The simply expanded variable may be evaluated before the target file for
the stat command is up to date or even exists. Switching to a recursively
expanded variable move the execution of the stat command to the location
where LDFLAGS_vmlinux is actually used, fixing the dependency issue
introduced by patch #6746/1.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Few architectures combine the GIC with an external interrupt
controller. On such systems it may be necessary to update both
the GIC registers and the external controller's registers to control
IRQ behavior.
This can be addressed in couple of possible methods.
1. Export common GIC routines along with 'struct irq_chip gic_chip'
and allow architectures to have custom function by override.
2. Provide architecture specific function pointer hooks
within GIC library and leave platforms to add the necessary
code as part of these hooks.
First one might be non-intrusive but have few shortcomings like arch
needs to have there own custom gic library. Locks used should be
common since it caters to same IRQs etc. Maintenance point of view
also it leads to multiple file fixes.
The second probably is cleaner and portable. It ensures that all the
common GIC infrastructure is not touched and also provides archs to
address their specific issue.
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Colin Cross <ccross@android.com>
Tested-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Populate the l2x0 set_debug function pointer with OMAP secure call
and enable the PL310 Errata 727915
This patch has dependency on the earlier patch
ARM: l2x0: Errata fix for flush by Way operation can cause data
corruption
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
PL310 implements the Clean & Invalidate by Way L2 cache maintenance
operation (offset 0x7FC). This operation runs in background so that
PL310 can handle normal accesses while it is in progress. Under very
rare circumstances, due to this erratum, write data can be lost when
PL310 treats a cacheable write transaction during a Clean & Invalidate
by Way operation.
Workaround:
Disable Write-Back and Cache Linefill (Debug Control Register)
Clean & Invalidate by Way (0x7FC)
Re-enable Write-Back and Cache Linefill (Debug Control Register)
This patch also removes any OMAP dependency on PL310 Errata's
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We currently presume a 4x expansion to guess the decompressed kernel size
in order to determine if the decompressed kernel is in conflict with
the location where zImage is loaded. This guess may cause many issues
by overestimating the final kernel image size:
- This may force a needless relocation if the location of zImage was
fine, wasting some precious microseconds of boot time.
- The relocation may be located way too far, possibly overwriting the
initrd image in RAM.
- If the kernel image includes a large already-compressed initramfs image
then the problem is even more exacerbated.
And if by some strange means the 4x guess is too low then we may overwrite
ourselves with the decompressed image.
So let's use the exact decompressed kernel image size instead. For that
we need to rely on the stat command, but this is hardly a new build
dependency as the kernel already depends on many external commands
to be built provided by the coreutils package where stat is found.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In the case of a conflict between the memory used by the compressed
kernel with its decompressor code and the memory used for the
decompressed kernel, we currently store the later after the former and
relocate it afterwards.
This would be more efficient to do this the other way around i.e.
relocate the compressed data up front instead, resulting in a smaller
copy. That also has the advantage of making the code smaller and more
straight forward.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
PTRACE_SINGLESTEP is a ptrace request designed to offer single-stepping
support to userspace when the underlying architecture has hardware
support for this operation.
On ARM, we set arch_has_single_step() to 1 and attempt to emulate hardware
single-stepping by disassembling the current instruction to determine the
next pc and placing a software breakpoint on that location.
Unfortunately this has the following problems:
1.) Only a subset of ARMv7 instructions are supported
2.) Thumb-2 is unsupported
3.) The code is not SMP safe
We could try to fix this code, but it turns out that because of the above
issues it is rarely used in practice. GDB, for example, uses PTRACE_POKETEXT
and PTRACE_PEEKTEXT to manage breakpoints itself and does not require any
kernel assistance.
This patch removes the single-step emulation code from ptrace meaning that
the PTRACE_SINGLESTEP request will return -EIO on ARM. Portable code must
check the return value from a ptrace call and handle the failure gracefully.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move L1_CACHE_SHIFT related options together, rather than spreading them
across two separate Kconfig files.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some installers would binary patch the kernel zImage to replace the
first few nops with custom instructions. This breaks the Thumb2 kernel
as the mode switch is right at the beginning. Let's move it towards the
end of the nop sequence instead.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Improve the documentation for the VFP hotplug notifier handler, so
that people better understand what's going on there and what has
been done for them.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In commit e616c59140, highmem support was
deactivated for SMP platforms without hardware TLB ops broadcast because
usage of kmap_high_get() requires that IRQs be disabled when kmap_lock
is locked which is incompatible with the IPI mechanism used by the
software TLB ops broadcast invoked through flush_all_zero_pkmaps().
The reason for kmap_high_get() is to ensure that the currently kmap'd
page usage count does not decrease to zero while we're using its
existing virtual mapping in an atomic context. With a VIVT cache this
is essential to do due to cache coherency issues, but with a VIPT cache
this is only an optimization so not to pay the price of establishing a
second mapping if an existing one can be used. However, on VIPT
platforms without hardware TLB maintenance we can give up on that
optimization in order to be able to use highmem.
From ARMv7 onwards the TLB ops are broadcasted in hardware, so let's
disable ARCH_NEEDS_KMAP_HIGH_GET only when CONFIG_SMP and
CONFIG_CPU_TLB_V6 are defined.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Saeed Bishara <saeed.bishara@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This cleans up after the conversion to irq_data. Rename the function
to match the method, and remove the now useless lookup of the irq
descriptor which is never used. Move the bitmask calculation out of
the irq_controller_lock region.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure appropriate locks are taken to ensure that IRQ migration off
the current CPU is race-free. We may have a concurrent set_affinity
via procfs running on another CPU in parallel with the IRQ migration,
resulting in unpredictable results.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The force argument to irq_set_affinity really should be 'true' as
moving IRQs off a CPU which is going down isn't optional.
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Current diagnostics are rather poor when things go wrong:
ipv6: relocation out of range, section 2 reloc 0 sym 'snmp_mib_free'
Let's include a little more information about the problem:
ipv6: section 2 reloc 0 sym 'snmp_mib_free': relocation 28 out of range (0xbf0000a4 -> 0xc11b4858)
so that we show exactly what the problem is - not only what type of
relocation but also the offending address range too.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We have 'install' and 'zinstall' for installing Image and zImage
kernels, so add 'uinstall' to complete the set.
This allows developers to have a ~/bin/installkernel script which (eg)
copies the kernel to the tftp server automatically once the kernel
has built, resulting in a better workflow.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/return_address.c:37:6: warning: symbol 'return_address' was not declared. Should it be static?
arch/arm/kernel/setup.c:76:14: warning: symbol 'processor_id' was not declared. Should it be static?
arch/arm/kernel/traps.c:259:1: warning: symbol 'die_lock' was not declared. Should it be static?
arch/arm/vfp/vfpmodule.c:156:6: warning: symbol 'vfp_raise_sigfpe' was not declared. Should it be static?
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Achieve better usage of the DMA coherent region by doing top-down
allocation rather than bottom up. If we ask for a 128kB allocation,
this will be aligned to 128kB and satisfied from the very bottom
address. If we then ask for a 600kB allocation, this will be aligned
to 1MB, and we will have a 896kB hole.
Performing top-down allocation resolves this by allocating the 128kB
at the very top, and then the 600kB can come in below it without any
unnecessary wastage.
This problem was reported by Janusz Krzysztofik, who had 2 x 128kB +
1 x 640kB allocations which wouldn't fit into 1MB.
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since the debug macros no longer depend on the machine type information,
the machine type lookup can be deferred to setup_arch() in setup.c which
simplifies the code somewhat.
We also move the __error_a functionality into setup.c for displaying a
message when a bad machine ID is passed to the kernel via the LL debug
code. We also log this into the kernel ring buffer which makes it
possible to retrieve the message via a debugger.
Original idea from Grant Likely.
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
arch/arm/mach-omap2/dma.c: Convert IS_ERR result to PTR_ERR
arm: omap2: mux: fix compile warning
omap1: Simplify use of omap_irq_flags
omap2+: Fix unused variable warning for omap_irq_base
Fix kernel-doc warning in kernel.h from commit 7ef88ad561
("BUILD_BUG_ON: make it handle more cases"):
Warning(include/linux/kernel.h:605): No description found for parameter 'condition'
Warning(include/linux/kernel.h:605): Excess function parameter 'cond' description in 'BUILD_BUG_ON'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nicolas Pitre
Santosh Shilimkar
Will Deacon
Russell King
Nicolas Pitre
Colin Tuckley
Linus Torvalds
Randy Dunlap