1. 26 8月, 2017 1 次提交
    • H
      scsi: aha152x: drop host reset · 819f80c9
      Hannes Reinecke 提交于
      The driver has both a bus and a host reset, where the host reset does a
      bus reset followed by an attempt to reset the chip registers to a
      default state.  However, as the bus reset always returned SUCCESS the
      host reset was never called, so the functionality of the register reset
      function was never validated.  Additionally, tha AIC-6260 chip has a
      hard reset line, which actually should be preferred for a host
      reset. But I haven't found a way how this can be triggered via software,
      so take the safe approach and drop the host reset.
      
      [mkp: typo]
      Signed-off-by: NHannes Reinecke <hare@suse.com>
      Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
      819f80c9
  2. 20 4月, 2017 1 次提交
    • D
      Annotate hardware config module parameters in drivers/scsi/ · 88f06b76
      David Howells 提交于
      When the kernel is running in secure boot mode, we lock down the kernel to
      prevent userspace from modifying the running kernel image.  Whilst this
      includes prohibiting access to things like /dev/mem, it must also prevent
      access by means of configuring driver modules in such a way as to cause a
      device to access or modify the kernel image.
      
      To this end, annotate module_param* statements that refer to hardware
      configuration and indicate for future reference what type of parameter they
      specify.  The parameter parser in the core sees this information and can
      skip such parameters with an error message if the kernel is locked down.
      The module initialisation then runs as normal, but just sees whatever the
      default values for those parameters is.
      
      Note that we do still need to do the module initialisation because some
      drivers have viable defaults set in case parameters aren't specified and
      some drivers support automatic configuration (e.g. PNP or PCI) in addition
      to manually coded parameters.
      
      This patch annotates drivers in drivers/scsi/.
      Suggested-by: NAlan Cox <gnomes@lxorguk.ukuu.org.uk>
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      cc: "Juergen E. Fischer" <fischer@norbit.de>
      cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
      cc: "Martin K. Petersen" <martin.petersen@oracle.com>
      cc: Dario Ballabio <ballabio_dario@emc.com>
      cc: Finn Thain <fthain@telegraphics.com.au>
      cc: Michael Schmitz <schmitzmic@gmail.com>
      cc: Achim Leubner <achim_leubner@adaptec.com>
      cc: linux-scsi@vger.kernel.org
      88f06b76
  3. 01 6月, 2015 1 次提交
  4. 03 2月, 2015 2 次提交
  5. 12 11月, 2014 1 次提交
  6. 29 10月, 2014 1 次提交
  7. 18 7月, 2014 1 次提交
  8. 20 3月, 2014 1 次提交
  9. 10 4月, 2013 1 次提交
  10. 04 1月, 2013 1 次提交
    • G
      Drivers: scsi: remove __dev* attributes. · 6f039790
      Greg Kroah-Hartman 提交于
      CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
      markings need to be removed.
      
      This change removes the use of __devinit, __devexit_p, __devinitdata,
      __devinitconst, and __devexit from these drivers.
      
      Based on patches originally written by Bill Pemberton, but redone by me
      in order to handle some of the coding style issues better, by hand.
      
      Cc: Bill Pemberton <wfp5p@virginia.edu>
      Cc: Adam Radford <linuxraid@lsi.com>
      Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6f039790
  11. 20 7月, 2012 1 次提交
  12. 29 3月, 2012 1 次提交
  13. 30 6月, 2011 1 次提交
  14. 17 11月, 2010 1 次提交
    • J
      SCSI host lock push-down · f281233d
      Jeff Garzik 提交于
      Move the mid-layer's ->queuecommand() invocation from being locked
      with the host lock to being unlocked to facilitate speeding up the
      critical path for drivers who don't need this lock taken anyway.
      
      The patch below presents a simple SCSI host lock push-down as an
      equivalent transformation.  No locking or other behavior should change
      with this patch.  All existing bugs and locking orders are preserved.
      
      Additionally, add one parameter to queuecommand,
      	struct Scsi_Host *
      and remove one parameter from queuecommand,
      	void (*done)(struct scsi_cmnd *)
      
      Scsi_Host* is a convenient pointer that most host drivers need anyway,
      and 'done' is redundant to struct scsi_cmnd->scsi_done.
      
      Minimal code disturbance was attempted with this change.  Most drivers
      needed only two one-line modifications for their host lock push-down.
      Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
      Acked-by: NJames Bottomley <James.Bottomley@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f281233d
  15. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  16. 16 10月, 2008 1 次提交
  17. 27 7月, 2008 1 次提交
  18. 23 5月, 2008 1 次提交
    • H
      scsi: fix integer as NULL pointer warning · 9bcf0910
      Harvey Harrison 提交于
      drivers/scsi/aha152x.c:3585:60: warning: Using plain integer as NULL pointer
      drivers/scsi/aha152x.c:3845:56: warning: Using plain integer as NULL pointer
      drivers/scsi/qla1280.c:2814:37: warning: Using plain integer as NULL pointer
      drivers/scsi/atp870u.c:750:47: warning: Using plain integer as NULL pointer
      drivers/scsi/3w-9xxx.c:1281:36: warning: Using plain integer as NULL pointer
      drivers/scsi/3w-9xxx.c:1293:36: warning: Using plain integer as NULL pointer
      drivers/scsi/3w-9xxx.c:1301:35: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:447:10: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:457:10: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:479:24: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:483:22: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:1213:23: warning: Using plain integer as NULL pointer
      drivers/scsi/hptiop.c:1214:23: warning: Using plain integer as NULL pointer
      Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9bcf0910
  19. 11 5月, 2008 2 次提交
    • J
      [SCSI] aha152x: Fix oops on module removal · 64976a03
      James Bottomley 提交于
      Reported-by: NFrank de Jong <frapex@xs4all.nl>
      > after trying to unload the module:
      > BUG: unable to handle kernel paging request at 00100100
      > IP: [<fb9ff667>] :aha152x:aha152x_exit+0x47/0x6a
      > *pde = 00000000
      > Oops: 0000 [#1] PREEMPT SMP
      > Modules linked in: aha152x(-) w83781d hwmon_vid tun ne 8390 bonding
      > usb_storage snd_usb_audio snd_usb_lib snd_rawmidi pwc snd_seq_device
      > compat_ioctl32 snd_hwdep videodev v4l1_compat 3c59x mii intel_agp
      > agpgart snd_pcm_oss snd_pcm snd_timer snd_page_alloc snd_mixer_oss snd
      >
      > Pid: 2837, comm: rmmod Not tainted (2.6.25.3 #1)
      > EIP: 0060:[<fb9ff667>] EFLAGS: 00210212 CPU: 0
      > EIP is at aha152x_exit+0x47/0x6a [aha152x]
      > EAX: 00000001 EBX: 000ffdc4 ECX: f7c517a8 EDX: 00000001
      > ESI: 00000000 EDI: 00000003 EBP: e7880000 ESP: e7881f58
      >   DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
      > Process rmmod (pid: 2837, ti=e7880000 task=f27eb580 task.ti=e7880000)
      > Stack: fba03700 c01419d2 31616861 00783235 e795ee70 c0157709 b7f24000 e79ae000
      >         c0158271 ffffffff b7f25000 e79ae004 e795e370 b7f25000 e795e37c e795e370
      >         009ae000 fba03700 00000880 e7881fa8 00000000 bf93ec20 bf93ec20 c0102faa
      > Call Trace:
      >   [<c01419d2>] sys_delete_module+0x112/0x1a0
      >   [<c0157709>] remove_vma+0x39/0x50
      >   [<c0158271>] do_munmap+0x181/0x1f0
      >   [<c0102faa>] sysenter_past_esp+0x5f/0x85
      >   [<c0490000>] rsc_parse+0x0/0x3c0
      
      The problem is that the driver calls aha152x_release() under a
      list_for_each_entry().  Unfortunately, aha152x_release() deletes from
      the list in question.  Fix this by using list_for_each_entry_safe().
      
      Cc: Stable Tree <stable@kernel.org>
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      64976a03
    • J
      [SCSI] aha152x: fix init suspiciously returned 1, it should follow 0/-E convention · ad2fa42d
      James Bottomley 提交于
      Reported-by: NFrank de Jong <frapex@xs4all.nl>
      > [1.] One line summary of the problem:
      > linux-2.6.25.3, aha152x'->init suspiciously returned 1, it should
      > follow 0/-E convention. The module / driver works okay. Unloading the
      > module is impossible.
      
      The driver is apparently returning 0 on failure and 1 on success.
      That's a bit unfortunate.  Fix it by altering to -ENODEV and 0.
      
      Cc: Stable Tree <stable@kernel.org>
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      ad2fa42d
  20. 29 4月, 2008 1 次提交
    • H
      scsi: fix integer as NULL pointer warnings · 172c122d
      Harvey Harrison 提交于
      drivers/scsi/aic7xxx/aic7770_osm.c:53:58: warning: Using plain integer as NULL pointer
      drivers/scsi/aic7xxx/aic7xxx_osm_pci.c:355:47: warning: Using plain integer as NULL pointer
      drivers/scsi/aic7xxx/aic7xxx_osm_pci.c:372:55: warning: Using plain integer as NULL pointer
      drivers/scsi/aha152x.c:997:28: warning: Using plain integer as NULL pointer
      drivers/scsi/aha152x.c:1003:28: warning: Using plain integer as NULL pointer
      drivers/scsi/aha152x.c:1165:46: warning: Using plain integer as NULL pointer
      drivers/scsi/fdomain.c:1446:40: warning: Using plain integer as NULL pointer
      drivers/scsi/sym53c8xx_2/sym_hipd.c:1650:51: warning: Using plain integer as NULL pointer
      drivers/scsi/sym53c8xx_2/sym_hipd.c:3171:42: warning: Using plain integer as NULL pointer
      drivers/scsi/sym53c8xx_2/sym_hipd.c:5732:52: warning: Using plain integer as NULL pointer
      drivers/scsi/ncr53c8xx.c:8189:31: warning: Using plain integer as NULL pointer
      drivers/scsi/ncr53c8xx.c:8225:34: warning: Using plain integer as NULL pointer
      drivers/scsi/dpt_i2o.c:156:32: warning: Using plain integer as NULL pointer
      drivers/scsi/ultrastor.c:954:42: warning: Using plain integer as NULL pointer
      drivers/scsi/ultrastor.c:1104:18: warning: Using plain integer as NULL pointer
      Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      172c122d
  21. 25 4月, 2008 1 次提交
    • J
      [SCSI] aha152x, eata, u14-34f: minor irq handler cleanups · e19166d5
      Jeff Garzik 提交于
      - remove pointless casts from void*
      
      - remove needless references to 'irq' function argument, when that
        information is already stored somewhere in a driver-private struct.
      
      - where the 'irq' function argument is known never to be used, rename
        it to 'dummy' to make this more obvious
      
      - remove always-false tests for dev_id==NULL
      
      - remove always-true tests for 'irq == host_struct->irq'
      
      - replace per-irq lookup functions and tables with a direct reference
        to data object obtained via 'dev_id' function argument, passed from
        request_irq()
      
      This change's main purpose is to prepare for the patchset in
      jgarzik/misc-2.6.git#irq-remove, that explores removal of the
      never-used 'irq' argument in each interrupt handler.
      Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
      e19166d5
  22. 12 1月, 2008 1 次提交
  23. 23 10月, 2007 1 次提交
  24. 20 10月, 2007 1 次提交
  25. 13 10月, 2007 1 次提交
  26. 04 8月, 2007 6 次提交
    • B
      [SCSI] aha152x: use data accessors and !use_sg cleanup · 2338545a
      Boaz Harrosh 提交于
      And finally this is the regular !use_sg cleanup
      and use of data accessors.
      Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      2338545a
    • B
      [SCSI] aha152x: Fix check_condition code-path · 45333ffa
      Boaz Harrosh 提交于
      check_condition code-path was similar but more
      complicated to Reset. It went like this:
      
        1. extra space was allocated at aha152x_scdata for mirroring
          scsi_cmnd members.
        2. At aha152x_internal_queue() every not check_condition
          (REQUEST_SENSE) command was copied to above members in
          case of error.
        3. At busfree_run() in the DONE_CS phase if a Status of
          SAM_STAT_CHECK_CONDITION was detected. The command was
          re-queued Internally using aha152x_internal_queue(,,check_condition,)
          The old command members are over written with the
          REQUEST_SENSE info.
        4. At busfree_run() in the DONE_CS phase again. If it is a
          check_condition command, info was restored from mirror
          made at first call to aha152x_internal_queue() (see 2)
          and the command is completed.
      
      What I did is:
      
        1. Allocate less space in aha152x_scdata only for the 16-byte
          original command. (which is actually not needed by scsi-ml
          anymore at this stage. But this is to much knowledge of scsi-ml)
        2. If Status == SAM_STAT_CHECK_CONDITION, then like before
           re-queue a REQUEST_SENSE command. But only now save original
           command members. (Less of them)
        3. In aha152x_internal_queue(), just like for Reset, use the
          check_condition hint to set differently the working members.
          execute the command.
        4. At busfree_run() in the DONE_CS phase again. restore needed
           members.
      
      While at it. This patch fixes a BUG. Old code when sending
      a REQUEST_SENSE for a failed command. Would than return with
      cmd->resid == 0 which was the status of the REQUEST_SENSE.
      The failing command resid was lost. And when would resid
      be interesting if not on a failing command?
      Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      45333ffa
    • B
      [SCSI] aha152x: Clean Reset path · 66acdb03
      Boaz Harrosh 提交于
      What Reset code was doing:  Save command's important/dangerous
      Info on stack. NULL those members from scsi_cmnd.
      Issue a Reset. wait for it to finish than restore members
      and return.
      
      What I do is save or NULL nothing. But use the "resetting"
      hint in aha152x_internal_queue() to NULL out working members
      and leave struct scsi_cmnd alone.
      
      The indent here looks funny but it will change/drop in last
      patch and it is clear this way what changed.
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      66acdb03
    • B
      [SCSI] aha152x: preliminary fixes and some comments · 0ceb4798
      Boaz Harrosh 提交于
        hunk by hunk:
        - CHECK_CONDITION is what happens to cmnd->status >> 1
          or after status_byte() macro. But here it is used
          directly on status which means 0x1 which is an undefined
          bit in the standard. And is a status that will never
          return from a target.
      
        - in busfree_run at the DONE_SC phase we have 3 distinct
          operation:
      	1-if(DONE_SC->SCp.phase & check_condition)
                The REQUEST_SENSE command return.
                - Restore original command
      	  - Than continue to operation 3.
      	2-if(DONE_SC->SCp.Status==SAM_STAT_CHECK_CONDITION)
                A regular command returned with a status.
      	  - Internally re-Q a REQUEST_SENSE.
      	  - Do not do operation 3.
      	3-
      	  - Complete the command and return it to scsi-ml
           So the 0x2 in both these operations (1,2) means the scsi
           check-condition status, hence SAM_STAT_CHECK_CONDITION
      
        - Here the code asks about !(DONE_SC->SCp.Status & not_issued)
          but "not_issued" is an enum belonging to the "phase" member
          and not to the Status returned from target. The reason this
          works is because not_issued==1 and Also CHECK_CONDITION==1
          (remember from hunk 1). So actually the code was asking
          !(DONE_SC->SCp.Status & CHECK_CONDITION). Which means
          "Has the status been read from target yet?"
          Staus is read at status_run(). "not_issued" is
          cleared in seldo_run() which is usually earlier than
          status_run().
      
        So this patch does nothing as far as assembly is concerned
        but it does let the reader understand what is going on.
      Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      0ceb4798
    • B
      [SCSI] aha152x: use bounce buffer · b1ee0795
      Boaz Harrosh 提交于
      Cause highmem buffers to be bounced to low memory until this
      driver supports highmem addresses.  Otherwise it just oopses
      on NULL buffer addresses.
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      b1ee0795
    • B
      [SCSI] aha152x: fix debug mode symbol conflict · 50535df3
      Boaz Harrosh 提交于
      The symbol <debug_locks> conflicts with the rather global one in
      include/linux/locks.h.
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
      Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
      50535df3
  27. 22 5月, 2007 1 次提交
  28. 15 2月, 2007 1 次提交
    • T
      [PATCH] remove many unneeded #includes of sched.h · cd354f1a
      Tim Schmielau 提交于
      After Al Viro (finally) succeeded in removing the sched.h #include in module.h
      recently, it makes sense again to remove other superfluous sched.h includes.
      There are quite a lot of files which include it but don't actually need
      anything defined in there.  Presumably these includes were once needed for
      macros that used to live in sched.h, but moved to other header files in the
      course of cleaning it up.
      
      To ease the pain, this time I did not fiddle with any header files and only
      removed #includes from .c-files, which tend to cause less trouble.
      
      Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
      arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
      allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
      configs in arch/arm/configs on arm.  I also checked that no new warnings were
      introduced by the patch (actually, some warnings are removed that were emitted
      by unnecessarily included header files).
      Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
      Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cd354f1a
  29. 22 11月, 2006 1 次提交
  30. 12 10月, 2006 1 次提交
  31. 07 10月, 2006 1 次提交
    • J
      Various drivers' irq handlers: kill dead code, needless casts · c7bec5ab
      Jeff Garzik 提交于
      - Eliminate casts to/from void*
      
      - Eliminate checks for conditions that never occur.  These typically
        fall into two classes:
      
      	1) Checking for 'dev_id == NULL', then it is never called with
      	NULL as an argument.
      
      	2) Checking for invalid irq number, when the only caller (the
      	system) guarantees the irq handler is called with the proper
      	'irq' number argument.
      Signed-off-by: NJeff Garzik <jeff@garzik.org>
      c7bec5ab
  32. 05 10月, 2006 1 次提交
    • D
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      David Howells 提交于
      Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
      of passing regs around manually through all ~1800 interrupt handlers in the
      Linux kernel.
      
      The regs pointer is used in few places, but it potentially costs both stack
      space and code to pass it around.  On the FRV arch, removing the regs parameter
      from all the genirq function results in a 20% speed up of the IRQ exit path
      (ie: from leaving timer_interrupt() to leaving do_IRQ()).
      
      Where appropriate, an arch may override the generic storage facility and do
      something different with the variable.  On FRV, for instance, the address is
      maintained in GR28 at all times inside the kernel as part of general exception
      handling.
      
      Having looked over the code, it appears that the parameter may be handed down
      through up to twenty or so layers of functions.  Consider a USB character
      device attached to a USB hub, attached to a USB controller that posts its
      interrupts through a cascaded auxiliary interrupt controller.  A character
      device driver may want to pass regs to the sysrq handler through the input
      layer which adds another few layers of parameter passing.
      
      I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
      main part of the code on FRV and i386, though I can't test most of the drivers.
      I've also done partial conversion for powerpc and MIPS - these at least compile
      with minimal configurations.
      
      This will affect all archs.  Mostly the changes should be relatively easy.
      Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
      
      	struct pt_regs *old_regs = set_irq_regs(regs);
      
      And put the old one back at the end:
      
      	set_irq_regs(old_regs);
      
      Don't pass regs through to generic_handle_irq() or __do_IRQ().
      
      In timer_interrupt(), this sort of change will be necessary:
      
      	-	update_process_times(user_mode(regs));
      	-	profile_tick(CPU_PROFILING, regs);
      	+	update_process_times(user_mode(get_irq_regs()));
      	+	profile_tick(CPU_PROFILING);
      
      I'd like to move update_process_times()'s use of get_irq_regs() into itself,
      except that i386, alone of the archs, uses something other than user_mode().
      
      Some notes on the interrupt handling in the drivers:
      
       (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
           the input_dev struct.
      
       (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
           something different depending on whether it's been supplied with a regs
           pointer or not.
      
       (*) Various IRQ handler function pointers have been moved to type
           irq_handler_t.
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  33. 24 9月, 2006 1 次提交