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: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
A negative offset could be used to index before the event buffer and
lead to a security breach.
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32)
Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace all DMA_64BIT_MASK macro with DMA_BIT_MASK(64)
Signed-off-by: Yang Hongyang<yanghy@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PCI side of driver should be devinit, not init
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now SCSI and others do their own command timeout handling.
Move those bits to the block layer.
Instead of having a timer per command, we try to be a bit more clever
and simply have one per-queue. This avoids the overhead of having to
tear down and setup a timer for each command, so it will result in a lot
less timer fiddling.
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This message appears on modprobe/rmmod/modprobe of the driver. It's
caused because if the driver has no instances, it returns an error
from gdth_init, which causes the module to fail to load.
Unfortunately, the module's pci driver is still registered at this
point.
Fix this by making gdth behave like a modern driver and insert even if
it doesn't find any instances (in case of hot plug or software driven
binding).
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The global timer handling is problematic in that if someone unbinds a
PCI gdth instance, the BUG_ON() in the timer will cause a panic.
Fix this by making the timer start and stop depending on whether there
are instances present. This should also permit binding and unbinding
to work.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- struct scsi_cmnd had a 16 bytes command buffer of its own.
This is an unnecessary duplication and copy of request's
cmd. It is probably left overs from the time that scsi_cmnd
could function without a request attached. So clean that up.
- Once above is done, few places, apart from scsi-ml, needed
adjustments due to changing the data type of scsi_cmnd->cmnd.
- Lots of drivers still use MAX_COMMAND_SIZE. So I have left
that #define but equate it to BLK_MAX_CDB. The way I see it
and is reflected in the patch below is.
MAX_COMMAND_SIZE - means: The longest fixed-length (*) SCSI CDB
as per the SCSI standard and is not related
to the implementation.
BLK_MAX_CDB. - The allocated space at the request level
- I have audit all ISA drivers and made sure none use ->cmnd in a DMA
Operation. Same audit was done by Andi Kleen.
(*)fixed-length here means commands that their size can be determined
by their opcode and the CDB does not carry a length specifier, (unlike
the VARIABLE_LENGTH_CMD(0x7f) command). This is actually not exactly
true and the SCSI standard also defines extended commands and
vendor specific commands that can be bigger than 16 bytes. The kernel
will support these using the same infrastructure used for VARLEN CDB's.
So in effect MAX_COMMAND_SIZE means the maximum size command
scsi-ml supports without specifying a cmd_len by ULD's
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
These are no longer necessary.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Joerg Dorchain: <joerg@dorchain.net>
Tested-by: Stefan Priebe <s.priebe@allied-internet.ag>
Tested-by: Jon Chelton <jchelton@ffpglobal.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- remove PCI device sort, which greatly simplifies PCI probe,
permitting direct, per-HBA function calls rather than an indirect
route to the same end result.
- remove need for pcistr[]
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
- Reduce uses of gdth_pci_str::pdev, preferring a local variable
(or function arg) 'pdev' instead.
- Reduce uses of gdth_pcistr array, preferring local variable
(or function arg) 'pcistr' instead.
- Eliminate lone use of gdth_pci_str::irq, using equivalent
pdev->irq instead
- Eliminate assign-only gdth_pci_str::io_mm
Note: If the indentation seems weird, that's because a line was
converted from spaces to tabs, when it was modified.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fix NULL pointer dereference during execution of Internal commands,
where gdth only allocates scp, but not scp->sense_buffer. The rest of
the code assumes that sense_buffer is allocated, which leads to a kernel
oops e.g. on reboot (during cache flush).
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The recent patch named:
[SCSI] gdth: !use_sg cleanup and use of scsi accessors
has done a bad job in handling internal commands issued by gdth_execute().
Internal commands are issued with device gdth_cmd_str ready made directly
to the card, without any mapping or translations of scsi commands. So here
I added a gdth_cmd_str pointer to the gdth_cmndinfo private structure which
is then copied directly to host.
following this patch is a cleanup that removes the home cooked accessors
and reverts them to regular scsi_cmnd accessors. Since they are not used
anymore. After review maybe the 2 patches should be squashed together.
FIXME: There is still a problem with gdth_get_info(). as reported there
is a WARN_ON trigerd in dma_free_coherent() when doing:
$ cat /proc/sys/gdth/0
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Joerg Dorchain: <joerg@dorchain.net>
Tested-by: Stefan Priebe <s.priebe@allied-internet.ag>
Tested-by: Jon Chelton <jchelton@ffpglobal.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
gdth_exit would first remove all cards then stop the timer
and would not sync with the timer function. This caused a crash
in gdth_timer() when module was unloaded.
So del_timer_sync the timer before we delete the cards.
also the reboot notifier function would crash. So clean
that up and fix the crashes.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Joerg Dorchain: <joerg@dorchain.net>
Tested-by: Stefan Priebe <s.priebe@allied-internet.ag>
Tested-by: Jon Chelton <jchelton@ffpglobal.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fix compilation warning in gdth.c, which was using the deprecated
pci_find_device.
drivers/scsi/gdth.c:645: warning: 'pci_find_device' is deprecated (declared at include/linux/pci.h:495)
Changing it to use pci_get_device, instead.
Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
The patch: "gdth: switch to modern scsi host registration"
missed one simple fact when moving a way from scsi_module.c.
That is to call scsi_scan_host() on the probed host.
With this the gdth driver from 2.6.24 is again able to
see drives and boot.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Joerg Dorchain <joerg@dorchain.net>
Tested-by: Stefan Priebe <s.priebe@allied-internet.ag>
Tested-by: Jon Chelton <jchelton@ffpglobal.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Neither gdth_get_status() nor __gdth_interrupt() need their 'irq' argument,
so remove it.
[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
This patch fixes the following build warnings:
WARNING: vmlinux.o(.text+0xbcffdb): Section mismatch: reference to .init.text.20:gdth_search_drives (between 'gdth_pci_probe_one' and 'gdth_start_timeout')
WARNING: vmlinux.o(.text+0xbd0102): Section mismatch: reference to .init.text.20:gdth_enable_int (between 'gdth_pci_probe_one' and 'gdth_start_timeout')
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
If the gdth module is loaded (or compiled in), the gdth_timeout function
gets started even if no actual gdth controllers are found b the probing.
That ends up not only being unnecessary, but also causes a crash due to
the function blindly just trying to pick the first entry off the
"gdth_instances" list, and accessing it - which obviously doesn't work
if the list is empty!
Noticed by Ingo Molnar.
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/scsi/gdth.c: In function ‘gdth_search_dev’:
drivers/scsi/gdth.c:646: warning: ‘pci_find_device’ is deprecated
(declared at include/linux/pci.h:482)
drivers/scsi/gdth.c: In function ‘gdth_init_isa’:
drivers/scsi/gdth.c:857: error: ‘gdth_irq_tab’ undeclared (first use in
this function)
drivers/scsi/gdth.c:857: error: (Each undeclared identifier is reported
only once
drivers/scsi/gdth.c:857: error: for each function it appears in.)
drivers/scsi/gdth.c: In function ‘gdth_copy_internal_data’:
drivers/scsi/gdth.c:2362: warning: unused variable ‘sg’
Looking into the code I notice that gdth_irq_tab is not declared with
CONFIG_ISA=y and !CONFIG_EISA.
The values seem to be same in 2.6.23 (I am not sure why it has been put
with #ifdefs in -mm) so I have just modified the #ifdef to take care of
CONFIG_ISA as well.
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
gdth_execute() will issue an internal, none scsi-standard commands
onto __gdth_queuecommand(). Since it is not recommended to set
struct scsi_cmnd IO members in llds, gdth now uses internal IO
members for IO. In the case of gdth_execute() these members will be
set properly. In case the command was issued from scsi-ml
(by gdth_queuecommand) they will be set from scsi IO accessors.
* define gdth IO accessors and use them throughout the driver.
* use an sg-of-one in gdth_execute() and fix gdth_special_cmd()
accordingly.
* Clean the not use_sg code path and company
Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Cleanup the rest of the scsi_cmnd->SCp members and move them
to gdth_cmndinfo:
SCp.this_residual => priority
SCp.buffers_residual => timeout
SCp.Status => status and dma_dir
SCp.Message => info
SCp.have_data_in => volatile wait_for_completion
SCp.sent_command => OpCode
SCp.phase => phase
- Two more members will be naturally removed in the !use_sg cleanup
TODO: What is the meaning of gdth_cmndinfo.phase? (rhetorically)
Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- scsi_cmnd and specifically ->SCp of, where heavily abused
with internal meaning members and flags. So introduce a new
struct gdth_cmndinfo, put it on ->host_scribble and define a
gdth_cmnd_priv() accessor to retrieve it from a scsi_cmnd.
- The structure now holds two members:
internal_command - replaces the IS_GDTH_INTERNAL_CMD() croft.
sense_paddr - which was a 64-bit spanning on 2 32-bit members of SCp.
More overloaded members from SCp and scsi_cmnd will be moved in a later
patch (For easy review).
- Split up gdth_queuecommand to an additional internal_function. The later
is the one called by gdth_execute(). This will be more evident later in
the scsi accessors patch, but it also facilitates in the differentiation
between internal_command and external. And the setup of gdth_cmndinfo of
each command.
Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Places like Initialization and Reset that Just loop on all devices can
use the link list with the list_for_each_entry macro.
But the io_ctrl from user mode now suffers performance-wise because
code has to do a sequential search for the requested host number.
I have isolated this search in a gdth_find_ha(int hanum) member
for future enhancement if needed.
Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Use scsi_add_host and friends and track instances ourselves. And
generally modernize the driver's structure.
- TODO: Next we can remove the controller table
- TODO: Fix use of deprecated pci_find_device()
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- gdth_get_status() returns a single device interrupt IStatus
- gdth_interrupt split to __gdth_interrupt() that receives
flags if is called from gdth_wait().
- Use dev_id passed from kernel and do not loop on all
controllers.
- gdth_wait(), get read of all global variables and call the new
__gdth_interrupt with these variables on the stack
Signed-off-by Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Based on same patch from Christoph Hellwig <hch@lst.de>
- Get rid of all the indirection in the Scsi_Host private data and always
put the gdth_ha_str directly into it.
- Change all internal functions prototype to recieve an "gdth_ha_str *ha"
pointer directlly and kill all that redundent access to the "gdth_ctr_tab[]"
controller-table.
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The virt_ctr option allows to register a new scsi_host for each bus
on the raid controller. This non-default option makes no sense with
the current scsi code and prevents cleaning up the host registration,
so remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
shuffle scsi_host_template members such that they appear in the
order in which they are defined in the header. this makes is easier
to verify when initializers are missing members.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
They are direct equivalents to {read,write}[bwl].
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
* Remove in-source changelog. It's archived permanently in git and
various kernel archives, and changelogs should exist purely in git.
* Remove 2.4.x kernel support. It is an active obstacle to
modernizing this driver, at this point. This includes killing
gdth_kcompat.h which is 100% redundant in modern kernels.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Split out per-device pci probing and put it under proper CONFIG_PCI.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Split eisa probing into it's own helper, and do proper error unwinding.
Protect EISA probind by the proper CONFIG_EISA symbol.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
(note: this is ontop of Jeff's pci cleanup patch)
Split out isa probing into a helper of it's own. Error handling is
cleaned up, but errors are not propagated yet. Also enclose the isa
probe under the proper CONFIG_ISA symbol instead of the !IA64 hack.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Rather than having internal commands abuse scsi_done to call
gdth_scsi_done, have all the places that use to call scsi_done directly
call gdth_scsi_done, which now checks whether the command was internal,
and calls scsi_done if not.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
The ->done member was being used to mark commands as being internal.
I decided to put a magic number in ->underflow instead. I believe this
to be safe as no current user of ->underflow has any of the bottom 9
bits set.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This patch
* removes struct members that duplicate pci_dev members
* replaces ha->stype usage with ha->pdev->device usage where feasible
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Achim Leubner <Achim_Leubner@adaptec.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Fix misspelled "spin_lock_irqrestore" to read "spin_unlock_irqrestore"
instead.
Presumably, GDTH_RTC doesn't get used a lot.
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Achim Leubner <achim_leubner@adaptec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Labeling a variable as __attribute_used__ is ambiguous: it means
__attribute__((unused)) for gcc <3.4 and __attribute__((used)) for gcc >=3.4.
There is no such thing as labeling a variable as __attribute__((used)). We
assume that we're simply suppressing a warning here if gdthtable[] is declared
but unreferenced.
Acked-by: Achim Leubner <achim_leubner@adaptec.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Recent alterations to the gdth_fill_raw_cmd() path no longer set the
sg_ranz field for zero transfer commands. However, this field is used
lower down in the function to initialise ha->cmd_len to the size of
the firmware packet. If this uninitialised field contains a bogus
value, ha->cmd_len can become much larger than the actual firmware
packet and end up oopsing in gdth_copy_cmd() as it tries to copy this
huge packet to the device (usually because it runs into an unallocated
page).
The fix is to initialise the sg_ranz field to zero at the start of
gdth_fill_raw_cmd().
Signed-off-by: Joerg Dorchain <joerg@dorchain.net>
Acked-by: "Leubner, Achim" <Achim_Leubner@adaptec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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: Tim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix uses of "&&" where "&" was obviously intended instead.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
