Let's factor out the need_resched() check instead of having it duplicated
in every pm_idle implementations to avoid inconsistencies (omap2_pm_idle
is missing it already).
The forceful re-enablement of IRQs after pm_idle has returned can go.
The warning certainly doesn't trigger for existing users.
To get rid of the pm_idle calling convention oddity, let's introduce
arm_pm_idle() allowing for the local_irq_enable() to be factored out
from SOC specific implementations. The default pm_idle function becomes
a wrapper for arm_pm_idle and it takes care of enabling IRQs closer to
where they are initially disabled.
And finally move the comment explaining the reason for that turning off
of IRQs to a more proper location.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-and-tested-by: Jamie Iles <jamie@jamieiles.com>
Remove the now empty arch_reset() from all the mach/system.h includes,
and remove its callsite. Remove arm_machine_restart() as this function
no longer does anything useful.
For samsung platforms, remove the include of mach/system-reset.h and
plat/system-reset.h from their respective mach/system.h headers as these
just define their arch_reset functions. As a result, the s3c2410 and
plat-samsung system-reset.h files are no longer referenced, so remove
these files entirely.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The DFSR and IFSR register format is different when LPAE is enabled. In
addition, DFSR and IFSR have similar definitions for the fault type.
This modifies the fault code to correctly handle the new format.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
We only need to set the system up for a soft-restart if we're going to
be doing a soft-restart. Provide a new function (soft_restart()) which
does the setup and final call for this, and make platforms use it.
Eliminate the call to setup_restart() from the default handler.
This means that platforms arch_reset() function is no longer called with
the page tables prepared for a soft-restart, and caches will still be
enabled.
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Krzysztof Ha■asa <khc@pm.waw.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Acked-by: Wan ZongShun <mcuos.com@gmail.com>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently, show_regs calls __backtrace which does
nothing if CONFIG_FRAME_POINTER is not set. Switch to
dump_stack which handles both CONFIG_FRAME_POINTER and
CONFIG_ARM_UNWIND correctly.
__backtrace is now superseded by dump_stack in general
and show_regs was the last caller so remove __backtrace
as well.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The CPU architecture really should not be changing at runtime, so
make it a global variable instead of a function.
The cpu_architecture() function declared in <asm/system.h> remains
the correct way to read this variable from C code.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Reviewed-by: Jon Medhurst <tixy@yxit.co.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The definition of __exception_irq_entry for
CONFIG_FUNCTION_GRAPH_TRACER=y needs linux/ftrace.h, but this creates a
circular dependency with it's current home in asm/system.h. Create
asm/exception.h and update all current users.
v4: - rebase to rmk/for-next
v3: - remove redundant includes of linux/ftrace.h
v2: - document the usage restricitions of __exception*
Cc: Zoltan Devai <zdevai@gmail.com>
Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since mandatory barriers may be used (explicitly or implicitly via readl
etc.) to ensure the ordering between Device and Normal memory accesses,
a DMB is not enough. This patch converts it to a DSB.
Cc: Colin Cross <ccross@android.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If CONFIG_CPU_V6 is enabled, we must avoid the byte/halfword/doubleword
exclusive operations, which aren't implemented before V6K. Use the
generic versions (or omit them) instead.
If CONFIG_CPU_V6 is not set, but CONFIG_CPU_32v6K is enabled, we have
the K extnesions, so use these new instructions.
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes below build error by adding the missing asm/memory.h,
which is needed for arch_is_coherent().
$ make pxa3xx_defconfig; make
CC init/do_mounts_rd.o
In file included from include/linux/list_bl.h:5,
from include/linux/rculist_bl.h:7,
from include/linux/dcache.h:7,
from include/linux/fs.h:381,
from init/do_mounts_rd.c:3:
include/linux/bit_spinlock.h: In function 'bit_spin_unlock':
include/linux/bit_spinlock.h:61: error: implicit declaration of function 'arch_is_coherent'
make[1]: *** [init/do_mounts_rd.o] Error 1
make: *** [init] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sev is used to send wakeup event to other cores in ARMv6K and above.
This has been moved from platform specific part to standard common
ARM header file (asm/system.h). Also introduced wfi() and wfe().
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When FUNCTION_GRAPH_TRACER is enabled, place do_IRQ() and friends in the
IRQ_ENTRY section so that the irq-related features of the function graph
tracer work.
Signed-off-by: Rabin Vincent <rabin@rab.in>
In order for CPUidle to work on SMP systems, an implementation of
cpu_idle_wait() is needed.
This patch duplicates the x86 implementation of cpu_idle_wait() for
ARM.
Tested-by: Colin Cross <ccross@android.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On ARM processors with hardware breakpoint and watchpoint support,
triggering these events results in a debug exception. These manifest
as prefetch and data aborts respectively.
arch/arm/mm/fault.c already provides hook_fault_code for hooking
into data aborts dependent on the DFSR. This patch adds a new function,
hook_ifault_code for hooking into prefetch aborts in the same manner.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: S. Karthikeyan <informkarthik@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add one more parameter to hook_fault_code() to be able to set 'code'
field of struct fsr_info.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide a configuration option to allow the ARMv6 to use normal
bufferable memory for coherent DMA. This option is forced to 'y'
for ARMv7, and offered as a configuration option on ARMv6.
Enabling this option requires drivers to have the necessary barriers
to ensure that data in DMA coherent memory is visible prior to the
DMA operation commencing.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The mandatory barriers (mb, rmb, wmb) are used even on uniprocessor
systems for things like ordering Normal Non-cacheable memory accesses
with DMA transfer (via Device memory writes). The current implementation
uses dmb() for mb() and friends but this is not sufficient. The DMB only
ensures the relative ordering of the observability of accesses by other
processors or devices acting as masters. In case of DMA transfers
started by writes to device memory, the relative ordering is not ensured
because accesses to slave ports of a device are not considered
observable by the DMB definition.
A DSB is required for the data to reach the main memory (even if mapped
as Normal Non-cacheable) before the device receives the notification to
begin the transfer. Furthermore, some L2 cache controllers (like L2x0 or
PL310) buffer stores to Normal Non-cacheable memory and this would need
to be drained with the outer_sync() function call.
The patch also allows platforms to define their own mandatory barriers
implementation by selecting CONFIG_ARCH_HAS_BARRIERS and providing a
mach/barriers.h file.
Note that the SMP barriers are unchanged (being DMBs as before) since
they are only guaranteed to work with Normal Cacheable memory.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Kernel debuggers want to be informed of die() events, so that they
can take some action to allow the problem to be inspected. Provide
the hook in a similar manner to x86.
Note that we currently don't implement the individual trap hooks.
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On ARMv7, it is invalid to map the same physical address multiple times
with different memory types. Since system RAM is already mapped as
'memory', subsequent remapping of it must retain this attribute.
However, DMA memory maps it as "strongly ordered". Fix this by introducing
'pgprot_dmacoherent()' which provides the necessary page table bits for
DMA mappings.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Add cmpxchg/cmpxchg64 support for ARMv6K and ARMv7 systems
(original patch from Catalin Marinas <catalin.marinas@arm.com>)
The cmpxchg and cmpxchg64 functions can be implemented using the
LDREX*/STREX* instructions. Since operand lengths other than 32bit are
required, the full implementations are only available if the ARMv6K
extensions are present (for the LDREXB, LDREXH and LDREXD instructions).
For ARMv6, only 32-bits cmpxchg is available.
Mathieu :
Make cmpxchg_local always available with best implementation for all type sizes (1, 2, 4 bytes).
Make cmpxchg64_local always available.
Use "Ir" constraint for "old" operand, like atomic.h atomic_cmpxchg does.
Change since v3 :
- Add "memory" clobbers (thanks to Nicolas Pitre)
- removed __asmeq(), only needed for old compilers, very unlikely on ARMv6+.
Note : ARMv7-M should eventually be ifdefed-out of cmpxchg64. But it's not
supported by the Linux kernel currently.
Put back arm < v6 cmpxchg support.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Mathieu Desnoyers pointed out that the ARM barriers were lacking:
- cmpxchg, xchg and atomic add return need memory barriers on
architectures which can reorder the relative order in which memory
read/writes can be seen between CPUs, which seems to include recent
ARM architectures. Those barriers are currently missing on ARM.
- test_and_xxx_bit were missing SMP barriers.
So put these barriers in. Provide separate atomic_add/atomic_sub
operations which do not require barriers.
Reported-Reviewed-and-Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Adds support for Faraday FA526 core. This core is used at least by:
Cortina Systems Gemini and Centroid family
Cavium Networks ECONA family
Grain Media GM8120
Pixelplus ImageARM
Prolific PL-1029
Faraday IP evaluation boards
v2:
- move TLB_BTB to separate patch
- update copyrights
Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
OMAP wishes to pass state to the boot loader upon reboot in order to
instruct it whether to wait for USB-based reflashing or not. There is
already a facility to do this via the reboot() syscall, except we ignore
the string passed to machine_restart().
This patch fixes things to pass this string to arch_reset(). This means
that we keep the reboot mode limited to telling the kernel _how_ to
perform the reboot which should be independent of what we request the
boot loader to do.
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
As a result of the ptebits changes, we ended up marking device mappings
as normal memory on ARMv7 CPUs, resulting in undesirable behaviour with
serial ports and the like. While reviewing the section mapping table
entries, other errors in the memory type settings for devices were
detected and confirmed to prevent Xscale3 platforms booting.
Tested on:
OMAP34xx (ARMv7),
OMAP24xx (ARMv6),
OMAP16xx (ARM926T, ARMv5),
PXA311 (Xscale3),
PXA272 (Xscale),
PXA255 (Xscale),
IXP42x (Xscale),
S3C2410 (ARM920T, ARMv4T),
ARM720T (ARMv4T)
StrongARM-110 (ARMv4)
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Tested-by: Mike Rapoport <mike@compulab.co.il>
Tested-by: Ben Dooks <ben-linux@fluff.org>
Tested-by: Anders Grafström <grfstrm@users.sourceforge.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add asm/cputype.h, moving functions and definitions from asm/system.h
there. Convert all users of 'processor_id' to the more efficient
read_cpuid_id() function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move platform independent header files to arch/arm/include/asm, leaving
those in asm/arch* and asm/plat* alone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
