diff options
| author | Sven Schnelle <svens@stackframe.org> | 2021-10-14 21:49:16 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2021-11-01 07:35:59 +0100 |
| commit | bc294838cc3443a2fbec58f8936ad4bd0a0b3055 (patch) | |
| tree | 50082d26870f6afd4a3a13814f4f98e11d08c27b /arch/parisc/Kconfig | |
| parent | ecac70366dce374014f070b7eacd5865a9ab3b13 (diff) | |
parisc: add support for TOC (transfer of control)
Almost all PA-RISC machines have either a button that
is labeled with 'TOC' or a BMC function to trigger a TOC.
TOC is a non-maskable interrupt that is sent to the processor.
This can be used for diagnostic purposes like obtaining a
stack trace/register dump or to enter KDB/KGDB.
As an example, on my c8000, TOC can be used with:
CONFIG_KGDB=y
CONFIG_KGDB_KDB=y
and the 'kgdboc=ttyS0,115200' appended to the command line.
Press ^[( on serial console, which will enter the BMC command line,
and enter 'TOC s':
root@(none):/# (
cli>TOC s
Sending TOC/INIT.
<Cpu3> 2800035d03e00000 0000000040c21ac8 CC_ERR_CHECK_TOC
<Cpu0> 2800035d00e00000 0000000040c21ad0 CC_ERR_CHECK_TOC
<Cpu2> 2800035d02e00000 0000000040c21ac8 CC_ERR_CHECK_TOC
<Cpu1> 2800035d01e00000 0000000040c21ad0 CC_ERR_CHECK_TOC
<Cpu3> 37000f7303e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu0> 37000f7300e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu2> 37000f7302e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu1> 37000f7301e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY
<Cpu3> 4300100803e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu0> 4300100800e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu2> 4300100802e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
<Cpu1> 4300100801e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC
Entering kdb (current=0x00000000411cef80, pid 0) on processor 0 due to NonMaskable Interrupt @ 0x40c21ad0
[0]kdb>
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/Kconfig')
| -rw-r--r-- | arch/parisc/Kconfig | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig index 906187a412ec..3296fcb90019 100644 --- a/arch/parisc/Kconfig +++ b/arch/parisc/Kconfig @@ -291,6 +291,20 @@ config SMP If you don't know what to do here, say N. +config TOC + bool "Support TOC switch" + default y if 64BIT || !SMP + help + Most PA-RISC machines have either a switch at the back of the machine + or a command in BMC to trigger a TOC interrupt. If you say Y here a + handler will be installed which will either show a backtrace on all + CPUs, or enter a possible configured debugger like kgdb/kdb. + + Note that with this option enabled, the kernel will use an additional 16KB + per possible CPU as a special stack for the TOC handler. + + If you don't want to debug the Kernel, say N. + config PARISC_CPU_TOPOLOGY bool "Support cpu topology definition" depends on SMP |