The return here doesn't release the locks or re-enable IRQs. But as
Andrew Morton points out, domain is never NULL. list_first_entry()
essentially never returns NULL and also we already verified that the list
is not empty.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Direct Cache Access is not supported on IOAT ver.3.0 multiple-IOH platforms.
This patch blocks registering of dca providers when multiple IOH detected with IOAT ver.3.0.
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
The message (if it must exist) should not be an error message.
IMHO such messages are useless.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This patch enables DCA support on multiple-IOH/multiple-IIO architectures.
It modifies dca module by replacing single dca_providers list
with dca_domains list, each domain containing separate list of providers.
This approach lets dca driver manage multiple domains, i.e. sets of providers
and requesters mapped back to the same PCI root complex device.
The driver takes care to register each requester to a provider
from the same domain.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Together with new fixes update driver version
and extend copyright dates ranges.
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Change spin_locks to irqsave to prevent dead-locks.
Protect adding and deleting to/from dca_providers list.
Drop the lock during dca_sysfs_add_req() and dca_sysfs_remove_req() calls
as they might sleep (use GFP_KERNEL allocation).
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are dmaengine users that would like to register dma devices at
subsys_initcall time to ensure channels are available by device_initcall
time.
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Mark dca_init as a subsys_initcall since it needs to be ready to go
before dependent drivers start registering themselves.
Cc: <stable@kernel.org>
Reported-and-tested-by: Mark Rustad <mark_rustad@Xiotech.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds to ioatdma and dca modules
support for Intel I/OAT DMA engine ver.3 (aka CB3 device).
The main features of I/OAT ver.3 are:
* 8 single channel DMA devices (8 channels total)
* 8 DCA providers, each can accept 2 requesters
* 8-bit TAG values and 32-bit extended APIC IDs
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Direct Cache Access (DCA) is a method for warming the CPU cache before data
is used, with the intent of lessening the impact of cache misses. This
patch adds a manager and interface for matching up client requests for DCA
services with devices that offer DCA services.
In order to use DCA, a module must do bus writes with the appropriate tag
bits set to trigger a cache read for a specific CPU. However, different
CPUs and chipsets can require different sets of tag bits, and the methods
for determining the correct bits may be simple hardcoding or may be a
hardware specific magic incantation. This interface is a way for DCA
clients to find the correct tag bits for the targeted CPU without needing
to know the specifics.
[Dave Miller] use DEFINE_SPINLOCK()
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
