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path: root/drivers/char/hpet.c
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2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
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 <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-09-26[PATCH] Don't print virtual address in HPET initializationAndi Kleen
virtual addresses don't belong into kernel logs for non debugging Cc: clemens@ladisch.de Signed-off-by: Andi Kleen <ak@suse.de>
2006-07-03[PATCH] make more file_operation structs staticArjan van de Ven
Mark the static struct file_operations in drivers/char as const. Making them const prevents accidental bugs, and moves them to the .rodata section so that they no longer do any false sharing; in addition with the proper debug option they are then protected against corruption.. [akpm@osdl.org: build fix] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-02[PATCH] irq-flags: drivers/char: Use the new IRQF_ constantsThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01HPET: fix ACPI memory range length handlingBjorn Helgaas
ACPI address space descriptors contain _MIN, _MAX, and _LEN. _MIN and _MAX are the bounds within which the region can be moved (this is clarified in Table 6-38 of the ACPI 3.0 spec). We should use _LEN to determine the size of the region, not _MAX - _MIN + 1. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Len Brown <len.brown@intel.com>
2006-02-14[PATCH] HPET: handle multiple ACPI EXTENDED_IRQ resourcesBjorn Helgaas
When the _CRS for a single HPET contains multiple EXTENDED_IRQ resources, we overwrote hdp->hd_nirqs every time we found one. So the driver worked when all the IRQs were described in a single EXTENDED_IRQ resource, but failed when multiple resources were used. (Strictly speaking, I think the latter is actually more correct, but both styles have been used.) Someday we should remove all the ACPI stuff from hpet.c and use PNP driver registration instead. But currently PNP_MAX_IRQ is 2, and HPETs often have more IRQs. Hint, hint, Adam :-) Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Acked-by: Bob Picco <robert.picco@hp.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Len Brown <len.brown@intel.com> Cc: Adam Belay <ambx1@neo.rr.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-10[ACPI] ACPICA 20050930Bob Moore
Completed a major overhaul of the Resource Manager code - specifically, optimizations in the area of the AML/internal resource conversion code. The code has been optimized to simplify and eliminate duplicated code, CPU stack use has been decreased by optimizing function parameters and local variables, and naming conventions across the manager have been standardized for clarity and ease of maintenance (this includes function, parameter, variable, and struct/typedef names.) All Resource Manager dispatch and information tables have been moved to a single location for clarity and ease of maintenance. One new file was created, named "rsinfo.c". The ACPI return macros (return_ACPI_STATUS, etc.) have been modified to guarantee that the argument is not evaluated twice, making them less prone to macro side-effects. However, since there exists the possibility of additional stack use if a particular compiler cannot optimize them (such as in the debug generation case), the original macros are optionally available. Note that some invocations of the return_VALUE macro may now cause size mismatch warnings; the return_UINT8 and return_UINT32 macros are provided to eliminate these. (From Randy Dunlap) Implemented a new mechanism to enable debug tracing for individual control methods. A new external interface, acpi_debug_trace(), is provided to enable this mechanism. The intent is to allow the host OS to easily enable and disable tracing for problematic control methods. This interface can be easily exposed to a user or debugger interface if desired. See the file psxface.c for details. acpi_ut_callocate() will now return a valid pointer if a length of zero is specified - a length of one is used and a warning is issued. This matches the behavior of acpi_ut_allocate(). Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2005-12-06Pull release into acpica branchLen Brown
2005-10-30[PATCH] hpet: hpet driver cleanupsRandy Dunlap
- Use kzalloc() instead of kmalloc + memset. - Clean/fix some printk's. - Use NULL for pointers instead of 0. - Combine hpet busy searching locations into a function call. Signed-off-by: Randy Dunlap <randy_d_dunlap@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: use HPET physical addresses for dup. detectionRandy Dunlap
- Use HPET physical address to detect duplicates, not logical addresses. Using logical (mapped) addresses fails to detect duplicates because ioremap() returns a new mapped address each time. - iounmap() regions when duplicate/busy areas are found. Signed-off-by: Randy Dunlap <randy_d_dunlap@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: allow HPET FIXED_MEM32 resource typeRandy Dunlap
Allow the ACPI HPET description table to use a resource type of FIXED_MEM32 for the HPET reource. Use the fixed resoure size of 1 KB for the HPET resource as per the HPET spec. Signed-off-by: Randy Dunlap <randy_d_dunlap@linux.intel.com> Acked-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: simplify initialization messageClemens Ladisch
When booting, display the timer frequency in Hertz instead of as tick length in nanoseconds. Apart from saving a local variable, this makes the message more easily comprehensible. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: remove superfluous indirectionsClemens Ladisch
In the hpet_ioctl_common() function, devp->hd_hpets is already cached in the hpetp variable, so we can use just that. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: fix access to multiple HPET devicesClemens Ladisch
Fix two instances where a function would access the first HPET device instead of the current one. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: fix uninitialized variable in hpet_register()Clemens Ladisch
Clear the ht_opaque field in the hpet_register() function before searching for a free timer to prevent the function from incorrectly assuming that the search succeeded afterwards. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: fix division by zero in HPET_INFOClemens Ladisch
Fix a division by zero that happened when the HPET_INFO ioctl was called before a timer frequency had been set. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: fix HPET_INFO calls from kernel spaceClemens Ladisch
Fix a wrong memory access in hpet_ioctl_common(). It was not possible to use the HPET_INFO ioctl from kernel space because it always called copy_to_user(). Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: allow shared interruptsClemens Ladisch
This patch adds support for shared HPET interrupts. The driver previously acknowledged interrupts for both edge and level interrupts, but didn't actually allow a shared interrupt in the latter case. We use a new per-timer flag to save whether the timer's interrupt might be shared, and use it to do the processing required for level interrupts only if necessary. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Acked-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: allow non-power-of-two frequenciesClemens Ladisch
It was only the RTC hardware that restricted interrupt frequencies to a power of two. There is no reason to take over this restriction into the HPET driver, so remove the offending check. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Acked-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: remove superfluous register readsClemens Ladisch
This patch removes several reads of a timer's config register that serve no purpose whatsoever. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Acked-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: remove unused variableClemens Ladisch
The variable hpet_ntimer is never read, so remove it. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Acked-by: Bob Picco <bob.picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] HPET: make frequency calculations 32 bit safeClemens Ladisch
On 32-bit architectures, the multiplication in the argument for hpet_time_div() often overflows. In the typical case of a 14.32 MHz timer, this happens when the desired frequency exceeds 61 Hz. To avoid this multiplication, we can precompute and store the hardware timer frequency, instead of the period, in the device structure, which leaves us with a simple division when computing the number of timer ticks. As a side effect, this also removes a theoretical bug where the timer interpolator's frequency would be computed as a 32-bit value even if the HPET frequency is greater than 2^32 Hz (the HPET spec allows up to 10 GHz). Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30[PATCH] hpet: disallow zero interrupt frequencyClemens Ladisch
Disallow setting an interrupt frequency of zero (which would result in a division by zero), and disallow enabling the interrupt when the frequency hasn't yet been set (which would use an interrupt period of zero). Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[PATCH] Fix mmap() of /dev/hpetKeir Fraser
The address passed to io_remap_pfn_range() in hpet_mmap() does not need to be converted using __pa(): it is already a physical address. This bug was found and the patch suggested by Clay Harris. I introduced this particular bug when making io_remap_pfn_range changes a few months ago. In fact mmap()ing /dev/hpet has *never* previously worked: before my changes __pa() was being executed on an ioremap()ed virtual address, which is also invalid. Signed-off-by: Keir Fraser <keir@xensource.com> Cc: Robert Picco <Robert.Picco@hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-22[ACPI] handle ACPICA 20050916's acpi_resource.type renameLen Brown
Signed-off-by: Len Brown <len.brown@intel.com>
2005-09-10[PATCH] fix unusual placement of inline keyword in hpetAdrian Bunk
With gcc -W: drivers/char/hpet.c:102: warning: `inline' is not at beginning of declaration drivers/char/hpet.c:109: warning: `inline' is not at beginning of declaration Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-08Merge linux-2.6 with linux-acpi-2.6Len Brown
2005-09-07[PATCH] hpet: fix drift and urlAlex Williamson
The HPET driver is using a parts per second drift factor instead of the standard parts per million drift the time interpolator code expects. This patch fixes that problem and updates the URL for the HPET spec. Signed-off-by: Alex Williamson <alex.williamson@hp.com> Cc: "Robert W. Picco" <bob.picco@hp.com> Acked-by: "Pallipadi, Venkatesh" <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-05[ACPI] Merge acpi-2.6.12 branch into 2.6.13-rc3Len Brown
Signed-off-by: Len Brown <len.brown@intel.com>
2005-08-04[ACPI] HPET driver now checks for acpi_register_gsi() errorsKenji Kaneshige
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Len Brown <len.brown@intel.com>
2005-06-25[PATCH] hpet: do_div fixJon Smirl
We don't need to use do_div() on a 32-bit quantity. Signed-off-by: Jon Smirl <jonsmirl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!