On machines with more than one exception level any system register that
might be modified by the "normal" exception level needs to be saved and
restored on taking a higher level exception. We already are saving
and restoring ESR and DEAR.
For critical level add SRR0/1.
For debug level add CSRR0/1 and SRR0/1.
For machine check level add DSRR0/1, CSRR0/1, and SRR0/1.
On FSL Book-E parts we always save/restore the MAS registers for critical,
debug, and machine check level exceptions. On 44x we always save/restore
the MMUCR.
Additionally, we save and restore the ksp_limit since we have to adjust it
for each exception level.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
* Cleanup the code a bit my allocating an INT_FRAME on our exception
stack there by make references go from GPR11-INT_FRAME_SIZE(r8) to
just GPR11(r8)
* simplify {lvl}_transfer_to_handler code by moving the copying of the
temp registers we use if we come from user space into the PROLOG
* If the exception came from kernel mode copy thread_info flags,
preempt, and task pointer from the process thread_info.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
For the additonal exception levels (critical, debug, machine check) on
40x/book-e we were using "static" allocations of the stack in the
associated head.S.
Move to a runtime allocation to make the code a bit easier to read as
we mimic how we handle IRQ stacks. Its also a bit easier to setup the
stack with a "dummy" thread_info in C code.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
We use the low bits of regs->trap as flag bits. We already indicate
critical and machine check level exceptions via this mechanism. Extend it
to indicate debug level exceptions.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The architecture allows for "Book-E" style debug interrupts to either go
to critial interrupts of their own debug interrupt level. To allow for
a dynamic kernel to support machines of either type we want to be able to
compile in the interrupt handling code for both exception levels.
Towards this goal we renamed the debug handling macros to specify the
interrupt level in their name (DEBUG_CRIT_EXCEPTION/DebugCrit and
DEBUG_DEBUG_EXCEPTION/DebugDebug).
Additionally, on the Freescale Book-e parts we expanded the exception
stacks to cover the maximum case of needing three exception stacks (normal,
machine check and debug).
There is some kernel text space optimization to be gained if a kernel is
configured for a specific Freescale implementation but we aren't handling
that now to allow for the single kernel image support.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This adds a cputable function pointer for the CPU-side machine
check handling. The semantic is still the same as the old one,
the one in ppc_md. overrides the one in cputable, though
ultimately we'll want to change that so the CPU gets first.
This removes CONFIG_440A which was a problem for multiplatform
kernels and instead fixes up the IVOR at runtime from a setup_cpu
function. The "A" version of the machine check also tweaks the
regs->trap value to differenciate the 2 versions at the C level.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Updated FP unavailable exception to refer to the correct
function in traps.c. head_booke.h was using the old name, KernelFP,
instead of kernel_fp_unavailable_exception.
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Updated patch for support for mpc8540_ads in arch/powerpc with a
flat OF device tree. This patch does not yet support PCI or I2C.
Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Signed-off-by: Jon Loeliger <jdl@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Kumar Gala
Benjamin Herrenschmidt
Becky Bruce