linux/drivers/firewire
Stefan Richter fcd46b3442 firewire: Enable remote DMA above 4 GB
This makes all of a machine's memory accessible to remote debugging via
FireWire, using the physical response unit (i.e. RDMA) of OHCI-1394 link
layer controllers.

This requires actual support by the controller.  The only ones currently
known to support it are Agere/LSI FW643.  Most if not all other OHCI-1394
controllers do not implement the optional Physical Upper Bound register.
With them, RDMA will continue to be limited to the lowermost 4 GB.

firewire-ohci's startup message in the kernel log is augmented to tell
whether the controller does expose more than 4 GB to RDMA.

While OHCI-1394 allows for a maximum Physical Upper Bound of
0xffff'0000'0000 (near 256 TB), this implementation sets it to
0x8000'0000'0000 (128 TB) in order to avoid interference with applications
that require interrupt-served asynchronous request reception at
respectively low addresses.

Note, this change does not switch remote DMA on.  It only increases the
range of remote access to all memory (instead of just 4 GB) whenever
remote DMA was switched on by other means.  The latter is achieved by
setting firewire-ohci's remote_dma parameter, or if the physical DMA
filter is opened through firewire-sbp2.

Derived from patch "firewire: Enable physical DMA above 4GB" by
Peter Hurley <peter@hurleysoftware.com> from March 27, 2013.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2014-01-20 01:11:13 +01:00
..
Kconfig firewire net, ipv6: IPv6 over Firewire (RFC3146) support. 2013-03-26 12:32:13 -04:00
Makefile ieee1394: move init_ohci1394_dma to drivers/firewire/ 2010-10-11 14:48:03 +02:00
core-card.c IEEE 1394 (FireWire) subsystem updates post v3.4: 2012-05-24 12:57:47 -07:00
core-cdev.c firewire: core: typecast from gfp_t to bool more safely 2013-07-30 15:46:18 +02:00
core-device.c firewire: remove support of fw_driver.driver.probe and .remove methods 2013-06-09 18:15:00 +02:00
core-iso.c firewire: core: fix multichannel IR with buffers larger than 2 GB 2012-06-17 19:35:26 +02:00
core-topology.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
core-transaction.c firewire: Enable remote DMA above 4 GB 2014-01-20 01:11:13 +01:00
core.h firewire: Enable remote DMA above 4 GB 2014-01-20 01:11:13 +01:00
init_ohci1394_dma.c various: Fix spelling of "asynchronous" in comments. 2012-11-19 14:32:13 +01:00
net.c firewire: introduce fw_driver.probe and .remove methods 2013-06-09 18:15:00 +02:00
nosy-user.h firewire: nosy: endianess fixes and annotations 2010-07-27 11:04:11 +02:00
nosy.c firewire: remove use of __devinitdata 2012-11-28 12:40:42 -08:00
nosy.h firewire: nosy: misc cleanups 2010-07-27 11:04:10 +02:00
ohci.c firewire: Enable remote DMA above 4 GB 2014-01-20 01:11:13 +01:00
ohci.h firewire: ohci: fix TI TSB82AA2 regression since 2.6.35 2010-10-17 14:09:12 +02:00
sbp2.c firewire: sbp2: bring back WRITE SAME support 2013-12-15 16:32:32 +01:00