Date: Sat, 05 Nov 2005 14:04:16 -0700 (MST) From: "M. Warner Losh" <imp@bsdimp.com> To: fierykylin@gmail.com Cc: freebsd-hackers@freebsd.org Subject: Re: misc questions about the device&driver arch Message-ID: <20051105.140416.69987626.imp@bsdimp.com> In-Reply-To: <87ab37ab0511032030o134b9316j83295dd303e4e44b@mail.gmail.com> References: <87ab37ab0511032030o134b9316j83295dd303e4e44b@mail.gmail.com>
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In message: <87ab37ab0511032030o134b9316j83295dd303e4e44b@mail.gmail.com>
kylin <fierykylin@gmail.com> writes:
: ///////////////
: pci bridge dynamic resize
: /////////////
: it seems that the device arch of freebsd is similar to what is revealed in
: window OS. i have read the pcie hotplug tps of windows longhorn ,it is said
: that with some hardware mechanisms the pci bridge driver can do global pci
: resource window reconfiguration.so good to the hotplugin pci device for it
: avoid prelocating resource for the device .
: i wonder ,if the mem /io/irq reconfiguration possible under freebsd .:)
: 1
Yes. Cardbus does it all the time. However, there's no pcie hot-plug
support yet, so the process for kicking off configuration of the new
device doesn't happen.
: //////////////
: is bus_data_generation
: /////////
: what idoes bus_data_generation for, is it the generation count for the
: device manager tree?
: void
: bus_data_generation_update(void)
: {
: bus_data_generation++;
: }
Anytime the device_t tree changes, this gets updated. It is used by
devinfo and friends.
: //////////////
: pci_write_config vs pci_write_config_method
: //////////////
: under the source code /dev/pci .there are functions name pci_write_config (
: pcivar.h) and pci_write_config_method(pci.c)
: they both call the parent method ,though the content is different ,but does
: that a liitle overlap whit each other?
pci_write_config is the user's interface. This gets translated into a
series of calls up the tree using pci_write_config_method to find the
right place in the tree to actually write to the configuration
registers.
Warner
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