Fix following warnings:
leon_pmc.c:15:14: warning: symbol 'pmc_leon_fixup_ids' was not declared. Should it be static?
leon_pmc.c:22:5: warning: symbol 'pmc_leon_need_fixup' was not declared. Should it be static?
leon_pmc.c:41:6: warning: symbol 'pmc_leon_idle_fixup' was not declared. Should it be static?
leon_pmc.c:65:6: warning: symbol 'pmc_leon_idle' was not declared. Should it be static?

Add static to definitions.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
leon_kernel.c:40:15: warning: symbol 'leon3_gptimer_idx' was not declared. Should it be static?
leon_kernel.c:68:6: warning: symbol 'leon_eirq_setup' was not declared. Should it be static?
leon_kernel.c:273:13: warning: symbol 'leon_percpu_timer_ce_interrupt' was not declared. Should it be static?

Define symbols as static.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings (both sparc32 and sparc64):
of_device_common.c:13:14: warning: symbol 'irq_of_parse_and_map' was not declared. Should it be static?
of_device_common.c:24:5: warning: symbol 'of_address_to_resource' was not declared. Should it be static?
of_device_common.c:37:14: warning: symbol 'of_iomap' was not declared. Should it be static?

Add missing includes.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
unaligned_32.c:146:15: warning: symbol 'safe_compute_effective_address' was not declared. Should it be static?
unaligned_32.c:235:17: warning: symbol 'kernel_unaligned_trap' was not declared. Should it be static?
unaligned_32.c:319:17: warning: symbol 'user_unaligned_trap' was not declared. Should it be static?

Add proper declarations in kernel.h + setup.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warning:
ptrace_32.c:444:16: warning: symbol 'syscall_trace' was not declared. Should it be static?

Add declaration in kernel.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
smp_32.c:300:6: warning: symbol 'arch_cpu_pre_starting' was not declared. Should it be static?
smp_32.c:320:6: warning: symbol 'arch_cpu_pre_online' was not declared. Should it be static?
smp_32.c:347:6: warning: symbol 'sparc_start_secondary' was not declared. Should it be static?

Add missing static definition.

This left one warning:
   warning: symbol 'setup_profiling_timer' was not declared.

This is a global symbol that has no declaration in any global header.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
auxio_32.c:23:14: warning: symbol 'auxio_register' was not declared. Should it be static?
auxio_32.c:26:13: warning: symbol 'auxio_probe' was not declared. Should it be static?
auxio_32.c:108:13: warning: symbol 'auxio_power_probe' was not declared. Should it be static?

Add proper decalarations for the above.

The leaves one sparse warning:
auxio_32.c:130:33: warning: cast removes address space of expression

This is here:
    auxio_power_register = (unsigned char *) of_ioremap()

This is __iomem that is removed from return value of of_ioremap()
The pointer is later used without any helpers in process_32.c:
    *auxio_power_register |= AUXIO_POWER_OFF;

It would be simple to introduce a few sbus() helpers.
But as I was not sure this was correct the warning are left as-is.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
leon_pci_grpci2.c:218:1: warning: symbol 'grpci2_dev_lock' was not declared. Should it be static?
leon_pci_grpci2.c:219:20: warning: symbol 'grpci2priv' was not declared. Should it be static?
leon_pci_grpci2.c:221:5: warning: symbol 'grpci2_map_irq' was not declared. Should it be static?
leon_pci_grpci2.c:564:6: warning: symbol 'grpci2_hw_init' was not declared. Should it be
static?

+ a lot of these:
leon_pci_grpci2.c:252:9: warning: incorrect type in argument 1 (different address spaces)

Declare the symbols static as they are only used in this file.
Added missing __iomem annotations.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
leon_pci_grpci1.c:104:5: warning: symbol 'grpci1_map_irq' was not declared. Should it be static?
leon_pci_grpci1.c:420:6: warning: symbol 'grpci1_hw_init' was not declared. Should it be static?
+ a lot of these:
leon_pci_grpci1.c:693:18: warning: incorrect type in argument 1 (different address spaces)

Added missing static to definitions.
Added __iomem annotations
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
tadpole.c:21:6: warning: symbol 'cpu_pwr_save' was not declared. Should it be static?
tadpole.c:101:13: warning: symbol 'clock_stop_probe' was not declared. Should it be static?

This actually revealed that cpu_pwr_save is only assigned.
It was left static with a TODO comment for now - this should be cleaned up later.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warning:
devices.c:114:13: warning: symbol 'device_scan' was not declared. Should it be static?

Add prototype to asm/setup.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following sparc32 warning:
cpu.c:430:29: warning: symbol 'cpuinfo_op' was not declared. Should it be static?

Fix following sparc64 warnings:
cpu.c:364:14: warning: symbol 'dcache_parity_tl1_occurred' was not declared. Should it be static?
cpu.c:365:14: warning: symbol 'icache_parity_tl1_occurred' was not declared. Should it be static?

Rearrange asm/cpu.h to share more stuff between sparc32 and sparc64.
Added missing include to cpu.c of kernel.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
windows.c:16:6: warning: symbol 'flush_user_windows' was not declared. Should it be static?
windows.c:109:6: warning: symbol 'try_to_clear_window_buffer' was not declared. Should it be static?

Add missing include of cacheflush.h + add declaration of try_to_clear_window_buffer in kernel.h
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
setup_32.c:106:15: warning: symbol 'cmdline_memory_size' was not declared. Should it be static?
setup_32.c:270:16: warning: symbol 'fake_swapper_regs' was not declared. Should it be static?
setup_32.c:368:55: warning: Using plain integer as NULL pointer

Add missing declaration of cmdline_memory_size and remove the local one in init_32.c
fake_swapper_regs was only used locally - so defined static.
When replacing 0 with NULL also add a few spaces around operators
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
ioport.c:189:38: warning: Using plain integer as NULL pointer
ioport.c:78:25: warning: symbol 'sparc_iomap' was not declared. Should it be static?
ioport.c:403:20: warning: symbol 'sbus_dma_ops' was not declared. Should it be static?
ioport.c:684:39: warning: Using plain integer as NULL pointer

Add one missing prototype, and use NULL.
sbus_dma_ops declared static.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
signal_32.c:62:17: warning: symbol 'do_sigreturn' was not declared. Should it be static?
signal_32.c:126:17: warning: symbol 'do_rt_sigreturn' was not declared. Should it be static?
signal_32.c:344:39: warning: incorrect type in initializer (different address spaces)
signal_32.c:344:39:    expected struct __siginfo_fpu_t [usertype] *fp
signal_32.c:344:39:    got void [noderef] <asn:1>*[assigned] tail
signal_32.c:346:45: warning: incorrect type in argument 2 (different address spaces)
signal_32.c:346:45:    expected struct __siginfo_fpu_t [noderef] [usertype] <asn:1>*fpu
signal_32.c:346:45:    got struct __siginfo_fpu_t [usertype] *fp
signal_32.c:352:41: warning: incorrect type in initializer (different address spaces)
signal_32.c:352:41:    expected struct __siginfo_rwin_t [usertype] *rwp
signal_32.c:352:41:    got void [noderef] <asn:1>*[assigned] tail
signal_32.c:354:48: warning: incorrect type in argument 2 (different address spaces)
signal_32.c:354:48:    expected struct __siginfo_rwin_t [noderef] [usertype] <asn:1>*rwin
signal_32.c:354:48:    got struct __siginfo_rwin_t [usertype] *rwp
signal_32.c:509:6: warning: symbol 'do_notify_resume' was not declared. Should it be static?
signal_32.c:520:16: warning: symbol 'do_sys_sigstack' was not declared. Should it be static?

Add missing prototypes and annotate two variables with __user.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
process_32.c:67:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static?
process_32.c:257:16: warning: symbol 'sparc_do_fork' was not declared. Should it be static?
process_32.c:411:5: warning: symbol 'dump_fpu' was not declared. Should it be static?

Add missing includes and add one missing prototype.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
irq_32.c:239:5: warning: symbol 'sparc_floppy_request_irq' was not declared. Should it be static?
irq_32.c:294:24: warning: symbol 'fdc_status' was not declared. Should it be static?
irq_32.c:297:6: warning: symbol 'pdma_vaddr' was not declared. Should it be static?
irq_32.c:300:15: warning: symbol 'pdma_size' was not declared. Should it be static?
irq_32.c:303:14: warning: symbol 'doing_pdma' was not declared. Should it be static?
irq_32.c:306:6: warning: symbol 'pdma_base' was not declared. Should it be static?
irq_32.c:309:15: warning: symbol 'pdma_areasize' was not declared. Should it be static?
irq_32.c:317:6: warning: symbol 'sparc_floppy_irq' was not declared. Should it be static?

The floppy parts were all added to iasm/setup.h - no other header files looked obvious.
floppy_32.h was not an option as this file can only be included once from the
floppy driver.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
sun4d_irq.c:146:6: warning: symbol 'sun4d_handler_irq' was not declared. Should it be static?
sun4d_irq.c:239:17: warning: symbol 'sun4d_irq' was not declared. Should it be static?
sun4d_irq.c:288:14: warning: symbol '_sun4d_build_device_irq' was not declared. Should it be static?
sun4d_irq.c:323:14: warning: symbol 'sun4d_build_device_irq' was not declared. Should it be static?
sun4d_irq.c:386:14: warning: symbol 'sun4d_build_timer_irq' was not declared. Should it be static?
sun4d_irq.c:482:13: warning: symbol 'sun4d_init_sbi_irq' was not declared. Should it be static?

Apply static when applicable, otherwise add prototype
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:

sun4m_irq.c:308:6: warning: symbol 'sun4m_nmi' was not declared. Should it be static?
sun4m_irq.c:396:28: warning: incorrect type in assignment (different address spaces)
sun4m_irq.c:396:28:    expected unsigned int volatile *extern [addressable] [toplevel] master_l10_counter
sun4d_irq.c:469:28: warning: incorrect type in assignment (different address spaces)
sun4d_irq.c:469:28:    expected unsigned int volatile *extern [addressable] [toplevel] master_l10_counter

master_l10_counter is a pointer to __iomem - add annotations.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warning:
traps_32.c:47:6: error: symbol 'die_if_kernel' redeclared with different type - different modifiers

Add __noreturn to both definition and declaration
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
srmmu.c:870:13: warning: symbol 'srmmu_paging_init' was not declared. Should it be static?
iommu.c:430:13: warning: symbol 'ld_mmu_iommu' was not declared. Should it be static?
leon_mm.c:21:5: warning: symbol 'srmmu_swprobe_trace' was not declared. Should it be static?

Add proper prototypes or define static to fix them.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warnings:
srmmu.c:78:5: warning: symbol 'flush_page_for_dma_global' was not declared. Should it be static?
srmmu.c:85:5: warning: symbol 'viking_mxcc_present' was not declared. Should it be static?
srmmu.c:103:6: warning: symbol 'srmmu_nocache_bitmap' was not declared. Should it be static?
srmmu.c:176:24: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:731:46: warning: Using plain integer as NULL pointer
srmmu.c:870:13: warning: symbol 'srmmu_paging_init' was not declared. Should it be static?

Add proper prototypes in mm_32.h and drop local prototype in init_32.c
Replace 0 with NULL
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warning:
init_32.c:112:22: warning: symbol 'bootmem_init' was not declared. Should it be static?

Fix by adding a proper prototype in pgtable_32.h and drop
the local prototype in srmmu.c
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix following warning:
fault_32.c:38:24: error: symbol 'unhandled_fault' redeclared with different type - different modifiers

When this warning was fixed several new warnings popped up - fix them too.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This file will be used for more than just srmmu stuff, so the old name was misleading.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull ftrace bugfix from Steven Rostedt:
 "Takao Indoh reported that he was able to cause a ftrace bug while
  loading a module and enabling function tracing at the same time.

  He uncovered a race where the module when loaded will convert the
  calls to mcount into nops, and expects the module's text to be RW.
  But when function tracing is enabled, it will convert all kernel text
  (core and module) from RO to RW to convert the nops to calls to ftrace
  to record the function.  After the convertion, it will convert all the
  text back from RW to RO.

  The issue is, it will also convert the module's text that is loading.
  If it converts it to RO before ftrace does its conversion, it will
  cause ftrace to fail and require a reboot to fix it again.

  This patch moves the ftrace module update that converts calls to
  mcount into nops to be done when the module state is still
  MODULE_STATE_UNFORMED.  This will ignore the module when the text is
  being converted from RW back to RO"

* tag 'trace-fixes-v3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/module: Hardcode ftrace_module_init() call into load_module()

Pull devicetree bug fixes from Grant Likely:
 "These are some important bug fixes that need to get into v3.15.

  This branch contains a pair of important bug fixes for the DT code:

   - Fix some incorrect binding property names before they enter common
     usage

   - Fix bug where some platform devices will be unable to get their
     interrupt number when they depend on an interrupt controller that
     is not available at device creation time.  This is a problem
     causing mainline to fail on a number of ARM platforms"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
  of/irq: do irq resolution in platform_get_irq
  of: selftest: add deferred probe interrupt test
  dt: Fix binding typos in clock-names and interrupt-names

Pull powerpc fixes from Ben Herrenschmidt:
 "Here is a bunch of post-merge window fixes that have been accumulating
  in patchwork while I was on vacation or buried under other stuff last
  week.

  We have the now usual batch of LE fixes from Anton (sadly some new
  stuff that went into this merge window had endian issues, we'll try to
  make sure we do better next time)

  Some fixes and cleanups to the new 24x7 performance monitoring stuff
  (mostly typos and cleaning up printk's)

  A series of fixes for an issue with our runlatch bit, which wasn't set
  properly for offlined threads/cores and under KVM, causing potentially
  some counters to misbehave along with possible power management
  issues.

  A fix for kexec nasty race where the new kernel wouldn't "see" the
  secondary processors having reached back into firmware in time.

  And finally a few other misc (and pretty simple) bug fixes"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (33 commits)
  powerpc/4xx: Fix section mismatch in ppc4xx_pci.c
  ppc/kvm: Clear the runlatch bit of a vcpu before napping
  ppc/kvm: Set the runlatch bit of a CPU just before starting guest
  ppc/powernv: Set the runlatch bits correctly for offline cpus
  powerpc/pseries: Protect remove_memory() with device hotplug lock
  powerpc: Fix error return in rtas_flash module init
  powerpc: Bump BOOT_COMMAND_LINE_SIZE to 2048
  powerpc: Bump COMMAND_LINE_SIZE to 2048
  powerpc: Rename duplicate COMMAND_LINE_SIZE define
  powerpc/perf/hv-24x7: Catalog version number is be64, not be32
  powerpc/perf/hv-24x7: Remove [static 4096], sparse chokes on it
  powerpc/perf/hv-24x7: Use (unsigned long) not (u32) values when calling plpar_hcall_norets()
  powerpc/perf/hv-gpci: Make device attr static
  powerpc/perf/hv_gpci: Probe failures use pr_debug(), and padding reduced
  powerpc/perf/hv_24x7: Probe errors changed to pr_debug(), padding fixed
  powerpc/mm: Fix tlbie to add AVAL fields for 64K pages
  powerpc/powernv: Fix little endian issues in OPAL dump code
  powerpc/powernv: Create OPAL sglist helper functions and fix endian issues
  powerpc/powernv: Fix little endian issues in OPAL error log code
  powerpc/powernv: Fix little endian issues with opal_do_notifier calls
  ...

BUG_ON() is a big hammer, and should be used _only_ if there is some
major corruption that you cannot possibly recover from, making it
imperative that the current process (and possibly the whole machine) be
terminated with extreme prejudice.

The trivial sanity check in the vmacache code is *not* such a fatal
error.  Recovering from it is absolutely trivial, and using BUG_ON()
just makes it harder to debug for no actual advantage.

To make matters worse, the placement of the BUG_ON() (only if the range
check matched) actually makes it harder to hit the sanity check to begin
with, so _if_ there is a bug (and we just got a report from Srivatsa
Bhat that this can indeed trigger), it is harder to debug not just
because the machine is possibly dead, but because we don't have better
coverage.

BUG_ON() must *die*.  Maybe we should add a checkpatch warning for it,
because it is simply just about the worst thing you can ever do if you
hit some "this cannot happen" situation.
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A race exists between module loading and enabling of function tracer.

	CPU 1				CPU 2
	-----				-----
  load_module()
   module->state = MODULE_STATE_COMING

				register_ftrace_function()
				 mutex_lock(&ftrace_lock);
				 ftrace_startup()
				  update_ftrace_function();
				   ftrace_arch_code_modify_prepare()
				    set_all_module_text_rw();
				   <enables-ftrace>
				    ftrace_arch_code_modify_post_process()
				     set_all_module_text_ro();

				[ here all module text is set to RO,
				  including the module that is
				  loading!! ]

   blocking_notifier_call_chain(MODULE_STATE_COMING);
    ftrace_init_module()

     [ tries to modify code, but it's RO, and fails!
       ftrace_bug() is called]

When this race happens, ftrace_bug() will produces a nasty warning and
all of the function tracing features will be disabled until reboot.

The simple solution is to treate module load the same way the core
kernel is treated at boot. To hardcode the ftrace function modification
of converting calls to mcount into nops. This is done in init/main.c
there's no reason it could not be done in load_module(). This gives
a better control of the changes and doesn't tie the state of the
module to its notifiers as much. Ftrace is special, it needs to be
treated as such.

The reason this would work, is that the ftrace_module_init() would be
called while the module is in MODULE_STATE_UNFORMED, which is ignored
by the set_all_module_text_ro() call.

Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.comReported-by: Takao Indoh <indou.takao@jp.fujitsu.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@vger.kernel.org # 2.6.38+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

This patch fixes this section mismatch:

WARNING: vmlinux.o(.text+0x1efc4): Section mismatch in reference from
the function apm821xx_pciex_init_port_hw() to the function
.init.text:ppc4xx_pciex_wait_on_sdr.isra.9()

The function apm821xx_pciex_init_port_hw() references the function
__init ppc4xx_pciex_wait_on_sdr.isra.9().  This is often because
apm821xx_pciex_init_port_hw lacks a __init annotation or the
annotation of ppc4xx_pciex_wait_on_sdr.isra.9 is wrong.

apm821xx_pciex_init_port_hw is only referenced by a struct in
__initdata, so it should be safe to add __init to
apm821xx_pciex_init_port_hw.
Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

When the guest cedes the vcpu or the vcpu has no guest to
run it naps. Clear the runlatch bit of the vcpu before
napping to indicate an idle cpu.
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

The secondary threads in the core are kept offline before launching guests
in kvm on powerpc: "371fefd6:KVM: PPC: Allow book3s_hv guests to use
SMT processor modes."

Hence their runlatch bits are cleared. When the secondary threads are called
in to start a guest, their runlatch bits need to be set to indicate that they
are busy. The primary thread has its runlatch bit set though, but there is no
harm in setting this bit once again. Hence set the runlatch bit for all
threads before they start guest.
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Up until now we have been setting the runlatch bits for a busy CPU and
clearing it when a CPU enters idle state. The runlatch bit has thus
been consistent with the utilization of a CPU as long as the CPU is online.

However when a CPU is hotplugged out the runlatch bit is not cleared. It
needs to be cleared to indicate an unused CPU. Hence this patch has the
runlatch bit cleared for an offline CPU just before entering an idle state
and sets it immediately after it exits the idle state.
Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

While testing memory hot-remove, I found following dead lock:

Process #1141 is drmgr, trying to remove some memory, i.e. memory499.
It holds the memory_hotplug_mutex, and blocks when trying to remove file
"online" under dir memory499, in kernfs_drain(), at
        wait_event(root->deactivate_waitq,
                   atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);

Process #1120 is trying to online memory499 by
   echo 1 > memory499/online

In .kernfs_fop_write, it uses kernfs_get_active() to increase
&kn->active, thus blocking process #1141. While itself is blocked later
when trying to acquire memory_hotplug_mutex, which is held by process

The backtrace of both processes are shown below:

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c000000000263ca4>] .online_pages+0x74/0x7b0
[<c00000000055b40c>] .memory_subsys_online+0x9c/0x150
[<c00000000053cbe8>] .device_online+0xb8/0x120
[<c00000000053cd04>] .online_store+0xb4/0xc0
[<c000000000538ce4>] .dev_attr_store+0x64/0xa0
[<c00000000030f4ec>] .sysfs_kf_write+0x7c/0xb0
[<c00000000030e574>] .kernfs_fop_write+0x154/0x1e0
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

[<c000000001b18600>] 0xc000000001b18600
[<c000000000015044>] .__switch_to+0x144/0x200
[<c00000000030be14>] .__kernfs_remove+0x204/0x300
[<c00000000030d428>] .kernfs_remove_by_name_ns+0x68/0xf0
[<c00000000030fb38>] .sysfs_remove_file_ns+0x38/0x60
[<c000000000539354>] .device_remove_attrs+0x54/0xc0
[<c000000000539fd8>] .device_del+0x158/0x250
[<c00000000053a104>] .device_unregister+0x34/0xa0
[<c00000000055bc14>] .unregister_memory_section+0x164/0x170
[<c00000000024ee18>] .__remove_pages+0x108/0x4c0
[<c00000000004b590>] .arch_remove_memory+0x60/0xc0
[<c00000000026446c>] .remove_memory+0x8c/0xe0
[<c00000000007f9f4>] .pseries_remove_memblock+0xd4/0x160
[<c00000000007fcfc>] .pseries_memory_notifier+0x27c/0x290
[<c0000000008ae6cc>] .notifier_call_chain+0x8c/0x100
[<c0000000000d858c>] .__blocking_notifier_call_chain+0x6c/0xe0
[<c00000000071ddec>] .of_property_notify+0x7c/0xc0
[<c00000000071ed3c>] .of_update_property+0x3c/0x1b0
[<c0000000000756cc>] .ofdt_write+0x3dc/0x740
[<c0000000002f60fc>] .proc_reg_write+0xac/0x110
[<c000000000268450>] .vfs_write+0xe0/0x260
[<c000000000269144>] .SyS_write+0x64/0x110
[<c000000000009ffc>] syscall_exit+0x0/0x7c

This patch uses lock_device_hotplug() to protect remove_memory() called
in pseries_remove_memblock(), which is also stated before function
remove_memory():

 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug
 * and online/offline operations before this call, as required by
 * try_offline_node().
 */
void __ref remove_memory(int nid, u64 start, u64 size)

With this lock held, the other process(#1120 above) trying to online the
memory block will retry the system call when calling
lock_device_hotplug_sysfs(), and finally find No such device error.
Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

module_init should return 0 or a negative errno.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Bump the boot wrapper BOOT_COMMAND_LINE_SIZE to match the
kernel.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

I've had a report that the current limit is too small for
an automated network based installer. Bump it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

We have two definitions of COMMAND_LINE_SIZE, one for the kernel
and one for the boot wrapper. I assume this is so the boot
wrapper can be self sufficient and not rely on kernel headers.

Having two defines with the same name is confusing, I just
updated the wrong one when trying to bump it.

Make the boot wrapper define unique by calling it
BOOT_COMMAND_LINE_SIZE.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>