This adds a flags parameter to SchedControl_Configure to enable
configuration of a sporadic SC.
This also allows flags to be added in the future as needed without
breaking the API.
This allows the user to configure an SC either to be constrained as a
sporadic task where accumulated time is only delayed to when a task has
become runnable (implementing the sporadic server algorithm) or
whenever the task becomes the current executing task (implementing the
sliding-window constraint as in constant-bandwidth servers).
This can be used to prevent non-realtime tasks from exceeding bandwidth
under any circumstances, even in an over-committed configuration, whilst
also allowing work-conserving tasks to be configured in the same system.
To implement sporadic servers, we need to ensure that the suspension of
a task cannot be used as a mechanism to amplify budget of a task by
granting that task access to effectively multiple periods worth of
replenishments within a single period.
To align the implementation of SCs with the model of sporadic servers we
must delay available time until the release of a task. Within seL4, a
release would be any time where an SC changes from not being associated
with a Running, RunningVM, or Restart thread to one that is.
This can occur when an SC is bound to a new thread in such a state or
when a thread changes to such a state from any non-running states.
Critically, replenishments should not be delayed at the point when an SC
becomes the current SC (as was the case prior to this commit). This has
the effect of enforcing a continuous, constant bandwidth which is a
restriction that is incompatible with standard scheduling logic.
Accounting for this requires inserting a new refill_unblock_check
call whenever a sporadic SC is unblocked and removing the
refill_unblock_check call from when said SC is scheduled.
Signed-off-by: Curtis Millar <curtis.millar@data61.csiro.au>
Most of the uses of these are in functions where the cap type is
statically known and the correct branch could be used directly, but the
compiler does not know this so having these as inlines causes a large
number of accesses to bitfields of unrelated cap types in functions that
manipulate caps.
Moving this out of line makes the results of changing cap bitfields less
noisy.
Signed-off-by: Stefan O'Rear <sorear@fastmail.com>
The base pointer is wrong, and it creates some nasty corruption down the
line (only affects debug builds).
Signed-off-by: Sylvain Gauthier <sylvain.gauthier@data61.csiro.au>
Special debug variables that were previously stored at the end of the
tcb_t struct often cause the struct to get too large for the power-of-2
sized untyped object definition. This change moves these variables into
a new structure named debug_tcb_t that is located between the TCB CNode
and the tcb_t struct within a tcb kernel object. Because tcb_t needs to
be stored on a power-of-2 aligned boundary and the TCB CNode only
contains < 5 slots, there is easily > 512 bytes of unused data in every
tcb object. The kernel verification needs to be sure that objects don't
overlap in memory and so this space can't be easily used in a release
build at the moment, but for debug configurations using it shouldn't be
an issue.
Signed-off-by: Kent McLeod <Kent.Mcleod@data61.csiro.au>
All the kernel header files now use pargma once rather than the ifndef,
as the pre-processed C files do not change while header files
are protected with pargma once. This will also solve any naming issues
caused by ifndef.
This commit also converts our own copyright headers to directly use
SPDX, but leaves all other copyright header intact, only adding the
SPDX ident. As far as possible this commit also merges multiple
Data61 copyright statements/headers into one for consistency.
Before this change, we set the replyObject in the thread state on recv
with no back pointer such that stray pointers would be left in the
thread state when a reply object was completed.
The new semantics are clearer and fix this problem by doing the
following:
- tcb->tcbReply is removed and the thread state field is always used,
this was unneccessary duplication previously
- the thread state value is set to the reply object only when the thread
is in BlockedOnReply or BlockedOnRecv
- the reply contains a back pointer, replyTCB, which points to that
thread
- if a thread has its reply removed, it must be set to
ThreadState_Inactive.
- deletion is easy in the blockedOnRecv case, we just unlink the reply
and the tcb.
- deletion is complicated for blockedOnReply. If we are deleing a tcb,
we remove the actual reply object and the call chain is broken. If we
are deleting a reply, we maintain the call chain by moving the tcb to
the next reply.
- we refactor the reply object interface to solve the above.
* reply_clear: removes the reply from any connections (tcb, sc)
* reply_unlink: just unlinks the tcb and reply, and sets the thread
state to inactive
* reply_remove: removes the reply from the call chain
* reply_remove_tcb: removes the exact reply that a tcb is bound to,
as we are removing that tcb. Breaks the call chain.
- seL4_TCB_Configure no longer takes a fault endpoint.
- seL4_TCB_SetSpace takes a cap in the callers cspace for the
fault endpoint, not the target tcbs.
- seL4_TCB_SetSchedParams now also takes a fault endpoint as above.
This change installs the fault endpoint cap into the tcb cnode
first validating it.
This means either of the functions that set it will now return an error
if the cap is not either a null cap or an endpoint with send and
grant rights.
Significantly, the cap passed to the function should be in the callers
cspace, not the target tcbs.
This allows users to define custom amounts of refills without
increasing the scheduling context size system wide.
also add libsel4 functions for refill size
This commit allows scheduling contexts to be bound
to notification objects. When a passive server
receives a notification it will receive the scheduling
context from the notification. When the server
blocks the scheduling context is returned.
This is the first part of the seL4 MCS. This commit:
* adds a scheduling context object. Threads without scheduling
context objects cannot be scheduled.
* replaces tcbTimeSlice with the scheduling context object
* adds seL4_SchedControl caps for each core
* adds seL4_SchedControl_Configure which allows users to configure
amount of ticks a scheduling context has, and set a core for the
scheduling context.
* adds seL4_SchedContext_Bind, Unbind and UnbindObject, which allows
a tcb to be bound to a scheduling context.
This changes the comments regarding the size of the TCB to be more
generally accurate to help manually determine the size of the TCB for
different configurations.
These files can be included normally using libsel4 include paths. This
removes situations where the same file is available under different
include paths due to symlinking into different directory structures.
Revocability of a cap, with respect to its parent, is a general property on caps and
makes sense to be abstracted. This allows for the addition of an arch case without
further complicating the cteInsert function itself.
A TCB object has two objects inside it, the cnode object and the 'actual tcb object'.
For simplicity of verification we would like the tcb_t portion of the object to also
be size aligned instead of just just being offset by the size of the cnode.
This definition is used as the size of the cnode portion of the TCB object (and not the tcb_t)
portion and so this provides a much less confusing name.
Adds a named constant of the IPC buffer size bits that can be used when checking the
size/alignment of an IPC buffer. This constant has a compile time assertion to ensure
it corresponds to the actual IPC buffer
Zombie caps perform bit packing that relied on the log2(wordBits), which was being
hard coded to 5. Whilst 5 is the correct value on 32-bit platforms, it is incorrect
on 64-bit ones. This changes the previously hardcoded 5 to be the, already existing,
wordRadix definition.
- when CONFIG_DEBUG is enabled, track all threads
- when CONFIG_PRINTING is enabled, provide seL4_DebugDumpScheduler which
allows the user to dump the state of the kernel scheduler.
This is a *breaking API change*
This commit:
* makes seL4_Fault_tag_t common between the kernel and libsel4
* deprecates the existing functions from sel4/messages.h includes
* introduces a new fault API in sel4/faults.h and
* sel4/sel4_arch/faults.h
* deprecates seL4_GetTag(), as the function did not work without
the user calling seL4_SetTag() first (seL4_MessageInfo is passed
in registers and not set in the IPC buffer)
* removes previously deprecated functions (deprecated prior to 3.0.0)
* updates the seL4 manual to reflect the changes
benchmark.h requires a definition of KS_LOG_PPTR, but its previous
placement in machine.h resulted in a circular include. This commit
factors out KS_LOG_PPTR and related definitions to a separate header,
creates the corresponding header for x86, and prevents circular
includes in the x86 builds
Where MCP = Maximum Controlled Priority
This commit adds:
* seL4_TCB_SetMCPriority
and changes the arguments to
* seL4_TCB_Configure
As of this commit, a thread cannot create or set a threads
priority (including itself) above its mcp. Previously the kernel
did this check against a threads priority, which prevented a thread
from setting it's own priority down and then up again.
Previously the return value of cap_get_capPtr was compared to 0 in
sameRegionAs to emulate a check in the abstract specification that
tests if the cap is a physical cap or not. Overloading 0 results
in a scenario where a legitimate deviceUntyped's children do not
get considered to be children because they have a capPtr of 0.
This change adds and explicit function that returns whether or not
a capability is physical or not, and uses that in sameRegionAs
