On 2011-08-29 18:23, Michael S. Tsirkin wrote: > On Mon, Aug 29, 2011 at 06:14:39PM +0200, Jan Kiszka wrote: >> On 2011-08-29 17:58, Michael S. Tsirkin wrote: >>> On Mon, Aug 29, 2011 at 05:42:16PM +0200, Jan Kiszka wrote: >>>> I still don't get what prevents converting ipr to allow plain mutex >>>> synchronization. My vision is: >>>> - push reset-on-error of ipr into workqueue (or threaded IRQ?) >>>> - require mutex synchronization for common config space access >>> >>> Meaning pci_user_ read/write config? >> >> And pci_dev_reset, yes. >> >>> >>>> and the >>>> full reset cycle >>>> - only exception: INTx status/masking access >>>> => use pci_lock + test for reset_in_progress, skip operation if >>>> that is the case >>>> >>>> That would allow to drop the whole block_user_cfg infrastructure. >>>> >>>> Jan >>> >>> We still need to block userspace access while INTx does >>> the status/masking access, right? >> >> Yes, pci_lock would do that for us. > > Well this means block_user_cfg is not going away, > this is what it really is: pci_lock + a bit to lock out userspace.
I does as we only end up with a mutex and pci_lock. No more hand-crafted queuing/blocking/waking. INTx masking is a bit special as it's the only thing that truly requires atomic context. But that's something we should address generically anyway. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
