check_sal_cache_flush is used to detect broken firmware that drops
pending interrupts.
The old implementation schedules a timer interrupt for itself in
the future by getting the current value of the Interval Timer
Counter + 1000 cycles, waits for the interrupt to be pended, calls
SAL_CACHE_FLUSH, and finally checks to see if the interrupt is
still pending.
This implementation can cause problems for virtual machine code if
the process of scheduling the timer interrupt takes more than 1000
cycles; the virtual machine can end up sleeping for several hundred
years while waiting for the ITC to wrap around.
The fix is to use platform_send_ipi. The processor will still send
an interrupt to itself, using the IA64_IPI_DM_INT delivery mode,
which causes the IPI to look like an external interrupt. The rest
of the SAL_CACHE_FLUSH + checking to see if the interrupt is still
pending remains unchanged.
This fix has been boot tested successfully on:
- intel tiger2
- hp rx6600
- hp rx5670
The rx5670 has known buggy firmware, where SAL_CACHE_FLUSH drops
pending interrupts. A boot test on this machine showed this message
on the console:
SAL: SAL_CACHE_FLUSH drops interrupts; PAL_CACHE_FLUSH will be used instead
Which proves that the self-inflicted IPI approach is viable. And
as expected, the other tested platforms correctly did not display
the warning.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
The sequence executed in check_sal_cache_flush:
- pend a timer interrupt
- call SAL_CACHE_FLUSH
- see if interrupt is still pending
can hang HP machines with buggy SAL_CACHE_FLUSH implementations.
Provide a kernel command-line argument to allow users skip this
check if desired. Using this parameter will force ia64_sal_cache_flush
to call ia64_pal_cache_flush() instead of SAL_CACHE_FLUSH.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This fixes regression introduced in 113134fcbc
Intel Tiger platforms hang when calling SAL_GET_PHYSICAL_ID_INFO
instead of properly returning -1 for unimplemented, so add a
version check.
SGI Altix platforms have an incorrect SAL version hard-coded into
their prom -- they encode 2.9, but actually implement 3.2 -- so
fix it up and allow ia64_sal_get_physical_id_info to keep
working.
Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Since kvm/module needs to use some unexported functions in kernel,
so export them with this patch.
Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Remove in-source externs, linux/init.h is included in all cases.
This is a fixups for "Dynamic kernel command-line" patch.
It also includes some uml __init fixups so that we can __initdata also its
command_line.
Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1. Rename saved_command_line into boot_command_line.
2. Set command_line as __initdata.
[akpm@osdl.org: move some declarations to the right place]
Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The check to see if the firmware drops interrupts during a
SAL_CACHE_FLUSH is done to early in the boot. SAL_CACHE_FLUSH expects
to be able to make PAL calls in virtual mode, on some cell based
machines a fault occurs causing a MCA. This patch moves the check
after mmu_context_init so the TLB and VHPT are properly setup.
Signed-off-by Troy Heber <troy.heber@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Sorry I didn't notice earlier, but that BUG_ON triggers for me on the
simulator. AFAICS the mask for itv is set in cpu_init(), which comes
after sal_init(). Consequently on the simulator the itv still has its
start value of zero. I've probably missed something, but I wonder why
at this stage of the boot you even need to save and restore the itv?
Signed-Off-By: Ian Wienand <ianw@gelato.unsw.edu.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>
If SAL_CACHE_FLUSH drops interrupts, complain about it and fall back to
using PAL_CACHE_FLUSH instead.
This is to work around a defect in HP rx5670 firmware: when an interrupt
occurs during SAL_CACHE_FLUSH, SAL drops the interrupt but leaves it marked
"in-service", which leaves the interrupt (and others of equal or lower
priority) masked.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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!
Alex Chiang
Zhang, Xiantao
Simon Arlott
Alon Bar-Lev
Troy Heber
Jörn Engel
Ian Wienand
Bjorn Helgaas
Linus Torvalds