Some machine classes need to allow VFP support to be built into the
kernel, but still allow the kernel to run even though VFP isn't
present. Unfortunately, the kernel hard-codes VFP instructions
into the thread switch, which prevents this being run-time selectable.
Solve this by introducing a notifier which things such as VFP can
hook into to be informed of events which affect the VFP subsystem
(eg, creation and destruction of threads, switches between threads.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from George G. Davis
The ARM VFP FPSCR register is corrupted when a condition flags modifying
VFP instruction is followed by a non-condition flags modifying VFP
instruction and both instructions raise exceptions. The fix is to
read the current FPSCR in between emulation of these two instructions
and use the current FPSCR value when handling the second exception.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The VFP code can leak VFP_NAN_FLAG into the FPSCR. It doesn't correspond
to any real FPSCR bit (and overlaps one of the exception flags).
Bug report from Daniel Jacobowitz
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Russell King