Commit Graph

10 Commits

Author SHA1 Message Date
Gustavo A. R. Silva fadbfc38dd hpilo: Replace one-element array with flexible-array member
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

For this particular case, it is important to notice that the cachelines
change from 7 to 6 after the flexible-array conversion:

$ pahole -C 'fifo' drivers/misc/hpilo.o
struct fifo {
	u64                        nrents;               /*     0     8 */
	u64                        imask;                /*     8     8 */
	u64                        merge;                /*    16     8 */
	u64                        reset;                /*    24     8 */
	u8                         pad_0[96];            /*    32    96 */
	/* --- cacheline 2 boundary (128 bytes) --- */
	u64                        head;                 /*   128     8 */
	u8                         pad_1[120];           /*   136   120 */
	/* --- cacheline 4 boundary (256 bytes) --- */
	u64                        tail;                 /*   256     8 */
	u8                         pad_2[120];           /*   264   120 */
	/* --- cacheline 6 boundary (384 bytes) --- */
	u64                        fifobar[1];           /*   384     8 */

	/* size: 392, cachelines: 7, members: 10 */
	/* last cacheline: 8 bytes */
};

$ pahole -C 'fifo' drivers/misc/hpilo.o
struct fifo {
	u64                        nrents;               /*     0     8 */
	u64                        imask;                /*     8     8 */
	u64                        merge;                /*    16     8 */
	u64                        reset;                /*    24     8 */
	u8                         pad_0[96];            /*    32    96 */
	/* --- cacheline 2 boundary (128 bytes) --- */
	u64                        head;                 /*   128     8 */
	u8                         pad_1[120];           /*   136   120 */
	/* --- cacheline 4 boundary (256 bytes) --- */
	u64                        tail;                 /*   256     8 */
	u8                         pad_2[120];           /*   264   120 */
	/* --- cacheline 6 boundary (384 bytes) --- */
	u64                        fifobar[];            /*   384     0 */

	/* size: 384, cachelines: 6, members: 10 */
};

Lastly, remove unnecessary parentheses in fifo_sz() and fix the following
checkpatch.pl warning for the whole fifo structure:

WARNING: please, no spaces at the start of a line

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/79

Tested-by: kernel test robot <lkp@intel.com>
Link: https://github.com/GustavoARSilva/linux-hardening/blob/master/cii/kernel-ci/hpilo-20200714.md
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200714154449.GA26153@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-14 18:21:25 +02:00
Nishad Kamdar 40688bd58d misc: Use the correct style for SPDX License Identifier
This patch corrects the SPDX License Identifier style
in header files for Miscellaneous device drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Link: https://lore.kernel.org/r/20190920155931.GA6251@nishad
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10 15:34:40 +02:00
Dhaval Shah 92d5f4ca47 misc: hpilo: Use SPDX-License-Identifier
SPDX-License-Identifier is used for the hpilo.

Signed-off-by: Dhaval Shah <dhaval.experiance@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-07 18:45:31 +01:00
Camuso, Tony 98dcd59dd0 misc: hpilo: increase number of max supported channels
Increase number of supported channels from 8 to 24.
Make the number of channels configurable via module parameter max_ccb.

Signed-off-by: Mark Rusk <mark.rusk@hp.com>
Signed-off-by: Tony Camuso <tony.camuso@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-14 17:22:12 -07:00
Prarit Bhargava cdf8afca24 hpilo: fix pointer warning in ilo_ccb_setup
Fix i386 PAE compile warning:

drivers/misc/hpilo.c: In function `ilo_ccb_setup':
drivers/misc/hpilo.c:274: warning: cast to pointer from integer of different size

dma_addr_t is 64 on i386 PAE which causes a size mismatch.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09 20:45:05 -07:00
David Altobelli 68ea809af4 hpilo: add locking comment
Add explanation about lock nesting and purpose of each lock in hpilo.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11 11:24:51 -08:00
David Altobelli 9f70484121 hpilo: add interrupt handler
Add interrupt handler to hpilo.  This is enablement for poll handler,
and it also simplifies the logic for handling an iLO reset, because now
only the interrupt handler needs to look for reset, the file system
interfaces only need to return failure when a reset has happened.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15 09:50:48 -07:00
David Altobelli 891f7d73ea hpilo: reduce frequency of IO operations
Change hpilo open and close logic to spin for 10usec between checking device,
rather than every usec.

Because the loop is coded to take up to 10ms, it seemed prudent to
increase the interval between polling the device, to reduce the load on
the system and allow more other work to happen.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:18 -07:00
David Altobelli c073b2db00 hpilo: open/close fix
The device can take a while to respond to an open/close request, so
increase the time kernel will wait for response (1 ms to 10ms).

Also, properly clean up a channel on a failed open, by calling the channel
close routine.  Just freeing the memory isn't sufficient, the device needs
to be informed that the channel is no longer open, and the device memory
cleared of references to freed dma buffer.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-05 12:56:46 -08:00
David Altobelli 89bcb05d9b HP iLO driver
A driver for the HP iLO/iLO2 management processor, which allows userspace
programs to query the management processor.  Programs can open a channel
to the device (/dev/hpilo/dXccbN), and use this to send/receive queries.  
The O_EXCL open flag is used to indicate that a particular channel cannot
be shared between processes.  This driver will replace various packages
HP has shipped, including hprsm and hp-ilo.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-21 21:55:02 -07:00