Use a per-CPU thread dispatch disable level. So instead of one global
thread dispatch disable level we have now one instance per processor.
This is a major performance improvement for SMP. On non-SMP
configurations this may simplifiy the interrupt entry/exit code.
The giant lock is still present, but it is now decoupled from the thread
dispatching in _Thread_Dispatch(), _Thread_Handler(),
_Thread_Restart_self() and the interrupt entry/exit. Access to the
giant lock is now available via _Giant_Acquire() and _Giant_Release().
The giant lock is still implicitly acquired via
_Thread_Dispatch_decrement_disable_level().
The giant lock is only acquired for high-level operations in interrupt
handlers (e.g. release of a semaphore, sending of an event).
As a side-effect this change fixes the lost thread dispatch necessary
indication bug in _Thread_Dispatch().
A per-CPU thread dispatch disable level greatly simplifies the SMP
support for the interrupt entry/exit code since no spin locks have to be
acquired in this area. It is only necessary to get the current
processor index and use this to calculate the address of the own per-CPU
control. This reduces the interrupt latency considerably.
All elements for the interrupt entry/exit code are now part of the
Per_CPU_Control structure: thread dispatch disable level, ISR nest level
and thread dispatch necessary. Nothing else is required (except CPU
port specific stuff like on SPARC).
The initial region (64 bytes) of SDRAM RTEMS image is remapped
to provide overlay of the initial/ROM exceptions table.
This area cannot be used for MMU mapping table. Different correctly
aligned block has to be used for MMU table. Remapping of SDRAM
(address 0x08200000) to address 0 is supported only on 1 MB block
granularity and that is why SDRAM_VEC area has to be 1 MB aligned too
but unused part of remapped region can be freely used for other
purposes (as MMU tables).
Signed-off-by: Pavel Pisa <ppisa@pikron.com>
The original version is missing void and result is that (*x >> 16) is
optimized to ldh rX,[rY]. But it is not allowed/supported to access
bus/address range used by AITC by other than 32 bit wide accesses
and 16-bit access results in the data abort exception.
The corrected version works on real hardware and is even
more readable.
Signed-off-by: Pavel Pisa <ppisa@pikron.com>
Move implementation specific parts of object.h and object.inl into new
header file objectimpl.h. The object.h contains now only the
application visible API.
Add and use _SMP_Get_current_processor() and
rtems_smp_get_current_processor().
Delete bsp_smp_interrupt_cpu().
Change type of current processor index from int to uint32_t to match
_SMP_Processor_count type.
