If an assembly function that calls back into c code is exported to
modules, we need to ensure r2 is setup correctly. There are only
two places crazy enough to do it (two of which are my fault).
Signed-off-by: Anton Blanchard <anton@samba.org>
ELFv2 doesn't use function descriptors, because it doesn't need to
load a new r2 when calling into a function. On the other hand, you're
supposed to use a local entry point for R_PPC_REL24 branches.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In ELFv2, r12 is supposed to equal to PC on entry to a function.
Our stubs use r11, so change swap that with r12.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ELFv2 doesn't use function descriptors, so we don't expect symbols to
start with ".". But because depmod and modpost strip ".", and we have
the special symbol ".TOC.", we still need to do it.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The new ELF ABI tends to use R_PPC64_REL16_LO and R_PPC64_REL16_HA
relocations (PC-relative), so implement them.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The kernel resolved the '.TOC.' to a fake symbol, so we need to fix it up
to point to our .toc section plus 0x8000.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For the ELFv2 ABI, powerpc introduces a magic symbol ".TOC.". If we
don't create a CRC for it (minus the leading ".", since we strip that)
we get a modpost warning about missing CRC and the CRC array seems to
be displaced by 1 so other CRCs mismatch too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
For the ELFv2 ABI, powerpc introduces a magic symbol ".TOC.". depmod
then complains that this doesn't resolve (so does modpost, but we could
easily fix that). To export this, we need to use asm.
modpost and depmod both strip "." from symbols for the old PPC64 ELFv1
ABI, so we actually export a "TOC.".
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There is no need to put a function descriptor in
__secondary_hold_spinloop. Use ppc_function_entry to get the
instruction address and put it in __secondary_hold_spinloop instead.
Also fix an issue where we assumed cur_cpu_spec held a function
descriptor.
Signed-off-by: Anton Blanchard <anton@samba.org>
TRACE_WITH_FRAME_BUFFER creates 32 byte stack frames. On ppc64
ABIv1 this is too small and a callee could corrupt the stack by
writing to the parameter save area (starting at offset 48).
Signed-off-by: Anton Blanchard <anton@samba.org>
Some of the assembler files in lib/ make use of the fact that in the
ELFv1 ABI, the caller guarantees to provide stack space to save the
parameter registers r3 ... r10. This guarantee is no longer present
in ELFv2 for functions that have no variable argument list and no
more than 8 arguments.
Change the affected routines to temporarily store registers in the
red zone and/or the top of their own stack frame (in the space
provided to save r31 .. r29, which is actually not used in these
routines).
In opal_query_takeover, simply always allocate a stack frame;
the routine is not performance critical.
Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Change how we setup registers for ret_from_kernel_thread. In
ABIv1, instead of passing a function descriptor in, dereference
it and pass the target in directly.
Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2.
Signed-off-by: Anton Blanchard <anton@samba.org>
The MMU hashtable and SLB branch patching code uses function
pointers for the update sites. This creates a difference between
ABIv1 and ABIv2 because we don't have function descriptors on
ABIv2.
Get rid of the function pointer and just point at the update
sites directly. This works on both ABIs.
Signed-off-by: Anton Blanchard <anton@samba.org>
To establish addressability quickly, ABIv2 requires the target
address of the function being called to be in r12. Fix a number of
places in assembly code that we do indirect function calls.
We need to avoid function descriptors on ABIv2 too.
Signed-off-by: Anton Blanchard <anton@samba.org>
Anton Blanchard
Rusty Russell
Ulrich Weigand