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| author | Patrick Williams <iawillia@us.ibm.com> | 2012-02-16 17:22:51 -0600 |
|---|---|---|
| committer | A. Patrick Williams III <iawillia@us.ibm.com> | 2012-02-20 13:09:02 -0600 |
| commit | 15713df3152439e6f3083442ce25e5d94b131c39 (patch) | |
| tree | 254a8602af9b41376cf4af93d02b479a36e9c666 /src/kernel | |
| parent | 795d84dc772c9ba7dc7921b6e784e51b003cd2e2 (diff) | |
| download | talos-hostboot-15713df3152439e6f3083442ce25e5d94b131c39.tar.gz talos-hostboot-15713df3152439e6f3083442ce25e5d94b131c39.zip | |
Handle hype_fac_unavail exception.
The P8 processor (in RFC02230 targeted for ISA 2.07) adds a
new SPR register HFSCR (Hypervisor Facility Status and Control
Register). This register allows the hypervisor to disable
access to some resources, such as floating point and VSX,
from a partition. The purpose of this is to save time in
saving the partition context when switching partitions.
Since we sometimes enable floating point instructions we need
to also enable the HFSCR[FP]. We could do this when enabling
floating point in the MSR, but the SPR does not exist in P7.
Instead we'll do it as-needed on the hw-thread the first time
it executes a FP instruction. The FP instruction will cause
the hype_fac_unavail exception and the exception handler will
set HFSCR appropriately.
Change-Id: I6c1e75939bb59142cbcf692fa56deb2271d6bdc3
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/676
Tested-by: Jenkins Server
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Douglas R. Gilbert <dgilbert@us.ibm.com>
Reviewed-by: A. Patrick Williams III <iawillia@us.ibm.com>
Diffstat (limited to 'src/kernel')
| -rw-r--r-- | src/kernel/start.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/kernel/start.S b/src/kernel/start.S index 1deaf46f1..c5af8652f 100644 --- a/src/kernel/start.S +++ b/src/kernel/start.S @@ -188,6 +188,22 @@ UNIMPL_INTERRUPT(perf_monitor, 0xF00) UNIMPL_INTERRUPT(vector_unavail, 0xF20) UNIMPL_INTERRUPT(vsx_unavail, 0xF40) +UNIMPL_INTERRUPT(fac_unavail, 0xF60) + + ;// P8 has a new HFSCR register which allows the hypervisor to disable + ;// access to facilities such as floating point to a partition, even if + ;// the partition enables via the MSR bits. Since the only of these + ;// facilities we allow is FP, we'll just set the HFSCR bits here if we + ;// get this exception. +.org _start + 0xF80 +hype_fac_unavail: + mtspr HSPRG0, r0 ;// Free up a temporary register. + mfspr r0,HFSCR + ori r0, r0, 1 ;// Set FP=1 (bit 63). + mtspr HFSCR, r0 + mfspr r0, HSPRG0 ;// Restore temporary + hrfid + ;// Softpatch Exception Vector ;// ;// This exception vector implements the softpatch / denormalization assist |
