diff options
author | Paul Mackerras <paulus@samba.org> | 2008-01-31 01:25:51 +0100 |
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committer | Paul Mackerras <paulus@samba.org> | 2008-01-31 01:25:51 +0100 |
commit | bd45ac0c5daae35e7c71138172e63df5cf644cf6 (patch) | |
tree | 5eb5a599bf6a9d7a8a34e802db932aa9e9555de4 /lib | |
parent | Merge branch 'for-2.6.25' of git://git.secretlab.ca/git/linux-2.6-mpc52xx (diff) | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog (diff) | |
download | linux-bd45ac0c5daae35e7c71138172e63df5cf644cf6.tar.xz linux-bd45ac0c5daae35e7c71138172e63df5cf644cf6.zip |
Merge branch 'linux-2.6'
Diffstat (limited to 'lib')
-rw-r--r-- | lib/Kconfig.debug | 98 | ||||
-rw-r--r-- | lib/Makefile | 3 | ||||
-rw-r--r-- | lib/find_next_bit.c | 43 | ||||
-rw-r--r-- | lib/kernel_lock.c | 123 | ||||
-rw-r--r-- | lib/kobject.c | 734 | ||||
-rw-r--r-- | lib/kobject_uevent.c | 38 | ||||
-rw-r--r-- | lib/kref.c | 15 | ||||
-rw-r--r-- | lib/pcounter.c | 58 | ||||
-rw-r--r-- | lib/rwsem.c | 8 | ||||
-rw-r--r-- | lib/scatterlist.c | 294 |
10 files changed, 995 insertions, 419 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a60109307d32..89f4035b526c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -79,6 +79,38 @@ config HEADERS_CHECK exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in your build tree), to make sure they're suitable. +config DEBUG_SECTION_MISMATCH + bool "Enable full Section mismatch analysis" + default n + help + The section mismatch analysis checks if there are illegal + references from one section to another section. + Linux will during link or during runtime drop some sections + and any use of code/data previously in these sections will + most likely result in an oops. + In the code functions and variables are annotated with + __init, __devinit etc. (see full list in include/linux/init.h) + which result in the code/data being placed in specific sections. + The section mismatch anaylsis are always done after a full + kernel build but enabling this options will in addition + do the following: + - Add the option -fno-inline-functions-called-once to gcc + When inlining a function annotated __init in a non-init + function we would loose the section information and thus + the analysis would not catch the illegal reference. + This options tell gcc to inline less but will also + result in a larger kernel. + - Run the section mismatch analysis for each module/built-in.o + When we run the section mismatch analysis on vmlinux.o we + looses valueable information about where the mismatch was + introduced. + Running the analysis for each module/built-in.o file + will tell where the mismatch happens much closer to the + source. The drawback is that we will report the same + mismatch at least twice. + - Enable verbose reporting from modpost to help solving + the section mismatches reported. + config DEBUG_KERNEL bool "Kernel debugging" help @@ -462,6 +494,30 @@ config RCU_TORTURE_TEST Say M if you want the RCU torture tests to build as a module. Say N if you are unsure. +config KPROBES_SANITY_TEST + bool "Kprobes sanity tests" + depends on DEBUG_KERNEL + depends on KPROBES + default n + help + This option provides for testing basic kprobes functionality on + boot. A sample kprobe, jprobe and kretprobe are inserted and + verified for functionality. + + Say N if you are unsure. + +config BACKTRACE_SELF_TEST + tristate "Self test for the backtrace code" + depends on DEBUG_KERNEL + default n + help + This option provides a kernel module that can be used to test + the kernel stack backtrace code. This option is not useful + for distributions or general kernels, but only for kernel + developers working on architecture code. + + Say N if you are unsure. + config LKDTM tristate "Linux Kernel Dump Test Tool Module" depends on DEBUG_KERNEL @@ -517,4 +573,46 @@ config FAULT_INJECTION_STACKTRACE_FILTER help Provide stacktrace filter for fault-injection capabilities +config LATENCYTOP + bool "Latency measuring infrastructure" + select FRAME_POINTER if !MIPS + select KALLSYMS + select KALLSYMS_ALL + select STACKTRACE + select SCHEDSTATS + select SCHED_DEBUG + depends on X86 || X86_64 + help + Enable this option if you want to use the LatencyTOP tool + to find out which userspace is blocking on what kernel operations. + +config PROVIDE_OHCI1394_DMA_INIT + bool "Provide code for enabling DMA over FireWire early on boot" + depends on PCI && X86 + help + If you want to debug problems which hang or crash the kernel early + on boot and the crashing machine has a FireWire port, you can use + this feature to remotely access the memory of the crashed machine + over FireWire. This employs remote DMA as part of the OHCI1394 + specification which is now the standard for FireWire controllers. + + With remote DMA, you can monitor the printk buffer remotely using + firescope and access all memory below 4GB using fireproxy from gdb. + Even controlling a kernel debugger is possible using remote DMA. + + Usage: + + If ohci1394_dma=early is used as boot parameter, it will initialize + all OHCI1394 controllers which are found in the PCI config space. + + As all changes to the FireWire bus such as enabling and disabling + devices cause a bus reset and thereby disable remote DMA for all + devices, be sure to have the cable plugged and FireWire enabled on + the debugging host before booting the debug target for debugging. + + This code (~1k) is freed after boot. By then, the firewire stack + in charge of the OHCI-1394 controllers should be used instead. + + See Documentation/debugging-via-ohci1394.txt for more information. + source "samples/Kconfig" diff --git a/lib/Makefile b/lib/Makefile index b6793ed28d84..543f2502b60a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ - proportions.o prio_heap.o + proportions.o prio_heap.o scatterlist.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o @@ -61,6 +61,7 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o obj-$(CONFIG_SMP) += percpu_counter.o +obj-$(CONFIG_SMP) += pcounter.o obj-$(CONFIG_AUDIT_GENERIC) += audit.o obj-$(CONFIG_SWIOTLB) += swiotlb.o diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c index bda0d71a2514..78ccd73a8841 100644 --- a/lib/find_next_bit.c +++ b/lib/find_next_bit.c @@ -178,4 +178,47 @@ found_middle_swap: EXPORT_SYMBOL(generic_find_next_zero_le_bit); +unsigned long generic_find_next_le_bit(const unsigned long *addr, unsigned + long size, unsigned long offset) +{ + const unsigned long *p = addr + BITOP_WORD(offset); + unsigned long result = offset & ~(BITS_PER_LONG - 1); + unsigned long tmp; + + if (offset >= size) + return size; + size -= result; + offset &= (BITS_PER_LONG - 1UL); + if (offset) { + tmp = ext2_swabp(p++); + tmp &= (~0UL << offset); + if (size < BITS_PER_LONG) + goto found_first; + if (tmp) + goto found_middle; + size -= BITS_PER_LONG; + result += BITS_PER_LONG; + } + + while (size & ~(BITS_PER_LONG - 1)) { + tmp = *(p++); + if (tmp) + goto found_middle_swap; + result += BITS_PER_LONG; + size -= BITS_PER_LONG; + } + if (!size) + return result; + tmp = ext2_swabp(p); +found_first: + tmp &= (~0UL >> (BITS_PER_LONG - size)); + if (tmp == 0UL) /* Are any bits set? */ + return result + size; /* Nope. */ +found_middle: + return result + __ffs(tmp); + +found_middle_swap: + return result + __ffs(ext2_swab(tmp)); +} +EXPORT_SYMBOL(generic_find_next_le_bit); #endif /* __BIG_ENDIAN */ diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c index f73e2f8c308f..812dbf00844b 100644 --- a/lib/kernel_lock.c +++ b/lib/kernel_lock.c @@ -9,7 +9,6 @@ #include <linux/module.h> #include <linux/kallsyms.h> -#ifdef CONFIG_PREEMPT_BKL /* * The 'big kernel semaphore' * @@ -86,128 +85,6 @@ void __lockfunc unlock_kernel(void) up(&kernel_sem); } -#else - -/* - * The 'big kernel lock' - * - * This spinlock is taken and released recursively by lock_kernel() - * and unlock_kernel(). It is transparently dropped and reacquired - * over schedule(). It is used to protect legacy code that hasn't - * been migrated to a proper locking design yet. - * - * Don't use in new code. - */ -static __cacheline_aligned_in_smp DEFINE_SPINLOCK(kernel_flag); - - -/* - * Acquire/release the underlying lock from the scheduler. - * - * This is called with preemption disabled, and should - * return an error value if it cannot get the lock and - * TIF_NEED_RESCHED gets set. - * - * If it successfully gets the lock, it should increment - * the preemption count like any spinlock does. - * - * (This works on UP too - _raw_spin_trylock will never - * return false in that case) - */ -int __lockfunc __reacquire_kernel_lock(void) -{ - while (!_raw_spin_trylock(&kernel_flag)) { - if (test_thread_flag(TIF_NEED_RESCHED)) - return -EAGAIN; - cpu_relax(); - } - preempt_disable(); - return 0; -} - -void __lockfunc __release_kernel_lock(void) -{ - _raw_spin_unlock(&kernel_flag); - preempt_enable_no_resched(); -} - -/* - * These are the BKL spinlocks - we try to be polite about preemption. - * If SMP is not on (ie UP preemption), this all goes away because the - * _raw_spin_trylock() will always succeed. - */ -#ifdef CONFIG_PREEMPT -static inline void __lock_kernel(void) -{ - preempt_disable(); - if (unlikely(!_raw_spin_trylock(&kernel_flag))) { - /* - * If preemption was disabled even before this - * was called, there's nothing we can be polite - * about - just spin. - */ - if (preempt_count() > 1) { - _raw_spin_lock(&kernel_flag); - return; - } - - /* - * Otherwise, let's wait for the kernel lock - * with preemption enabled.. - */ - do { - preempt_enable(); - while (spin_is_locked(&kernel_flag)) - cpu_relax(); - preempt_disable(); - } while (!_raw_spin_trylock(&kernel_flag)); - } -} - -#else - -/* - * Non-preemption case - just get the spinlock - */ -static inline void __lock_kernel(void) -{ - _raw_spin_lock(&kernel_flag); -} -#endif - -static inline void __unlock_kernel(void) -{ - /* - * the BKL is not covered by lockdep, so we open-code the - * unlocking sequence (and thus avoid the dep-chain ops): - */ - _raw_spin_unlock(&kernel_flag); - preempt_enable(); -} - -/* - * Getting the big kernel lock. - * - * This cannot happen asynchronously, so we only need to - * worry about other CPU's. - */ -void __lockfunc lock_kernel(void) -{ - int depth = current->lock_depth+1; - if (likely(!depth)) - __lock_kernel(); - current->lock_depth = depth; -} - -void __lockfunc unlock_kernel(void) -{ - BUG_ON(current->lock_depth < 0); - if (likely(--current->lock_depth < 0)) - __unlock_kernel(); -} - -#endif - EXPORT_SYMBOL(lock_kernel); EXPORT_SYMBOL(unlock_kernel); diff --git a/lib/kobject.c b/lib/kobject.c index 3590f022a609..1d63ead1815e 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -18,58 +18,57 @@ #include <linux/stat.h> #include <linux/slab.h> -/** - * populate_dir - populate directory with attributes. - * @kobj: object we're working on. - * - * Most subsystems have a set of default attributes that - * are associated with an object that registers with them. - * This is a helper called during object registration that - * loops through the default attributes of the subsystem - * and creates attributes files for them in sysfs. +/* + * populate_dir - populate directory with attributes. + * @kobj: object we're working on. * + * Most subsystems have a set of default attributes that are associated + * with an object that registers with them. This is a helper called during + * object registration that loops through the default attributes of the + * subsystem and creates attributes files for them in sysfs. */ - -static int populate_dir(struct kobject * kobj) +static int populate_dir(struct kobject *kobj) { - struct kobj_type * t = get_ktype(kobj); - struct attribute * attr; + struct kobj_type *t = get_ktype(kobj); + struct attribute *attr; int error = 0; int i; - + if (t && t->default_attrs) { for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { - if ((error = sysfs_create_file(kobj,attr))) + error = sysfs_create_file(kobj, attr); + if (error) break; } } return error; } -static int create_dir(struct kobject * kobj) +static int create_dir(struct kobject *kobj) { int error = 0; if (kobject_name(kobj)) { error = sysfs_create_dir(kobj); if (!error) { - if ((error = populate_dir(kobj))) + error = populate_dir(kobj); + if (error) sysfs_remove_dir(kobj); } } return error; } -static inline struct kobject * to_kobj(struct list_head * entry) +static inline struct kobject *to_kobj(struct list_head *entry) { - return container_of(entry,struct kobject,entry); + return container_of(entry, struct kobject, entry); } static int get_kobj_path_length(struct kobject *kobj) { int length = 1; - struct kobject * parent = kobj; + struct kobject *parent = kobj; - /* walk up the ancestors until we hit the one pointing to the + /* walk up the ancestors until we hit the one pointing to the * root. * Add 1 to strlen for leading '/' of each level. */ @@ -84,18 +83,19 @@ static int get_kobj_path_length(struct kobject *kobj) static void fill_kobj_path(struct kobject *kobj, char *path, int length) { - struct kobject * parent; + struct kobject *parent; --length; for (parent = kobj; parent; parent = parent->parent) { int cur = strlen(kobject_name(parent)); /* back up enough to print this name with '/' */ length -= cur; - strncpy (path + length, kobject_name(parent), cur); + strncpy(path + length, kobject_name(parent), cur); *(path + --length) = '/'; } - pr_debug("%s: path = '%s'\n",__FUNCTION__,path); + pr_debug("kobject: '%s' (%p): %s: path = '%s'\n", kobject_name(kobj), + kobj, __FUNCTION__, path); } /** @@ -123,179 +123,286 @@ char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) } EXPORT_SYMBOL_GPL(kobject_get_path); -/** - * kobject_init - initialize object. - * @kobj: object in question. - */ -void kobject_init(struct kobject * kobj) +/* add the kobject to its kset's list */ +static void kobj_kset_join(struct kobject *kobj) { - if (!kobj) + if (!kobj->kset) return; - kref_init(&kobj->kref); - INIT_LIST_HEAD(&kobj->entry); - kobj->kset = kset_get(kobj->kset); + + kset_get(kobj->kset); + spin_lock(&kobj->kset->list_lock); + list_add_tail(&kobj->entry, &kobj->kset->list); + spin_unlock(&kobj->kset->list_lock); } +/* remove the kobject from its kset's list */ +static void kobj_kset_leave(struct kobject *kobj) +{ + if (!kobj->kset) + return; -/** - * unlink - remove kobject from kset list. - * @kobj: kobject. - * - * Remove the kobject from the kset list and decrement - * its parent's refcount. - * This is separated out, so we can use it in both - * kobject_del() and kobject_add() on error. - */ + spin_lock(&kobj->kset->list_lock); + list_del_init(&kobj->entry); + spin_unlock(&kobj->kset->list_lock); + kset_put(kobj->kset); +} -static void unlink(struct kobject * kobj) +static void kobject_init_internal(struct kobject *kobj) { - if (kobj->kset) { - spin_lock(&kobj->kset->list_lock); - list_del_init(&kobj->entry); - spin_unlock(&kobj->kset->list_lock); - } - kobject_put(kobj); + if (!kobj) + return; + kref_init(&kobj->kref); + INIT_LIST_HEAD(&kobj->entry); } -/** - * kobject_add - add an object to the hierarchy. - * @kobj: object. - */ -int kobject_add(struct kobject * kobj) +static int kobject_add_internal(struct kobject *kobj) { int error = 0; - struct kobject * parent; + struct kobject *parent; - if (!(kobj = kobject_get(kobj))) + if (!kobj) return -ENOENT; - if (!kobj->k_name) - kobject_set_name(kobj, "NO_NAME"); - if (!*kobj->k_name) { - pr_debug("kobject attempted to be registered with no name!\n"); + + if (!kobj->name || !kobj->name[0]) { + pr_debug("kobject: (%p): attempted to be registered with empty " + "name!\n", kobj); WARN_ON(1); - kobject_put(kobj); return -EINVAL; } - parent = kobject_get(kobj->parent); - pr_debug("kobject %s: registering. parent: %s, set: %s\n", - kobject_name(kobj), parent ? kobject_name(parent) : "<NULL>", - kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>" ); + parent = kobject_get(kobj->parent); + /* join kset if set, use it as parent if we do not already have one */ if (kobj->kset) { - spin_lock(&kobj->kset->list_lock); - if (!parent) parent = kobject_get(&kobj->kset->kobj); - - list_add_tail(&kobj->entry,&kobj->kset->list); - spin_unlock(&kobj->kset->list_lock); + kobj_kset_join(kobj); kobj->parent = parent; } + pr_debug("kobject: '%s' (%p): %s: parent: '%s', set: '%s'\n", + kobject_name(kobj), kobj, __FUNCTION__, + parent ? kobject_name(parent) : "<NULL>", + kobj->kset ? kobject_name(&kobj->kset->kobj) : "<NULL>"); + error = create_dir(kobj); if (error) { - /* unlink does the kobject_put() for us */ - unlink(kobj); + kobj_kset_leave(kobj); kobject_put(parent); + kobj->parent = NULL; /* be noisy on error issues */ if (error == -EEXIST) - printk(KERN_ERR "kobject_add failed for %s with " + printk(KERN_ERR "%s failed for %s with " "-EEXIST, don't try to register things with " "the same name in the same directory.\n", - kobject_name(kobj)); + __FUNCTION__, kobject_name(kobj)); else - printk(KERN_ERR "kobject_add failed for %s (%d)\n", - kobject_name(kobj), error); + printk(KERN_ERR "%s failed for %s (%d)\n", + __FUNCTION__, kobject_name(kobj), error); dump_stack(); - } + } else + kobj->state_in_sysfs = 1; return error; } /** - * kobject_register - initialize and add an object. - * @kobj: object in question. + * kobject_set_name_vargs - Set the name of an kobject + * @kobj: struct kobject to set the name of + * @fmt: format string used to build the name + * @vargs: vargs to format the string. */ - -int kobject_register(struct kobject * kobj) +static int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, + va_list vargs) { - int error = -EINVAL; - if (kobj) { - kobject_init(kobj); - error = kobject_add(kobj); - if (!error) - kobject_uevent(kobj, KOBJ_ADD); - } - return error; -} + va_list aq; + char *name; + + va_copy(aq, vargs); + name = kvasprintf(GFP_KERNEL, fmt, vargs); + va_end(aq); + if (!name) + return -ENOMEM; + + /* Free the old name, if necessary. */ + kfree(kobj->name); + + /* Now, set the new name */ + kobj->name = name; + + return 0; +} /** * kobject_set_name - Set the name of a kobject - * @kobj: kobject to name + * @kobj: struct kobject to set the name of * @fmt: format string used to build the name * * This sets the name of the kobject. If you have already added the * kobject to the system, you must call kobject_rename() in order to * change the name of the kobject. */ -int kobject_set_name(struct kobject * kobj, const char * fmt, ...) +int kobject_set_name(struct kobject *kobj, const char *fmt, ...) { - int error = 0; - int limit; - int need; va_list args; - char *name; + int retval; - /* find out how big a buffer we need */ - name = kmalloc(1024, GFP_KERNEL); - if (!name) { - error = -ENOMEM; - goto done; - } va_start(args, fmt); - need = vsnprintf(name, 1024, fmt, args); + retval = kobject_set_name_vargs(kobj, fmt, args); va_end(args); - kfree(name); - /* Allocate the new space and copy the string in */ - limit = need + 1; - name = kmalloc(limit, GFP_KERNEL); - if (!name) { - error = -ENOMEM; - goto done; + return retval; +} +EXPORT_SYMBOL(kobject_set_name); + +/** + * kobject_init - initialize a kobject structure + * @kobj: pointer to the kobject to initialize + * @ktype: pointer to the ktype for this kobject. + * + * This function will properly initialize a kobject such that it can then + * be passed to the kobject_add() call. + * + * After this function is called, the kobject MUST be cleaned up by a call + * to kobject_put(), not by a call to kfree directly to ensure that all of + * the memory is cleaned up properly. + */ +void kobject_init(struct kobject *kobj, struct kobj_type *ktype) +{ + char *err_str; + + if (!kobj) { + err_str = "invalid kobject pointer!"; + goto error; + } + if (!ktype) { + err_str = "must have a ktype to be initialized properly!\n"; + goto error; + } + if (kobj->state_initialized) { + /* do not error out as sometimes we can recover */ + printk(KERN_ERR "kobject (%p): tried to init an initialized " + "object, something is seriously wrong.\n", kobj); + dump_stack(); } - va_start(args, fmt); - need = vsnprintf(name, limit, fmt, args); - va_end(args); - /* something wrong with the string we copied? */ - if (need >= limit) { - kfree(name); - error = -EFAULT; - goto done; + kref_init(&kobj->kref); + INIT_LIST_HEAD(&kobj->entry); + kobj->ktype = ktype; + kobj->state_in_sysfs = 0; + kobj->state_add_uevent_sent = 0; + kobj->state_remove_uevent_sent = 0; + kobj->state_initialized = 1; + return; + +error: + printk(KERN_ERR "kobject (%p): %s\n", kobj, err_str); + dump_stack(); +} +EXPORT_SYMBOL(kobject_init); + +static int kobject_add_varg(struct kobject *kobj, struct kobject *parent, + const char *fmt, va_list vargs) +{ + va_list aq; + int retval; + + va_copy(aq, vargs); + retval = kobject_set_name_vargs(kobj, fmt, aq); + va_end(aq); + if (retval) { + printk(KERN_ERR "kobject: can not set name properly!\n"); + return retval; } + kobj->parent = parent; + return kobject_add_internal(kobj); +} - /* Free the old name, if necessary. */ - kfree(kobj->k_name); +/** + * kobject_add - the main kobject add function + * @kobj: the kobject to add + * @parent: pointer to the parent of the kobject. + * @fmt: format to name the kobject with. + * + * The kobject name is set and added to the kobject hierarchy in this + * function. + * + * If @parent is set, then the parent of the @kobj will be set to it. + * If @parent is NULL, then the parent of the @kobj will be set to the + * kobject associted with the kset assigned to this kobject. If no kset + * is assigned to the kobject, then the kobject will be located in the + * root of the sysfs tree. + * + * If this function returns an error, kobject_put() must be called to + * properly clean up the memory associated with the object. + * Under no instance should the kobject that is passed to this function + * be directly freed with a call to kfree(), that can leak memory. + * + * Note, no "add" uevent will be created with this call, the caller should set + * up all of the necessary sysfs files for the object and then call + * kobject_uevent() with the UEVENT_ADD parameter to ensure that + * userspace is properly notified of this kobject's creation. + */ +int kobject_add(struct kobject *kobj, struct kobject *parent, + const char *fmt, ...) +{ + va_list args; + int retval; - /* Now, set the new name */ - kobj->k_name = name; -done: - return error; + if (!kobj) + return -EINVAL; + + if (!kobj->state_initialized) { + printk(KERN_ERR "kobject '%s' (%p): tried to add an " + "uninitialized object, something is seriously wrong.\n", + kobject_name(kobj), kobj); + dump_stack(); + return -EINVAL; + } + va_start(args, fmt); + retval = kobject_add_varg(kobj, parent, fmt, args); + va_end(args); + + return retval; } -EXPORT_SYMBOL(kobject_set_name); +EXPORT_SYMBOL(kobject_add); /** - * kobject_rename - change the name of an object - * @kobj: object in question. - * @new_name: object's new name + * kobject_init_and_add - initialize a kobject structure and add it to the kobject hierarchy + * @kobj: pointer to the kobject to initialize + * @ktype: pointer to the ktype for this kobject. + * @parent: pointer to the parent of this kobject. + * @fmt: the name of the kobject. + * + * This function combines the call to kobject_init() and + * kobject_add(). The same type of error handling after a call to + * kobject_add() and kobject lifetime rules are the same here. */ +int kobject_init_and_add(struct kobject *kobj, struct kobj_type *ktype, + struct kobject *parent, const char *fmt, ...) +{ + va_list args; + int retval; + + kobject_init(kobj, ktype); + + va_start(args, fmt); + retval = kobject_add_varg(kobj, parent, fmt, args); + va_end(args); + + return retval; +} +EXPORT_SYMBOL_GPL(kobject_init_and_add); -int kobject_rename(struct kobject * kobj, const char *new_name) +/** + * kobject_rename - change the name of an object + * @kobj: object in question. + * @new_name: object's new name + */ +int kobject_rename(struct kobject *kobj, const char *new_name) { int error = 0; const char *devpath = NULL; @@ -334,8 +441,6 @@ int kobject_rename(struct kobject * kobj, const char *new_name) sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); envp[0] = devpath_string; envp[1] = NULL; - /* Note : if we want to send the new name alone, not the full path, - * we could probably use kobject_name(kobj); */ error = sysfs_rename_dir(kobj, new_name); @@ -354,11 +459,10 @@ out: } /** - * kobject_move - move object to another parent - * @kobj: object in question. - * @new_parent: object's new parent (can be NULL) + * kobject_move - move object to another parent + * @kobj: object in question. + * @new_parent: object's new parent (can be NULL) */ - int kobject_move(struct kobject *kobj, struct kobject *new_parent) { int error; @@ -406,68 +510,74 @@ out: } /** - * kobject_del - unlink kobject from hierarchy. - * @kobj: object. + * kobject_del - unlink kobject from hierarchy. + * @kobj: object. */ - -void kobject_del(struct kobject * kobj) +void kobject_del(struct kobject *kobj) { if (!kobj) return; - sysfs_remove_dir(kobj); - unlink(kobj); -} -/** - * kobject_unregister - remove object from hierarchy and decrement refcount. - * @kobj: object going away. - */ - -void kobject_unregister(struct kobject * kobj) -{ - if (!kobj) - return; - pr_debug("kobject %s: unregistering\n",kobject_name(kobj)); - kobject_uevent(kobj, KOBJ_REMOVE); - kobject_del(kobj); - kobject_put(kobj); + sysfs_remove_dir(kobj); + kobj->state_in_sysfs = 0; + kobj_kset_leave(kobj); + kobject_put(kobj->parent); + kobj->parent = NULL; } /** - * kobject_get - increment refcount for object. - * @kobj: object. + * kobject_get - increment refcount for object. + * @kobj: object. */ - -struct kobject * kobject_get(struct kobject * kobj) +struct kobject *kobject_get(struct kobject *kobj) { if (kobj) kref_get(&kobj->kref); return kobj; } -/** - * kobject_cleanup - free kobject resources. - * @kobj: object. +/* + * kobject_cleanup - free kobject resources. + * @kobj: object to cleanup */ - -void kobject_cleanup(struct kobject * kobj) +static void kobject_cleanup(struct kobject *kobj) { - struct kobj_type * t = get_ktype(kobj); - struct kset * s = kobj->kset; - struct kobject * parent = kobj->parent; - const char *name = kobj->k_name; + struct kobj_type *t = get_ktype(kobj); + const char *name = kobj->name; + + pr_debug("kobject: '%s' (%p): %s\n", + kobject_name(kobj), kobj, __FUNCTION__); + + if (t && !t->release) + pr_debug("kobject: '%s' (%p): does not have a release() " + "function, it is broken and must be fixed.\n", + kobject_name(kobj), kobj); + + /* send "remove" if the caller did not do it but sent "add" */ + if (kobj->state_add_uevent_sent && !kobj->state_remove_uevent_sent) { + pr_debug("kobject: '%s' (%p): auto cleanup 'remove' event\n", + kobject_name(kobj), kobj); + kobject_uevent(kobj, KOBJ_REMOVE); + } + + /* remove from sysfs if the caller did not do it */ + if (kobj->state_in_sysfs) { + pr_debug("kobject: '%s' (%p): auto cleanup kobject_del\n", + kobject_name(kobj), kobj); + kobject_del(kobj); + } - pr_debug("kobject %s: cleaning up\n",kobject_name(kobj)); if (t && t->release) { + pr_debug("kobject: '%s' (%p): calling ktype release\n", + kobject_name(kobj), kobj); t->release(kobj); - /* If we have a release function, we can guess that this was - * not a statically allocated kobject, so we should be safe to - * free the name */ + } + + /* free name if we allocated it */ + if (name) { + pr_debug("kobject: '%s': free name\n", name); kfree(name); } - if (s) - kset_put(s); - kobject_put(parent); } static void kobject_release(struct kref *kref) @@ -476,107 +586,130 @@ static void kobject_release(struct kref *kref) } /** - * kobject_put - decrement refcount for object. - * @kobj: object. + * kobject_put - decrement refcount for object. + * @kobj: object. * - * Decrement the refcount, and if 0, call kobject_cleanup(). + * Decrement the refcount, and if 0, call kobject_cleanup(). */ -void kobject_put(struct kobject * kobj) +void kobject_put(struct kobject *kobj) { if (kobj) kref_put(&kobj->kref, kobject_release); } - -static void dir_release(struct kobject *kobj) +static void dynamic_kobj_release(struct kobject *kobj) { + pr_debug("kobject: (%p): %s\n", kobj, __FUNCTION__); kfree(kobj); } -static struct kobj_type dir_ktype = { - .release = dir_release, - .sysfs_ops = NULL, - .default_attrs = NULL, +static struct kobj_type dynamic_kobj_ktype = { + .release = dynamic_kobj_release, + .sysfs_ops = &kobj_sysfs_ops, }; /** - * kobject_kset_add_dir - add sub directory of object. - * @kset: kset the directory is belongs to. - * @parent: object in which a directory is created. - * @name: directory name. + * kobject_create - create a struct kobject dynamically * - * Add a plain directory object as child of given object. + * This function creates a kobject structure dynamically and sets it up + * to be a "dynamic" kobject with a default release function set up. + * + * If the kobject was not able to be created, NULL will be returned. + * The kobject structure returned from here must be cleaned up with a + * call to kobject_put() and not kfree(), as kobject_init() has + * already been called on this structure. */ -struct kobject *kobject_kset_add_dir(struct kset *kset, - struct kobject *parent, const char *name) +struct kobject *kobject_create(void) { - struct kobject *k; - int ret; - - if (!parent) - return NULL; - - k = kzalloc(sizeof(*k), GFP_KERNEL); - if (!k) - return NULL; + struct kobject *kobj; - k->kset = kset; - k->parent = parent; - k->ktype = &dir_ktype; - kobject_set_name(k, name); - ret = kobject_register(k); - if (ret < 0) { - printk(KERN_WARNING "%s: kobject_register error: %d\n", - __func__, ret); - kobject_del(k); + kobj = kzalloc(sizeof(*kobj), GFP_KERNEL); + if (!kobj) return NULL; - } - return k; + kobject_init(kobj, &dynamic_kobj_ktype); + return kobj; } /** - * kobject_add_dir - add sub directory of object. - * @parent: object in which a directory is created. - * @name: directory name. + * kobject_create_and_add - create a struct kobject dynamically and register it with sysfs + * + * @name: the name for the kset + * @parent: the parent kobject of this kobject, if any. + * + * This function creates a kset structure dynamically and registers it + * with sysfs. When you are finished with this structure, call + * kobject_put() and the structure will be dynamically freed when + * it is no longer being used. * - * Add a plain directory object as child of given object. + * If the kobject was not able to be created, NULL will be returned. */ -struct kobject *kobject_add_dir(struct kobject *parent, const char *name) +struct kobject *kobject_create_and_add(const char *name, struct kobject *parent) { - return kobject_kset_add_dir(NULL, parent, name); + struct kobject *kobj; + int retval; + + kobj = kobject_create(); + if (!kobj) + return NULL; + + retval = kobject_add(kobj, parent, "%s", name); + if (retval) { + printk(KERN_WARNING "%s: kobject_add error: %d\n", + __FUNCTION__, retval); + kobject_put(kobj); + kobj = NULL; + } + return kobj; } +EXPORT_SYMBOL_GPL(kobject_create_and_add); /** - * kset_init - initialize a kset for use - * @k: kset + * kset_init - initialize a kset for use + * @k: kset */ - -void kset_init(struct kset * k) +void kset_init(struct kset *k) { - kobject_init(&k->kobj); + kobject_init_internal(&k->kobj); INIT_LIST_HEAD(&k->list); spin_lock_init(&k->list_lock); } +/* default kobject attribute operations */ +static ssize_t kobj_attr_show(struct kobject *kobj, struct attribute *attr, + char *buf) +{ + struct kobj_attribute *kattr; + ssize_t ret = -EIO; -/** - * kset_add - add a kset object to the hierarchy. - * @k: kset. - */ + kattr = container_of(attr, struct kobj_attribute, attr); + if (kattr->show) + ret = kattr->show(kobj, kattr, buf); + return ret; +} -int kset_add(struct kset * k) +static ssize_t kobj_attr_store(struct kobject *kobj, struct attribute *attr, + const char *buf, size_t count) { - return kobject_add(&k->kobj); + struct kobj_attribute *kattr; + ssize_t ret = -EIO; + + kattr = container_of(attr, struct kobj_attribute, attr); + if (kattr->store) + ret = kattr->store(kobj, kattr, buf, count); + return ret; } +struct sysfs_ops kobj_sysfs_ops = { + .show = kobj_attr_show, + .store = kobj_attr_store, +}; /** - * kset_register - initialize and add a kset. - * @k: kset. + * kset_register - initialize and add a kset. + * @k: kset. */ - -int kset_register(struct kset * k) +int kset_register(struct kset *k) { int err; @@ -584,46 +717,42 @@ int kset_register(struct kset * k) return -EINVAL; kset_init(k); - err = kset_add(k); + err = kobject_add_internal(&k->kobj); if (err) return err; kobject_uevent(&k->kobj, KOBJ_ADD); return 0; } - /** - * kset_unregister - remove a kset. - * @k: kset. + * kset_unregister - remove a kset. + * @k: kset. */ - -void kset_unregister(struct kset * k) +void kset_unregister(struct kset *k) { if (!k) return; - kobject_unregister(&k->kobj); + kobject_put(&k->kobj); } - /** - * kset_find_obj - search for object in kset. - * @kset: kset we're looking in. - * @name: object's name. + * kset_find_obj - search for object in kset. + * @kset: kset we're looking in. + * @name: object's name. * - * Lock kset via @kset->subsys, and iterate over @kset->list, - * looking for a matching kobject. If matching object is found - * take a reference and return the object. + * Lock kset via @kset->subsys, and iterate over @kset->list, + * looking for a matching kobject. If matching object is found + * take a reference and return the object. */ - -struct kobject * kset_find_obj(struct kset * kset, const char * name) +struct kobject *kset_find_obj(struct kset *kset, const char *name) { - struct list_head * entry; - struct kobject * ret = NULL; + struct list_head *entry; + struct kobject *ret = NULL; spin_lock(&kset->list_lock); - list_for_each(entry,&kset->list) { - struct kobject * k = to_kobj(entry); - if (kobject_name(k) && !strcmp(kobject_name(k),name)) { + list_for_each(entry, &kset->list) { + struct kobject *k = to_kobj(entry); + if (kobject_name(k) && !strcmp(kobject_name(k), name)) { ret = kobject_get(k); break; } @@ -632,47 +761,94 @@ struct kobject * kset_find_obj(struct kset * kset, const char * name) return ret; } -int subsystem_register(struct kset *s) +static void kset_release(struct kobject *kobj) { - return kset_register(s); + struct kset *kset = container_of(kobj, struct kset, kobj); + pr_debug("kobject: '%s' (%p): %s\n", + kobject_name(kobj), kobj, __FUNCTION__); + kfree(kset); } -void subsystem_unregister(struct kset *s) +static struct kobj_type kset_ktype = { + .sysfs_ops = &kobj_sysfs_ops, + .release = kset_release, +}; + +/** + * kset_create - create a struct kset dynamically + * + * @name: the name for the kset + * @uevent_ops: a struct kset_uevent_ops for the kset + * @parent_kobj: the parent kobject of this kset, if any. + * + * This function creates a kset structure dynamically. This structure can + * then be registered with the system and show up in sysfs with a call to + * kset_register(). When you are finished with this structure, if + * kset_register() has been called, call kset_unregister() and the + * structure will be dynamically freed when it is no longer being used. + * + * If the kset was not able to be created, NULL will be returned. + */ +static struct kset *kset_create(const char *name, + struct kset_uevent_ops *uevent_ops, + struct kobject *parent_kobj) { - kset_unregister(s); + struct kset *kset; + + kset = kzalloc(sizeof(*kset), GFP_KERNEL); + if (!kset) + return NULL; + kobject_set_name(&kset->kobj, name); + kset->uevent_ops = uevent_ops; + kset->kobj.parent = parent_kobj; + + /* + * The kobject of this kset will have a type of kset_ktype and belong to + * no kset itself. That way we can properly free it when it is + * finished being used. + */ + kset->kobj.ktype = &kset_ktype; + kset->kobj.kset = NULL; + + return kset; } /** - * subsystem_create_file - export sysfs attribute file. - * @s: subsystem. - * @a: subsystem attribute descriptor. + * kset_create_and_add - create a struct kset dynamically and add it to sysfs + * + * @name: the name for the kset + * @uevent_ops: a struct kset_uevent_ops for the kset + * @parent_kobj: the parent kobject of this kset, if any. + * + * This function creates a kset structure dynamically and registers it + * with sysfs. When you are finished with this structure, call + * kset_unregister() and the structure will be dynamically freed when it + * is no longer being used. + * + * If the kset was not able to be created, NULL will be returned. */ - -int subsys_create_file(struct kset *s, struct subsys_attribute *a) +struct kset *kset_create_and_add(const char *name, + struct kset_uevent_ops *uevent_ops, + struct kobject *parent_kobj) { - int error = 0; - - if (!s || !a) - return -EINVAL; + struct kset *kset; + int error; - if (kset_get(s)) { - error = sysfs_create_file(&s->kobj, &a->attr); - kset_put(s); + kset = kset_create(name, uevent_ops, parent_kobj); + if (!kset) + return NULL; + error = kset_register(kset); + if (error) { + kfree(kset); + return NULL; } - return error; + return kset; } +EXPORT_SYMBOL_GPL(kset_create_and_add); -EXPORT_SYMBOL(kobject_init); -EXPORT_SYMBOL(kobject_register); -EXPORT_SYMBOL(kobject_unregister); EXPORT_SYMBOL(kobject_get); EXPORT_SYMBOL(kobject_put); -EXPORT_SYMBOL(kobject_add); EXPORT_SYMBOL(kobject_del); EXPORT_SYMBOL(kset_register); EXPORT_SYMBOL(kset_unregister); - -EXPORT_SYMBOL(subsystem_register); -EXPORT_SYMBOL(subsystem_unregister); -EXPORT_SYMBOL(subsys_create_file); diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 5886147252d0..5a402e2982af 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -98,7 +98,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, int i = 0; int retval = 0; - pr_debug("%s\n", __FUNCTION__); + pr_debug("kobject: '%s' (%p): %s\n", + kobject_name(kobj), kobj, __FUNCTION__); /* search the kset we belong to */ top_kobj = kobj; @@ -106,7 +107,9 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, top_kobj = top_kobj->parent; if (!top_kobj->kset) { - pr_debug("kobject attempted to send uevent without kset!\n"); + pr_debug("kobject: '%s' (%p): %s: attempted to send uevent " + "without kset!\n", kobject_name(kobj), kobj, + __FUNCTION__); return -EINVAL; } @@ -116,7 +119,9 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, /* skip the event, if the filter returns zero. */ if (uevent_ops && uevent_ops->filter) if (!uevent_ops->filter(kset, kobj)) { - pr_debug("kobject filter function caused the event to drop!\n"); + pr_debug("kobject: '%s' (%p): %s: filter function " + "caused the event to drop!\n", + kobject_name(kobj), kobj, __FUNCTION__); return 0; } @@ -126,7 +131,9 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, else subsystem = kobject_name(&kset->kobj); if (!subsystem) { - pr_debug("unset subsystem caused the event to drop!\n"); + pr_debug("kobject: '%s' (%p): %s: unset subsystem caused the " + "event to drop!\n", kobject_name(kobj), kobj, + __FUNCTION__); return 0; } @@ -166,12 +173,24 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, if (uevent_ops && uevent_ops->uevent) { retval = uevent_ops->uevent(kset, kobj, env); if (retval) { - pr_debug ("%s - uevent() returned %d\n", - __FUNCTION__, retval); + pr_debug("kobject: '%s' (%p): %s: uevent() returned " + "%d\n", kobject_name(kobj), kobj, + __FUNCTION__, retval); goto exit; } } + /* + * Mark "add" and "remove" events in the object to ensure proper + * events to userspace during automatic cleanup. If the object did + * send an "add" event, "remove" will automatically generated by + * the core, if not already done by the caller. + */ + if (action == KOBJ_ADD) + kobj->state_add_uevent_sent = 1; + else if (action == KOBJ_REMOVE) + kobj->state_remove_uevent_sent = 1; + /* we will send an event, so request a new sequence number */ spin_lock(&sequence_lock); seq = ++uevent_seqnum; @@ -219,11 +238,12 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, retval = add_uevent_var(env, "HOME=/"); if (retval) goto exit; - retval = add_uevent_var(env, "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); + retval = add_uevent_var(env, + "PATH=/sbin:/bin:/usr/sbin:/usr/bin"); if (retval) goto exit; - call_usermodehelper (argv[0], argv, env->envp, UMH_WAIT_EXEC); + call_usermodehelper(argv[0], argv, env->envp, UMH_WAIT_EXEC); } exit: @@ -231,7 +251,6 @@ exit: kfree(env); return retval; } - EXPORT_SYMBOL_GPL(kobject_uevent_env); /** @@ -247,7 +266,6 @@ int kobject_uevent(struct kobject *kobj, enum kobject_action action) { return kobject_uevent_env(kobj, action, NULL); } - EXPORT_SYMBOL_GPL(kobject_uevent); /** diff --git a/lib/kref.c b/lib/kref.c index a6dc3ec328e0..9ecd6e865610 100644 --- a/lib/kref.c +++ b/lib/kref.c @@ -15,13 +15,23 @@ #include <linux/module.h> /** + * kref_set - initialize object and set refcount to requested number. + * @kref: object in question. + * @num: initial reference counter + */ +void kref_set(struct kref *kref, int num) +{ + atomic_set(&kref->refcount, num); + smp_mb(); +} + +/** * kref_init - initialize object. * @kref: object in question. */ void kref_init(struct kref *kref) { - atomic_set(&kref->refcount,1); - smp_mb(); + kref_set(kref, 1); } /** @@ -61,6 +71,7 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref)) return 0; } +EXPORT_SYMBOL(kref_set); EXPORT_SYMBOL(kref_init); EXPORT_SYMBOL(kref_get); EXPORT_SYMBOL(kref_put); diff --git a/lib/pcounter.c b/lib/pcounter.c new file mode 100644 index 000000000000..9b56807da93b --- /dev/null +++ b/lib/pcounter.c @@ -0,0 +1,58 @@ +/* + * Define default pcounter functions + * Note that often used pcounters use dedicated functions to get a speed increase. + * (see DEFINE_PCOUNTER/REF_PCOUNTER_MEMBER) + */ + +#include <linux/module.h> +#include <linux/pcounter.h> +#include <linux/smp.h> +#include <linux/cpumask.h> + +static void pcounter_dyn_add(struct pcounter *self, int inc) +{ + per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc; +} + +static int pcounter_dyn_getval(const struct pcounter *self, int cpu) +{ + return per_cpu_ptr(self->per_cpu_values, cpu)[0]; +} + +int pcounter_getval(const struct pcounter *self) +{ + int res = 0, cpu; + + for_each_possible_cpu(cpu) + res += self->getval(self, cpu); + + return res; +} +EXPORT_SYMBOL_GPL(pcounter_getval); + +int pcounter_alloc(struct pcounter *self) +{ + int rc = 0; + if (self->add == NULL) { + self->per_cpu_values = alloc_percpu(int); + if (self->per_cpu_values != NULL) { + self->add = pcounter_dyn_add; + self->getval = pcounter_dyn_getval; + } else + rc = 1; + } + return rc; +} +EXPORT_SYMBOL_GPL(pcounter_alloc); + +void pcounter_free(struct pcounter *self) +{ + if (self->per_cpu_values != NULL) { + free_percpu(self->per_cpu_values); + self->per_cpu_values = NULL; + self->getval = NULL; + self->add = NULL; + } +} +EXPORT_SYMBOL_GPL(pcounter_free); + diff --git a/lib/rwsem.c b/lib/rwsem.c index 7d02700a4b0e..3e3365e5665e 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -187,7 +187,7 @@ rwsem_down_failed_common(struct rw_semaphore *sem, /* * wait for the read lock to be granted */ -struct rw_semaphore fastcall __sched * +asmregparm struct rw_semaphore __sched * rwsem_down_read_failed(struct rw_semaphore *sem) { struct rwsem_waiter waiter; @@ -201,7 +201,7 @@ rwsem_down_read_failed(struct rw_semaphore *sem) /* * wait for the write lock to be granted */ -struct rw_semaphore fastcall __sched * +asmregparm struct rw_semaphore __sched * rwsem_down_write_failed(struct rw_semaphore *sem) { struct rwsem_waiter waiter; @@ -216,7 +216,7 @@ rwsem_down_write_failed(struct rw_semaphore *sem) * handle waking up a waiter on the semaphore * - up_read/up_write has decremented the active part of count if we come here */ -struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem) +asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem) { unsigned long flags; @@ -236,7 +236,7 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem) * - caller incremented waiting part of count and discovered it still negative * - just wake up any readers at the front of the queue */ -struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem) +asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem) { unsigned long flags; diff --git a/lib/scatterlist.c b/lib/scatterlist.c new file mode 100644 index 000000000000..acca4901046c --- /dev/null +++ b/lib/scatterlist.c @@ -0,0 +1,294 @@ +/* + * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com> + * + * Scatterlist handling helpers. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ +#include <linux/module.h> +#include <linux/scatterlist.h> + +/** + * sg_next - return the next scatterlist entry in a list + * @sg: The current sg entry + * + * Description: + * Usually the next entry will be @sg@ + 1, but if this sg element is part + * of a chained scatterlist, it could jump to the start of a new + * scatterlist array. + * + **/ +struct scatterlist *sg_next(struct scatterlist *sg) +{ +#ifdef CONFIG_DEBUG_SG + BUG_ON(sg->sg_magic != SG_MAGIC); +#endif + if (sg_is_last(sg)) + return NULL; + + sg++; + if (unlikely(sg_is_chain(sg))) + sg = sg_chain_ptr(sg); + + return sg; +} +EXPORT_SYMBOL(sg_next); + +/** + * sg_last - return the last scatterlist entry in a list + * @sgl: First entry in the scatterlist + * @nents: Number of entries in the scatterlist + * + * Description: + * Should only be used casually, it (currently) scans the entire list + * to get the last entry. + * + * Note that the @sgl@ pointer passed in need not be the first one, + * the important bit is that @nents@ denotes the number of entries that + * exist from @sgl@. + * + **/ +struct scatterlist *sg_last(struct scatterlist *sgl, unsigned int nents) +{ +#ifndef ARCH_HAS_SG_CHAIN + struct scatterlist *ret = &sgl[nents - 1]; +#else + struct scatterlist *sg, *ret = NULL; + unsigned int i; + + for_each_sg(sgl, sg, nents, i) + ret = sg; + +#endif +#ifdef CONFIG_DEBUG_SG + BUG_ON(sgl[0].sg_magic != SG_MAGIC); + BUG_ON(!sg_is_last(ret)); +#endif + return ret; +} +EXPORT_SYMBOL(sg_last); + +/** + * sg_init_table - Initialize SG table + * @sgl: The SG table + * @nents: Number of entries in table + * + * Notes: + * If this is part of a chained sg table, sg_mark_end() should be + * used only on the last table part. + * + **/ +void sg_init_table(struct scatterlist *sgl, unsigned int nents) +{ + memset(sgl, 0, sizeof(*sgl) * nents); +#ifdef CONFIG_DEBUG_SG + { + unsigned int i; + for (i = 0; i < nents; i++) + sgl[i].sg_magic = SG_MAGIC; + } +#endif + sg_mark_end(&sgl[nents - 1]); +} +EXPORT_SYMBOL(sg_init_table); + +/** + * sg_init_one - Initialize a single entry sg list + * @sg: SG entry + * @buf: Virtual address for IO + * @buflen: IO length + * + **/ +void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen) +{ + sg_init_table(sg, 1); + sg_set_buf(sg, buf, buflen); +} +EXPORT_SYMBOL(sg_init_one); + +/* + * The default behaviour of sg_alloc_table() is to use these kmalloc/kfree + * helpers. + */ +static struct scatterlist *sg_kmalloc(unsigned int nents, gfp_t gfp_mask) +{ + if (nents == SG_MAX_SINGLE_ALLOC) + return (struct scatterlist *) __get_free_page(gfp_mask); + else + return kmalloc(nents * sizeof(struct scatterlist), gfp_mask); +} + +static void sg_kfree(struct scatterlist *sg, unsigned int nents) +{ + if (nents == SG_MAX_SINGLE_ALLOC) + free_page((unsigned long) sg); + else + kfree(sg); +} + +/** + * __sg_free_table - Free a previously mapped sg table + * @table: The sg table header to use + * @max_ents: The maximum number of entries per single scatterlist + * @free_fn: Free function + * + * Description: + * Free an sg table previously allocated and setup with + * __sg_alloc_table(). The @max_ents value must be identical to + * that previously used with __sg_alloc_table(). + * + **/ +void __sg_free_table(struct sg_table *table, unsigned int max_ents, + sg_free_fn *free_fn) +{ + struct scatterlist *sgl, *next; + + if (unlikely(!table->sgl)) + return; + + sgl = table->sgl; + while (table->orig_nents) { + unsigned int alloc_size = table->orig_nents; + unsigned int sg_size; + + /* + * If we have more than max_ents segments left, + * then assign 'next' to the sg table after the current one. + * sg_size is then one less than alloc size, since the last + * element is the chain pointer. + */ + if (alloc_size > max_ents) { + next = sg_chain_ptr(&sgl[max_ents - 1]); + alloc_size = max_ents; + sg_size = alloc_size - 1; + } else { + sg_size = alloc_size; + next = NULL; + } + + table->orig_nents -= sg_size; + free_fn(sgl, alloc_size); + sgl = next; + } + + table->sgl = NULL; +} +EXPORT_SYMBOL(__sg_free_table); + +/** + * sg_free_table - Free a previously allocated sg table + * @table: The mapped sg table header + * + **/ +void sg_free_table(struct sg_table *table) +{ + __sg_free_table(table, SG_MAX_SINGLE_ALLOC, sg_kfree); +} +EXPORT_SYMBOL(sg_free_table); + +/** + * __sg_alloc_table - Allocate and initialize an sg table with given allocator + * @table: The sg table header to use + * @nents: Number of entries in sg list + * @max_ents: The maximum number of entries the allocator returns per call + * @gfp_mask: GFP allocation mask + * @alloc_fn: Allocator to use + * + * Description: + * This function returns a @table @nents long. The allocator is + * defined to return scatterlist chunks of maximum size @max_ents. + * Thus if @nents is bigger than @max_ents, the scatterlists will be + * chained in units of @max_ents. + * + * Notes: + * If this function returns non-0 (eg failure), the caller must call + * __sg_free_table() to cleanup any leftover allocations. + * + **/ +int __sg_alloc_table(struct sg_table *table, unsigned int nents, + unsigned int max_ents, gfp_t gfp_mask, + sg_alloc_fn *alloc_fn) +{ + struct scatterlist *sg, *prv; + unsigned int left; + +#ifndef ARCH_HAS_SG_CHAIN + BUG_ON(nents > max_ents); +#endif + + memset(table, 0, sizeof(*table)); + + left = nents; + prv = NULL; + do { + unsigned int sg_size, alloc_size = left; + + if (alloc_size > max_ents) { + alloc_size = max_ents; + sg_size = alloc_size - 1; + } else + sg_size = alloc_size; + + left -= sg_size; + + sg = alloc_fn(alloc_size, gfp_mask); + if (unlikely(!sg)) + return -ENOMEM; + + sg_init_table(sg, alloc_size); + table->nents = table->orig_nents += sg_size; + + /* + * If this is the first mapping, assign the sg table header. + * If this is not the first mapping, chain previous part. + */ + if (prv) + sg_chain(prv, max_ents, sg); + else + table->sgl = sg; + + /* + * If no more entries after this one, mark the end + */ + if (!left) + sg_mark_end(&sg[sg_size - 1]); + + /* + * only really needed for mempool backed sg allocations (like + * SCSI), a possible improvement here would be to pass the + * table pointer into the allocator and let that clear these + * flags + */ + gfp_mask &= ~__GFP_WAIT; + gfp_mask |= __GFP_HIGH; + prv = sg; + } while (left); + + return 0; +} +EXPORT_SYMBOL(__sg_alloc_table); + +/** + * sg_alloc_table - Allocate and initialize an sg table + * @table: The sg table header to use + * @nents: Number of entries in sg list + * @gfp_mask: GFP allocation mask + * + * Description: + * Allocate and initialize an sg table. If @nents@ is larger than + * SG_MAX_SINGLE_ALLOC a chained sg table will be setup. + * + **/ +int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask) +{ + int ret; + + ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC, + gfp_mask, sg_kmalloc); + if (unlikely(ret)) + __sg_free_table(table, SG_MAX_SINGLE_ALLOC, sg_kfree); + + return ret; +} +EXPORT_SYMBOL(sg_alloc_table); |