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authorJiri Kosina <jkosina@suse.cz>2010-08-10 07:22:08 -0400
committerJiri Kosina <jkosina@suse.cz>2010-08-10 07:22:08 -0400
commitfb8231a8b139035476f2a8aaac837d0099b66dad (patch)
tree2875806beb96ea0cdab292146767a5085721dc6a /lib
parent426d31071ac476ea62c62656b242930c17b58c00 (diff)
parentf6cec0ae58c17522a7bc4e2f39dae19f199ab534 (diff)
Merge branch 'master' into for-next
Conflicts: arch/arm/mach-omap1/board-nokia770.c
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug61
-rw-r--r--lib/flex_array.c25
-rw-r--r--lib/iommu-helper.c9
-rw-r--r--lib/ioremap.c10
-rw-r--r--lib/list_debug.c6
-rw-r--r--lib/percpu_counter.c27
-rw-r--r--lib/radix-tree.c94
-rw-r--r--lib/rwsem.c150
-rw-r--r--lib/vsprintf.c14
9 files changed, 290 insertions, 106 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index dfdc0347b05d..79e0dff1cdcb 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -76,7 +76,6 @@ config UNUSED_SYMBOLS
76 76
77config DEBUG_FS 77config DEBUG_FS
78 bool "Debug Filesystem" 78 bool "Debug Filesystem"
79 depends on SYSFS
80 help 79 help
81 debugfs is a virtual file system that kernel developers use to put 80 debugfs is a virtual file system that kernel developers use to put
82 debugging files into. Enable this option to be able to read and 81 debugging files into. Enable this option to be able to read and
@@ -152,28 +151,33 @@ config DEBUG_SHIRQ
152 Drivers ought to be able to handle interrupts coming in at those 151 Drivers ought to be able to handle interrupts coming in at those
153 points; some don't and need to be caught. 152 points; some don't and need to be caught.
154 153
155config DETECT_SOFTLOCKUP 154config LOCKUP_DETECTOR
156 bool "Detect Soft Lockups" 155 bool "Detect Hard and Soft Lockups"
157 depends on DEBUG_KERNEL && !S390 156 depends on DEBUG_KERNEL && !S390
158 default y
159 help 157 help
160 Say Y here to enable the kernel to detect "soft lockups", 158 Say Y here to enable the kernel to act as a watchdog to detect
161 which are bugs that cause the kernel to loop in kernel 159 hard and soft lockups.
160
161 Softlockups are bugs that cause the kernel to loop in kernel
162 mode for more than 60 seconds, without giving other tasks a 162 mode for more than 60 seconds, without giving other tasks a
163 chance to run. 163 chance to run. The current stack trace is displayed upon
164 detection and the system will stay locked up.
164 165
165 When a soft-lockup is detected, the kernel will print the 166 Hardlockups are bugs that cause the CPU to loop in kernel mode
166 current stack trace (which you should report), but the 167 for more than 60 seconds, without letting other interrupts have a
167 system will stay locked up. This feature has negligible 168 chance to run. The current stack trace is displayed upon detection
168 overhead. 169 and the system will stay locked up.
169 170
170 (Note that "hard lockups" are separate type of bugs that 171 The overhead should be minimal. A periodic hrtimer runs to
171 can be detected via the NMI-watchdog, on platforms that 172 generate interrupts and kick the watchdog task every 10-12 seconds.
172 support it.) 173 An NMI is generated every 60 seconds or so to check for hardlockups.
174
175config HARDLOCKUP_DETECTOR
176 def_bool LOCKUP_DETECTOR && PERF_EVENTS && HAVE_PERF_EVENTS_NMI
173 177
174config BOOTPARAM_SOFTLOCKUP_PANIC 178config BOOTPARAM_SOFTLOCKUP_PANIC
175 bool "Panic (Reboot) On Soft Lockups" 179 bool "Panic (Reboot) On Soft Lockups"
176 depends on DETECT_SOFTLOCKUP 180 depends on LOCKUP_DETECTOR
177 help 181 help
178 Say Y here to enable the kernel to panic on "soft lockups", 182 Say Y here to enable the kernel to panic on "soft lockups",
179 which are bugs that cause the kernel to loop in kernel 183 which are bugs that cause the kernel to loop in kernel
@@ -190,7 +194,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC
190 194
191config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE 195config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
192 int 196 int
193 depends on DETECT_SOFTLOCKUP 197 depends on LOCKUP_DETECTOR
194 range 0 1 198 range 0 1
195 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC 199 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
196 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC 200 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
@@ -307,6 +311,12 @@ config DEBUG_OBJECTS_WORK
307 work queue routines to track the life time of work objects and 311 work queue routines to track the life time of work objects and
308 validate the work operations. 312 validate the work operations.
309 313
314config DEBUG_OBJECTS_RCU_HEAD
315 bool "Debug RCU callbacks objects"
316 depends on DEBUG_OBJECTS && PREEMPT
317 help
318 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
319
310config DEBUG_OBJECTS_ENABLE_DEFAULT 320config DEBUG_OBJECTS_ENABLE_DEFAULT
311 int "debug_objects bootup default value (0-1)" 321 int "debug_objects bootup default value (0-1)"
312 range 0 1 322 range 0 1
@@ -528,7 +538,7 @@ config LOCKDEP
528 bool 538 bool
529 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT 539 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
530 select STACKTRACE 540 select STACKTRACE
531 select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 541 select FRAME_POINTER if !MIPS && !PPC && !ARM_UNWIND && !S390 && !MICROBLAZE
532 select KALLSYMS 542 select KALLSYMS
533 select KALLSYMS_ALL 543 select KALLSYMS_ALL
534 544
@@ -628,6 +638,19 @@ config DEBUG_INFO
628 638
629 If unsure, say N. 639 If unsure, say N.
630 640
641config DEBUG_INFO_REDUCED
642 bool "Reduce debugging information"
643 depends on DEBUG_INFO
644 help
645 If you say Y here gcc is instructed to generate less debugging
646 information for structure types. This means that tools that
647 need full debugging information (like kgdb or systemtap) won't
648 be happy. But if you merely need debugging information to
649 resolve line numbers there is no loss. Advantage is that
650 build directory object sizes shrink dramatically over a full
651 DEBUG_INFO build and compile times are reduced too.
652 Only works with newer gcc versions.
653
631config DEBUG_VM 654config DEBUG_VM
632 bool "Debug VM" 655 bool "Debug VM"
633 depends on DEBUG_KERNEL 656 depends on DEBUG_KERNEL
@@ -958,13 +981,13 @@ config FAULT_INJECTION_STACKTRACE_FILTER
958 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT 981 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
959 depends on !X86_64 982 depends on !X86_64
960 select STACKTRACE 983 select STACKTRACE
961 select FRAME_POINTER if !PPC && !S390 984 select FRAME_POINTER if !PPC && !S390 && !MICROBLAZE
962 help 985 help
963 Provide stacktrace filter for fault-injection capabilities 986 Provide stacktrace filter for fault-injection capabilities
964 987
965config LATENCYTOP 988config LATENCYTOP
966 bool "Latency measuring infrastructure" 989 bool "Latency measuring infrastructure"
967 select FRAME_POINTER if !MIPS && !PPC && !S390 990 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE
968 select KALLSYMS 991 select KALLSYMS
969 select KALLSYMS_ALL 992 select KALLSYMS_ALL
970 select STACKTRACE 993 select STACKTRACE
diff --git a/lib/flex_array.c b/lib/flex_array.c
index 41b1804fa728..77a6fea7481e 100644
--- a/lib/flex_array.c
+++ b/lib/flex_array.c
@@ -171,6 +171,8 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags)
171 * Note that this *copies* the contents of @src into 171 * Note that this *copies* the contents of @src into
172 * the array. If you are trying to store an array of 172 * the array. If you are trying to store an array of
173 * pointers, make sure to pass in &ptr instead of ptr. 173 * pointers, make sure to pass in &ptr instead of ptr.
174 * You may instead wish to use the flex_array_put_ptr()
175 * helper function.
174 * 176 *
175 * Locking must be provided by the caller. 177 * Locking must be provided by the caller.
176 */ 178 */
@@ -265,7 +267,8 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start,
265 * 267 *
266 * Returns a pointer to the data at index @element_nr. Note 268 * Returns a pointer to the data at index @element_nr. Note
267 * that this is a copy of the data that was passed in. If you 269 * that this is a copy of the data that was passed in. If you
268 * are using this to store pointers, you'll get back &ptr. 270 * are using this to store pointers, you'll get back &ptr. You
271 * may instead wish to use the flex_array_get_ptr helper.
269 * 272 *
270 * Locking must be provided by the caller. 273 * Locking must be provided by the caller.
271 */ 274 */
@@ -286,6 +289,26 @@ void *flex_array_get(struct flex_array *fa, unsigned int element_nr)
286 return &part->elements[index_inside_part(fa, element_nr)]; 289 return &part->elements[index_inside_part(fa, element_nr)];
287} 290}
288 291
292/**
293 * flex_array_get_ptr - pull a ptr back out of the array
294 * @fa: the flex array from which to extract data
295 * @element_nr: index of the element to fetch from the array
296 *
297 * Returns the pointer placed in the flex array at element_nr using
298 * flex_array_put_ptr(). This function should not be called if the
299 * element in question was not set using the _put_ptr() helper.
300 */
301void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr)
302{
303 void **tmp;
304
305 tmp = flex_array_get(fa, element_nr);
306 if (!tmp)
307 return NULL;
308
309 return *tmp;
310}
311
289static int part_is_free(struct flex_array_part *part) 312static int part_is_free(struct flex_array_part *part)
290{ 313{
291 int i; 314 int i;
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index c0251f4ad08b..da053313ee5c 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -38,12 +38,3 @@ again:
38 return -1; 38 return -1;
39} 39}
40EXPORT_SYMBOL(iommu_area_alloc); 40EXPORT_SYMBOL(iommu_area_alloc);
41
42unsigned long iommu_num_pages(unsigned long addr, unsigned long len,
43 unsigned long io_page_size)
44{
45 unsigned long size = (addr & (io_page_size - 1)) + len;
46
47 return DIV_ROUND_UP(size, io_page_size);
48}
49EXPORT_SYMBOL(iommu_num_pages);
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 14c6078f17a2..5730ecd3eb66 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -13,10 +13,10 @@
13#include <asm/pgtable.h> 13#include <asm/pgtable.h>
14 14
15static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, 15static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
16 unsigned long end, unsigned long phys_addr, pgprot_t prot) 16 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
17{ 17{
18 pte_t *pte; 18 pte_t *pte;
19 unsigned long pfn; 19 u64 pfn;
20 20
21 pfn = phys_addr >> PAGE_SHIFT; 21 pfn = phys_addr >> PAGE_SHIFT;
22 pte = pte_alloc_kernel(pmd, addr); 22 pte = pte_alloc_kernel(pmd, addr);
@@ -31,7 +31,7 @@ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
31} 31}
32 32
33static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, 33static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
34 unsigned long end, unsigned long phys_addr, pgprot_t prot) 34 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
35{ 35{
36 pmd_t *pmd; 36 pmd_t *pmd;
37 unsigned long next; 37 unsigned long next;
@@ -49,7 +49,7 @@ static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
49} 49}
50 50
51static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr, 51static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
52 unsigned long end, unsigned long phys_addr, pgprot_t prot) 52 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
53{ 53{
54 pud_t *pud; 54 pud_t *pud;
55 unsigned long next; 55 unsigned long next;
@@ -67,7 +67,7 @@ static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
67} 67}
68 68
69int ioremap_page_range(unsigned long addr, 69int ioremap_page_range(unsigned long addr,
70 unsigned long end, unsigned long phys_addr, pgprot_t prot) 70 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
71{ 71{
72 pgd_t *pgd; 72 pgd_t *pgd;
73 unsigned long start; 73 unsigned long start;
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 1a39f4e3ae1f..344c710d16ca 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -43,6 +43,12 @@ EXPORT_SYMBOL(__list_add);
43 */ 43 */
44void list_del(struct list_head *entry) 44void list_del(struct list_head *entry)
45{ 45{
46 WARN(entry->next == LIST_POISON1,
47 "list_del corruption, next is LIST_POISON1 (%p)\n",
48 LIST_POISON1);
49 WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2,
50 "list_del corruption, prev is LIST_POISON2 (%p)\n",
51 LIST_POISON2);
46 WARN(entry->prev->next != entry, 52 WARN(entry->prev->next != entry,
47 "list_del corruption. prev->next should be %p, " 53 "list_del corruption. prev->next should be %p, "
48 "but was %p\n", entry, entry->prev->next); 54 "but was %p\n", entry, entry->prev->next);
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index aeaa6d734447..ec9048e74f44 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -137,6 +137,33 @@ static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
137 return NOTIFY_OK; 137 return NOTIFY_OK;
138} 138}
139 139
140/*
141 * Compare counter against given value.
142 * Return 1 if greater, 0 if equal and -1 if less
143 */
144int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
145{
146 s64 count;
147
148 count = percpu_counter_read(fbc);
149 /* Check to see if rough count will be sufficient for comparison */
150 if (abs(count - rhs) > (percpu_counter_batch*num_online_cpus())) {
151 if (count > rhs)
152 return 1;
153 else
154 return -1;
155 }
156 /* Need to use precise count */
157 count = percpu_counter_sum(fbc);
158 if (count > rhs)
159 return 1;
160 else if (count < rhs)
161 return -1;
162 else
163 return 0;
164}
165EXPORT_SYMBOL(percpu_counter_compare);
166
140static int __init percpu_counter_startup(void) 167static int __init percpu_counter_startup(void)
141{ 168{
142 compute_batch_value(); 169 compute_batch_value();
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 05da38bcc298..e907858498a6 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -609,6 +609,100 @@ int radix_tree_tag_get(struct radix_tree_root *root,
609EXPORT_SYMBOL(radix_tree_tag_get); 609EXPORT_SYMBOL(radix_tree_tag_get);
610 610
611/** 611/**
612 * radix_tree_range_tag_if_tagged - for each item in given range set given
613 * tag if item has another tag set
614 * @root: radix tree root
615 * @first_indexp: pointer to a starting index of a range to scan
616 * @last_index: last index of a range to scan
617 * @nr_to_tag: maximum number items to tag
618 * @iftag: tag index to test
619 * @settag: tag index to set if tested tag is set
620 *
621 * This function scans range of radix tree from first_index to last_index
622 * (inclusive). For each item in the range if iftag is set, the function sets
623 * also settag. The function stops either after tagging nr_to_tag items or
624 * after reaching last_index.
625 *
626 * The function returns number of leaves where the tag was set and sets
627 * *first_indexp to the first unscanned index.
628 */
629unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
630 unsigned long *first_indexp, unsigned long last_index,
631 unsigned long nr_to_tag,
632 unsigned int iftag, unsigned int settag)
633{
634 unsigned int height = root->height, shift;
635 unsigned long tagged = 0, index = *first_indexp;
636 struct radix_tree_node *open_slots[height], *slot;
637
638 last_index = min(last_index, radix_tree_maxindex(height));
639 if (index > last_index)
640 return 0;
641 if (!nr_to_tag)
642 return 0;
643 if (!root_tag_get(root, iftag)) {
644 *first_indexp = last_index + 1;
645 return 0;
646 }
647 if (height == 0) {
648 *first_indexp = last_index + 1;
649 root_tag_set(root, settag);
650 return 1;
651 }
652
653 shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
654 slot = radix_tree_indirect_to_ptr(root->rnode);
655
656 for (;;) {
657 int offset;
658
659 offset = (index >> shift) & RADIX_TREE_MAP_MASK;
660 if (!slot->slots[offset])
661 goto next;
662 if (!tag_get(slot, iftag, offset))
663 goto next;
664 tag_set(slot, settag, offset);
665 if (height == 1) {
666 tagged++;
667 goto next;
668 }
669 /* Go down one level */
670 height--;
671 shift -= RADIX_TREE_MAP_SHIFT;
672 open_slots[height] = slot;
673 slot = slot->slots[offset];
674 continue;
675next:
676 /* Go to next item at level determined by 'shift' */
677 index = ((index >> shift) + 1) << shift;
678 if (index > last_index)
679 break;
680 if (tagged >= nr_to_tag)
681 break;
682 while (((index >> shift) & RADIX_TREE_MAP_MASK) == 0) {
683 /*
684 * We've fully scanned this node. Go up. Because
685 * last_index is guaranteed to be in the tree, what
686 * we do below cannot wander astray.
687 */
688 slot = open_slots[height];
689 height++;
690 shift += RADIX_TREE_MAP_SHIFT;
691 }
692 }
693 /*
694 * The iftag must have been set somewhere because otherwise
695 * we would return immediated at the beginning of the function
696 */
697 root_tag_set(root, settag);
698 *first_indexp = index;
699
700 return tagged;
701}
702EXPORT_SYMBOL(radix_tree_range_tag_if_tagged);
703
704
705/**
612 * radix_tree_next_hole - find the next hole (not-present entry) 706 * radix_tree_next_hole - find the next hole (not-present entry)
613 * @root: tree root 707 * @root: tree root
614 * @index: index key 708 * @index: index key
diff --git a/lib/rwsem.c b/lib/rwsem.c
index ceba8e28807a..f236d7cd5cf3 100644
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -36,45 +36,56 @@ struct rwsem_waiter {
36#define RWSEM_WAITING_FOR_WRITE 0x00000002 36#define RWSEM_WAITING_FOR_WRITE 0x00000002
37}; 37};
38 38
39/* Wake types for __rwsem_do_wake(). Note that RWSEM_WAKE_NO_ACTIVE and
40 * RWSEM_WAKE_READ_OWNED imply that the spinlock must have been kept held
41 * since the rwsem value was observed.
42 */
43#define RWSEM_WAKE_ANY 0 /* Wake whatever's at head of wait list */
44#define RWSEM_WAKE_NO_ACTIVE 1 /* rwsem was observed with no active thread */
45#define RWSEM_WAKE_READ_OWNED 2 /* rwsem was observed to be read owned */
46
39/* 47/*
40 * handle the lock release when processes blocked on it that can now run 48 * handle the lock release when processes blocked on it that can now run
41 * - if we come here from up_xxxx(), then: 49 * - if we come here from up_xxxx(), then:
42 * - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed) 50 * - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed)
43 * - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so) 51 * - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so)
44 * - there must be someone on the queue 52 * - there must be someone on the queue
45 * - the spinlock must be held by the caller 53 * - the spinlock must be held by the caller
46 * - woken process blocks are discarded from the list after having task zeroed 54 * - woken process blocks are discarded from the list after having task zeroed
47 * - writers are only woken if downgrading is false 55 * - writers are only woken if downgrading is false
48 */ 56 */
49static inline struct rw_semaphore * 57static struct rw_semaphore *
50__rwsem_do_wake(struct rw_semaphore *sem, int downgrading) 58__rwsem_do_wake(struct rw_semaphore *sem, int wake_type)
51{ 59{
52 struct rwsem_waiter *waiter; 60 struct rwsem_waiter *waiter;
53 struct task_struct *tsk; 61 struct task_struct *tsk;
54 struct list_head *next; 62 struct list_head *next;
55 signed long oldcount, woken, loop; 63 signed long oldcount, woken, loop, adjustment;
56
57 if (downgrading)
58 goto dont_wake_writers;
59
60 /* if we came through an up_xxxx() call, we only only wake someone up
61 * if we can transition the active part of the count from 0 -> 1
62 */
63 try_again:
64 oldcount = rwsem_atomic_update(RWSEM_ACTIVE_BIAS, sem)
65 - RWSEM_ACTIVE_BIAS;
66 if (oldcount & RWSEM_ACTIVE_MASK)
67 goto undo;
68 64
69 waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); 65 waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
70
71 /* try to grant a single write lock if there's a writer at the front
72 * of the queue - note we leave the 'active part' of the count
73 * incremented by 1 and the waiting part incremented by 0x00010000
74 */
75 if (!(waiter->flags & RWSEM_WAITING_FOR_WRITE)) 66 if (!(waiter->flags & RWSEM_WAITING_FOR_WRITE))
76 goto readers_only; 67 goto readers_only;
77 68
69 if (wake_type == RWSEM_WAKE_READ_OWNED)
70 /* Another active reader was observed, so wakeup is not
71 * likely to succeed. Save the atomic op.
72 */
73 goto out;
74
75 /* There's a writer at the front of the queue - try to grant it the
76 * write lock. However, we only wake this writer if we can transition
77 * the active part of the count from 0 -> 1
78 */
79 adjustment = RWSEM_ACTIVE_WRITE_BIAS;
80 if (waiter->list.next == &sem->wait_list)
81 adjustment -= RWSEM_WAITING_BIAS;
82
83 try_again_write:
84 oldcount = rwsem_atomic_update(adjustment, sem) - adjustment;
85 if (oldcount & RWSEM_ACTIVE_MASK)
86 /* Someone grabbed the sem already */
87 goto undo_write;
88
78 /* We must be careful not to touch 'waiter' after we set ->task = NULL. 89 /* We must be careful not to touch 'waiter' after we set ->task = NULL.
79 * It is an allocated on the waiter's stack and may become invalid at 90 * It is an allocated on the waiter's stack and may become invalid at
80 * any time after that point (due to a wakeup from another source). 91 * any time after that point (due to a wakeup from another source).
@@ -87,18 +98,30 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
87 put_task_struct(tsk); 98 put_task_struct(tsk);
88 goto out; 99 goto out;
89 100
90 /* don't want to wake any writers */ 101 readers_only:
91 dont_wake_writers: 102 /* If we come here from up_xxxx(), another thread might have reached
92 waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); 103 * rwsem_down_failed_common() before we acquired the spinlock and
93 if (waiter->flags & RWSEM_WAITING_FOR_WRITE) 104 * woken up a waiter, making it now active. We prefer to check for
105 * this first in order to not spend too much time with the spinlock
106 * held if we're not going to be able to wake up readers in the end.
107 *
108 * Note that we do not need to update the rwsem count: any writer
109 * trying to acquire rwsem will run rwsem_down_write_failed() due
110 * to the waiting threads and block trying to acquire the spinlock.
111 *
112 * We use a dummy atomic update in order to acquire the cache line
113 * exclusively since we expect to succeed and run the final rwsem
114 * count adjustment pretty soon.
115 */
116 if (wake_type == RWSEM_WAKE_ANY &&
117 rwsem_atomic_update(0, sem) < RWSEM_WAITING_BIAS)
118 /* Someone grabbed the sem for write already */
94 goto out; 119 goto out;
95 120
96 /* grant an infinite number of read locks to the readers at the front 121 /* Grant an infinite number of read locks to the readers at the front
97 * of the queue 122 * of the queue. Note we increment the 'active part' of the count by
98 * - note we increment the 'active part' of the count by the number of 123 * the number of readers before waking any processes up.
99 * readers before waking any processes up
100 */ 124 */
101 readers_only:
102 woken = 0; 125 woken = 0;
103 do { 126 do {
104 woken++; 127 woken++;
@@ -111,16 +134,15 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
111 134
112 } while (waiter->flags & RWSEM_WAITING_FOR_READ); 135 } while (waiter->flags & RWSEM_WAITING_FOR_READ);
113 136
114 loop = woken; 137 adjustment = woken * RWSEM_ACTIVE_READ_BIAS;
115 woken *= RWSEM_ACTIVE_BIAS - RWSEM_WAITING_BIAS; 138 if (waiter->flags & RWSEM_WAITING_FOR_READ)
116 if (!downgrading) 139 /* hit end of list above */
117 /* we'd already done one increment earlier */ 140 adjustment -= RWSEM_WAITING_BIAS;
118 woken -= RWSEM_ACTIVE_BIAS;
119 141
120 rwsem_atomic_add(woken, sem); 142 rwsem_atomic_add(adjustment, sem);
121 143
122 next = sem->wait_list.next; 144 next = sem->wait_list.next;
123 for (; loop > 0; loop--) { 145 for (loop = woken; loop > 0; loop--) {
124 waiter = list_entry(next, struct rwsem_waiter, list); 146 waiter = list_entry(next, struct rwsem_waiter, list);
125 next = waiter->list.next; 147 next = waiter->list.next;
126 tsk = waiter->task; 148 tsk = waiter->task;
@@ -138,10 +160,10 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
138 160
139 /* undo the change to the active count, but check for a transition 161 /* undo the change to the active count, but check for a transition
140 * 1->0 */ 162 * 1->0 */
141 undo: 163 undo_write:
142 if (rwsem_atomic_update(-RWSEM_ACTIVE_BIAS, sem) & RWSEM_ACTIVE_MASK) 164 if (rwsem_atomic_update(-adjustment, sem) & RWSEM_ACTIVE_MASK)
143 goto out; 165 goto out;
144 goto try_again; 166 goto try_again_write;
145} 167}
146 168
147/* 169/*
@@ -149,8 +171,9 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
149 */ 171 */
150static struct rw_semaphore __sched * 172static struct rw_semaphore __sched *
151rwsem_down_failed_common(struct rw_semaphore *sem, 173rwsem_down_failed_common(struct rw_semaphore *sem,
152 struct rwsem_waiter *waiter, signed long adjustment) 174 unsigned int flags, signed long adjustment)
153{ 175{
176 struct rwsem_waiter waiter;
154 struct task_struct *tsk = current; 177 struct task_struct *tsk = current;
155 signed long count; 178 signed long count;
156 179
@@ -158,23 +181,34 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
158 181
159 /* set up my own style of waitqueue */ 182 /* set up my own style of waitqueue */
160 spin_lock_irq(&sem->wait_lock); 183 spin_lock_irq(&sem->wait_lock);
161 waiter->task = tsk; 184 waiter.task = tsk;
185 waiter.flags = flags;
162 get_task_struct(tsk); 186 get_task_struct(tsk);
163 187
164 list_add_tail(&waiter->list, &sem->wait_list); 188 if (list_empty(&sem->wait_list))
189 adjustment += RWSEM_WAITING_BIAS;
190 list_add_tail(&waiter.list, &sem->wait_list);
165 191
166 /* we're now waiting on the lock, but no longer actively read-locking */ 192 /* we're now waiting on the lock, but no longer actively locking */
167 count = rwsem_atomic_update(adjustment, sem); 193 count = rwsem_atomic_update(adjustment, sem);
168 194
169 /* if there are no active locks, wake the front queued process(es) up */ 195 /* If there are no active locks, wake the front queued process(es) up.
170 if (!(count & RWSEM_ACTIVE_MASK)) 196 *
171 sem = __rwsem_do_wake(sem, 0); 197 * Alternatively, if we're called from a failed down_write(), there
198 * were already threads queued before us and there are no active
199 * writers, the lock must be read owned; so we try to wake any read
200 * locks that were queued ahead of us. */
201 if (count == RWSEM_WAITING_BIAS)
202 sem = __rwsem_do_wake(sem, RWSEM_WAKE_NO_ACTIVE);
203 else if (count > RWSEM_WAITING_BIAS &&
204 adjustment == -RWSEM_ACTIVE_WRITE_BIAS)
205 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
172 206
173 spin_unlock_irq(&sem->wait_lock); 207 spin_unlock_irq(&sem->wait_lock);
174 208
175 /* wait to be given the lock */ 209 /* wait to be given the lock */
176 for (;;) { 210 for (;;) {
177 if (!waiter->task) 211 if (!waiter.task)
178 break; 212 break;
179 schedule(); 213 schedule();
180 set_task_state(tsk, TASK_UNINTERRUPTIBLE); 214 set_task_state(tsk, TASK_UNINTERRUPTIBLE);
@@ -191,12 +225,8 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
191asmregparm struct rw_semaphore __sched * 225asmregparm struct rw_semaphore __sched *
192rwsem_down_read_failed(struct rw_semaphore *sem) 226rwsem_down_read_failed(struct rw_semaphore *sem)
193{ 227{
194 struct rwsem_waiter waiter; 228 return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_READ,
195 229 -RWSEM_ACTIVE_READ_BIAS);
196 waiter.flags = RWSEM_WAITING_FOR_READ;
197 rwsem_down_failed_common(sem, &waiter,
198 RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
199 return sem;
200} 230}
201 231
202/* 232/*
@@ -205,12 +235,8 @@ rwsem_down_read_failed(struct rw_semaphore *sem)
205asmregparm struct rw_semaphore __sched * 235asmregparm struct rw_semaphore __sched *
206rwsem_down_write_failed(struct rw_semaphore *sem) 236rwsem_down_write_failed(struct rw_semaphore *sem)
207{ 237{
208 struct rwsem_waiter waiter; 238 return rwsem_down_failed_common(sem, RWSEM_WAITING_FOR_WRITE,
209 239 -RWSEM_ACTIVE_WRITE_BIAS);
210 waiter.flags = RWSEM_WAITING_FOR_WRITE;
211 rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
212
213 return sem;
214} 240}
215 241
216/* 242/*
@@ -225,7 +251,7 @@ asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
225 251
226 /* do nothing if list empty */ 252 /* do nothing if list empty */
227 if (!list_empty(&sem->wait_list)) 253 if (!list_empty(&sem->wait_list))
228 sem = __rwsem_do_wake(sem, 0); 254 sem = __rwsem_do_wake(sem, RWSEM_WAKE_ANY);
229 255
230 spin_unlock_irqrestore(&sem->wait_lock, flags); 256 spin_unlock_irqrestore(&sem->wait_lock, flags);
231 257
@@ -245,7 +271,7 @@ asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
245 271
246 /* do nothing if list empty */ 272 /* do nothing if list empty */
247 if (!list_empty(&sem->wait_list)) 273 if (!list_empty(&sem->wait_list))
248 sem = __rwsem_do_wake(sem, 1); 274 sem = __rwsem_do_wake(sem, RWSEM_WAKE_READ_OWNED);
249 275
250 spin_unlock_irqrestore(&sem->wait_lock, flags); 276 spin_unlock_irqrestore(&sem->wait_lock, flags);
251 277
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 4ee19d0d3910..7af9d841c43b 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -146,19 +146,16 @@ int strict_strtoul(const char *cp, unsigned int base, unsigned long *res)
146{ 146{
147 char *tail; 147 char *tail;
148 unsigned long val; 148 unsigned long val;
149 size_t len;
150 149
151 *res = 0; 150 *res = 0;
152 len = strlen(cp); 151 if (!*cp)
153 if (len == 0)
154 return -EINVAL; 152 return -EINVAL;
155 153
156 val = simple_strtoul(cp, &tail, base); 154 val = simple_strtoul(cp, &tail, base);
157 if (tail == cp) 155 if (tail == cp)
158 return -EINVAL; 156 return -EINVAL;
159 157
160 if ((*tail == '\0') || 158 if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
161 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
162 *res = val; 159 *res = val;
163 return 0; 160 return 0;
164 } 161 }
@@ -220,18 +217,15 @@ int strict_strtoull(const char *cp, unsigned int base, unsigned long long *res)
220{ 217{
221 char *tail; 218 char *tail;
222 unsigned long long val; 219 unsigned long long val;
223 size_t len;
224 220
225 *res = 0; 221 *res = 0;
226 len = strlen(cp); 222 if (!*cp)
227 if (len == 0)
228 return -EINVAL; 223 return -EINVAL;
229 224
230 val = simple_strtoull(cp, &tail, base); 225 val = simple_strtoull(cp, &tail, base);
231 if (tail == cp) 226 if (tail == cp)
232 return -EINVAL; 227 return -EINVAL;
233 if ((*tail == '\0') || 228 if ((tail[0] == '\0') || (tail[0] == '\n' && tail[1] == '\0')) {
234 ((len == (size_t)(tail - cp) + 1) && (*tail == '\n'))) {
235 *res = val; 229 *res = val;
236 return 0; 230 return 0;
237 } 231 }