We need to check for existence of the a.out.h header in the source tree,
not the object tree, if we want it to get the right answer with O=.
Signed-off-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This patch adds an API for doing read-modify-write updates to a pte's
protection bits which may race against hardware updates to the pte.
After reading the pte, the hardware may asynchonously set the accessed
or dirty bits on a pte, which would be lost when writing back the
modified pte value.
The existing technique to handle this race is to use
ptep_get_and_clear() atomically fetch the old pte value and clear it
in memory. This has the effect of marking the pte as non-present,
which will prevent the hardware from updating its state. When the new
value is written back, the pte will be present again, and the hardware
can resume updating the access/dirty flags.
When running in a virtualized environment, pagetable updates are
relatively expensive, since they generally involve some trap into the
hypervisor. To mitigate the cost of these updates, we tend to batch
them.
However, because of the atomic nature of ptep_get_and_clear(), it is
inherently non-batchable. This new interface allows batching by
giving the underlying implementation enough information to open a
transaction between the read and write phases:
ptep_modify_prot_start() returns the current pte value, and puts the
pte entry into a state where either the hardware will not update the
pte, or if it does, the updates will be preserved on commit.
ptep_modify_prot_commit() writes back the updated pte, makes sure that
any hardware updates made since ptep_modify_prot_start() are
preserved.
ptep_modify_prot_start() and _commit() must be exactly paired, and
used while holding the appropriate pte lock. They do not protect
against other software updates of the pte in any way.
The current implementations of ptep_modify_prot_start and _commit are
functionally unchanged from before: _start() uses ptep_get_and_clear()
fetch the pte and zero the entry, preventing any hardware updates.
_commit() simply writes the new pte value back knowing that the
hardware has not updated the pte in the meantime.
The only current user of this interface is mprotect
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
.. allowing it to be write-protected just as other read-only data
under CONFIG_DEBUG_RODATA.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add C99-style constructor macros for fixed types to
<asm-generic/int-*.h>. Since Linux uses names like "u64" instead of
"uint64_t", the constructor macros are called U64_C() instead of
UINT64_C() and so forth.
These macros allow specific sizes to be specified as
U64_C(0x123456789abcdef), without gcc issuing warnings as it will if
one writes (u64)0x123456789abcdef.
When used from assembly, these macros pass their argument unchanged.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Unaligned access is ok for the following arches:
cris, m68k, mn10300, powerpc, s390, x86
Arches that use the memmove implementation for native endian, and
the byteshifting for the opposite endianness.
h8300, m32r, xtensa
Packed struct for native endian, byteshifting for other endian:
alpha, blackfin, ia64, parisc, sparc, sparc64, mips, sh
m86knommu is generic_be for Coldfire, otherwise unaligned access is ok.
frv, arm chooses endianness based on compiler settings, uses the byteshifting
versions. Remove the unaligned trap handler from frv as it is now unused.
v850 is le, uses the byteshifting versions for both be and le.
Remove the now unused asm-generic implementation.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the spirit of a number of other asm-generic header files,
generalize asm-generic/ioctl.h to allow arch-specific ioctl.h headers
to simply override _IOC_SIZEBITS and/or _IOC_DIRBITS before including
this header file, allowing a number of ioctl.h header files to be
shortened considerably.
Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new function gpiochip_reserve() to reserve ranges of gpios that platform
code has pre-allocated. That is, this marks gpio numbers which will be
claimed by drivers that haven't yet been loaded, and thus are not available
for dynamic gpio number allocation.
[akpm@linux-foundation.org: remove unneeded __must_check]
[david-b@pacbell.net: don't export gpiochip_reserve (section fix)]
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As long as one or more GPIOs on a gpio chip are used its driver should not be
unloaded. The existing mechanism (gpiochip_remove failure) doesn't address
that, since rmmod can no longer be made to fail by having the cleanup code
report errors. Module usecounts are the solution.
Assuming standard "initialize struct to zero" policies, this change won't
affect SOC platform drivers. However, drivers for external chips (on I2C and
SPI busses) should be updated if they can be built as modules.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
[ gpio_ensure_requested() needs to update module usecounts too ]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use __fls for fls64 on 64-bit archs. The implementation for
64-bit archs is moved from x86_64 to asm-generic.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a generic __fls implementation in the same spirit as
the generic __ffs one. It finds the last (most significant)
set bit in the given long value.
Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This moves an optimization for searching constant-sized small
bitmaps form x86_64-specific to generic code.
On an i386 defconfig (the x86#testing one), the size of vmlinux hardly
changes with this applied. I have observed only four places where this
optimization avoids a call into find_next_bit:
In the functions return_unused_surplus_pages, alloc_fresh_huge_page,
and adjust_pool_surplus, this patch avoids a call for a 1-bit bitmap.
In __next_cpu a call is avoided for a 32-bit bitmap. That's it.
On x86_64, 52 locations are optimized with a minimal increase in
code size:
Current #testing defconfig:
146 x bsf, 27 x find_next_*bit
text data bss dec hex filename
5392637 846592 724424 6963653 6a41c5 vmlinux
After removing the x86_64 specific optimization for find_next_*bit:
94 x bsf, 79 x find_next_*bit
text data bss dec hex filename
5392358 846592 724424 6963374 6a40ae vmlinux
After this patch (making the optimization generic):
146 x bsf, 27 x find_next_*bit
text data bss dec hex filename
5392396 846592 724424 6963412 6a40d4 vmlinux
[ tglx@linutronix.de: build fixes ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86 has ioremap_wc for wc remap. Also introduce a generic ioremap_wc
aliased to ioremap_uc so that drivers can use this interface transparently.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Create a simple macro to always return a pointer to the node_to_cpumask(node)
value. This relies on compiler optimization to remove the extra indirection:
#define node_to_cpumask_ptr(v, node) \
cpumask_t _##v = node_to_cpumask(node), *v = &_##v
For those systems with a large cpumask size, then a true pointer
to the array element can be used:
#define node_to_cpumask_ptr(v, node) \
cpumask_t *v = &(node_to_cpumask_map[node])
A node_to_cpumask_ptr_next() macro is provided to access another
node_to_cpumask value.
The other change is to always include asm-generic/topology.h moving the
ifdef CONFIG_NUMA to this same file.
Note: there are no references to either of these new macros in this patch,
only the definition.
Based on 2.6.25-rc5-mm1
# alpha
Cc: Richard Henderson <rth@twiddle.net>
# fujitsu
Cc: David Howells <dhowells@redhat.com>
# ia64
Cc: Tony Luck <tony.luck@intel.com>
# powerpc
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anton Blanchard <anton@samba.org>
# sparc
Cc: David S. Miller <davem@davemloft.net>
Cc: William L. Irwin <wli@holomorphy.com>
# x86
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently include/linux/kvm.h is not considered by make headers_install,
because Kbuild cannot handle " unifdef-$(CONFIG_FOO) += foo.h. This problem
was introduced by
commit fb56dbb31c
Author: Avi Kivity <avi@qumranet.com>
Date: Sun Dec 2 10:50:06 2007 +0200
KVM: Export include/linux/kvm.h only if $ARCH actually supports KVM
Currently, make headers_check barfs due to <asm/kvm.h>, which <linux/kvm.h>
includes, not existing. Rather than add a zillion <asm/kvm.h>s, export kvm.
only if the arch actually supports it.
Signed-off-by: Avi Kivity <avi@qumranet.com>
which makes this an 2.6.25 regression.
One way of solving the issue is to enhance Kbuild, but Avi and David conviced
me, that changing headers_install is not the way to go. This patch changes
the definition for linux/kvm.h to unifdef-y.
If unifdef-y is used for linux/kvm.h "make headers_check" will fail on all
architectures without asm/kvm.h. Therefore, this patch also provides
asm/kvm.h on all architectures.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Avi Kivity <avi@qumranet.com>
Cc: Sam Ravnborg <sam@ravnborg.org
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.25-rc1 percpu changes broke CONFIG_DEBUG_PREEMPT's per_cpu checking
on several architectures. On s390, sparc64 and x86 it's been weakened to
not checking at all; whereas on powerpc64 it's become too strict, issuing
warnings from __raw_get_cpu_var in io_schedule and init_timer for example.
Fix this by weakening powerpc's __my_cpu_offset to use the non-checking
local_paca instead of get_paca (which itself contains such a check);
and strengthening the generic my_cpu_offset to go the old slow way via
smp_processor_id when CONFIG_DEBUG_PREEMPT (debug_smp_processor_id is
where all the knowledge of what's correct when lives).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Reviewed-by: Mike Travis <travis@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When adding __devinitconst etc. the __initconst variant
were missed.
Add this one and proper definitions for .head.text for use
in .S files.
The naming .head.text is preferred over .text.head as the
latter will conflict for a function named head when introducing
-ffunctions-sections.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Mike Travis
Ingo Molnar
Christoph Lameter
David Woodhouse
Jeremy Fitzhardinge
Jan Beulich
David Brownell
H. Peter Anvin
Roman Zippel
Robert P. J. Day
Jeff Dike
Harvey Harrison
Anton Vorontsov
Guennadi Liakhovetski
Alexander van Heukelum
venkatesh.pallipadi@intel.com
Christian Borntraeger
Hugh Dickins
Sam Ravnborg