linux/arch
Ohad Ben-Cohen c3c1250e93 hwspinlock/core/omap: fix id issues on multiple hwspinlock devices
hwspinlock devices provide system-wide hardware locks that are used
by remote processors that have no other way to achieve synchronization.

To achieve that, each physical lock must have a system-wide id number
that is agreed upon, otherwise remote processors can't possibly assume
they're using the same hardware lock.

Usually boards have a single hwspinlock device, which provides several
hwspinlocks, and in this case, they can be trivially numbered 0 to
(num-of-locks - 1).

In case boards have several hwspinlocks devices, a different base id
should be used for each hwspinlock device (they can't all use 0 as
a starting id!).

While this is certainly not common, it's just plain wrong to just
silently use 0 as a base id whenever the hwspinlock driver is probed.

This patch provides a hwspinlock_pdata structure, that boards can use
to set a different base id for each of the hwspinlock devices they may
have, and demonstrates how to use it with the omap hwspinlock driver.

While we're at it, make sure the hwspinlock core prints an explicit
error message in case an hwspinlock is registered with an id number
that already exists; this will help users catch such base id issues.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2011-09-21 19:45:32 +03:00
..
alpha All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
arm hwspinlock/core/omap: fix id issues on multiple hwspinlock devices 2011-09-21 19:45:32 +03:00
avr32 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
blackfin All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
cris All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
frv All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
h8300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
ia64 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
m32r All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
m68k All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
microblaze All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mips All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
mn10300 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
openrisc Add missing DMA ops 2011-09-11 09:50:39 +02:00
parisc remove remaining references to nfsservctl 2011-08-29 16:31:59 -07:00
powerpc Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2011-08-31 08:58:36 -07:00
s390 All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
score modules: make arch's use default loader hooks 2011-07-24 22:06:04 +09:30
sh Merge branch 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-3.x 2011-08-29 13:34:48 -07:00
sparc sparc64: Only Panther cheetah+ chips have POPC. 2011-08-29 21:14:29 -07:00
tile Merge branch 'apei-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2011-08-03 21:53:27 -10:00
um ptrace: unify show_regs() prototype 2011-07-26 16:49:43 -07:00
unicore32 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 2011-07-29 23:35:05 -07:00
x86 Fix pointer dereference before call to pcie_bus_configure_settings 2011-09-09 19:49:58 -07:00
xtensa All Arch: remove linkage for sys_nfsservctl system call 2011-08-26 15:09:58 -07:00
.gitignore
Kconfig Add Kconfig option ARCH_HAVE_NMI_SAFE_CMPXCHG 2011-08-03 11:12:37 -04:00