Change the strategy for using the FPU in the kernel. The kernel FPU state
is now shared with all processes/threads. As a result, you can now use the
FPU in true process context (instead of just in

Change the strategy for using the FPU in the kernel. The kernel FPU state
is now shared with all processes/threads. As a result, you can now use the
FPU in true process context (instead of just in kernel threads), but you
need to make sure you restore the default FPU state before calling
fpu_kernel_exit() if you change rounding mode, precision or exception masks.

Lots of discussion with thib@ and Mike Belopuhov.

ok thib@, deraadt@

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Don't leak the contents of the FPU and SSE registers between processes.

ok deraadt@

Make sure that the FPU IPIs shoot down the right FPU context and not the FPU
context of some random process that happened to be switched onto the FPU
after the decision was made to send the IPI.

fpu_kernel_{enter,exit}; Functions to allow the use of
the FPU in the kernel.

From Mike Belopuhov; Little bits by myself.

Comments/OK kettenis@

space nit and use nitems().

ok kettenis@

Fix "fp_save ipi didn't" panic, and move i386/amd64 closer in the process.
Positive test results by a handful of people. Ok kettenis@

fix some problems with lazy fpu context handling:
put the "fninit" where it belongs logically
deal with XMM exceptions
From NetBSD (drochner)

Kernel stack can be swapped. This means that stuff that's on the stack
should never be referenced outside the context of the process to which
this stack belongs unless we do the PHOLD/PRELE dance. Lo

Kernel stack can be swapped. This means that stuff that's on the stack
should never be referenced outside the context of the process to which
this stack belongs unless we do the PHOLD/PRELE dance. Loads of code
doesn't follow the rules here. Instead of trying to track down all
offenders and fix this hairy situation, it makes much more sense
to not swap kernel stacks.

From art@, tested by many some time ago.

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oops. forgot fnclex define (:

from todays freebsd advisory: fxrstor on amd cpu does not restore fip,fdp,fop thus leaking other proc's execution history; deraadt@ ok

Remove the advertising clause in the UCB license which Berkeley
rescinded 22 July 1999.
Checked by ian@, deraadt@ and millert@, arm portion checked by drahn@

count fpu lazy context switches; deraadt@ ok

SIGFPE signal codes.
ok deraadt@

Fix ldmxcsr asm macro.
ok deraadt@

SMP support. Big parts from NetBSD, but with some really serious debugging
done by me, niklas and others. Especially wrt. NXE support.

Still needs some polishing, especially in dmesg messages, but w

SMP support. Big parts from NetBSD, but with some really serious debugging
done by me, niklas and others. Especially wrt. NXE support.

Still needs some polishing, especially in dmesg messages, but we're now
building kernel faster than ever.

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Initialize MXCSR when FPU is first used. ok deraadt@

zap bad message; spotted by pvalchev

typo

an amd64 arch support.
hacked by art@ from netbsd sources and then later debugged
by me into the shape where it can host itself.
no bootloader yet as needs redoing from the
recent advanced i386 sourc

an amd64 arch support.
hacked by art@ from netbsd sources and then later debugged
by me into the shape where it can host itself.
no bootloader yet as needs redoing from the
recent advanced i386 sources (anyone? ;)

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