Embedded.Hypervisor category defines GSPRG0..3 physical registers for guests.
Avoid SPRG4-7 usage as scratch in host exception handlers, otherwise guest
SPRG4-7 registers will be clobbered.
For bolted TLB miss exception handlers, which is the version currently
supported by KVM, use SPRN_SPRG_GEN_SCRATCH aka SPRG0 instead of
SPRN_SPRG_TLB_SCRATCH aka SPRG6. Keep using TLB PACA slots to fit in one
64-byte cache line.
For critical exception handlers use SPRG3 instead of SPRG7. Provide a routine
to store and restore user-visible SPRGs. This will be subsequently used
to restore VDSO information in SPRG3. Add EX_R13 to paca slots to free up
SPRG3 and change the critical exception epilog to use it.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Guest Doorbell interrupts use guest save and restore registers. Add a new
Guest Doorbell exception type to accommodate GSRR0/1 SPRs usage in exception
prolog and fix the exception handler.
Signed-off-by: NMihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On MMUs such as FSL where we can guarantee the entire linear mapping is
bolted, we don't need to worry about linear TLB misses.  If on top of
that we do a full table walk, we get rid of all recursive TLB faults, and
can dispense with some state saving.  This gains a few percent on
TLB-miss-heavy workloads, and around 50% on a benchmark that had a high
rate of virtual page table faults under the normal handler.

While touching the EX_TLB layout, remove EX_TLB_MMUCR0, EX_TLB_SRR0, and
EX_TLB_SRR1 as they're not used.

[BenH: Fixed build with 64K pages (wsp config)]
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Not all 64-bit Book-3E parts will have fixed IVORs so add a function that
cpusetup code can call to setup the base IVORs (0..15) to match the fixed
offsets.  We need to 'or' part of interrupt_base_book3e into the IVORs
since on parts that have them the IVPR doesn't extend as far down.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This adds various definitions and macros used by the exception and TLB
miss handling on 64-bit BookE

It also adds the definitions of the SPRGs used for various exception types
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>