diff --git a/en/projects/busdma/index.sgml b/en/projects/busdma/index.sgml index 3c1f171abb..8eaccd7b33 100644 --- a/en/projects/busdma/index.sgml +++ b/en/projects/busdma/index.sgml @@ -1,1188 +1,1188 @@ - + %includes; N/A"> Done"> In progress"> Needs testing"> Not done"> Unknown"> %developers; ]> &header;

Contents

Project Goal

busdma

The busdma interfaces permit hardware device drivers to operate on a variety of platforms avoiding the encoding of platform-specific access methods into drivers. This lowers the maintenance costs for drivers across platforms, and improves the chances that a driver will "just work" on a new platform. Modifying a driver to make use of busdma is relatively straight forward, but does require familiarity with both the device driver and busdma primitives. For busdma to be used in FreeBSD, two sets of changes are generally required: adaptation of the busdma implementation to run on all platforms, and adaptation of drivers to use the framework. As such, status information on this project is broken down into platform support, and driver support (sorted by category). Completing this work requires a thorough audit of the system device drivers, then prioritized conversion of drivers.

INTR_MPSAFE

Hardware drivers register their interrupt handler with the bus_setup_intr() function. Setting the flag INTR_MPSAFE tells the system interrupt code to call the interrupt routine without holding the Giant mutex. This can give a significant performance gain on SMP systems.

Drivers can set this flag even if they are not fully locked down as long as their interrupt routine is careful about not touching other data structures in the driver. An easy way to do this is to check and clear the hardware interrupt status registers and then schedule the interrupt processing for a taskqueue or kernel thread.

SMPng locked

Drivers should employ mutexes and sx locks to protect their data structures and hardware registers from competing threads. Mutex operations are somewhat expensive, so a good strategy is combine as many atomic operations into a single mutex acquisition as possible.

p!=a safety

Intel PAE support requires that pointers and physical address representations be of differing sizes. This means that drivers must be written to use vm_paddr_t or bus_addr_t rather than assuming that physical addresses can be represented using a void *. In addition, format strings and casts must be carefully handled.

The task list below is not intended to be complete, but does represent a set of relevant and/or important components of the overall work. The "Responsible" field identifies a developer who has expressed willingness to be responsible for completing the identified task; this doesn't preclude others working on it, but suggests that coordination with the responsible party might be appropriate so as to avoid unnecessary duplication of work, and to maximize forward progress. If beginning work on a new area of substantial size, or one that appears unclaimed, it may be worth dropping an e-mail to &a.mux; to see if any progress has been made.

The definition of the date field varies depending on the status of a task. For completed tasks, it refers to the date completed or reported completed. For in-progress tasks, it refers to the date of the last update of the entry. For stalled tasks, it refers to the date that the task was declared stalled. For new tasks, it refers to the date the task was added to the list.

Tasks are sorted first by status, then by date.

Platform Support Status

Task Responsible Last updated Status Details
alpha &a.gallatin; December 10, 2002 &status.done; There may be problems for systems with large amounts of memory.
amd64 &a.peter; July 1, 2003 &status.done; Fully supported.
ia64 &a.marcel; December 10, 2002 &status.done; There may be problems for systems with large amounts of memory.
i386 &a.sam; December 9, 2002 &status.done; Fully supported.
powerpc &a.hmp; January 15, 2003 &status.done; Fully supported.
sparc64 &a.tmm; January 6, 2003 &status.done; Fully supported.

Network Interface Driver Status

- - + +
Driver Responsible Last updated busdma INTR_MPSAFE SMPng locked a!=p 4.x status Notes
if_ar     &status.new; &status.new; &status.new; &status.new; &status.new; kvtop()
if_bge &a.wpaul; April 13, 2004 &status.done; &status.done; &status.done; &status.done; &status.new;  
if_cs     &status.new; &status.new; &status.new; &status.new; &status.new;  
if_dc &a.mux; April 13, 2004 &status.done; &status.done; &status.done; &status.untested; &status.new; MPSAFE subject to use of MTX_RECURSE
if_de &a.mux; April 13, 2004 &status.done; &status.new; &status.new; &status.new; &status.done;  
if_ed     &status.new; &status.new; &status.new; &status.new; &status.new; kvtop()
if_em &a.pdeuskar; April 13, 2004 &status.done; &status.done; &status.done; &status.done; &status.new;  
if_en &a.harti; April 13, 2004 &status.done; &status.new; &status.new; &status.untested; &status.new; Locking present; not yet marked INTR_MPSAFE?
if_ep &a.imp; April 13, 2004 &status.na; &status.done; &status.done; &status.done; &status.na; Mutes marked MTX_RECURSE.
if_ex &a.imp; April 13, 2004 &status.na; &status.new; &status.new; &status.new; &status.na; not fully evaluated.
if_fxp &a.mux; April 13, 2004 &status.done; &status.done; &status.done; &status.done; &status.new;  
if_fwe     &status.new; &status.new; &status.new; &status.new; &status.new;  
if_gem &a.tmm; January 6, 2003 &status.done; &status.new; &status.new; &status.new; N/A  
if_gx   April 13, 2004 &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(); locking present; not marked INTR_MPSAFE? Mutex marked MTX_RECURSE.
if_hme &a.tmm; January 6, 2003 &status.done; &status.new; &status.new; &status.new; N/A  
if_idt     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_lge     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_lmc     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_lnc &a.obrien;   &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(). Please contact &a.phk; for info/hardware.
if_mn     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(). Please contact &a.phk; for info/hardware.
if_my     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_nge     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_pcn &a.obrien; April 13, 2004 &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(); locking present; not yet marked INTR_MPSAFE? Mutex marked MTX_RECURSE.
if_pdq     &status.new; &status.new; &status.new; &status.new; &status.new; mostly busdma, except for vtophys()
if_rl &a.wpaul; April 13, 2004 &status.done; &status.new; &status.new; &status.new; &status.new; Locking present; not yet marked INTR_MPSAFE? Mutex marked MTX_RECURSE.
if_sf   April 13, 2004 &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(); locking present; not yet marked INTR_MPSAFE? Mutex marked MTX_RECURSE.
if_sis &a.wpaul; April 13, 2004 &status.done; &status.done; &status.new; &status.new; &status.new; Locking present; not yet marked INTR_MPSAFE? Mutex marked MTX_RECURSE.
if_sk     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_sr     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_ste     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
if_ti     &status.new; &status.new; &status.new; &status.new; &status.new;  
if_tl     &status.new; &status.new; &status.new; &status.new; &status.new;  
if_tx &a.mux; April 19, 2003 &status.done; &status.new; &status.new; &status.untested; &status.new; vtophys()
if_txp &a.will; July 18, 2003 &status.wip; &status.new; &status.new; &status.new; &status.new;  
if_vr Christian S.J. Peron <maneo@bsdpro.com> January 20, 2003   April 23, 2004 &status.wip; &status.new; &status.new; &status.new; &status.new;  
if_wb     &status.new; &status.new; &status.new; &status.new; &status.new;  
if_wi &a.sam;, &a.imp; November 4, 2003 &status.unknown; &status.done; &status.unknown; &status.unknown; &status.unknown;  
if_xl &a.mux; April 13, 2004 &status.done; &status.new; &status.done; &status.done; &status.new; Locking present; not marked as INTR_MPSAFE; mutex is marked MTX_RECURSE.

Storage Device Driver Status

Driver Responsible Last updated busdma INTR_MPSAFE SMPng locked a!=p 4.x status Notes
aac &a.scottl; February 8, 2003 &status.done; &status.done; &status.done; &status.done; &status.new; PCI-64 capable, not endian clean
adv   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
aha   April 13, 2004 &status.done; &status.wip; &status.wip; &status.new; &status.new; Uses BUSDMA, but may pun bus address with host address
ahb   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
aic7xxx   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
amd   December 14, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
amr   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
asr &a.obrien; January 4, 2003 &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
ata &a.sos; December 9, 2002 &status.done; &status.done; &status.done; &status.done; &status.new;  
buslogic     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
ciss   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
ct     &status.new; &status.new; &status.new; &status.new; &status.new;  
dpt     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
ida   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
iir     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
isp   February 8, 2003 &status.done; &status.done; &status.new; &status.new; &status.new;  
mlx &a.scottl; February 8, 2003 &status.done; &status.wip; &status.wip; &status.new; &status.new;  
mly &a.scottl; February 8, 2003 &status.done; &status.wip; &status.wip; &status.new; &status.new;  
mpt   December 9, 2002 &status.done; &status.done; &status.new; &status.new; &status.new;  
ncr     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(). Please contact &a.phk; for a possible source of hardware.
pst     &status.new; &status.done; &status.new; &status.new; &status.new; vtophys()
stg   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new; At least, it looks like it may well be.
sym   December 19, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
trm &a.cognet; December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  
twe   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  

Miscellaneous Device Driver Status

Driver Responsible Last updated busdma INTR_MPSAFE SMPng locked a!=p 4.x status Notes
agp &a.cognet; January 23, 2003 &status.wip; &status.new; &status.new; &status.new; &status.new; vtophys()
bktr &a.cognet; January 15, 2003 &status.wip; &status.new; &status.new; &status.new; &status.new; vtophys()
digi     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
drm &a.anholt; October 27, 2003 &status.wip; &status.done; &status.done; &status.wip; &status.wip; vtophys(). The locking could use some review.
fb     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
firewire &a.simokawa; April 17, 2003 &status.done; &status.new; &status.new; &status.done; &status.new; vtophys()
hea     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
hfa     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
hifn &a.sam; April 13, 2004 &status.done; &status.done; &status.done; &status.new; &status.new;  
meteor     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys()
musycc     &status.new; &status.new; &status.new; &status.new; &status.new; vtophys(). Please contact &a.phk; for info/hardware.
pcm &a.cognet; February 20, 2003 &status.done; &status.done; &status.new; &status.new; &status.new;  
ubsec &a.sam; April 13, 2004 &status.done; &status.done; &status.done; &status.new; &status.new; vtophys() is used in debugging printf
usb &a.jmg; July 24, 2003 &status.done; &status.new; &status.new; &status.new; &status.new; a!=p should be clean, but requires further testing
wds   December 9, 2002 &status.done; &status.new; &status.new; &status.new; &status.new;  

Documentation Status

Task Responsible Last updated Status Notes
manpages for the busdma API &a.hmp; January 15, 2003 &status.done;  
&footer;