Since commit 2ada0ed, "Return From Interrupt" is broken for PPC processors
because some interrupt specifics bits of SRR1 are copied to MSR.
SRR1 is a save of MSR during interrupt.
During RFI, MSR must be restored from SRR1.
But some bits of SRR1 are interrupt-specific and are not used for MSR saving.
This is the specification (ISA 2.06) at chapter 6.4.3 (Interrupt Processing):
"2. Bits 33:36 and 42:47 of SRR1 or HSRR1 are loaded with information specific
to the interrupt type.
3. Bits 0:32, 37:41, and 48:63 of SRR1 or HSRR1 are loaded with a copy of the
corresponding bits of the MSR."
Below is a representation of MSR bits which are not saved:
0:15 16:31 32 33:36 37:41 42:47 48:63
——— | ——— | — X X X X — — — — — X X X X X X | ————
0000 0000 | 7 | 8 | 3 | F | 0000
History:
In the initial Qemu implementation (e1833e1), the mask 0x783F0000 was used for
saving MSR in SRR1. But all the bits 32:47 were cleared during RFI restoring.
This was wrong. The commit 2ada0ed explains that this breaks Altivec.
Indeed, bit 38 (for Altivec support) must be saved and restored.
The change of 2ada0ed was to restore all the bits of SRR1 to MSR.
But it's also wrong.
Explanation:
As an example, let's see what's happening after a TLB miss.
According to the e300 manual (E300CORERM table 5-6), the TLB miss interrupts
set the bits 44-47 for KEY, I/D, WAY and S/L. These bits are specifics to the
interrupt and must not be copied into MSR at the end of the interrupt.
With the current implementation, a TLB miss overwrite bits POW, TGPR and ILE.
Fix:
It shouldn't be needed to filter-out bits on MSR saving when interrupt occurs.
Specific bits overwrite MSR ones in SRR1.
But at the end of interrupt (RFI), specifics bits must be cleared before
restoring MSR from SRR1. The mask 0x783F0000 apply here.
Discussion:
The bits of the mask 0x783F0000 are cleared after an interrupt.
I cannot find a specification which talks about this
but I assume it is the truth since Linux can run this way.
Maybe it's not perfect but it's better (works for e300).
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
The recent transition to always have the DCR helper functions take 32 bit
values broke the PPC64 target, as target_long became 64 bits there.
This patch changes DCR helpers to target_long arguments, and cast the values
to 32 bit when needed.
Fixes PPC64 build with --enable-debug-tcg
Based on a patch from Alexander Graf <agraf@suse.de>
Reported-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
For what I know DCR is always 32 bits wide, so we should also use uint32_t to
pass it along the stacks.
This fixes a warning when compiling qemu-system-ppc64 with KVM enabled, making
it compile without --disable-werror
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Fix the alternate time base the same way as the default timebase. SPR_ATBL
should return a 64-bit value on 64 bit implementations.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
On PPC we have a 64-bit time base. Usually (PPC32) this is accessed using
two separate 32 bit SPR accesses to SPR_TBU and SPR_TBL.
On PPC64 the SPR_TBL register acts as 64 bit though, so we get the full
64 bits as return value. If we only take the lower ones, fine. But Linux
wants to see all 64 bits or it breaks.
This patch makes PPC64 Linux work even after TB crossed the 32-bit boundary,
which usually happened a few seconds after bootup.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
In the very least, a change like this requires discussion on the list.
The naming convention is goofy and it causes a massive merge problem. Something
like this _must_ be presented on the list first so people can provide input
and cope with it.
This reverts commit 99a0949b72.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We do this so we can check on the corresponding stc{w,d}x. whether the
value has changed. It's a poor man's form of implementing atomic
operations and is valid only for NPTL usermode Linux emulation.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: malc <av1474@comtv.ru>
Work around buffer and ioctlsocket argument type signedness problems
Suppress a prototype which is unused on mingw32
Expand a macro to avoid warnings from some GCC versions
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The current implementation masks some MSR bits from SRR1 as it is
given on rfi(d). This looks pretty wrong and breaks Altivec.
Signed-off-by: Alexander Graf <alex@csgraf.de>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6754 c046a42c-6fe2-441c-8c8c-71466251a162
In order to modify SLB entries on recent PPC64 machines, the slbmte
instruction is used.
This patch implements the slbmte instruction and makes the "bridge"
mode code use the slb set functions, so we can move the SLB into
the CPU struct later.
This is required for Linux to run on PPC64.
Signed-off-by: Alexander Graf <alex@csgraf.de>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6747 c046a42c-6fe2-441c-8c8c-71466251a162
These simplify the implementation of the floating-point Altivec
instructions and reduce clutter.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6511 c046a42c-6fe2-441c-8c8c-71466251a162
Do this so we can set float statuses once per mtvscr, rather than once
per Altivec instruction.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6508 c046a42c-6fe2-441c-8c8c-71466251a162
Only one of Altivec and SPE will be available on a given chip.
Signed-off-by: Nathan Froyd <froydnj@codesourcery.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6506 c046a42c-6fe2-441c-8c8c-71466251a162
This is a large patch that changes all occurrences of logfile/loglevel
global variables to use the new qemu_log*() macros.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6338 c046a42c-6fe2-441c-8c8c-71466251a162
Use macros to avoid #ifdefs on debugging code.
This patch doesn't try to merge logging macros from different files,
but just unify the debugging code #ifdefs onto a macro on each file. A
further cleanup can unify the debugging macros on a common header, later
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6332 c046a42c-6fe2-441c-8c8c-71466251a162
