Add support to record scheduler operations. This support is especially
important for tests in SMP configurations since the thread switch extension is
quite difficult to use due to the asynchronous nature of thread dispatching.
In contrast, the scheduler operations occur normally in a deterministic order.
Update #3716.
This function may be used to burn a couple of processor cycles with
minimum impact on the system bus. It may be used in busy wait loops.
Since it is a global function, it is possible to wrap it in device
driver test code.
Restrict the affinity set to the set of online processors. Make sure
the affinity set for an interrupt vector contains at least one online
processor.
Update #3269.
Do not initialize Thread_Control::libc_reent if
CONFIGURE_DISABLE_NEWLIB_REENTRANCY is defined. This helps to catch errors
with a NULL pointer exception rather than a corruption of the thread control
block.
At the moment the line discipline start function (l_start) has no
possibility to get feedback about the number of characters that have
been sent. This patch passes that information via an additional
parameter.
The change might trigger a warning on existing code because of a pointer
mismatch but it shouldn't break it. An existing function with the old
API will just ignore the additional parameter.
Update #4493
GCC versions prior to 6.1 used a RTEMS thread model based on
rtems_gxx_*() functions. GCC version 6.1 or later uses the
self-contained synchronization objects of Newlib <sys/lock.h> for the
RTEMS thread model.
Remove the obsolete implementation.
Close#3143.
This is done to get the target path for the overlay nodes which is very useful
in many cases. For example, Xen hypervisor needs it when applying overlays
because Xen needs to do further processing of the overlay nodes, e.g. mapping of
resources(IRQs and IOMMUs) to other VMs, creation of SMMU pagetables, etc.
Signed-off-by: Vikram Garhwal <fnu.vikram@xilinx.com>
Message-Id: <1637204036-382159-2-git-send-email-fnu.vikram@xilinx.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
With -Wsign-compare, compilers warn about a mismatching signedness in
the different legs of the conditional operator, in fdtget.c.
In the questionable expression, we are constructing a 16-bit value out of
two unsigned 8-bit values, however are relying on the compiler's
automatic expansion of the uint8_t to a larger type, to survive the left
shift. This larger type happens to be an "int", so this part of the
expression becomes signed.
Fix this by explicitly blowing up the uint8_t to a larger *unsigned* type,
before doing the left shift. And while we are at it, convert the hardly
readable conditional operator usage into a sane switch/case expression.
This fixes "make fdtget", when compiled with -Wsign-compare.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Message-Id: <20210618172030.9684-3-andre.przywara@arm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Changes in v3:
- Remove noop version sets
- Set version correctly on loaded fdt in fdt_open_into
Fixes: f1879e1a50eb ("Add limited read-only support for older (V2 and V3) device tree to libfdt.")
Signed-off-by: Justin Covell <jujugoboom@gmail.com>
Message-Id: <20201229041749.2187-1-jujugoboom@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commits 6dcb8ba4 "libfdt: Add helpers for accessing unaligned words"
introduced changes to support unaligned reads for ARM platforms and
11738cf01f15 "libfdt: Don't use memcpy to handle unaligned reads on ARM"
improved the performance of these helpers.
On further discussion, while there are potential cases where we could be
used on platforms that do not fixup unaligned reads for us, making this
choice the default is very expensive in terms of binary size and access
time. To address this, introduce and use new fdt{32,64}_ld_ functions
that call fdt{32,64}_to_cpu() as was done prior to the above mentioned
commits. Leave the existing load functions as unaligned-safe and
include comments in both cases.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Message-Id: <20201211022736.31657-1-trini@konsulko.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In _Workspace_Initialize_for_one_area(), properly check if there is enough
free memory available for the configured workspace size.
The bug was introduced by commit 3d0620b607.
Since the previous Interrupt Manager Extension API moved to the
Interrupt Manager, we can move the interfaces to <rtems/rtems/intr.h> so
that they are available via #include <rtems.h>.
The BSPs provide memory for the separate C Program Heap initialization
via _Memory_Get(). Most BSPs provide exactly one memory area. Only two
BSPs provide more than one memory area (arm/altera-cyclone-v and
bsps/powerpc/mpc55xxevb). Only if more than one memory area is
provided, there is a need to use _Heap_Extend(). Provide two
implementations to initialize the separate C Program Heap and let the
BSP select one of the implementations based on the number of provided
memory areas. This gets rid of a dependency on _Heap_Extend(). It
also avoids dead code sections for most BSPs.
Change licence to BSD-2-Clause according to file history.
Update #3053.
The BSPs provide memory for the workspace initialization via
_Memory_Get(). Most BSPs provide exactly one memory area. Only two
BSPs provide more than one memory area (arm/altera-cyclone-v and
bsps/powerpc/mpc55xxevb). Only if more than one memory area is
provided, there is a need to use _Heap_Extend(). Provide two
implementations to initialize the workspace handler and let the BSP
select one of the implementations based on the number of provided memory
areas. This gets rid of a dependency on _Heap_Extend(). It also avoids
dead code sections for most BSPs.
The _Thread_queue_Extract() does not deal with potential priority
updates and the SMP locking protocol handling. Use
_Thread_queue_Continue(). For the POSIX signals processing this is
currently probably unnecessary, however, the use case is similar to the
restart so use the same appoach.
Close#4546.
Remove the THREAD_WAIT_STATE_READY_AGAIN and simply use the initial value to
indicate that a thread does not wait on something. Rename
THREAD_WAIT_FLAGS_INITIAL to THREAD_WAIT_STATE_READY. This change is necessary
so that _Thread_Continue() can be called for threads which never waited on
something (for example dormant threads).
Update #4546.
Remove _Thread_queue_Extract_with_proxy() and move the proxy extraction
to _Thread_MP_Extract_proxy(). Move similar code blocks of the previous
caller of _Thread_queue_Extract_with_proxy() to helper functions.
Update #4546.
Return an error status for the following error condition in
rtems_scheduler_remove_processor():
While an attempt is made to remove a processor from a scheduler, while
the processor is the only processor owned by the scheduler, if a thread
exists which uses the scheduler as a helping scheduler, then the
processor shall not be removed.
The reason is that ask for help requests and withdraw node requests are
processed asynchronously in any order. An ask for help request carried
out on a scheduler without a processor is undefined behaviour.
Update error status description.
Update #4544.
Process ask for help requests on the current processor. This avoids
using inter-processor interrupts to make the system behaviour a bit more
predictable.
Update #4531.
Simplify callers of _Scheduler_SMP_Schedule_highest_ready(). Move the node
state change and the extraction from scheduled into
_Scheduler_SMP_Schedule_highest_ready(). Move the idle thread release to the
caller which have more information about the presence of an idle thread.
Update #4531.
This patch fixes an issue with the idle thread handling in the SMP
scheduler framework used for the MrsP locking protocol. The approach to
use a simple chain of unused idle threads is broken for schedulers which
support thread to processor affinity. The reason is that the thread to
processor affinity introduces another ordering indicator which may under
certain conditions lead to a reordering of idle threads in the scheduled
chain. This reordering is not propagated to the chain of unused idle
threads. This could lead to use an idle thread for a sticky scheduler
node which is already in use. This locks up the system in infinite
loops in the thread context switch procedure.
To fix this, the SMP scheduler implementations must now provide
callbacks to get and release an unused idle thread.
Update #4531.
This patch fixes the following broken behaviour:
While a thread is scheduled on a helping scheduler, while it does not
own a MrsP semaphore, if it obtains a MrsP semaphore, then no
scheduler node using an idle thread and the ceiling priority of the
semaphore is unblocked for the home scheduler.
This could lead to priority inversion issues and is not in line
with the MrsP protocol.
Introduce two new scheduler operations which are only enabled if
RTEMS_SMP is defined. The operations are used to make the scheduler
node of the home scheduler sticky and to clean the sticky property.
This helps to keep the sticky handing out of the frequently used
priority update operation.
Close#4532.
Rework the handling of the affine ready queue for the EDF SMP scheduler.
Do the queue handling in the node insert, move, and extract operations.
Remove the queue handling from _Scheduler_EDF_SMP_Allocate_processor().
Update #4531.
