IORESOURCE_DMA cannot be assigned without utilizing the interface
provided by CONFIG_ISA_DMA_API, specifically request_dma() and
free_dma(). Thus, there's a strict dependency on the config option and
limits IORESOURCE_DMA only to architectures that support ISA-style DMA.
ia64 is not one of those architectures, so pnp_check_dma() no longer
needs to be special-cased for that architecture.
pnp_assign_resources() will now return -EINVAL if IORESOURCE_DMA is
attempted on such a kernel.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ACPI devices are often involved in address space conflicts with PCI devices,
so I think it's worth logging the resources they use. Otherwise we have to
depend on lspnp or groping around in sysfs to find them.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
With fa35b4926, I broke a lot of PNP resource assignment. That commit made
PNPACPI include bridge windows as PNP resources, and PNP resource assignment
treats any enabled overlapping PNP resources as conflicts. Since PCI host
bridge windows typically include most of the I/O port space, this makes PNP
port assigments fail.
The PCI host bridge driver will eventually use those PNP window resources,
so we should make PNP ignore them when checking for conflicts.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=15903
Reported-and-tested-by: Pavel Kysilka <goldenfish@linuxsoft.cz>
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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>
Add support for bus number resources. This is for bridges with a range of
bus numbers behind them. Previously, PNP ignored bus number resources.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Jesse accidentally applied v1 [1] of the patchset instead of v2 [2]. This
is the diff between v1 and v2.
The changes in this patch are:
- tidied vsprintf stack buffer to shrink and compute size more
accurately
- use %pR for decoding and %pr for "raw" (with type and flags) instead
of adding %pRt and %pRf
[1] http://lkml.org/lkml/2009/10/6/491
[2] http://lkml.org/lkml/2009/10/13/441
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Add a PNP resource range check function, indicating whether a resource
has been assigned to any device.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
[apw@canonical.com: fixed up exports et al]
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
PnP encodes the resource type directly as its struct resource->flags value
which is an unsigned long. Make it so...
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pnp_dbg() is equivalent to dev_dbg() except that we can turn it
on at boot-time with the "pnp.debug" kernel parameter, so we don't
have to build a new kernel image.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch just fixes indentation of a couple debug messages.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
If an IDE controller is in compatibility mode, it expects to use
IRQs 14 and 15, so PNP should avoid them.
This patch should resolve this problem report:
parallel driver grabs IRQ14 preventing legacy SFF ATA controller from working
https://bugzilla.novell.com/show_bug.cgi?id=375836
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
ISAPNP, PNPBIOS, and ACPI describe the "possible resource settings" of
a device, i.e., the possibilities an OS bus driver has when it assigns
I/O port, MMIO, and other resources to the device.
PNP used to maintain this "possible resource setting" information in
one independent option structure and a list of dependent option
structures for each device. Each of these option structures had lists
of I/O, memory, IRQ, and DMA resources, for example:
dev
independent options
ind-io0 -> ind-io1 ...
ind-mem0 -> ind-mem1 ...
...
dependent option set 0
dep0-io0 -> dep0-io1 ...
dep0-mem0 -> dep0-mem1 ...
...
dependent option set 1
dep1-io0 -> dep1-io1 ...
dep1-mem0 -> dep1-mem1 ...
...
...
This data structure was designed for ISAPNP, where the OS configures
device resource settings by writing directly to configuration
registers. The OS can write the registers in arbitrary order much
like it writes PCI BARs.
However, for PNPBIOS and ACPI devices, the OS uses firmware interfaces
that perform device configuration, and it is important to pass the
desired settings to those interfaces in the correct order. The OS
learns the correct order by using firmware interfaces that return the
"current resource settings" and "possible resource settings," but the
option structures above doesn't store the ordering information.
This patch replaces the independent and dependent lists with a single
list of options. For example, a device might have possible resource
settings like this:
dev
options
ind-io0 -> dep0-io0 -> dep1->io0 -> ind-io1 ...
All the possible settings are in the same list, in the order they
come from the firmware "possible resource settings" list. Each entry
is tagged with an independent/dependent flag. Dependent entries also
have a "set number" and an optional priority value. All dependent
entries must be assigned from the same set. For example, the OS can
use all the entries from dependent set 0, or all the entries from
dependent set 1, but it cannot mix entries from set 0 with entries
from set 1.
Prior to this patch PNP didn't keep track of the order of this list,
and it assigned all independent options first, then all dependent
ones. Using the example above, that resulted in a "desired
configuration" list like this:
ind->io0 -> ind->io1 -> depN-io0 ...
instead of the list the firmware expects, which looks like this:
ind->io0 -> depN-io0 -> ind-io1 ...
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
No functional change; just rename "data" to something more
descriptive.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch moves all the option allocations (pnp_mem, pnp_port, etc)
into the pnp_register_{mem,port,irq,dma}_resource() functions. This
will make it easier to rework the option data structures.
The non-trivial part of this patch is the IRQ handling. The backends
have to allocate a local pnp_irq_mask_t bitmap, populate it, and pass
a pointer to pnp_register_irq_resource().
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI Address Space Descriptors can be up to 64 bits wide.
We should keep track of the whole thing when parsing resource
options, so this patch changes PNP port and mem option
fields from "unsigned short" and "unsigned int" to
"resource_size_t".
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This adds a typedef for the IRQ bitmap, which should cause
no functional change, but will make it easier to pass a
pointer to a bitmap to pnp_register_irq_resource().
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
As part of a heuristic to identify modem devices, 8250_pnp.c
checks to see whether a device can be configured at any of the
legacy COM port addresses.
This patch moves the code that traverses the PNP "possible resource
options" from 8250_pnp.c to the PNP subsystem. This encapsulation
is important because a future patch will change the implementation
of those resource options.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
We used to have a fixed-size resource table. If a device had
twenty resources when the table only had space for ten, we didn't
need ten warnings, so we added the ratelimit.
Now that we can dynamically allocate new resources, we should
only get failures if the allocation fails. That should be
rare enough that we don't need to ratelimit the messages.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
PNP used to have a fixed-size pnp_resource_table for tracking the
resources used by a device. This table often overflowed, so we've
had to increase the table size, which wastes memory because most
devices have very few resources.
This patch replaces the table with a linked list of resources where
the entries are allocated on demand.
This removes messages like these:
pnpacpi: exceeded the max number of IO resources
00:01: too many I/O port resources
References:
http://bugzilla.kernel.org/show_bug.cgi?id=9535http://bugzilla.kernel.org/show_bug.cgi?id=9740http://lkml.org/lkml/2007/11/30/110
This patch also changes the way PNP uses the IORESOURCE_UNSET,
IORESOURCE_AUTO, and IORESOURCE_DISABLED flags.
Prior to this patch, the pnp_resource_table entries used the flags
like this:
IORESOURCE_UNSET
This table entry is unused and available for use. When this flag
is set, we shouldn't look at anything else in the resource structure.
This flag is set when a resource table entry is initialized.
IORESOURCE_AUTO
This resource was assigned automatically by pnp_assign_{io,mem,etc}().
This flag is set when a resource table entry is initialized and
cleared whenever we discover a resource setting by reading an ISAPNP
config register, parsing a PNPBIOS resource data stream, parsing an
ACPI _CRS list, or interpreting a sysfs "set" command.
Resources marked IORESOURCE_AUTO are reinitialized and marked as
IORESOURCE_UNSET by pnp_clean_resource_table() in these cases:
- before we attempt to assign resources automatically,
- if we fail to assign resources automatically,
- after disabling a device
IORESOURCE_DISABLED
Set by pnp_assign_{io,mem,etc}() when automatic assignment fails.
Also set by PNPBIOS and PNPACPI for:
- invalid IRQs or GSI registration failures
- invalid DMA channels
- I/O ports above 0x10000
- mem ranges with negative length
After this patch, there is no pnp_resource_table, and the resource list
entries use the flags like this:
IORESOURCE_UNSET
This flag is no longer used in PNP. Instead of keeping
IORESOURCE_UNSET entries in the resource list, we remove
entries from the list and free them.
IORESOURCE_AUTO
No change in meaning: it still means the resource was assigned
automatically by pnp_assign_{port,mem,etc}(), but these functions
now set the bit explicitly.
We still "clean" a device's resource list in the same places,
but rather than reinitializing IORESOURCE_AUTO entries, we
just remove them from the list.
Note that IORESOURCE_AUTO entries are always at the end of the
list, so removing them doesn't reorder other list entries.
This is because non-IORESOURCE_AUTO entries are added by the
ISAPNP, PNPBIOS, or PNPACPI "get resources" methods and by the
sysfs "set" command. In each of these cases, we completely free
the resource list first.
IORESOURCE_DISABLED
In addition to the cases where we used to set this flag, ISAPNP now
adds an IORESOURCE_DISABLED resource when it reads a configuration
register with a "disabled" value.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Given a struct resource, this returns the type (IO, MEM, IRQ, DMA).
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
The subsequent AD181x quirk patch would like this as part of the API.
pnp_register_dependent_option() adds to the same dependent chain the quirk is
walking which is fairly unclean. This enables a private option chain build
which it can then just add onto the end when done.
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Tested-by: Uwe Bugla <uwe.bugla@gmx.de>
Acked-by: Uwe Bugla <uwe.bugla@gmx.de>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Len Brown <len.brown@intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a pnp_add_mem_resource() that can be used by all the PNP
backends. This consolidates a little more pnp_resource_table
knowledge into one place.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a pnp_add_io_resource() that can be used by all the PNP
backends. This consolidates a little more pnp_resource_table
knowledge into one place.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a pnp_add_dma_resource() that can be used by all the PNP
backends. This consolidates a little more pnp_resource_table
knowledge into one place.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add a pnp_add_irq_resource() that can be used by all the PNP
backends. This consolidates a little more pnp_resource_table
knowledge into one place.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This encapsulates the code to locate a new pnp_resource of the
desired type. Currently this uses the pnp_resource_table, but
it will soon change to find a resource in a linked list.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
In some places, we need to get the struct pnp_resource, not just
the struct resource, because ISAPNP needs to store the register
index in the pnp_resource.
I don't like pnp_get_pnp_resource() and hope that it is temporary,
but we need it for a little while.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch adds a "struct pnp_resource". This currently
contains only a struct resource, but we will soon need
additional PNP-specific information.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
There are no remaining references to the PNP_MAX_* constants or
the pnp_resource_table structure outside of the PNP core. Make
them private to the PNP core.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Remove some PNP_MAX_* uses. The pnp_resource_table isn't
dynamic yet, but with pnp_get_resource(), we can start moving
away from the table size constants.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This removes more direct references to pnp_resource_table.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The caller already has the struct resource pointer, so no need for
pnp_check_port(), pnp_check_mem(), etc., to look it up again.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This patch removes a use of "idx" in pnp_check_port() and similar
functions, in preparation for replacing idx with a pointer to the
resource itself.
I split this out because it changes the behavior slightly: we used
to check for conflicts only with earlier resources, e.g., we checked
resource 2 against resources 0 and 1 but not against 3, 4, etc. Now
we will check against all resources except 2.
Since resources are assigned in ascending order, the old behavior
was probably safe, but I don't like to depend on that ordering.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Use a temporary "res" pointer to replace repeated lookups in
the pnp resource tables.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Cosmetic only: just use "i" instead of "tmp".
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This adds a pnp_get_resource() that works the same way as
platform_get_resource(). This will enable us to consolidate
many pnp_resource_table references in one place, which will
make it easier to make the table dynamic.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Add debug output to resource option registration functions (enabled
by CONFIG_PNP_DEBUG). This uses dev_printk, so I had to add pnp_dev
arguments at the same time.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
There should be a pci_dev_put when breaking out of a loop that iterates
over calls to pci_get_device and similar functions.
This was fixed using the following semantic patch.
// <smpl>
@@
identifier d;
type T;
expression e;
iterator for_each_pci_dev;
@@
T *d;
...
for_each_pci_dev(d)
{... when != pci_dev_put(d)
when != e = d
(
return d;
|
+ pci_dev_put(d);
? return ...;
)
...}
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Greg KH <greg@kroah.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we have the struct pnp_dev available, we can use dev_info(), dev_err(),
etc., to give a little more information and consistency.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove some null pointer checks. Null pointers in these areas indicate
programming errors, and I think it's better to oops immediately rather
than return an error that is easily ignored.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-by: Adam Belay <abelay@novell.com>
Signed-off-by: Len Brown <len.brown@intel.com>
These are manual fixups after running Lindent. No functional change.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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)
Suppress the "setup_irq: irq handler mismatch" coming out of pnp_check_irq():
failures are expected here.
Cc: <stable@kernel.org>
Cc: Santiago Garcia Mantinan <manty@manty.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Based on a patch series originally from Vivek Goyal <vgoyal@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
