diff options
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/cnt32_to_63.h | 80 | ||||
-rw-r--r-- | include/linux/hrtimer.h | 18 | ||||
-rw-r--r-- | include/linux/pci.h | 8 | ||||
-rw-r--r-- | include/linux/ramfs.h | 1 | ||||
-rw-r--r-- | include/linux/smb.h | 2 | ||||
-rw-r--r-- | include/linux/stacktrace.h | 2 |
6 files changed, 103 insertions, 8 deletions
diff --git a/include/linux/cnt32_to_63.h b/include/linux/cnt32_to_63.h new file mode 100644 index 00000000000..8c0f9505b48 --- /dev/null +++ b/include/linux/cnt32_to_63.h @@ -0,0 +1,80 @@ +/* + * Extend a 32-bit counter to 63 bits + * + * Author: Nicolas Pitre + * Created: December 3, 2006 + * Copyright: MontaVista Software, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + */ + +#ifndef __LINUX_CNT32_TO_63_H__ +#define __LINUX_CNT32_TO_63_H__ + +#include <linux/compiler.h> +#include <linux/types.h> +#include <asm/byteorder.h> + +/* this is used only to give gcc a clue about good code generation */ +union cnt32_to_63 { + struct { +#if defined(__LITTLE_ENDIAN) + u32 lo, hi; +#elif defined(__BIG_ENDIAN) + u32 hi, lo; +#endif + }; + u64 val; +}; + + +/** + * cnt32_to_63 - Expand a 32-bit counter to a 63-bit counter + * @cnt_lo: The low part of the counter + * + * Many hardware clock counters are only 32 bits wide and therefore have + * a relatively short period making wrap-arounds rather frequent. This + * is a problem when implementing sched_clock() for example, where a 64-bit + * non-wrapping monotonic value is expected to be returned. + * + * To overcome that limitation, let's extend a 32-bit counter to 63 bits + * in a completely lock free fashion. Bits 0 to 31 of the clock are provided + * by the hardware while bits 32 to 62 are stored in memory. The top bit in + * memory is used to synchronize with the hardware clock half-period. When + * the top bit of both counters (hardware and in memory) differ then the + * memory is updated with a new value, incrementing it when the hardware + * counter wraps around. + * + * Because a word store in memory is atomic then the incremented value will + * always be in synch with the top bit indicating to any potential concurrent + * reader if the value in memory is up to date or not with regards to the + * needed increment. And any race in updating the value in memory is harmless + * as the same value would simply be stored more than once. + * + * The only restriction for the algorithm to work properly is that this + * code must be executed at least once per each half period of the 32-bit + * counter to properly update the state bit in memory. This is usually not a + * problem in practice, but if it is then a kernel timer could be scheduled + * to manage for this code to be executed often enough. + * + * Note that the top bit (bit 63) in the returned value should be considered + * as garbage. It is not cleared here because callers are likely to use a + * multiplier on the returned value which can get rid of the top bit + * implicitly by making the multiplier even, therefore saving on a runtime + * clear-bit instruction. Otherwise caller must remember to clear the top + * bit explicitly. + */ +#define cnt32_to_63(cnt_lo) \ +({ \ + static volatile u32 __m_cnt_hi; \ + union cnt32_to_63 __x; \ + __x.hi = __m_cnt_hi; \ + __x.lo = (cnt_lo); \ + if (unlikely((s32)(__x.hi ^ __x.lo) < 0)) \ + __m_cnt_hi = __x.hi = (__x.hi ^ 0x80000000) + (__x.hi >> 31); \ + __x.val; \ +}) + +#endif diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h index 6d93dce61cb..2f245fe63bd 100644 --- a/include/linux/hrtimer.h +++ b/include/linux/hrtimer.h @@ -47,14 +47,22 @@ enum hrtimer_restart { * HRTIMER_CB_IRQSAFE: Callback may run in hardirq context * HRTIMER_CB_IRQSAFE_NO_RESTART: Callback may run in hardirq context and * does not restart the timer - * HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: Callback must run in hardirq context - * Special mode for tick emultation + * HRTIMER_CB_IRQSAFE_PERCPU: Callback must run in hardirq context + * Special mode for tick emulation and + * scheduler timer. Such timers are per + * cpu and not allowed to be migrated on + * cpu unplug. + * HRTIMER_CB_IRQSAFE_UNLOCKED: Callback should run in hardirq context + * with timer->base lock unlocked + * used for timers which call wakeup to + * avoid lock order problems with rq->lock */ enum hrtimer_cb_mode { HRTIMER_CB_SOFTIRQ, HRTIMER_CB_IRQSAFE, HRTIMER_CB_IRQSAFE_NO_RESTART, - HRTIMER_CB_IRQSAFE_NO_SOFTIRQ, + HRTIMER_CB_IRQSAFE_PERCPU, + HRTIMER_CB_IRQSAFE_UNLOCKED, }; /* @@ -67,9 +75,10 @@ enum hrtimer_cb_mode { * 0x02 callback function running * 0x04 callback pending (high resolution mode) * - * Special case: + * Special cases: * 0x03 callback function running and enqueued * (was requeued on another CPU) + * 0x09 timer was migrated on CPU hotunplug * The "callback function running and enqueued" status is only possible on * SMP. It happens for example when a posix timer expired and the callback * queued a signal. Between dropping the lock which protects the posix timer @@ -87,6 +96,7 @@ enum hrtimer_cb_mode { #define HRTIMER_STATE_ENQUEUED 0x01 #define HRTIMER_STATE_CALLBACK 0x02 #define HRTIMER_STATE_PENDING 0x04 +#define HRTIMER_STATE_MIGRATE 0x08 /** * struct hrtimer - the basic hrtimer structure diff --git a/include/linux/pci.h b/include/linux/pci.h index c0e14008a3c..98dc6243a70 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -534,7 +534,7 @@ extern void pci_sort_breadthfirst(void); #ifdef CONFIG_PCI_LEGACY struct pci_dev __deprecated *pci_find_device(unsigned int vendor, unsigned int device, - const struct pci_dev *from); + struct pci_dev *from); struct pci_dev __deprecated *pci_find_slot(unsigned int bus, unsigned int devfn); #endif /* CONFIG_PCI_LEGACY */ @@ -550,7 +550,7 @@ struct pci_dev *pci_get_device(unsigned int vendor, unsigned int device, struct pci_dev *from); struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, unsigned int ss_vendor, unsigned int ss_device, - const struct pci_dev *from); + struct pci_dev *from); struct pci_dev *pci_get_slot(struct pci_bus *bus, unsigned int devfn); struct pci_dev *pci_get_bus_and_slot(unsigned int bus, unsigned int devfn); struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from); @@ -816,7 +816,7 @@ _PCI_NOP_ALL(write,) static inline struct pci_dev *pci_find_device(unsigned int vendor, unsigned int device, - const struct pci_dev *from) + struct pci_dev *from) { return NULL; } @@ -838,7 +838,7 @@ static inline struct pci_dev *pci_get_subsys(unsigned int vendor, unsigned int device, unsigned int ss_vendor, unsigned int ss_device, - const struct pci_dev *from) + struct pci_dev *from) { return NULL; } diff --git a/include/linux/ramfs.h b/include/linux/ramfs.h index b160fb18e8d..37aaf2b3986 100644 --- a/include/linux/ramfs.h +++ b/include/linux/ramfs.h @@ -6,6 +6,7 @@ extern int ramfs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt); #ifndef CONFIG_MMU +extern int ramfs_nommu_expand_for_mapping(struct inode *inode, size_t newsize); extern unsigned long ramfs_nommu_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, diff --git a/include/linux/smb.h b/include/linux/smb.h index caa43b2370c..82fefddc598 100644 --- a/include/linux/smb.h +++ b/include/linux/smb.h @@ -11,7 +11,9 @@ #include <linux/types.h> #include <linux/magic.h> +#ifdef __KERNEL__ #include <linux/time.h> +#endif enum smb_protocol { SMB_PROTOCOL_NONE, diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h index 5da9794b2d7..b106fd8e0d5 100644 --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -1,6 +1,8 @@ #ifndef __LINUX_STACKTRACE_H #define __LINUX_STACKTRACE_H +struct task_struct; + #ifdef CONFIG_STACKTRACE struct stack_trace { unsigned int nr_entries, max_entries; |