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path: root/include/linux/msi.h
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2007-03-12[PATCH] msi: Safer state caching.Eric W. Biederman
There are two ways pci_save_state and pci_restore_state are used. As helper functions during suspend/resume, and as helper functions around a hardware reset event. When used as helper functions around a hardware reset event there is no reason to believe the calls will be paired, nor is there a good reason to believe that if we restore the msi state from before the reset that it will match the current msi state. Since arch code may change the msi message without going through the driver, drivers currently do not have enough information to even know when to call pci_save_state to ensure they will have msi state in sync with the other kernel irq reception data structures. It turns out the solution is straight forward, cache the state in the existing msi data structures (not the magic pci saved things) and have the msi code update the cached state each time we write to the hardware. This means we never need to read the hardware to figure out what the hardware state should be. By modifying the caching in this manner we get to remove our save_state routines and only need to provide restore_state routines. The only fields that were at all tricky to regenerate were the msi and msi-x control registers and the way we regenerate them currently is a bit dependent upon assumptions on how we use the allow msi registers to be configured and used making the code a little bit brittle. If we ever change what cases we allow or how we configure the msi bits we can address the fragility then. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Auke Kok <auke-jan.h.kok@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-07msi: Make MSI useable more architecturesEric W. Biederman
The arch hooks arch_setup_msi_irq and arch_teardown_msi_irq are now responsible for allocating and freeing the linux irq in addition to setting up the the linux irq to work with the interrupt. arch_setup_msi_irq now takes a pci_device and a msi_desc and returns an irq. With this change in place this code should be useable by all platforms except those that won't let the OS touch the hardware like ppc RTAS. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07PCI: cleanup MSI codeSatoru Takeuchi
Cleanup MSI code as follows: - fix some types - fix strange local variable definition - delete unnecessary blank line - add comment to #endif which is far from corresponding #ifdef Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-04[PATCH] msi: refactor and move the msi irq_chip into the arch codeEric W. Biederman
It turns out msi_ops was simply not enough to abstract the architecture specific details of msi. So I have moved the resposibility of constructing the struct irq_chip to the architectures, and have two architecture specific functions arch_setup_msi_irq, and arch_teardown_msi_irq. For simple architectures those functions can do all of the work. For architectures with platform dependencies they can call into the appropriate platform code. With this msi.c is finally free of assuming you have an apic, and this actually takes less code. The helpers for the architecture specific code are declared in the linux/msi.h to keep them separate from the msi functions used by drivers in linux/pci.h Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tony Luck <tony.luck@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>