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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/arch/sparc/kernel
Linus Torvalds 710d60cbf1 Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu hotplug updates from Thomas Gleixner:
 "This is the first part of the ongoing cpu hotplug rework:

   - Initial implementation of the state machine

   - Runs all online and prepare down callbacks on the plugged cpu and
     not on some random processor

   - Replaces busy loop waiting with completions

   - Adds tracepoints so the states can be followed"

More detailed commentary on this work from an earlier email:
 "What's wrong with the current cpu hotplug infrastructure?

   - Asymmetry

     The hotplug notifier mechanism is asymmetric versus the bringup and
     teardown.  This is mostly caused by the notifier mechanism.

   - Largely undocumented dependencies

     While some notifiers use explicitely defined notifier priorities,
     we have quite some notifiers which use numerical priorities to
     express dependencies without any documentation why.

   - Control processor driven

     Most of the bringup/teardown of a cpu is driven by a control
     processor.  While it is understandable, that preperatory steps,
     like idle thread creation, memory allocation for and initialization
     of essential facilities needs to be done before a cpu can boot,
     there is no reason why everything else must run on a control
     processor.  Before this patch series, bringup looks like this:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

       bring the rest up

   - All or nothing approach

     There is no way to do partial bringups.  That's something which is
     really desired because we waste e.g.  at boot substantial amount of
     time just busy waiting that the cpu comes to life.  That's stupid
     as we could very well do preparatory steps and the initial IPI for
     other cpus and then go back and do the necessary low level
     synchronization with the freshly booted cpu.

   - Minimal debuggability

     Due to the notifier based design, it's impossible to switch between
     two stages of the bringup/teardown back and forth in order to test
     the correctness.  So in many hotplug notifiers the cancel
     mechanisms are either not existant or completely untested.

   - Notifier [un]registering is tedious

     To [un]register notifiers we need to protect against hotplug at
     every callsite.  There is no mechanism that bringup/teardown
     callbacks are issued on the online cpus, so every caller needs to
     do it itself.  That also includes error rollback.

  What's the new design?

     The base of the new design is a symmetric state machine, where both
     the control processor and the booting/dying cpu execute a well
     defined set of states.  Each state is symmetric in the end, except
     for some well defined exceptions, and the bringup/teardown can be
     stopped and reversed at almost all states.

     So the bringup of a cpu will look like this in the future:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu

                                       bring itself up

     The synchronization step does not require the control cpu to wait.
     That mechanism can be done asynchronously via a worker or some
     other mechanism.

     The teardown can be made very similar, so that the dying cpu cleans
     up and brings itself down.  Cleanups which need to be done after
     the cpu is gone, can be scheduled asynchronously as well.

  There is a long way to this, as we need to refactor the notion when a
  cpu is available.  Today we set the cpu online right after it comes
  out of the low level bringup, which is not really correct.

  The proper mechanism is to set it to available, i.e. cpu local
  threads, like softirqd, hotplug thread etc. can be scheduled on that
  cpu, and once it finished all booting steps, it's set to online, so
  general workloads can be scheduled on it.  The reverse happens on
  teardown.  First thing to do is to forbid scheduling of general
  workloads, then teardown all the per cpu resources and finally shut it
  off completely.

  This patch series implements the basic infrastructure for this at the
  core level.  This includes the following:

   - Basic state machine implementation with well defined states, so
     ordering and prioritization can be expressed.

   - Interfaces to [un]register state callbacks

     This invokes the bringup/teardown callback on all online cpus with
     the proper protection in place and [un]installs the callbacks in
     the state machine array.

     For callbacks which have no particular ordering requirement we have
     a dynamic state space, so that drivers don't have to register an
     explicit hotplug state.

     If a callback fails, the code automatically does a rollback to the
     previous state.

   - Sysfs interface to drive the state machine to a particular step.

     This is only partially functional today.  Full functionality and
     therefor testability will be achieved once we converted all
     existing hotplug notifiers over to the new scheme.

   - Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying
     processor:

       Control CPU                     Booting CPU

       do preparatory steps
       kick cpu into life

                                       do low level init

       sync with booting cpu           sync with control cpu
       wait for boot
                                       bring itself up

                                       Signal completion to control cpu

     In a previous step of this work we've done a full tree mechanical
     conversion of all hotplug notifiers to the new scheme.  The balance
     is a net removal of about 4000 lines of code.

     This is not included in this series, as we decided to take a
     different approach.  Instead of mechanically converting everything
     over, we will do a proper overhaul of the usage sites one by one so
     they nicely fit into the symmetric callback scheme.

     I decided to do that after I looked at the ugliness of some of the
     converted sites and figured out that their hotplug mechanism is
     completely buggered anyway.  So there is no point to do a
     mechanical conversion first as we need to go through the usage
     sites one by one again in order to achieve a full symmetric and
     testable behaviour"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  cpu/hotplug: Document states better
  cpu/hotplug: Fix smpboot thread ordering
  cpu/hotplug: Remove redundant state check
  cpu/hotplug: Plug death reporting race
  rcu: Make CPU_DYING_IDLE an explicit call
  cpu/hotplug: Make wait for dead cpu completion based
  cpu/hotplug: Let upcoming cpu bring itself fully up
  arch/hotplug: Call into idle with a proper state
  cpu/hotplug: Move online calls to hotplugged cpu
  cpu/hotplug: Create hotplug threads
  cpu/hotplug: Split out the state walk into functions
  cpu/hotplug: Unpark smpboot threads from the state machine
  cpu/hotplug: Move scheduler cpu_online notifier to hotplug core
  cpu/hotplug: Implement setup/removal interface
  cpu/hotplug: Make target state writeable
  cpu/hotplug: Add sysfs state interface
  cpu/hotplug: Hand in target state to _cpu_up/down
  cpu/hotplug: Convert the hotplugged cpu work to a state machine
  cpu/hotplug: Convert to a state machine for the control processor
  cpu/hotplug: Add tracepoints
  ...
2016-03-15 13:50:29 -07:00
..
.gitignore
apc.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
asm-offsets.c [PATCH] sparc32: vm_area_struct access for old Sun SPARCs. 2013-07-10 13:56:10 -07:00
audit.c sparc64: fix sparse warnings in compat_audit.c 2014-05-18 19:01:34 -07:00
auxio_32.c sparc32: fix sparse warning in auxio_32.c 2014-05-18 19:01:27 -07:00
auxio_64.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
btext.c sparc64: fix sparse warning in btext.c 2014-05-18 19:01:30 -07:00
central.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
cherrs.S
chmc.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
compat_audit.c sparc64: fix sparse warnings in compat_audit.c 2014-05-18 19:01:34 -07:00
cpu.c sparc64: correctly recognise M6 and M7 cpu type 2014-09-09 15:24:10 -07:00
cpumap.c sparc64: support M6 and M7 for building CPU distribution map 2014-09-09 15:24:10 -07:00
cpumap.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
devices.c sparc32: drop tadpole specific code 2014-05-18 19:01:29 -07:00
dma.c
ds.c sparc64: Move request_irq() from ldc_bind() to ldc_alloc() 2014-09-16 18:31:31 -07:00
dtlb_miss.S
dtlb_prot.S sparc64: Fix corrupted thread fault code. 2014-10-18 23:03:09 -04:00
ebus.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
entry.h sparc: Resolve conflict between sparc v9 and M7 on usage of bit 9 of TTE 2015-05-31 22:15:01 -07:00
entry.S sparc: Fix system call tracing register handling. 2016-01-21 16:06:00 -08:00
etrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
etrap_64.S sparc64: clear syscall_noerror on the entry to syscall, not on the exit 2012-10-14 19:26:52 -04:00
fpu_traps.S
ftrace.c ftrace: Do not pass data to ftrace_dyn_arch_init 2014-03-07 10:06:14 -05:00
getsetcc.S
head_32.S sparc32: drop swapper_pg_dir 2012-07-26 16:46:15 -07:00
head_64.S locking/lockdep: Eliminate lockdep_init() 2016-02-09 12:03:25 +01:00
helpers.S
hvapi.c sparc: perf: Add support M7 processor 2015-03-19 18:54:49 -07:00
hvcalls.S Add sun4v_wdt watchdog driver 2016-01-31 11:06:24 -08:00
hvtramp.S sparc64: Fix register corruption in top-most kernel stack frame during boot. 2014-10-24 09:52:49 -07:00
idprom.c net: Add eth_platform_get_mac_address() helper. 2016-01-06 16:31:56 -05:00
iommu_common.h remove <asm/scatterlist.h> 2015-05-05 13:35:39 -06:00
iommu.c iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}(). 2015-11-04 11:30:57 -08:00
ioport.c sparc32: dma_alloc_coherent must honour gfp flags 2014-09-10 14:03:28 -07:00
irq_32.c sparc32: fix sparse warnings in irq_32.c 2014-04-29 01:12:25 -04:00
irq_64.c sparc/irq: Use access helper irq_data_get_affinity_mask() 2015-07-31 22:20:05 +02:00
irq.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
itlb_miss.S
ivec.S
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kernel.h sparc64: fix sparse warning in kgdb_64.c 2014-05-18 19:01:34 -07:00
kgdb_32.c sparc: explicitly include sched.h to get task_thread_info declaration 2013-02-06 11:04:10 -08:00
kgdb_64.c sparc64: fix sparse warning in kgdb_64.c 2014-05-18 19:01:34 -07:00
kprobes.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
kstack.h
ktlb.S sparc64: Adjust vmalloc region size based upon available virtual address bits. 2014-10-05 16:53:40 -07:00
ldc.c iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}(). 2015-11-04 11:30:57 -08:00
led.c
leon_kernel.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
leon_pci_grpci1.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
leon_pci_grpci2.c genirq: Remove irq argument from irq flow handlers 2015-09-16 15:47:51 +02:00
leon_pci.c PCI: Cleanup control flow 2015-03-19 10:17:22 -05:00
leon_pmc.c sparc32: fix sparse warnings in leon_pmc.c 2014-04-29 01:12:27 -04:00
leon_smp.c sparc32, leon: Align ccall_info to prevent unaligned traps on crosscall 2014-12-11 18:51:56 -08:00
Makefile sparc32: drop tadpole specific code 2014-05-18 19:01:29 -07:00
mdesc.c new helpers: no_seek_end_llseek{,_size}() 2015-12-23 10:41:31 -05:00
misctrap.S
module.c mm: vmalloc: pass additional vm_flags to __vmalloc_node_range() 2015-02-13 21:21:42 -08:00
nmi.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
of_device_32.c sparc32: rename sparc_irq_config to sparc_config 2012-04-15 10:28:49 -07:00
of_device_64.c devicetree: add helper inline for retrieving a node's full name 2012-07-06 07:16:34 -05:00
of_device_common.c sparc: fix sparse warnings in of_device_common.c 2014-04-29 01:12:27 -04:00
of_device_common.h
pci_common.c sparc/PCI: Add mem64 resource parsing for root bus 2015-10-29 17:35:46 -05:00
pci_fire.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_impl.h sparc/PCI: Add mem64 resource parsing for root bus 2015-10-29 17:35:46 -05:00
pci_msi.c PCI/MSI: Rename mask/unmask_msi_irq treewide 2014-11-23 13:01:45 +01:00
pci_psycho.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_sabre.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
pci_schizo.c Driver core patches for 3.19-rc1 2014-12-14 16:10:09 -08:00
pci_sun4v_asm.S
pci_sun4v.c iommu-common: Fix error code used in iommu_tbl_range_{alloc,free}(). 2015-11-04 11:30:57 -08:00
pci_sun4v.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
pci.c sparc/PCI: Add mem64 resource parsing for root bus 2015-10-29 17:35:46 -05:00
pcic.c PCI: Assign resources before drivers claim devices (pci_scan_bus()) 2015-03-12 15:04:01 -05:00
pcr.c sparc: perf: Add support M7 processor 2015-03-19 18:54:49 -07:00
perf_event.c sparc64: Perf should save/restore fault info 2015-12-24 12:12:46 -05:00
pmc.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
power.c sparc: kernel: drop owner assignment from platform_drivers 2014-10-20 16:20:15 +02:00
process_32.c sched, sparc32: Update scheduler comments in copy_thread() 2015-08-04 09:48:12 +02:00
process_64.c sparc: Touch NMI watchdog when walking cpus and calling printk 2015-03-19 18:54:50 -07:00
prom_32.c
prom_64.c sparc64: fix sparse warning in prom_64.c 2014-05-18 19:01:31 -07:00
prom_common.c of: Fix locking vs. interrupts 2013-06-13 22:12:14 +01:00
prom_irqtrans.c
prom.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
psycho_common.c
psycho_common.h sparc: drop use of extern for prototypes in arch/sparc/* 2014-05-18 19:01:29 -07:00
ptrace_32.c sparc32: fix sparse warning in ptrace_32.c 2014-04-29 01:12:26 -04:00
ptrace_64.c ARCH: AUDIT: audit_syscall_entry() should not require the arch 2014-09-23 16:21:26 -04:00
reboot.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
rtrap_32.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
rtrap_64.S sparc64: Don't set %pil in rtrap_nmi too early 2015-12-24 12:07:16 -05:00
sbus.c sparc: kernel/sbus.c: fix memory leakage 2013-01-21 14:33:00 -08:00
setup_32.c sparc32: fix sparse warnings in setup_32.c 2014-04-29 01:12:25 -04:00
setup_64.c sparc64: Add ADI capability to cpu capabilities 2015-12-24 12:05:06 -05:00
signal32.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
signal_32.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
signal_64.c sparc64: Fix sparc64_set_context stack handling. 2016-03-01 00:25:32 -05:00
sigutil_32.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sigutil_64.c Disintegrate asm/system.h for Sparc 2012-03-28 18:30:03 +01:00
sigutil.h
smp_32.c arch/hotplug: Call into idle with a proper state 2016-03-01 20:36:57 +01:00
smp_64.c arch/hotplug: Call into idle with a proper state 2016-03-01 20:36:57 +01:00
sparc_ksyms_32.c sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
sparc_ksyms_64.c Add sun4v_wdt watchdog driver 2016-01-31 11:06:24 -08:00
spiterrs.S
sstate.c
stacktrace.c
starfire.c arch: sparc: kernel: starfire.c: Remove unused function 2015-03-01 21:33:58 -08:00
sun4d_irq.c sparc/irq: Use helper irq_data_get_irq_handler_data() 2015-07-31 22:20:05 +02:00
sun4d_smp.c sparc: Replace __get_cpu_var uses 2014-08-26 13:45:55 -04:00
sun4m_irq.c sparc/irq: Use helper irq_data_get_irq_handler_data() 2015-07-31 22:20:05 +02:00
sun4m_smp.c sparc/time: Migrate to new 'set-state' interface 2015-08-10 11:41:05 +02:00
sun4v_ivec.S
sun4v_tlb_miss.S sparc64: sun4v TLB error power off events 2014-09-16 17:46:44 -07:00
sys32.S sparc: Hook up renameat2 syscall. 2014-07-21 22:27:56 -07:00
sys_sparc32.c sparc64: fix sparse warnings in sys_sparc32.c 2014-05-18 19:01:31 -07:00
sys_sparc_32.c sparc32: fix sparse warnings in sys_sparc_32.c 2014-05-18 19:01:28 -07:00
sys_sparc_64.c mm: ASLR: use get_random_long() 2016-02-27 10:28:52 -08:00
syscalls.S sparc: Fix system call tracing register handling. 2016-01-21 16:06:00 -08:00
sysfs.c sparc64: fix format string mismatch in arch/sparc/kernel/sysfs.c 2014-05-21 12:54:42 -07:00
systbls_32.S sparc: Hook up copy_file_range syscall. 2016-01-21 15:51:17 -08:00
systbls_64.S sparc: Hook up copy_file_range syscall. 2016-01-21 15:51:17 -08:00
systbls.h sparc64: fix sparse warnings in sys_sparc32.c 2014-05-18 19:01:31 -07:00
time_32.c sparc/time: Migrate to new 'set-state' interface 2015-08-10 11:41:05 +02:00
time_64.c sparc/time: Migrate to new 'set-state' interface 2015-08-10 11:41:05 +02:00
trampoline_32.S sparc: delete non-required instances of include <linux/init.h> 2014-01-28 23:38:23 -08:00
trampoline_64.S sparc64: Fix register corruption in top-most kernel stack frame during boot. 2014-10-24 09:52:49 -07:00
traps_32.c sparc: Remove signal translation and exec_domain 2015-04-12 21:03:21 +02:00
traps_64.c sparc: Remove signal translation and exec_domain 2015-04-12 21:03:21 +02:00
tsb.S sparc64: Fix corrupted thread fault code. 2014-10-18 23:03:09 -04:00
ttable_32.S sparc32: move trap table to a separate file 2012-05-19 23:27:25 -07:00
ttable_64.S sparc64: renamed ttable.S to ttable_64.S 2012-05-19 23:26:41 -07:00
una_asm_32.S
una_asm_64.S
unaligned_32.c sparc: use %s for unaligned panic 2014-07-21 21:37:06 -07:00
unaligned_64.c sparc64: Don't restrict fp regs for no-fault loads 2015-11-04 15:00:49 -05:00
utrap.S
vio.c sparc64: Add vio_set_intr() to enable/disable Rx interrupts 2014-09-30 14:40:45 -07:00
viohs.c sparc: VIO protocol version 1.6 2014-09-30 14:17:08 -07:00
visemul.c sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
vmlinux.lds.S sparc: Resolve conflict between sparc v9 and M7 on usage of bit 9 of TTE 2015-05-31 22:15:01 -07:00
windows.c sparc32: fix sparse warnings in windows.c 2014-04-29 01:12:25 -04:00
winfixup.S sparc64: Make montmul/montsqr/mpmul usable in 32-bit threads. 2012-10-26 15:18:37 -07:00
wof.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00
wuf.S sparc32: introduce support for run-time patching for all shared assembler code 2012-05-27 23:52:49 -07:00