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: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Note that if scsi_bufflen(cmd) is not zero, the command always has an
sg list. So this patch doesn't do the error checking in
fill_from_dev_buffer and fetch_to_dev_buffer did.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Looks-OK-to: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
As we no longer need to calculate the data length of the whole scatterlist,
we can abort the loop earlier and coalesce req_len and act_len into one
variable, making fill_from_dev_buffer() more similar to fetch_to_dev_buffer().
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
ps3rom does:
scsi_for_each_sg(cmd, sgpnt, scsi_sg_count(cmd), k) {
kaddr = kmap_atomic(sg_page(sgpnt), KM_IRQ0);
We cannot do something like that with the clustering enabled (or we
can use scsi_kmap_atomic_sg).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
sg driver rounds up the length in struct scatterlist to be a multiple
of 512 in some conditions. So LLDs can't use the data length in a sg
list to calculate residual. Instead, the length in struct scsi_cmnd
should be used.
[Geert: the variable buflen already contains scsi_bufflen(cmd)]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
It should be desired that 64 KiB is available for ATAPI transferrring.
(Historically) in SCSI/block layer sector size is defined as 512 during
sector-byte calculation.
Originally in ps3rom.c CD_FRAMESIZE (2048) was used, which limited
/sys/block/sr0/queue/max_sectors_kb to 16 KiB (32 sectors).
Signed-off-by: Aegis Lin <aegislin@gmail.com>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Fix fallout from 18dabf473e15850c0dbc8ff13ac1e2806d542c15:
In file included from include/linux/dma-mapping.h:52,
from drivers/base/dma-mapping.c:10:
include/asm/dma-mapping.h: In function 'dma_map_sg':
include/asm/dma-mapping.h:288: error: 'struct scatterlist' has no member named 'page'
include/asm/dma-mapping.h:288: error: 'struct scatterlist' has no member named 'page'
include/asm/dma-mapping.h:288: error: 'struct scatterlist' has no member named 'page'
include/asm/dma-mapping.h:289: error: 'struct scatterlist' has no member named 'page'
include/asm/dma-mapping.h:290: error: 'struct scatterlist' has no member named 'page'
include/asm/dma-mapping.h: In function 'dma_sync_sg_for_cpu':
include/asm/dma-mapping.h:331: error: 'struct scatterlist' has no member named 'page'
drivers/scsi/ps3rom.c: In function 'fetch_to_dev_buffer':
drivers/scsi/ps3rom.c:150: error: 'struct scatterlist' has no member named 'page'
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This converts ps3rom driver to use the new accessors for the sg lists
and the parameters.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Add a BD/DVD/CD-ROM Storage Driver for the PS3:
- Implemented as a SCSI device driver
- Uses software scatter-gather with a 64 KiB bounce buffer as the hypervisor
doesn't support scatter-gather
Cc: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jeff Garzik
Tejun Heo
Geert Uytterhoeven
Stephen Rothwell
FUJITA Tomonori
Aegis Lin
Olof Johansson
Jens Axboe