Revert "resources: support allocating space within a region from the top down"

This reverts commit e7f8567db9a7f6b3151b0b275e245c1cef0d9c70. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Revert "resources: support allocating space within a region from the top down"
This reverts commit e7f8567db9a7f6b3151b0b275e245c1cef0d9c70. Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Bjorn Helgaas · Jesse Barnes
1 parent 6db45b76ea
Showing 3 changed files with 4 additions and 100 deletions Side-by-side Diff
Documentation/kernel-parameters.txt
include/linux/ioport.h
kernel/resource.c
@@ -2175,11 +2175,6 @@
 	reset_devices	[KNL] Force drivers to reset the underlying device
 			during initialization.
  
-	resource_alloc_from_bottom
-			Allocate new resources from the beginning of available
-			space, not the end.  If you need to use this, please
-			report a bug.
-
 	resume=		[SWSUSP]
 			Specify the partition device for software suspend
  
@@ -112,7 +112,6 @@
 /* PC/ISA/whatever - the normal PC address spaces: IO and memory */
 extern struct resource ioport_resource;
 extern struct resource iomem_resource;
-extern int resource_alloc_from_bottom;
  
 extern struct resource *request_resource_conflict(struct resource *root, struct resource *new);
 extern int request_resource(struct resource *root, struct resource *new);
@@ -40,23 +40,6 @@
  
 static DEFINE_RWLOCK(resource_lock);
  
-/*
- * By default, we allocate free space bottom-up.  The architecture can request
- * top-down by clearing this flag.  The user can override the architecture's
- * choice with the "resource_alloc_from_bottom" kernel boot option, but that
- * should only be a debugging tool.
- */
-int resource_alloc_from_bottom = 1;
-
-static __init int setup_alloc_from_bottom(char *s)
-{
-	printk(KERN_INFO
-	       "resource: allocating from bottom-up; please report a bug\n");
-	resource_alloc_from_bottom = 1;
-	return 0;
-}
-early_param("resource_alloc_from_bottom", setup_alloc_from_bottom);
-
 static void *r_next(struct seq_file *m, void *v, loff_t *pos)
 {
 	struct resource *p = v;
  
  
@@ -397,75 +380,8 @@
 }
  
 /*
- * Find the resource before "child" in the sibling list of "root" children.
- */
-static struct resource *find_sibling_prev(struct resource *root, struct resource *child)
-{
-	struct resource *this;
-
-	for (this = root->child; this; this = this->sibling)
-		if (this->sibling == child)
-			return this;
-
-	return NULL;
-}
-
-/*
  * Find empty slot in the resource tree given range and alignment.
- * This version allocates from the end of the root resource first.
  */
-static int find_resource_from_top(struct resource *root, struct resource *new,
-				  resource_size_t size, resource_size_t min,
-				  resource_size_t max, resource_size_t align,
-				  resource_size_t (*alignf)(void *,
-						   const struct resource *,
-						   resource_size_t,
-						   resource_size_t),
-				  void *alignf_data)
-{
-	struct resource *this;
-	struct resource tmp, avail, alloc;
-
-	tmp.start = root->end;
-	tmp.end = root->end;
-
-	this = find_sibling_prev(root, NULL);
-	for (;;) {
-		if (this) {
-			if (this->end < root->end)
-				tmp.start = this->end + 1;
-		} else
-			tmp.start = root->start;
-
-		resource_clip(&tmp, min, max);
-
-		/* Check for overflow after ALIGN() */
-		avail = *new;
-		avail.start = ALIGN(tmp.start, align);
-		avail.end = tmp.end;
-		if (avail.start >= tmp.start) {
-			alloc.start = alignf(alignf_data, &avail, size, align);
-			alloc.end = alloc.start + size - 1;
-			if (resource_contains(&avail, &alloc)) {
-				new->start = alloc.start;
-				new->end = alloc.end;
-				return 0;
-			}
-		}
-
-		if (!this || this->start == root->start)
-			break;
-
-		tmp.end = this->start - 1;
-		this = find_sibling_prev(root, this);
-	}
-	return -EBUSY;
-}
-
-/*
- * Find empty slot in the resource tree given range and alignment.
- * This version allocates from the beginning of the root resource first.
- */
 static int find_resource(struct resource *root, struct resource *new,
 			 resource_size_t size, resource_size_t min,
 			 resource_size_t max, resource_size_t align,
  
@@ -480,15 +396,14 @@
  
 	tmp.start = root->start;
 	/*
-	 * Skip past an allocated resource that starts at 0, since the
-	 * assignment of this->start - 1 to tmp->end below would cause an
-	 * underflow.
+	 * Skip past an allocated resource that starts at 0, since the assignment
+	 * of this->start - 1 to tmp->end below would cause an underflow.
 	 */
 	if (this && this->start == 0) {
 		tmp.start = this->end + 1;
 		this = this->sibling;
 	}
-	for (;;) {
+	for(;;) {
 		if (this)
 			tmp.end = this->start - 1;
 		else
  
@@ -509,10 +424,8 @@
 				return 0;
 			}
 		}
-
 		if (!this)
 			break;
-
 		tmp.start = this->end + 1;
 		this = this->sibling;
 	}
@@ -545,10 +458,7 @@
 		alignf = simple_align_resource;
  
 	write_lock(&resource_lock);
-	if (resource_alloc_from_bottom)
-		err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
-	else
-		err = find_resource_from_top(root, new, size, min, max, align, alignf, alignf_data);
+	err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
 	if (err >= 0 && __request_resource(root, new))
 		err = -EBUSY;
 	write_unlock(&resource_lock);
...	...	@@ -2175,11 +2175,6 @@
2175	2175	reset_devices [KNL] Force drivers to reset the underlying device
2176	2176	during initialization.
2177	2177
2178		- resource_alloc_from_bottom
2179		- Allocate new resources from the beginning of available
2180		- space, not the end. If you need to use this, please
2181		- report a bug.
2182		-
2183	2178	resume= [SWSUSP]
2184	2179	Specify the partition device for software suspend
2185	2180
...	...	@@ -112,7 +112,6 @@
112	112	/* PC/ISA/whatever - the normal PC address spaces: IO and memory */
113	113	extern struct resource ioport_resource;
114	114	extern struct resource iomem_resource;
115		-extern int resource_alloc_from_bottom;
116	115
117	116	extern struct resource request_resource_conflict(struct resource root, struct resource *new);
118	117	extern int request_resource(struct resource root, struct resource new);
...	...	@@ -40,23 +40,6 @@
40	40
41	41	static DEFINE_RWLOCK(resource_lock);
42	42
43		-/*
44		- * By default, we allocate free space bottom-up. The architecture can request
45		- * top-down by clearing this flag. The user can override the architecture's
46		- * choice with the "resource_alloc_from_bottom" kernel boot option, but that
47		- * should only be a debugging tool.
48		- */
49		-int resource_alloc_from_bottom = 1;
50		-
51		-static __init int setup_alloc_from_bottom(char *s)
52		-{
53		- printk(KERN_INFO
54		- "resource: allocating from bottom-up; please report a bug\n");
55		- resource_alloc_from_bottom = 1;
56		- return 0;
57		-}
58		-early_param("resource_alloc_from_bottom", setup_alloc_from_bottom);
59		-
60	43	static void r_next(struct seq_file m, void v, loff_t pos)
61	44	{
62	45	struct resource *p = v;
63	46
64	47
...	...	@@ -397,75 +380,8 @@
397	380	}
398	381
399	382	/*
400		- * Find the resource before "child" in the sibling list of "root" children.
401		- */
402		-static struct resource find_sibling_prev(struct resource root, struct resource *child)
403		-{
404		- struct resource *this;
405		-
406		- for (this = root->child; this; this = this->sibling)
407		- if (this->sibling == child)
408		- return this;
409		-
410		- return NULL;
411		-}
412		-
413		-/*
414	383	* Find empty slot in the resource tree given range and alignment.
415		- * This version allocates from the end of the root resource first.
416	384	*/
417		-static int find_resource_from_top(struct resource root, struct resource new,
418		- resource_size_t size, resource_size_t min,
419		- resource_size_t max, resource_size_t align,
420		- resource_size_t (alignf)(void ,
421		- const struct resource *,
422		- resource_size_t,
423		- resource_size_t),
424		- void *alignf_data)
425		-{
426		- struct resource *this;
427		- struct resource tmp, avail, alloc;
428		-
429		- tmp.start = root->end;
430		- tmp.end = root->end;
431		-
432		- this = find_sibling_prev(root, NULL);
433		- for (;;) {
434		- if (this) {
435		- if (this->end < root->end)
436		- tmp.start = this->end + 1;
437		- } else
438		- tmp.start = root->start;
439		-
440		- resource_clip(&tmp, min, max);
441		-
442		- /* Check for overflow after ALIGN() */
443		- avail = *new;
444		- avail.start = ALIGN(tmp.start, align);
445		- avail.end = tmp.end;
446		- if (avail.start >= tmp.start) {
447		- alloc.start = alignf(alignf_data, &avail, size, align);
448		- alloc.end = alloc.start + size - 1;
449		- if (resource_contains(&avail, &alloc)) {
450		- new->start = alloc.start;
451		- new->end = alloc.end;
452		- return 0;
453		- }
454		- }
455		-
456		- if (!this \|\| this->start == root->start)
457		- break;
458		-
459		- tmp.end = this->start - 1;
460		- this = find_sibling_prev(root, this);
461		- }
462		- return -EBUSY;
463		-}
464		-
465		-/*
466		- * Find empty slot in the resource tree given range and alignment.
467		- * This version allocates from the beginning of the root resource first.
468		- */
469	385	static int find_resource(struct resource root, struct resource new,
470	386	resource_size_t size, resource_size_t min,
471	387	resource_size_t max, resource_size_t align,
472	388
...	...	@@ -480,15 +396,14 @@
480	396
481	397	tmp.start = root->start;
482	398	/*
483		- * Skip past an allocated resource that starts at 0, since the
484		- * assignment of this->start - 1 to tmp->end below would cause an
485		- * underflow.
	399	+ * Skip past an allocated resource that starts at 0, since the assignment
	400	+ * of this->start - 1 to tmp->end below would cause an underflow.
486	401	*/
487	402	if (this && this->start == 0) {
488	403	tmp.start = this->end + 1;
489	404	this = this->sibling;
490	405	}
491		- for (;;) {
	406	+ for(;;) {
492	407	if (this)
493	408	tmp.end = this->start - 1;
494	409	else
495	410
...	...	@@ -509,10 +424,8 @@
509	424	return 0;
510	425	}
511	426	}
512		-
513	427	if (!this)
514	428	break;
515		-
516	429	tmp.start = this->end + 1;
517	430	this = this->sibling;
518	431	}
...	...	@@ -545,10 +458,7 @@
545	458	alignf = simple_align_resource;
546	459
547	460	write_lock(&resource_lock);
548		- if (resource_alloc_from_bottom)
549		- err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
550		- else
551		- err = find_resource_from_top(root, new, size, min, max, align, alignf, alignf_data);
	461	+ err = find_resource(root, new, size, min, max, align, alignf, alignf_data);
552	462	if (err >= 0 && __request_resource(root, new))
553	463	err = -EBUSY;
554	464	write_unlock(&resource_lock);