This adds an emulation layer for implementations
that lack the l.lwa and l.swa instructions.
It handles these instructions both in kernel space and
user space.
Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
[shorne@gmail.com: Added delay slot pc adjust logic]
Signed-off-by: Stafford Horne <shorne@gmail.com>
During page fault handling we check the last instruction to understand
if the fault was for a read or for a write. By default we fall back to
read. New instructions were added to the openrisc 1.1 spec for an
atomic load/store pair (l.lwa/l.swa).
This patch adds the opcode for l.swa (0x33) allowing it to be treated as
a write operation.
Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
[shorne@gmail.com: expanded a bit on the comment]
Signed-off-by: Stafford Horne <shorne@gmail.com>
Fix signal handling for when signals are handled as the result of timers
or exceptions, previous code assumed syscalls. This was noticeable with X
crashing where it uses SIGALRM.
This patch restores all regs before returning to userspace via
_resume_userspace instead of via syscall return path.
The rt_sigreturn syscall is more like a context switch than a function
call; it entails a return from one context (the signal handler) to another
(the process in question). For a context switch like this there are
effectively no call-saved regs that remain constant across the transition.
Reported-by: Sebastian Macke <sebastian@macke.de>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Tested-by: Guenter Roeck <linux@roeck-us.net>
[shorne@gmail.com: Updated comment better reflect change and issue]
Signed-off-by: Stafford Horne <shorne@gmail.com>
The mainline signal handling code for OpenRISC has been buggy since day
one with respect to syscall restart. This patch significantly reworks
the signal handling code:
i) Move the "work pending" loop to C code (borrowed from ARM arch)
ii) Allow a tracer to muck about with the IP and skip syscall restart
in that case (again, borrowed from ARM)
iii) Make signal handling WRT syscall restart actually work
v) Make the signal handling code look more like that of other
architectures so that it's easier for others to follow
Reported-by: Anders Nystrom <anders@southpole.se>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Pull OpenRISC updates from Jonas Bonn:
"An equal number of bug fixes and trivial cleanups; no new features.
- Two patches to fix errors thrown by the updated toolchain.
- Three other bug fixes.
- Four trivial cleanups."
* 'for-upstream' of git://openrisc.net/jonas/linux:
openrisc: add missing header inclusion
openrisc: really pass correct arg to schedule_tail
Add bitops include needed for ext2 filesystem
openrisc: update DTLB-miss handler last
openrisc: fix up vmalloc page table loading
openrisc idle: delete pm_idle
openrisc: remove CONFIG_SYMBOL_PREFIX
openrisc: avoid using function parameter regs in reset vector
openrisc: remove unused current_regs
Commit 287ad220cd tried to set up the argument
to schedule_tail, but ended up using TI_STACK which isn't a defined symbol.
Sadly, the old openrisc compiler silently ignores this fact and it was first
discovered now when building with an updated toolchain.
Reported-by: Christian Svensson <blue@cmd.nu>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
vmalloc'ed pages are faulted into a process' page tables on demand. In
order to facilitate this, do_page_fault needs to know whether it was
called via a page fault exception or a TLB-miss exception.
This patch adds a wrapper around the _x_page_fault_handler entry points
that the TLB-miss exceptions can call into in order to have the relevant
parameter set to satisfy do_page_fault.
This fixes a bug and is "good enough" for now. That said, this whole
handling of vmalloc needs to be audited for correctness at some point.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
schedule_tail() requires that the 'prev' task be passed as an argument
to it. This arg is set in _switch, just before 'returning' to one of
the ret_* functions where schedule_tail is invoked.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
The function sys_or1k_atomic was using call-saved registers without
restoring their value before returning. This is a faux pas: either
we need to restore their values or use scratch regs; the latter is
less code so that's the route this patch takes.
Thanks to David Hennerström for doing most of the heavy-lifting in
tracking this one down.
Reported-by: Davd Hennerström <david.hennerstrom@aacmicrotec.com>
Signed-off-by: Jonas Bonn <jonas@southpole.se>
The pt_regs struct had both a 'syscallno' field and an 'orig_gpr11' field
and it wasn't really clear how these were supposed to be used. This patch
removes the syscallno field altogether and makes orig_gpr11 work more
like other architectures: keep track of syscall number in progress or
hold -1 for non-syscall exceptions.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Architecture code and early setup routines for booting Linux.
Signed-off-by: Jonas Bonn <jonas@southpole.se>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
