Recent 64-bit server processors (POWER6 and POWER7) have a "Come-From
Address Register" (CFAR), that records the address of the most recent
branch or rfid (return from interrupt) instruction for debugging purposes.

This saves the value of the CFAR in the exception entry code and stores
it in the exception frame.  We also make xmon print the CFAR value in
its register dump code.

Rather than extend the pt_regs struct at this time, we steal the orig_gpr3
field, which is only used for system calls, and use it for the CFAR value
for all exceptions/interrupts other than system calls.  This means we
don't save the CFAR on system calls, which is not a great problem since
system calls tend not to happen unexpectedly, and also avoids adding the
overhead of reading the CFAR to the system call entry path.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some of the 64bit PPC CPU features are MMU-related, so this patch moves
them to MMU_FTR_ bits.  All cpu_has_feature()-style tests are moved to
mmu_has_feature(), and seven feature bits are freed as a result.
Signed-off-by: NMatt Evans <matt@ozlabs.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Use the new MSR_64BIT in a few places. Some of these are already ifdef'ed
for BOOKE vs BOOKS, but it's still clearer, MSR_SF does not immediately
parse as "MSR bit for 64bit".
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Commit ddd588b5 ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():

	lib/lib.a(show_mem.o): In function `show_mem':
	show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
	arch/sparc/mm/built-in.o:(.text+0xd70): first defined here

The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.

Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reported-by: NJames Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Noone is using tty argument so let's get rid of it.
Acked-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: NJason Wessel <jason.wessel@windriver.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Using perf to trace L1 dcache misses and dumping data addresses I found a few
variables taking a lot of misses. Since they are almost never written, they
should go into the __read_mostly section.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch provides an extended_cede_processor() helper function
which takes the cede latency hint as an argument. This hint is to be passed
on to the hypervisor to cede to the corresponding state on platforms
which support it.
Signed-off-by: NGautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NArun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Prior to the arch/ppc -> arch/powerpc transition, xmon had support for single
stepping on 4xx boards.  The functionality was lost when arch/ppc was removed.
This patch restores single step support for 44x boards, and Book-E in general.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The xmon code relies on MSR_RI being non-zero to indicate that an exception
is recoverable.  If it is not, it prints a warning message.  However, the
PowerPC 4xx cores do not have an MSR_RI bit and this warning is produced for
every xmon event.

This introduces an unrecoverable_excp function to determine if an exception
is recoverable or not.  This gets rid of the erroneous warnings on 4xx.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This contains all the bits that didn't fit in previous patches :-) This
includes the actual exception handlers assembly, the changes to the
kernel entry, other misc bits and wiring it all up in Kconfig.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Gets rid of this warning:

arch/powerpc/xmon/xmon.c: In function 'dump_log_buf':
arch/powerpc/xmon/xmon.c:2133: warning: unused variable 'i'
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Hello All,

Quite a while back Michael Ellerman had posted a patch to add support to xmon to print the contents of the console log pointed to by __log_buf.
Here's the link to that patch - http://ozlabs.org/pipermail/linuxppc64-dev/2005-March/003657.html
I've ported the patch in the above link to 2.6.30-rc5 and have tested it.

Thanks & regards,
Vinay

Signed-off-by: Michael Ellerman <michael at ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Today the arch/powerpc/xmon/setjmp.S file contains only the
xmon_save_regs function.  We want to use it for kdump purposes, so
let's move the file into arch/powerpc/kernel/ and give the function a
more generic name (ppc_save_regs).
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This makes sure we don't try to call find_bug or is_warning_bug when
CONFIG_BUG=n and CONFIG_XMON=y.  Otherwise we get these errors:

arch/powerpc/xmon/xmon.c: In function ‘print_bug_trap’:
arch/powerpc/xmon/xmon.c:1364: error: implicit declaration of function ‘find_bug’
arch/powerpc/xmon/xmon.c:1364: warning: assignment makes pointer from integer without a cast
arch/powerpc/xmon/xmon.c:1367: error: implicit declaration of function ‘is_warning_bug’
arch/powerpc/xmon/xmon.c:1374: error: dereferencing pointer to incomplete type
make[2]: *** [arch/powerpc/xmon/xmon.o] Error 1
make[1]: *** [arch/powerpc/xmon] Error 2
make: *** [sub-make] Error 2
Signed-off-by: NPaul Mackerras <paulus@samba.org>

According to the CBEA, the SPU dsisr is not updated for class 0
exceptions.

spu_stopped() is testing the dsisr that was passed to it from the class
0 exception handler, so we return a false positive here.

This patch cleans up the interrupt handler and erroneous tests in
spu_stopped. It also removes the fields from the csa since it is not
needed to process class 0 events.
Signed-off-by: NLuke Browning <lukebrowning@us.ibm.com>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>

This is a little messier than I'd like because xmon.h only exists
on powerpc and we can't have a static inline and an extern declaration
visible at the same time.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

warning: Using plain integer as NULL pointer
warning: Using plain integer as NULL pointer
warning: symbol 'excprint' was not declared. Should it be static?
warning: symbol 'prregs' was not declared. Should it be static?
warning: symbol 'cacheflush' was not declared. Should it be static?
warning: symbol 'read_spr' was not declared. Should it be static?
warning: symbol 'write_spr' was not declared. Should it be static?
warning: symbol 'super_regs' was not declared. Should it be static?
warning: symbol 'mread' was not declared. Should it be static?
warning: symbol 'mwrite' was not declared. Should it be static?
warning: symbol 'byterev' was not declared. Should it be static?
warning: symbol 'memex' was not declared. Should it be static?
warning: symbol 'bsesc' was not declared. Should it be static?
warning: symbol 'dump' was not declared. Should it be static?
warning: symbol 'prdump' was not declared. Should it be static?
warning: symbol 'generic_inst_dump' was not declared. Should it be static?
warning: symbol 'ppc_inst_dump' was not declared. Should it be static?
warning: symbol 'memops' was not declared. Should it be static?
warning: symbol 'memdiffs' was not declared. Should it be static?
warning: symbol 'memlocate' was not declared. Should it be static?
warning: symbol 'memzcan' was not declared. Should it be static?
warning: symbol 'proccall' was not declared. Should it be static?
warning: symbol 'scannl' was not declared. Should it be static?
warning: symbol 'hexdigit' was not declared. Should it be static?
warning: symbol 'flush_input' was not declared. Should it be static?
warning: symbol 'inchar' was not declared. Should it be static?
warning: symbol 'take_input' was not declared. Should it be static?
warning: symbol 'xmon_init' was not declared. Should it be static?
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

SPU class 0 & 1 exceptions may occur in parallel, so we may end up
overwriting csa.dsisr.

This change adds dedicated fields for each class to the spu and the spu
context so that fault data is not overwritten.
Signed-off-by: NLuke Browning <lukebr@linux.vnet.ibm.com>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>

This moves various definitions used all over the place to parse stack
frames to ptrace.h so only one definition is needed.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Now that we have the alpaca, the reg_save_ptr is no longer needed in the
paca.  Eradicate all global uses of it and make it static in the iSeries
lpardata.c
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This makes the setjmp/longjmp code used by xmon, generically available
to other code.  It also removes the requirement for debugger hooks to
be only called on 0x300 (data storage) exception.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds a bit more detail to the xmon SLB output.  When the valid
bit is set, this displays the ESID and VSID values, as well as
decoding the segment size -- 1T or 256M -- and displaying the LLP
bits.  This supresses the output for any slb entries that contain only
zeros.

sample output from power6 (1T segment support):
00 c000000008000000 40004f7ca3000500  1T  ESID=   c00000  VSID=       4f7ca3 LLP:100
01 d000000008000000 4000eb71b0000400  1T  ESID=   d00000  VSID=       eb71b0 LLP:  0
08 0000000018000000 0000c8499f8ccc80 256M ESID=        1  VSID=    c8499f8cc LLP:  0
09 00000000f8000000 0000d2c1a8e46c80 256M ESID=        f  VSID=    d2c1a8e46 LLP:  0
10 0000000048000000 0000ca87eab1dc80 256M ESID=        4  VSID=    ca87eab1d LLP:  0
43 cf00000008000000 400011b260000500  1T  ESID=   cf0000  VSID=       11b260 LLP:100

sample output from power5 (notice the non-valid but non-zero entries)
10 0000000008000000 00004fd0e077ac80 256M ESID=        0  VSID=    4fd0e077a LLP:  0
11 00000000f8000000 00005b085830fc80 256M ESID=        f  VSID=    5b085830f LLP:  0
12 0000000048000000 000052ce99fe6c80 256M ESID=        4  VSID=    52ce99fe6 LLP:  0
13 0000000018000000 000050904ed95c80 256M ESID=        1  VSID=    50904ed95 LLP:  0
14 cf00000008000000 0000d59aca40f500 256M ESID=cf0000000  VSID=    d59aca40f LLP:100
15 c000000078000000 000045cb97751500 256M ESID=c00000007  VSID=    45cb97751 LLP:100

Tested on power5 and power6.
Signed-Off-By: NWill Schmidt <will_schmidt@vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Currently we hardwire the number of SLBs to 64, but PAPR says we
should use the ibm,slb-size property to obtain the number of SLB
entries.  This uses this property instead of assuming 64.  If no
property is found, we assume 64 entries as before.

This soft patches the SLB handler, so it shouldn't change performance
at all.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds a function to xmon to dump the content of the 44x processor
TLB with a little bit of decoding (but not much).
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

In some configuration, xmon help string is larger than xmon_printf
buffer.  We need not to use printf.  This patch adds xmon_puts and
change to use it to show help string.
Signed-off-by: NKou Ishizaki <kou.ishizaki@toshiba.co.jp>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

xmon_early and xmon_off are only used in this file.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Several kallsyms_lookup() pass dummy arguments but only need, say, module's
name.  Make kallsyms_lookup() accept NULLs where possible.

Also, makes picture clearer about what interfaces are needed for all symbol
resolving business.
Signed-off-by: NAlexey Dobriyan <adobriyan@sw.ru>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Whenever we enter xmon we get a WARN_ON out of the rtas code since it
thinks interrupts are still on:

Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xd000000000080008
cpu 0x3: Vector: 300 (Data Access) at [c0000000075dba00]
    pc: d000000000080008: .doit+0x8/0x40 [oopser]
    lr: c000000000077704: .sys_init_module+0x1664/0x1824
    sp: c0000000075dbc80
   msr: 9000000000009032
   dar: 0
 dsisr: 42000000
  current = 0xc000000003fa64b0
  paca    = 0xc000000000694280
    pid   = 2260, comm = insmod

------------[ cut here ]------------
Badness at arch/powerpc/kernel/entry_64.S:651
Call Trace:
[C0000000075DAE70] [C00000000000EB64] .show_stack+0x68/0x1b0 (unreliable)
[C0000000075DAF10] [C000000000216254] .report_bug+0x94/0xe8
[C0000000075DAFA0] [C00000000047B140] __kprobes_text_start+0x178/0x584
[C0000000075DB040] [C0000000000044F4] program_check_common+0xf4/0x100
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

My patch to add spu disassembly (af89fb80)
removed a newline from the xmon help that it shouldn't have, put it back.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

It doesn't make any sense to have a priority field in the physical spu
structure.  Move it into the spu context instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

This makes powerpc use the generic BUG machinery.  The biggest reports the
function name, since it is redundant with kallsyms, and not needed in general.

There is an overall reduction of code, since module_32/64 duplicated several
functions.

Unfortunately there's no way to tell gcc that BUG won't return, so the BUG
macro includes a goto loop.  This will generate a real jmp instruction, which
is never used.

[akpm@osdl.org: build fix]
[paulus@samba.org: remove infinite loop in BUG_ON]
Signed-off-by: NJeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

xmon still does not run on iSeries, but this allows us to build a combined
kernel that includes it.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

It may be desireable to build a kernel for cell without
spufs, e.g. as the initial kboot kernel. This requires
that the SPU specific parts of the core dump and the xmon
code depend on CONFIG_SPU_BASE instead of CONFIG_PPC_CELL.
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

This fixes the xmon support for the cell spu to be compatable with the split
spu platform code.
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

While adding spu disassembly support it struck me that we're actually
carrying quite a lot of code around, just to do disassembly in the case
of a crash.

While on large systems it's not an issue, on smaller ones it might be
nice to have xmon - but without the weight of the disassembly support.
For a Cell build this saves ~230KB (!), and for pSeries ~195KB.

We still support the 'di' and 'sdi' commands, however they just dump
the instruction in hex.

Move the definitions into a header to clean xmon.c just a tiny bit.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

This patch adds a "sdi" command to xmon, to disassemble the contents
of an spu's local store.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

In order to do disassembly of spu binaries in xmon, we need to abstract
the disassembly function from ppc_inst_dump.

We do this by making the actual disassembly function a function pointer
that we pass to ppc_inst_dump(). To save updating all the callers, we
turn ppc_inst_dump() into generic_inst_dump() and make ppc_inst_dump()
a wrapper which always uses print_insn_powerpc().

Currently we pass the dialect into print_insn_powerpc(), but we always
pass 0 - so just make it a local.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>

Add a command to xmon to dump the memory of a spu's local store.
This mimics the 'd' command which dumps regular memory, but does
a little hand holding by taking the user supplied address and
finding that offset in the local store for the specified spu.

This makes it easy for example to look at what was executing on a spu:

1:mon> ss
...
Stopped spu 04 (was running)
...
1:mon> sf 4
Dumping spu fields at address c0000000019e0a00:
...
  problem->spu_npc_RW     = 0x228
...
1:mon> sd 4 0x228
d000080080318228 01a00c021cffc408 4020007f217ff488  |........@ ..!...|

Aha, 01a00c02, which is of course rdch $2,$ch24 !

--

Updated to only do the setjmp goo around the spu access, and not
around prdump because it does its own (via mread).

Also the num variable is now common between sf and sd, so you don't
have to keep typing the spu number in if you're repeating commands
on the same spu.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NArnd Bergmann <arnd.bergmann@de.ibm.com>