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)
Typedef the IRQ handler function type.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1356d1e5fd256997e3d3dce0777ab787d0515c7a commit)
Typedef the IRQ flow handler function type.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 8e973fbdf5716b93a0a8c0365be33a31ca0fa351 commit)
There is a bug in the current version of the itmtouch USB touchscreen
driver. The if statment that checks if pressure is being applied to the
touch screen is now missing a ! (not), so events are no longer being
reported correctly.
The original source code for this line was as follows:
#define UCP(x) ((unsigned char*)(x))
#define UCOM(x,y,z) ((UCP((x)->transfer_buffer)[y]) & (z))
...
if (!UCOM(urb, 7, 0x20)) {
And was cleaned to:
unsigned char *data = urb->transfer_buffer;
....
if (data[7] & 0x20) {
(note the lack of '!')
This has been tested on an LG L1510BF and an LG1510SF touch screen.
Signed-off-by: Mark Assad <massad@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
[POWERPC] cell: fix bugs found by sparse
[POWERPC] spiderpic: enable new style devtree support
[POWERPC] Update cell_defconfig
[POWERPC] spufs: add infrastructure for finding elf objects
[POWERPC] spufs: support new OF device tree format
[POWERPC] spufs: add support for read/write on cntl
[POWERPC] spufs: remove support for ancient firmware
[POWERPC] spufs: make mailbox functions handle multiple elements
[POWERPC] spufs: use correct pg_prot for mapping SPU local store
[POWERPC] spufs: Add infrastructure needed for gang scheduling
[POWERPC] spufs: implement error event delivery to user space
[POWERPC] spufs: fix context switch during page fault
[POWERPC] spufs: scheduler support for NUMA.
[POWERPC] spufs: cell spu problem state mapping updates
do_timer now wants to know how many ticks have elapsed. Now that we
have to calculate that, we can eliminate some of the clever code that
avoided having to calculate that. Also add some more documentation.
I'd like to thank Grant Grundler for helping me with this.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Panic if we can't register the parisc bus or the root parisc device.
There's no way we can boot without them, so let the user know ASAP.
If we can't register a parisc device, handle the failure gracefully.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
The utsname virtualisation broke parisc_newuname compilation.
Rewrite the implementation to call sys_newuname() like sparc64 does.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
max() doesn't like comparing an unsigned long and a resource_size_t,
so make the local variables resource_size_t too.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
When CONFIG_SYSCTL_SYSCALL isn't defined, do_sysctl doesn't exist and
we fail to link. Fix with an ifdef, the same way sparc64 did.
Also add some minor changes to be more like sparc64.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
- Some long constants should be marked 'ul'.
- When using desc->handler_data to pass an __iomem
register area, we need to add casts to and from
__iomem.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This enables support for new firmware test releases.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds defaults for new configuration options added since
2.6.18 and it enables the option for 64kb pages by default.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This adds an 'object-id' file that the spe library can
use to store a pointer to its ELF object. This was
originally meant for use by oprofile, but is now
also used by the GNU debugger, if available.
In order for oprofile to find the location in an spu-elf
binary where an event counter triggered, we need a way
to identify the binary in the first place.
Unfortunately, that binary itself can be embedded in a
powerpc ELF binary. Since we can assume it is mapped into
the effective address space of the running process,
have that one write the pointer value into a new spufs
file.
When a context switch occurs, pass the user value to
the profiler so that can look at the mapped file (with
some care).
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The properties we used traditionally in the device tree are somewhat
nonstandard. This adds support for a more conventional format using
'interrupts' and 'reg' properties.
The interrupts are specified in three cells (class 0, 1 and 2) and
registered at the interrupt-parent.
The reg property contains either three or four register areas in the
order 'local-store', 'problem', 'priv2', and 'priv1', so the priv1 one
can be left out in case of hypervisor driven systems that access these
through hcalls.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Writing to cntl can be used to stop execution on the
spu and to restart it, reading from cntl gives the
contents of the current status register.
The access is always in ascii, as for most other files.
This was always meant to be there, but we had a little
problem with writing to runctl so it was left out so
far.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Any firmware that still uses the 'spc' nodes already
stopped running for other reasons, so let's get rid of this.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since libspe2 will provide a function that can read/write
multiple mailbox elements at once, the kernel should handle
that efficiently.
read/write on the three mailbox files can now access the
spe context multiple times to operate on any number of
mailbox data elements.
If the spu application keeps writing to its outbound
mailbox, the read call will pick up all the data in a
single system call.
Unfortunately, if the user passes an invalid pointer,
we may lose a mailbox element on read, since we can't
put it back. This probably impossible to solve, if the
user also accesses the mailbox through direct register
access.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This hopefully fixes a long-standing bug in the spu file system.
An spu context comes with local memory that can be either saved
in kernel pages or point directly to a physical SPE.
When mapping the physical SPE, that mapping needs to be cache-inhibited.
For simplicity, we used to map the kernel backing memory that way
too, but unfortunately that was not only inefficient, but also incorrect
because the same page could then be accessed simultaneously through
a cacheable and a cache-inhibited mapping, which is not allowed
by the powerpc specification and in our case caused data inconsistency
for which we did a really ugly workaround in user space.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add the concept of a gang to spufs as a new type of object.
So far, this has no impact whatsover on scheduling, but makes
it possible to add that later.
A new type of object in spufs is now a spu_gang. It is created
with the spu_create system call with the flags argument set
to SPU_CREATE_GANG (0x2). Inside of a spu_gang, it
is then possible to create spu_context objects, which until
now was only possible at the root of spufs.
There is a new member in struct spu_context pointing to
the spu_gang it belongs to, if any. The spu_gang maintains
a list of spu_context structures that are its children.
This information can then be used in the scheduler in the
future.
There is still a bug that needs to be resolved in this
basic infrastructure regarding the order in which objects
are removed. When the spu_gang file descriptor is closed
before the spu_context descriptors, we leak the dentry
and inode for the gang. Any ideas how to cleanly solve
this are appreciated.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This tries to fix spufs so we have an interface closer to what is
specified in the man page for events returned in the third argument of
spu_run.
Fortunately, libspe has never been using the returned contents of that
register, as they were the same as the return code of spu_run (duh!).
Unlike the specification that we never implemented correctly, we now
require a SPU_CREATE_EVENTS_ENABLED flag passed to spu_create, in
order to get the new behavior. When this flag is not passed, spu_run
will simply ignore the third argument now.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
For better explanation, I break down the page fault handling into steps:
1) There is a page fault caused by DMA operation initiated by SPU and
DMA is suspended.
2) The interrupt handler 'spu_irq_class_1()/__spu_trap_data_map()' is
called and it just wakes up the sleeping spe-manager thread.
3) by PPE scheduler, the corresponding bottom half,
spu_irq_class_1_bottom() is called in process context and DMA is
restarted.
There can be a quite large time gap between 2) and 3) and I found
the following problem:
Between 2) and 3) If the context becomes unbound, 3) is not executed
because when the spe-manager thread is awaken, the context is already
saved. (This situation can happen, for example, when a high priority spe
thread newly started in that time gap)
But the actual problem is that the corresponding SPU context does not
work even if it is bound again to a SPU.
Besides I can see the following warning in mambo simulator when the
context becomes
unbound(in save_mfc_cmd()), i.e. when unbind() is called for the
context after step 2) before 3) :
'WARNING: 61392752237: SPE2: MFC_CMD_QUEUE channel count of 15 is
inconsistent with number of available DMA queue entries of 16'
After I go through available documents, I found that the problem is
because the suspended DMA is not restarted when it is bound again.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds NUMA support to the the spufs scheduler.
The new arch/powerpc/platforms/cell/spufs/sched.c is greatly
simplified, in an attempt to reduce complexity while adding
support for NUMA scheduler domains. SPUs are allocated starting
from the calling thread's node, moving to others as supported by
current->cpus_allowed. Preemption is gone as it was buggy, but
should be re-enabled in another patch when stable.
The new arch/powerpc/platforms/cell/spu_base.c maintains idle
lists on a per-node basis, and allows caller to specify which
node(s) an SPU should be allocated from, while passing -1 tells
spu_alloc() that any node is allowed.
Since the patch removes the currently implemented preemptive
scheduling, it is technically a regression, but practically
all users have since migrated to this version, as it is
part of the IBM SDK and the yellowdog distribution, so there
is not much point holding it back while the new preemptive
scheduling patch gets delayed further.
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds a new "psmap" file to spufs that allows mmap of all of
the problem state mapping of SPEs. It is compatible with 64k pages. In
addition, it removes mmap ability of individual files when using 64k
pages, with the exception of signal1 and signal2 which will both map the
entire 64k page holding both registers. It also removes
CONFIG_SPUFS_MMAP as there is no point in not building mmap support in
spufs.
It goes along a separate patch to libspe implementing usage of that new
file to access problem state registers.
Another patch will follow up to fix races opened up by accessing
the 'runcntl' register directly, which is made possible with this
patch.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
- handle clear_user() error
- handle and properly unwind from sysfs errors thrown during mod init
- adjust order of calls in megasas_exit() to precisely match
registration order in megasas_init()
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Updated for extra attribute and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Handle and unwind from errors returned by driver model functions.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Notice and handle sysfs errors in module init, tape init
- Properly unwind errors in module init
- Remove bogus st_sysfs_class==NULL test, it is guaranteed !NULL at that point
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- Properly handle and unwind errors in init_sd(). Fixes leaks on error,
if class_register() or scsi_register_driver() failed.
- Ensure that exit_sd() execution order is the perfect inverse of
initialization order.
FIXME: If some-but-not-all register_blkdev() calls fail, we wind up
calling unregister_blkdev() for block devices we did not register.
This was a pre-existing bug.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
- check all sysfs-related return codes, and propagate them back to callers
- properly unwind errors in osst_probe(), init_osst(). This fixes a
leak that occured if scsi driver registration failed, and fixes an
oops if sysfs creation returned an error.
(unrelated)
- kzalloc() cleanup in new_tape_buf()
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Remove the obsolete hosts.h file under drivers/scsi.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Changes the obsolete Scsi_Cmnd to struct scsi_cmnd in aic7xxx_old.c.
Also replacing lots of whitespaces with tabs in structures and functions
which have been changed.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Retry internal operation after unit check instead of aborting them.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Add timeout handler for common-I/O-layer-internal I/O operations.
Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The include of linux/smp.h needs to be done before the #if that
checks for the compiler version. Seems like fallout from the
inline assembly cleanup patch vs. the directed yield patch.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix a race condition during AP device registration and unregistration.
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
While the machine owns us an interrupt in these cases (and we should get
one), reality isn't always like that...
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fix new restore_sigregs function. It copies the user space copy of the
old psw without correcting the psw.mask and the psw.addr high order bit.
While we are at it, simplify save_sigregs a bit.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
