park, TX. USA.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*
**************************************************************************/
/*
* Authors:
* Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
*/
#ifndef _DRM_MM_H_
#define _DRM_MM_H_
/*
* Generic range manager structs
*/
#include <linux/list.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>
#endif
struct drm_mm_node {
struct list_head node_list;
struct list_head hole_stack;
unsigned hole_follows : 1;
unsigned scanned_block : 1;
unsigned scanned_prev_free : 1;
unsigned scanned_next_free : 1;
unsigned scanned_preceeds_hole : 1;
unsigned allocated : 1;
unsigned long color;
unsigned long start;
unsigned long size;
struct drm_mm *mm;
};
struct drm_mm {
/* List of all memory nodes that immediately precede a free hole. */
struct list_head hole_stack;
/* head_node.node_list is the list of all memory nodes, ordered
* according to the (increasing) start address of the memory node. */
struct drm_mm_node head_node;
struct list_head unused_nodes;
int num_unused;
spinlock_t unused_lock;
unsigned int scan_check_range : 1;
unsigned scan_alignment;
unsigned long scan_color;
unsigned long scan_size;
unsigned long scan_hit_start;
unsigned long scan_hit_end;
unsigned scanned_blocks;
unsigned long scan_start;
unsigned long scan_end;
struct drm_mm_node *prev_scanned_node;
void (*color_adjust)(struct drm_mm_node *node, unsigned long color,
unsigned long *start, unsigned long *end);
};
static inline bool drm_mm_node_allocated(struct drm_mm_node *node)
{
return node->allocated;
}
static inline bool drm_mm_initialized(struct drm_mm *mm)
{
return mm->hole_stack.next;
}
static inline unsigned long __drm_mm_hole_node_start(struct drm_mm_node *hole_node)
{
return hole_node->start + hole_node->size;
}
static inline unsigned long drm_mm_hole_node_start(struct drm_mm_node *hole_node)
{
BUG_ON(!hole_node->hole_follows);
return __drm_mm_hole_node_start(hole_node);
}
static inline unsigned long __drm_mm_hole_node_end(struct drm_mm_node *hole_node)
{
return list_entry(hole_node->node_list.next,
struct drm_mm_node, node_list)->start;
}
static inline unsigned long drm_mm_hole_node_end(struct drm_mm_node *hole_node)
{
return __drm_mm_hole_node_end(hole_node);
}
#define drm_mm_for_each_node(entry, mm) list_for_each_entry(entry, \
&(mm)->head_node.node_list, \
node_list)
#define drm_mm_for_each_scanned_node_reverse(entry, n, mm) \
for (entry = (mm)->prev_scanned_node, \
next = entry ? list_entry(entry->node_list.next, \
struct drm_mm_node, node_list) : NULL; \
entry != NULL; entry = next, \
next = entry ? list_entry(entry->node_list.next, \
struct drm_mm_node, node_list) : NULL) \
/* 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.
*/
#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); \
&entry->hole_stack != &(mm)->hole_stack ? \
hole_start = drm_mm_hole_node_start(entry), \
hole_end = drm_mm_hole_node_end(entry), \
1 : 0; \
entry = list_entry(entry->hole_stack.next, struct drm_mm_node, hole_stack))
/*
* Basic range manager support (drm_mm.c)
*/
extern struct drm_mm_node *drm_mm_create_block(struct drm_mm *mm,
unsigned long start,
unsigned long size,
bool atomic);
extern struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
unsigned long color,
int atomic);
extern struct drm_mm_node *drm_mm_get_block_range_generic(
struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
unsigned long color,
unsigned long start,
unsigned long end,
int atomic);
static inline struct drm_mm_node *drm_mm_get_block(struct drm_mm_node *parent,
unsigned long size,
unsigned alignment)
{
return drm_mm_get_block_generic(parent, size, alignment, 0, 0);
}
static inline struct drm_mm_node *drm_mm_get_block_atomic(struct drm_mm_node *parent,
unsigned long size,
unsigned alignment)
{
return drm_mm_get_block_generic(parent, size, alignment, 0, 1);
}
static inline struct drm_mm_node *drm_mm_get_block_range(
struct drm_mm_node *parent,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end)
{
return drm_mm_get_block_range_generic(parent, size, alignment, 0,
start, end, 0);
}
static inline struct drm_mm_node *drm_mm_get_color_block_range(
struct drm_mm_node *parent,
unsigned long size,
unsigned alignment,
unsigned long color,
unsigned long start,
unsigned long end)
{
return drm_mm_get_block_range_generic(parent, size, alignment, color,
start, end, 0);
}
static inline struct drm_mm_node *drm_mm_get_block_atomic_range(
struct drm_mm_node *parent,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end)
{
return drm_mm_get_block_range_generic(parent, size, alignment, 0,
start, end, 1);
}
extern int drm_mm_insert_node(struct drm_mm *mm,
struct drm_mm_node *node,
unsigned long size,
unsigned alignment);
extern int drm_mm_insert_node_in_range(struct drm_mm *mm,
struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end);
extern int drm_mm_insert_node_generic(struct drm_mm *mm,
struct drm_mm_node *node,
unsigned long size,
unsigned alignment,
unsigned long color);
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);
extern void drm_mm_put_block(struct drm_mm_node *cur);
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 struct drm_mm_node *drm_mm_search_free_generic(const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color,
bool best_match);
extern struct drm_mm_node *drm_mm_search_free_in_range_generic(
const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color,
unsigned long start,
unsigned long end,
bool best_match);
static inline struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
bool best_match)
{
return drm_mm_search_free_generic(mm,size, alignment, 0, best_match);
}
static inline struct drm_mm_node *drm_mm_search_free_in_range(
const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long start,
unsigned long end,
bool best_match)
{
return drm_mm_search_free_in_range_generic(mm, size, alignment, 0,
start, end, best_match);
}
static inline struct drm_mm_node *drm_mm_search_free_color(const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color,
bool best_match)
{
return drm_mm_search_free_generic(mm,size, alignment, color, best_match);
}
static inline struct drm_mm_node *drm_mm_search_free_in_range_color(
const struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color,
unsigned long start,
unsigned long end,
bool best_match)
{
return drm_mm_search_free_in_range_generic(mm, size, alignment, color,
start, end, best_match);
}
extern int 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);
extern int drm_mm_pre_get(struct drm_mm *mm);
static inline struct drm_mm *drm_get_mm(struct drm_mm_node *block)
{
return block->mm;
}
void drm_mm_init_scan(struct drm_mm *mm,
unsigned long size,
unsigned alignment,
unsigned long color);
void drm_mm_init_scan_with_range(struct drm_mm *mm,
unsigned long size,
unsigned alignment,
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);
extern 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
#endif