kernel.git/arch/powerpc/kernel/irq.c, branch linux-2.6.19.y

[PATCH] extern doesn't make sense on a definition of function...

2006-10-09T21:19:07Z

Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

[POWERPC] Fix up after irq changes

2006-10-07T12:08:26Z

Remove struct pt_regs * from all handlers. Also remove the regs argument from get_irq() functions. Compile tested with arch/powerpc/config/* and arch/ppc/configs/prep_defconfig Signed-off-by: Olaf Hering Signed-off-by: Paul Mackerras

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

2006-10-05T14:10:12Z

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)

[POWERPC] Fix loop logic in irq_alloc_virt()

2006-09-26T05:24:34Z

There's a bug in irq_alloc_virt() if it's asked for more than 1 interrupt, if it can't find a slot it might look past the end of the irq_map. To be clear: the bug is that the continue affects the inner for loop, not the outer one, so i becomes j + 1 and then we continue the inner loop without checking if i is still <= limit. This fixes it. No one in the kernel actually calls this with count > 1, so it's not critical. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

Merge branch 'merge'

2006-08-31T05:45:48Z

[POWERPC] Fix performance regression in IRQ radix tree locking

2006-08-30T00:36:16Z

When reworking the powerpc irq code, I figured out that we were using the radix tree in a racy way. As a temporary fix, I put a spinlock in there. However, this can have a significant impact on performances. This patch reworks that to use a smarter technique based on the fact that what we need is in fact a rwlock with extremely rare writers (thus optimized for the read path). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

Merge branch 'merge'

2006-08-25T04:56:07Z

[POWERPC] Fix irq radix tree remapping typo

2006-08-17T06:41:11Z

The code for using the radix tree for reverse mapping of interrupts has a typo that causes it to create incorrect mappings if the software and hardware numbers happen to be different. This would, among others, cause the IDE interrupt to fail on js20's. This fixes it. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras

[POWERPC] Export msi symbols

2006-08-08T07:06:59Z

Forgot to export symbols for MSI. Signed-off-by: Jake Moilanen Acked-by: Segher Boessenkool Signed-off-by: Paul Mackerras

[PATCH] powerpc: fix trigger handling in the new irq code

2006-07-10T20:24:20Z

This patch slightly reworks the new irq code to fix a small design error. I removed the passing of the trigger to the map() calls entirely, it was not a good idea to have one call do two different things. It also fixes a couple of corner cases. Mapping a linux virtual irq to a physical irq now does only that. Setting the trigger is a different action which has a different call. The main changes are: - I no longer call host->ops->map() for an already mapped irq, I just return the virtual number that was already mapped. It was called before to give an opportunity to change the trigger, but that was causing issues as that could happen while the interrupt was in use by a device, and because of the trigger change, map would potentially muck around with things in a racy way. That was causing much burden on a given's controller implementation of map() to get it right. This is much simpler now. map() is only called on the initial mapping of an irq, meaning that you know that this irq is _not_ being used. You can initialize the hardware if you want (though you don't have to). - Controllers that can handle different type of triggers (level/edge/etc...) now implement the standard irq_chip->set_type() call as defined by the generic code. That means that you can use the standard set_irq_type() to configure an irq line manually if you wish or (though I don't like that interface), pass explicit trigger flags to request_irq() as defined by the generic kernel interfaces. Also, using those interfaces guarantees that your controller set_type callback is called with the descriptor lock held, thus providing locking against activity on the same interrupt (including mask/unmask/etc...) automatically. A result is that, for example, MPIC's own map() implementation calls irq_set_type(NONE) to configure the hardware to the default triggers. - To allow the above, the irq_map array entry for the new mapped interrupt is now set before map() callback is called for the controller. - The irq_create_of_mapping() (also used by irq_of_parse_and_map()) function for mapping interrupts from the device-tree now also call the separate set_irq_type(), and only does so if there is a change in the trigger type. - While I was at it, I changed pci_read_irq_line() (which is the helper I would expect most archs to use in their pcibios_fixup() to get the PCI interrupt routing from the device tree) to also handle a fallback when the DT mapping fails consisting of reading the PCI_INTERRUPT_PIN to know wether the device has an interrupt at all, and the the PCI_INTERRUPT_LINE to get an interrupt number from the device. That number is then mapped using the default controller, and the trigger is set to level low. That default behaviour works for several platforms that don't have a proper interrupt tree like Pegasos. If it doesn't work for your platform, then either provide a proper interrupt tree from the firmware so that fallback isn't needed, or don't call pci_read_irq_line() - Add back a bit that got dropped by my main rework patch for properly clearing pending IPIs on pSeries when using a kexec Signed-off-by: Benjamin Herrenschmidt Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds