Hi John, John Keller wrote:
Hi, This is FYI. If VECTOR_DOMAIN_PERCPU is NOT enabled: The "irq == vector" is always true in the following cases: - reserve_irq_vector(), which is used only by SN - create_irq() used on the system that has NO I/O SAPICCould you say a bit more about this case. I see create_irq() calling find_unassigned_vector() and find_unassigned_irq(). How is "irq == vector" guaranteed to be always true in this case?
It's guaranteed as follows: - When find_unassigned_vector()/find_unassigned_irq() search available vector and irq, it always start to search from IA64_FIRST_DEVICE_VECTOR. - clear_irq_vector() releases both vector and irq. Thanks, Yasuaki
John- assign_irq_vector() with AUTO_ASSIGN specified - Vectors outside FIRST_DEVICE_VECTOR to LAST_DEVICE_VECTOR The "irq == vector" is not always true in the folliwng cases: - create_irq() used on the system that has I/O SAPICs. - assign_irq_vector() with the value other than AUTO_ASSIGN specified on the system has I/O SAPICs. And it is not ensured that those are true even in the future. Yasuaki, could you check if it is correct? Thanks, Kenji Kaneshige 2007-08-02 (木) の 08:26 -0500 に John Keller さんは書きました:Yes, we'll take a look at it. JohnHi Kenji-san I believe we need this property, but I am not 100% sure, so I am going to forward your patch to our team who maintain the IRQ code for Altix. Mike, Aaron or John, would one of you have time to take a look at this? Thanks, Jes Kenji Kaneshige wrote:Hi Jes-san, Russ-san, Christoph-san and SN platform developers, I glanced over the SN code, and I found SN platform doesn't have SN specific irq_to_vector() function, though it has SN specific local_vector_to_irq() function. I guess it was OK because maybe SN platform depends on irq == vector and old generic irq_to_vector() was just returning the same value as irq. The irq_to_vector() function, however, has been changed by vector domain support, and currently it can return the different value from irq, even when VECTOR_DOMAIN_PERCPU is not enabled. This can happen when an interrupt thorough I/O SAPIC is unregistered and another interupt is registered. So if my guess (SN platform depends on irq == vector) is true, something problem might happen on SN platform when PCI hotplugging or driver reloading. If it is true that SN platform depends on irq == vector, we need to implement SN specific irq_to_vector() that returns the same value as irq, I think. I made sample patches to implement platform specific irq_to_vector() as follows. Note that [PATCH 2/2] is not tested yet because I don't have any SN platform unfortunately. [PATCH 1/2] Add base support for platform_irq_to_vector() [PATCH 2/2] Implement platform_irq_to_vector() for SN Could you give me comments? Thanks, Kenji Kaneshige- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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