lwn.git/include/linux/rtc.h, branch v2.6.19.2

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] constify rtc_class_ops: update drivers

2006-10-01T07:39:25+00:00

Update RTC framework so that drivers can constify their method tables, moving them from ".data" to ".rodata". Then update the drivers. Signed-off-by: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Correct rtc_wkalrm comments

2006-06-30T18:25:38+00:00

This corrects the comments describing the 'enabled' and 'pending' flags in struct rtc_wkalrm of include/linux/rtc.h. Signed-off-by: Andrew Victor Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] RTC: Add rtc_year_days() to calculate tm_yday

2006-06-25T17:01:14+00:00

RTC: Add exported function rtc_year_days() to calculate the tm_yday value. Signed-off-by: Andrew Victor Signed-off-by: Alessandro Zummo Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rtc subsystem: add capability checks

2006-06-25T17:01:14+00:00

Centralize CAP_SYS_XXX checks to avoid duplicate code and missing checks in the drivers. Signed-off-by: Alessandro Zummo Cc: Richard Purdie Cc: Yoichi Yuasa Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] RTC: rtc-dev UIE emulation

2006-06-25T17:01:13+00:00

Import genrtc's RTC UIE emulation (CONFIG_GEN_RTC_X) to rtc-dev driver with slight adjustments/refinements. This makes UIE-less rtc drivers work better with programs doing read/poll on /dev/rtc, such as hwclock. This emulation should not harm rtc drivers with UIE support, since rtc_dev_ioctl() calls underlaying rtc driver's ioctl() first. Signed-off-by: Atsushi Nemoto Acked-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] RTC subsystem: class

2006-03-27T16:44:51+00:00

Add the basic RTC subsystem infrastructure to the kernel. rtc/class.c - registration facilities for RTC drivers rtc/interface.c - kernel/rtc interface functions rtc/hctosys.c - snippet of code that copies hw clock to sw clock at bootup, if configured to do so. Signed-off-by: Alessandro Zummo Acked-by: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] RTC Subsystem: library functions

2006-03-27T16:44:50+00:00

RTC and date/time related functions. Signed-off-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rtc.h broke strace(1) builds

2006-03-22T15:53:55+00:00

Git patch 52dfa9a64cfb3dd01fa1ee1150d589481e54e28e [PATCH] move rtc_interrupt() prototype to rtc.h broke strace(1) builds. The below moves the kernel-only additions lower, under the already provided #ifdef __KERNEL__ statement. Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] move rtc_interrupt() prototype to rtc.h

2006-01-09T04:13:47+00:00

This patch moves the rtc_interrupt() prototype to rtc.h and removes the prototypes from C files. It also renames static rtc_interrupt() functions in arch/arm/mach-integrator/time.c and arch/sh64/kernel/time.c to avoid compile problems. Signed-off-by: Adrian Bunk Signed-off-by: Paul Gortmaker Acked-by: Paul Mundt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds