Meelis Roos reported that kernels built with gcc-4.9 do not boot, we
eventually narrowed this down to only impacting machines using
UltraSPARC-III and derivitive cpus.

The crash happens right when the first user process is spawned:

[   54.451346] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[   54.451346]
[   54.571516] CPU: 1 PID: 1 Comm: init Not tainted 3.16.0-rc2-00211-gd7933ab7 #96
[   54.666431] Call Trace:
[   54.698453]  [0000000000762f8c] panic+0xb0/0x224
[   54.759071]  [000000000045cf68] do_exit+0x948/0x960
[   54.823123]  [000000000042cbc0] fault_in_user_windows+0xe0/0x100
[   54.902036]  [0000000000404ad0] __handle_user_windows+0x0/0x10
[   54.978662] Press Stop-A (L1-A) to return to the boot prom
[   55.050713] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004

Further investigation showed that compiling only per_cpu_patch() with
an older compiler fixes the boot.

Detailed analysis showed that the function is not being miscompiled by
gcc-4.9, but it is using a different register allocation ordering.

With the gcc-4.9 compiled function, something during the code patching
causes some of the %i* input registers to get corrupted.  Perhaps
we have a TLB miss path into the firmware that is deep enough to
cause a register window spill and subsequent restore when we get
back from the TLB miss trap.

Let's plug this up by doing two things:

1) Stop using the firmware stack for client interface calls into
   the firmware.  Just use the kernel's stack.

2) As soon as we can, call into a new function "start_early_boot()"
   to put a one-register-window buffer between the firmware's
   deepest stack frame and the top-most initial kernel one.
Reported-by: NMeelis Roos <mroos@linux.ee>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prom_init() returns void.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we switched sparc from using 'int's to 'phandle's (which is a u32), we
neglected to do anything with the various checks for -1.  For those tests,
explicitly cast the phandles to s32.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Completely unused.

Based upon a patch by Julian Calaby.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than passing around ints everywhere, use the
phandle type where appropriate for the various functions
that talk to the PROM.
Signed-off-by: NAndres Salomon <dilinger@queued.net>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

- all files with identical names copied and renamed to *_64.c
- the remaning files copied as is
- added sparc64 specific files to sparc/prom/Makefile
- teach sparc64 Makefile to look into sparc/prom/
- delete unused Makefile from sparc64/prom/

linking order was not kept for sparc64 with this change.
It was not possible to keep linking order for both sparc and sparc64
and as sparc64 see more testing than sparc it was natural to
break linking order on sparc64. Should it have any effect it
would be detected sooner this way.

printf_32.c and printf_64.c are obvious candidates to be merged
but they are not 100% equal so that was left for later
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the CVS keywords that weren't updated for a long time
from comments.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The early per-cpu handling needs a slight tweak to work when booting
on a non-zero cpu.

We got away with this for a long time, but can't any longer as now
even printk() calls functions (cpu_clock() for example) that thus make
early references to per-cpu variables.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Report 'sun4v' when appropriate in /proc/cpuinfo

Remove all the verifications of the OBP version string.  Just
make sure it's there, and report it raw in the bootup logs and
via /proc/cpuinfo.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We look for "SUNW,sun4v" in the 'compatible' property
of the root OBP device tree node.

Protect every %ver register access, to make sure it is
not touched on sun4v, as %ver is hyperprivileged there.

Lock kernel TLB entries using hypervisor calls instead of
calls into OBP.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No longer used.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of all of this cpu-specific code to remap the kernel
to the correct location, use portable firmware calls to do
this instead.

What we do now is the following in position independant
assembler:

	chosen_node = prom_finddevice("/chosen");
	prom_mmu_ihandle_cache = prom_getint(chosen_node, "mmu");
	vaddr = 4MB_ALIGN(current_text_addr());
	prom_translate(vaddr, &paddr_high, &paddr_low, &mode);
	prom_boot_mapping_mode = mode;
	prom_boot_mapping_phys_high = paddr_high;
	prom_boot_mapping_phys_low = paddr_low;
	prom_map(-1, 8 * 1024 * 1024, KERNBASE, paddr_low);

and that replaces the massive amount of by-hand TLB probing and
programming we used to do here.

The new code should also handle properly the case where the kernel
is mapped at the correct address already (think: future kexec
support).

Consequently, the bulk of remap_kernel() dies as does the entirety
of arch/sparc64/prom/map.S

We try to share some strings in the PROM library with the ones used
at bootup, and while we're here mark input strings to oplib.h routines
with "const" when appropriate.

There are many more simplifications now possible.  For one thing, we
can consolidate the two copies we now have of a lot of cpu setup code
sitting in head.S and trampoline.S.

This is a significant step towards CONFIG_DEBUG_PAGEALLOC support.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!