Impact: sync 32 and 64-bit code

Merge load_gs_base() into switch_to_new_gdt().  Load the GDT and
per-cpu state for the boot cpu when its new area is set up.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: optimization

mb() generates an mfence instruction, which is not needed here.  Only
a compiler barrier is needed, and that is handled by the memory clobber
in the wrmsrl function.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

Rename init_gdt() to setup_percpu_segment(), and move it to
setup_percpu.c.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: standardize all x86 platforms on same setup code

With the preceding changes, Voyager can use the same per-cpu setup
code as all the other x86 platforms.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: minor cleanup
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: Small cleanup

Define BOOT_PERCPU_OFFSET and use it for this_cpu_offset and
__per_cpu_offset initializers.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: Minor build optimization
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: Code movement

Move the variable definitions to apic.c.  Ifdef the copying of
the two early per-cpu variables, since Voyager doesn't use them.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

The way the code is written, align is always PAGE_SIZE.  Simplify
the code by removing the align variable.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: Code movement, no functional change.

Move setup_cpu_local_masks() to kernel/cpu/common.c, where the
masks are defined.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: Code movement, no functional change.

Move the 64-bit NUMA code from setup_percpu.c to numa_64.c
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: minor optimization

Eliminates the need for two loops over possible cpus.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

This patch fixes this linker error:

 WARNING: Absolute relocations present
 Offset     Info     Type     Sym.Value Sym.Name
 c0a4e07d 00e78001   R_386_32 c0ab0000  __per_cpu_load

Now, __per_cpu_load is a section-relative symbol:

 c0aa4000 D __per_cpu_load
 c0aa4000 A __per_cpu_load_abs
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: build fix

This build error:

 arch/x86/xen/suspend.c:22: error: implicit declaration of function 'fix_to_virt'
 arch/x86/xen/suspend.c:22: error: 'FIX_PARAVIRT_BOOTMAP' undeclared (first use in this function)
 arch/x86/xen/suspend.c:22: error: (Each undeclared identifier is reported only once
 arch/x86/xen/suspend.c:22: error: for each function it appears in.)

triggers because the hardirq.h unification removed an implicit fixmap.h
include - on which arch/x86/xen/suspend.c depended. Add the fixmap.h
include explicitly.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: shrink size of irq_cpustat_t when possible
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: better code generation and removal of unused field for 32bit

In general, use the 64-bit version.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

APIC definitions aren't needed here.  Remove the include and fix
up the fallout.

tj: added include to mce_intel_64.c.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: bogus irq_cpustat field removed

idle_timestamp is left over from the removed irqbalance code.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Make X86 SGI Ultraviolet support configurable. Saves about 13K of text size
on my modest config.

   text    data     bss     dec     hex filename
6770537 1158680  694356 8623573  8395d5 vmlinux
6757492 1157664  694228 8609384  835e68 vmlinux.nouv
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix more build-failure fallout from the UV cleanup - the UV drivers
were not updated to include <asm/uv/uv.h>.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix:

  arch/x86/mm/tlb.c:47: error: ‘CONFIG_X86_INTERNODE_CACHE_BYTES’ undeclared here (not in a function)

The CONFIG_X86_INTERNODE_CACHE_BYTES symbol is only defined on 64-bit,
because vsmp support is 64-bit only. Define it on 32-bit too - where it
will always be equal to X86_L1_CACHE_BYTES.

Also move the default of X86_L1_CACHE_BYTES (which is separate from the
more commonly used L1_CACHE_SHIFT kconfig symbol) from 128 bytes to
64 bytes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/mm/fault.c

Fix:

 arch/x86/mm/srat_64.c: In function ‘acpi_numa_processor_affinity_init’:
 arch/x86/mm/srat_64.c:141: error: implicit declaration of function ‘get_uv_system_type’
 arch/x86/mm/srat_64.c:141: error: ‘UV_X2APIC’ undeclared (first use in this function)
 arch/x86/mm/srat_64.c:141: error: (Each undeclared identifier is reported only once
 arch/x86/mm/srat_64.c:141: error: for each function it appears in.)

A couple of UV definitions were moved to asm/uv/uv.h, but srat_64.c did
not include that header. Add it.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Now that it's unified, move the (SMP) TLB flushing code from arch/x86/kernel/
to arch/x86/mm/, where it belongs logically.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
	arch/x86/kernel/tlb_32.c

Merge it here because both the cpumask changes and the ongoing percpu
work is touching the TLB code. The percpu changes take precedence, as
they eliminate tlb_32.c altogether.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: file rename

tlb_64.c is now the tlb code for both 32 and 64.  Rename it to tlb.c.
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: less contention when issuing invalidate IPI, cleanup

Make x86_32 use the same tlb code as 64bit.  The 64bit code uses
multiple IPI vectors for tlb shootdown to reduce contention.  This
patch makes x86_32 allocate the same 8 IPIs as x86_64 and share the
code paths.

Note that the usage of asmlinkage is inconsistent for x86_32 and 64
and calls for further cleanup.  This has been noted with a FIXME
comment in tlb_64.c.
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: clean up, ipi vector number reordering for x86_32

Make the following changes to prepare for tlb merge.

* reorder x86_32 ip vectors

* adjust tlb_32.c and tlb_64.c such that their logics coincide exactly
	- on spurious invalidate ipi, tlb_32 acks the irq
	- tlb_64 now has proper memory barriers around clearing
          flush_cpumask (no change in generated code)

* unexport flush_tlb_page from tlb_32.c, there's no user

* use unsigned int for cpu id

* drop unnecessary includes from tlb_64.c
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

Make the following uv related cleanups.

* collect visible uv related definitions and interfaces into uv/uv.h
  and use it.  this cleans up the messy situation where on 64bit, uv
  is defined properly, on 32bit generic it's dummy and on the rest
  undefined.  after this clean up, uv is defined on 64 and dummy on
  32.

* update uv_flush_tlb_others() such that it takes cpumask of
  to-be-flushed cpus as argument, instead of that minus self, and
  returns yet-to-be-flushed cpumask, instead of modifying the passed
  in parameter.  this interface change will ease dummy implementation
  of uv_flush_tlb_others() and makes uv tlb flush related stuff
  defined in tlb_uv proper.
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup, better irq_regs code generation for x86_64

Make 64-bit use the same optimizations as 32-bit.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

tj: * changed cpu to unsigned as was done on mmu_context_64.h as cpu
      id is officially unsigned int
    * added missing ';' to 32bit version of deactivate_mm()
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

%fs is currently set to __KERNEL_DS at boot, and conditionally
switched to __KERNEL_PERCPU for secondary cpus.  Instead, initialize
GDT_ENTRY_PERCPU to the same attributes as GDT_ENTRY_KERNEL_DS and
set %fs to __KERNEL_PERCPU unconditionally.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: slightly better code generation for percpu_to_op()

The processor will sign-extend 32-bit immediate values in 64-bit
operations.  Use the 'e' constraint ("32-bit signed integer constant,
or a symbolic reference known to fit that range") for 64-bit constants.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup && more compact percpu area layout with future changes

Move 64-bit GDT to page-aligned section and clean up comment
formatting.
Signed-off-by: NBrian Gerst <brgerst@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup

In switch_to(), instead of taking offset to irq_stack_union.stack,
make it a proper percpu access using __percpu_arg() and per_cpu_var().
Signed-off-by: NTejun Heo <tj@kernel.org>

Impact: cleanup, restructure code to improve assembly

gcc isn't _all_ that smart about spilling registers to stack or reusing
stack slots, even with branch annotations. do_page_fault contained a lot
of functionality, so split unlikely paths into their own functions, and
mark them as noinline just to be sure. I consider this actually to be
somewhat of a cleanup too: the main function now contains about half
the number of lines so the normal path is easier to read, while the error
cases are also nicely split away.

Also, ensure the order of arguments to functions is always the same: regs,
addr, error_code. This can reduce code size a tiny bit, and just looks neater
too.

And add a couple of branch annotations.

Before:
  do_page_fault:
          subq    $360, %rsp      #,

After:
  do_page_fault:
          subq    $56, %rsp       #,

bloat-o-meter:
  add/remove: 8/0 grow/shrink: 0/1 up/down: 2222/-1680 (542)
  function                                     old     new   delta
  __bad_area_nosemaphore                         -     506    +506
  no_context                                     -     474    +474
  vmalloc_fault                                  -     424    +424
  spurious_fault                                 -     358    +358
  mm_fault_error                                 -     272    +272
  bad_area_access_error                          -      89     +89
  bad_area                                       -      89     +89
  bad_area_nosemaphore                           -      10     +10
  do_page_fault                               2464     784   -1680

Yes, the total size increases by 542 bytes, due to the extra function calls.
But these will very rarely be called (except for vmalloc_fault) in a normal
workload. Importantly, do_page_fault is less than 1/3rd it's original size,
and touches far less stack.

Existing gotos and branch hints did move a lot of the infrequently used text
out of the fastpath, but that's even further improved after this patch.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>