"To fully support self-modifying code in any situation, it is imperative that
a CPUSHA intrcution is executed before the execution of the first self-modified
instruction. The CPUSHA instruction has the effect of ensuring that there is
no stale data iin memory, the pipeline is flushed, and instruction prefetches
are repeated and taken from external memory."
I verified that this is the only way (I can think of) to make the sigtramp
regression test work on 68040. doing cpushl dc; cinvl ic; over the affected
address range, then nop (to synchronize the pipeline) is not enough; apparently
the nop does not FLUSH the pipeline and prefetch...
Note that the 68060 UM has copied the above cited passage, but in fact this is
not true. This might be connected to the fact that the 68060 does ensure
memory access order under most conditions.
- remove "need-flag" for mac68k esp driver, as it is not used in anywhere
and conflicts with IPsec ESP header.
This should be the only MD change in IPv6 support, except kernel config file.
Very sorry if you have any compilation problem with it (I believe it is okay).
If your favorite arch is not included in here, please add a
call to ip6intr() from softintr handle.
some internal reference counting on PT pages. We still allocate them
with the page fault routine (a wire-fault, now), but no longer free
PT pages from pmap_pageable().
has PAGEABLE and INTRSAFE flags. PAGEABLE now really means "pageable",
not "allocate vm_map_entry's from non-static pool", so update all map
creations to reflect that. INTRSAFE maps are maps that are used in
interrupt context (e.g. kmem_map, mb_map), and thus use the static
map entry pool (XXX as does kernel_map, for now). This will eventually
change now these maps are locked, as well.
managed pages, into KVA space. Since the pages are managed, we should
use pmap_enter(), not pmap_kenter_pa().
Also, when entering the mappings, enter with an access_type of
VM_PROT_READ | VM_PROT_WRITE. We do this for a couple of reasons:
(1) On systems that have H/W mod/ref attributes, the hardware
may not be able to track mod/ref done by a bus master.
(2) On systems that have to do mod/ref emulation, this prevents
a mod/ref page fault from potentially happening while in an
interrupt context, which can be problematic.
This latter change is fairly important if we ever want to be able to
transfer DMA-safe memory pages to anonymous memory objects; we will need
to know that the pages are modified, or else data could be lost!
Note that while the pages are unowned (i.e. "just DMA-safe memory pages"),
they won't consume any swap resources, as the mappings are wired, and
the pages aren't on the active or inactive queues.
the child inherits the stack pointer from the parent (traditional
behavior). Like the signal stack, the stack area is secified as
a low address and a size; machine-dependent code accounts for stack
direction.
This is required for clone(2).
define a flag UVM_PGA_USERESERVE to allow non-kernel object
allocations to use pages from the reserve.
use the new flag for allocations in pmap modules.
