android_kernel_xiaomi_sm8350/arch
David S. Miller 4f0234f4f9 [SPARC64]: Initial LDOM cpu hotplug support.
Only adding cpus is supports at the moment, removal
will come next.

When new cpus are configured, the machine description is
updated.  When we get the configure request we pass in a
cpu mask of to-be-added cpus to the mdesc CPU node parser
so it only fetches information for those cpus.  That code
also proceeds to update the SMT/multi-core scheduling bitmaps.

cpu_up() does all the work and we return the status back
over the DS channel.

CPUs via dr-cpu need to be booted straight out of the
hypervisor, and this requires:

1) A new trampoline mechanism.  CPUs are booted straight
   out of the hypervisor with MMU disabled and running in
   physical addresses with no mappings installed in the TLB.

   The new hvtramp.S code sets up the critical cpu state,
   installs the locked TLB mappings for the kernel, and
   turns the MMU on.  It then proceeds to follow the logic
   of the existing trampoline.S SMP cpu bringup code.

2) All calls into OBP have to be disallowed when domaining
   is enabled.  Since cpus boot straight into the kernel from
   the hypervisor, OBP has no state about that cpu and therefore
   cannot handle being invoked on that cpu.

   Luckily it's only a handful of interfaces which can be called
   after the OBP device tree is obtained.  For example, rebooting,
   halting, powering-off, and setting options node variables.

CPU removal support will require some infrastructure changes
here.  Namely we'll have to process the requests via a true
kernel thread instead of in a workqueue.  workqueues run on
a per-cpu thread, but when unconfiguring we might need to
force the thread to execute on another cpu if the current cpu
is the one being removed.  Removal of a cpu also causes the kernel
to destroy that cpu's workqueue running thread.

Another issue on removal is that we may have interrupts still
pointing to the cpu-to-be-removed.  So new code will be needed
to walk the active INO list and retarget those cpus as-needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2007-07-16 04:04:40 -07:00
..
alpha PCI: Only build PCI syscalls on architectures that want them 2007-07-11 16:02:13 -07:00
arm Merge branch 'ioat-md-accel-for-linus' of git://lost.foo-projects.org/~dwillia2/git/iop 2007-07-13 10:52:27 -07:00
arm26
avr32 [AVR32] Update defconfigs 2007-06-23 15:43:48 +02:00
blackfin Blackfin arch: add missing CONFIG_LARGE_ALLOCS when upstream merging 2007-07-12 14:55:05 +08:00
cris
frv
h8300 h8300 trival patches 2007-06-01 08:18:29 -07:00
i386 Revert "[CPUFREQ] powernow-k8: clarify number of cores." 2007-07-13 10:43:52 -07:00
ia64 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2007-07-12 13:41:29 -07:00
m32r
m68k x86_64: Quieten Atari keyboard warnings in Kconfig 2007-06-20 14:27:26 -07:00
m68knommu m68knommu: fix ColdFire timer off by 1 2007-06-08 17:23:32 -07:00
mips [MIPS] Make show_code static and add __user tag 2007-07-13 17:40:01 +01:00
parisc [PARISC] unwinder improvements 2007-06-21 17:46:22 -04:00
powerpc the wrong variable checked after request_irq() 2007-07-15 16:40:51 -07:00
ppc Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6 2007-07-12 13:40:57 -07:00
s390 missing argument in bin_attribute ->read()/->write() 2007-07-15 16:40:52 -07:00
sh sh: Handle -ERESTART_RESTARTBLOCK for restartable syscalls. 2007-06-19 12:33:21 +09:00
sh64 sh64: Handle -ERESTART_RESTARTBLOCK for restartable syscalls. 2007-06-19 12:41:32 +09:00
sparc PCI: Only build PCI syscalls on architectures that want them 2007-07-11 16:02:13 -07:00
sparc64 [SPARC64]: Initial LDOM cpu hotplug support. 2007-07-16 04:04:40 -07:00
um uml: remove PAGE_SIZE from libc code 2007-06-16 13:16:16 -07:00
v850
x86_64 [CPUFREQ] the overdue removal of X86_SPEEDSTEP_CENTRINO_ACPI 2007-07-13 01:29:51 -04:00
xtensa [XTENSA] Remove non-rt signal handling 2007-05-31 17:49:32 -07:00