Impact: cleanup
Rename init_gdt() to setup_percpu_segment(), and move it to
setup_percpu.c.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: minor optimization
Eliminates the need for two loops over possible cpus.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
debugobjects: add and use INIT_WORK_ON_STACK
rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
relay: fix lock imbalance in relay_late_setup_files
oprofile: fix uninitialized use of struct op_entry
rcu: move Kconfig menu
softlock: fix false panic which can occur if softlockup_thresh is reduced
rcu: add __cpuinit to rcu_init_percpu_data()
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
hrtimers: fix inconsistent lock state on resume in hres_timers_resume
time-sched.c: tick_nohz_update_jiffies should be static
locking, hpet: annotate false positive warning
kernel/fork.c: unused variable 'ret'
itimers: remove the per-cpu-ish-ness
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (29 commits)
xen: unitialised return value in xenbus_write_transaction
x86: fix section mismatch warning
x86: unmask CPUID levels on Intel CPUs, fix
x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.
x86: use standard PIT frequency
xen: handle highmem pages correctly when shrinking a domain
x86, mm: fix pte_free()
xen: actually release memory when shrinking domain
x86: unmask CPUID levels on Intel CPUs
x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h>
x86: fix PTE corruption issue while mapping RAM using /dev/mem
x86: mtrr fix debug boot parameter
x86: fix page attribute corruption with cpa()
Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"
x86: use early clobbers in usercopy*.c
x86: remove kernel_physical_mapping_init() from init section
fix: crash: IP: __bitmap_intersects+0x48/0x73
cpufreq: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write
work_on_cpu: Use our own workqueue.
work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
...
Impact: re-enable CPUID unmasking on affected processors
As far as I am capable of discerning from the documentation,
MSR_IA32_MISC_ENABLE should be available for all family 0xf CPUs, as
well as family 6 for model >= 0xd (newer Pentium M).
The documentation on this isn't ideal, so we need to be on the lookout
for errors, still.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Here function vmi_activate calls a init function activate_vmi , which
causes the following section mismatch warnings:
LD arch/x86/kernel/built-in.o
WARNING: arch/x86/kernel/built-in.o(.text+0x13ba9): Section mismatch
in reference from the function vmi_activate() to the function
.init.text:vmi_time_init()
The function vmi_activate() references
the function __init vmi_time_init().
This is often because vmi_activate lacks a __init
annotation or the annotation of vmi_time_init is wrong.
WARNING: arch/x86/kernel/built-in.o(.text+0x13bd1): Section mismatch
in reference from the function vmi_activate() to the function
.devinit.text:vmi_time_bsp_init()
The function vmi_activate() references
the function __devinit vmi_time_bsp_init().
This is often because vmi_activate lacks a __devinit
annotation or the annotation of vmi_time_bsp_init is wrong.
WARNING: arch/x86/kernel/built-in.o(.text+0x13bdb): Section mismatch
in reference from the function vmi_activate() to the function
.devinit.text:vmi_time_ap_init()
The function vmi_activate() references
the function __devinit vmi_time_ap_init().
This is often because vmi_activate lacks a __devinit
annotation or the annotation of vmi_time_ap_init is wrong.
Fix it by marking vmi_activate() as __init too.
Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: cleanup
Remove such constructs:
#ifdef CONFIG_EARLY_PRINTK
call early_printk
#else
call printk
#endif
Not only are they ugly, they are also pointless: a call to printk()
maps to early_printk during early bootup anyway, if CONFIG_EARLY_PRINTK
is enabled.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix boot hang on pre-model-15 Intel CPUs
rdmsrl_safe() does not work in very early bootup code yet, because we
dont have the pagefault handler installed yet so exception section
does not get parsed. rdmsr_safe() will just crash and hang the bootup.
So limit the MSR_IA32_MISC_ENABLE MSR read to those CPU types that
support it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Fixes potential crashes on misconfigured systems.
Some CPU features require specific CPUID levels to be available in
order to function, as they contain information about the operation of
a specific feature. However, some BIOSes and virtualization software
provide the ability to mask CPUID levels in order to support legacy
operating systems. We try to enable such CPUID levels when we know
how to do it, but for the remaining cases, filter out such CPU
features when there is no way for us to support them.
Do this in one place, in the CPUID code, with a table-driven approach.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: Cleanup
When PAT was originally introduced, it was handled specially for a few
reasons:
- PAT bugs are hard to track down, so we wanted to maintain a
whitelist of CPUs.
- The i386 and x86-64 CPUID code was not yet unified.
Both of these are now obsolete, so handle PAT like any other features,
including ordinary feature blacklisting due to known bugs.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: use new framework
Use {get|put}_user_try, catch, and _ex in arch/x86/kernel/signal.c.
Note: this patch contains "WARNING: line over 80 characters", because when
introducing new block I insert an indent to avoid mistakes by edit.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: bogus irq_cpustat field removed
idle_timestamp is left over from the removed irqbalance code.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
pte_flags() was introduced as a new pvop in order to extract just the
flags portion of a pte, which is a potentially cheaper operation than
extracting the page number as well. It turns out this operation is
not needed, because simply using a mask to extract the flags from a
pte is sufficient for all current users.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: Fix debugobjects warning
debugobject enabled kernels spit out a warning in hpet code due to a
workqueue which is initialized on stack.
Add INIT_WORK_ON_STACK() which calls init_timer_on_stack() and use it
in hpet.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Impact: Fixes crashes with misconfigured BIOSes on XSAVE hardware
Avuton Olrich reported early boot crashes with v2.6.28 and
bisected it down to dc1e35c6e9
("x86, xsave: enable xsave/xrstor on cpus with xsave support").
If the CPUID limit bit in MSR_IA32_MISC_ENABLE is set, clear it to
make all CPUID information available. This is required for some
features to work, in particular XSAVE.
Reported-and-bisected-by: Avuton Olrich <avuton@gmail.com>
Tested-by: Avuton Olrich <avuton@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
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: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
while looking at:
http://bugzilla.kernel.org/show_bug.cgi?id=11541
I realized that the mtrr.show param cannot work, because
the code is processed much too early.
This patch:
- Declares mtrr.show as early_param
- Stays consistent with the previous param (which I doubt
that it ever worked), so mtrr.show=1 would still work
- Declares mtrr_show as initdata
Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo 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: Ingo 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: Ingo Molnar <mingo@elte.hu>
This reverts commit 4217458daf.
Justin Madru bisected this commit, it was causing weird Firefox
crashes.
The reason is that GCC mis-optimizes (re-uses) the on-stack parameters of
the calling frame, which corrupts the syscall return pt_regs state and
thus corrupts user-space register state.
So we go back to the slightly less clean but more optimization-safe
method of getting to pt_regs. Also add a comment to explain this.
Resolves: http://bugzilla.kernel.org/show_bug.cgi?id=12505
Reported-and-bisected-by: Justin Madru <jdm64@gawab.com>
Tested-by: Justin Madru <jdm64@gawab.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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: Tejun 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: Tejun 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: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun 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: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup
Remove byte locks implementation, which was introduced by Jeremy in
8efcbab6 ("paravirt: introduce a "lock-byte" spinlock implementation"),
but turned out to be dead code that is not used by any in-kernel
virtualization guest (Xen uses its own variant of spinlocks implementation
and KVM is not planning to move to byte locks).
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: x86_64 percpu area layout change, irq_stack now at the beginning
Now that the PDA is empty except for the stack canary, it can be removed.
The irqstack is moved to the start of the per-cpu section. If the stack
protector is enabled, the canary overlaps the bottom 48 bytes of the irqstack.
tj: * updated subject
* dropped asm relocation of irq_stack_ptr
* updated comments a bit
* rebased on top of stack canary changes
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup
Use cpu_number to determine if the adjustment is necessary.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup
Copy the code to cpu_init() to satisfy the requirement that the cpu
be reinitialized. Remove all other calls, since the segments are
already initialized in head_64.S.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: cleanup
Make the following cleanups.
* remove duplicate comment from boot_init_stack_canary() which fits
better in the other place - cpu_idle().
* move stack_canary offset check from __switch_to() to
boot_init_stack_canary().
Signed-off-by: Tejun Heo <tj@kernel.org>
-tip testing found this crash:
> [ 35.258515] calling acpi_cpufreq_init+0x0/0x127 @ 1
> [ 35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [ 35.267554] PGD 0
> [ 35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...
Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: use new work_on_cpu function to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().
Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Dieter Ries <clip2@gmx.de>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since commit 75c46fa, "x64, x2apic/intr-remap: MSI and MSI-X
support for interrupt remapping infrastructure", x86 has had an
implementation of arch_setup_msi_irqs().
That implementation does not call arch_setup_msi_irq(), instead it calls
setup_irq(). No other x86 code calls arch_setup_msi_irq().
That leaves only arch_setup_msi_irqs() in drivers/pci/msi.c, but that
routine is overridden by the x86 version of arch_setup_msi_irqs().
So arch_setup_msi_irq() is dead code, remove it.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The function setup_cpu_local_masks() has been marked __init, in
order to remove the following section mismatch messages:
WARNING: vmlinux.o(.text+0x3c2c7): Section mismatch in reference from the function setup_cpu_local_masks() to the function .init.text:alloc_bootmem_cpumask_var()
The function setup_cpu_local_masks() references
the function __init alloc_bootmem_cpumask_var().
This is often because setup_cpu_local_masks lacks a __init
annotation or the annotation of alloc_bootmem_cpumask_var is wrong.
WARNING: vmlinux.o(.text+0x3c2d3): Section mismatch in reference from the function setup_cpu_local_masks() to the function .init.text:alloc_bootmem_cpumask_var()
The function setup_cpu_local_masks() references
the function __init alloc_bootmem_cpumask_var().
This is often because setup_cpu_local_masks lacks a __init
annotation or the annotation of alloc_bootmem_cpumask_var is wrong.
WARNING: vmlinux.o(.text+0x3c2df): Section mismatch in reference from the function setup_cpu_local_masks() to the function .init.text:alloc_bootmem_cpumask_var()
The function setup_cpu_local_masks() references
the function __init alloc_bootmem_cpumask_var().
This is often because setup_cpu_local_masks lacks a __init
annotation or the annotation of alloc_bootmem_cpumask_var is wrong.
WARNING: vmlinux.o(.text+0x3c2eb): Section mismatch in reference from the function setup_cpu_local_masks() to the function .init.text:alloc_bootmem_cpumask_var()
The function setup_cpu_local_masks() references
the function __init alloc_bootmem_cpumask_var().
This is often because setup_cpu_local_masks lacks a __init
annotation or the annotation of alloc_bootmem_cpumask_var is wrong.
Signed-off-by: Leonardo Potenza <lpotenza@inwind.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: add debug warning
Fire off one message if two apic's discovered with different
apic versions. (this code is only called during CPU init)
The goal of this is to pave the way of the removal of the apic_version[]
array. We dont expect any apic version incompatibilities in the x86
landscape of systems [if so we dont handle them very well and probably
never will handle deep apic version assymetries well], but it's prudent
to have a debug check for one kernel cycle nevertheless.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
tj: * in asm-offsets_64.c, pda.h inclusion shouldn't be removed as pda
is still referenced in the file
* s/oldrsp/old_rsp/
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Also clean up PER_CPU_VAR usage in xen-asm_64.S
tj: * remove now unused stack_thread_info()
* s/kernelstack/kernel_stack/
* added FIXME comment in xen-asm_64.S
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
tj: moved cpu_number definition out of CONFIG_HAVE_SETUP_PER_CPU_AREA
for voyager.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Move the exception stacks to per-cpu, removing specific allocation code.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Move the irqstackptr variable from the PDA to per-cpu. Make the
stacks themselves per-cpu, removing some specific allocation code.
Add a seperate flag (is_boot_cpu) to simplify the per-cpu boot
adjustments.
tj: * sprinkle some underbars around.
* irq_stack_ptr is not used till traps_init(), no reason to
initialize it early. On SMP, just leaving it NULL till proper
initialization in setup_per_cpu_areas() works. Dropped
is_boot_cpu and early irq_stack_ptr initialization.
* do DECLARE/DEFINE_PER_CPU(char[IRQ_STACK_SIZE], irq_stack)
instead of (char, irq_stack[IRQ_STACK_SIZE]).
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Impact: use new work_on_cpu function to reduce stack usage
Replace the saving of current->cpus_allowed and set_cpus_allowed_ptr() with
a work_on_cpu function for drv_read() and drv_write().
Basically converts do_drv_{read,write} into "work_on_cpu" functions that
are now called by drv_read and drv_write.
Note: This patch basically reverts 50c668d6 which reverted 7503bfba, now
that the work_on_cpu() function is more stable.
Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Dieter Ries <clip2@gmx.de>
Tested-by: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: <cpufreq@vger.kernel.org>
Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster
depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y.
This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y
and CONFIG_FREEZER=n.
Reported-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Len Brown <len.brown@intel.com>
On x86_64, if get_per_cpu_var() is used before per cpu area is setup
(if lockdep is turned on, it happens), it needs this_cpu_off to point
to __per_cpu_load. Initialize accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
It is an optimization and a cleanup, and adds the following new
generic percpu methods:
percpu_read()
percpu_write()
percpu_add()
percpu_sub()
percpu_and()
percpu_or()
percpu_xor()
and implements support for them on x86. (other architectures will fall
back to a default implementation)
The advantage is that for example to read a local percpu variable,
instead of this sequence:
return __get_cpu_var(var);
ffffffff8102ca2b: 48 8b 14 fd 80 09 74 mov -0x7e8bf680(,%rdi,8),%rdx
ffffffff8102ca32: 81
ffffffff8102ca33: 48 c7 c0 d8 59 00 00 mov $0x59d8,%rax
ffffffff8102ca3a: 48 8b 04 10 mov (%rax,%rdx,1),%rax
We can get a single instruction by using the optimized variants:
return percpu_read(var);
ffffffff8102ca3f: 65 48 8b 05 91 8f fd mov %gs:0x7efd8f91(%rip),%rax
I also cleaned up the x86-specific APIs and made the x86 code use
these new generic percpu primitives.
tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out
* added percpu_and() for completeness's sake
* made generic percpu ops atomic against preemption
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
Do the following cleanups:
* kill x86_64_init_pda() which now is equivalent to pda_init()
* use per_cpu_offset() instead of cpu_pda() when initializing
initial_gs
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
pda is now a percpu variable and there's no reason it can't use plain
x86 percpu accessors. Add x86_test_and_clear_bit_percpu() and replace
pda op implementations with wrappers around x86 percpu accessors.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
As pda is now allocated in percpu area, it can easily be made a proper
percpu variable. Make it so by defining per cpu symbol from linker
script and declaring it in C code for SMP and simply defining it for
UP. This change cleans up code and brings SMP and UP closer a bit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now that pda is allocated as part of percpu, percpu doesn't need to be
accessed through pda. Unify x86_64 SMP percpu access with x86_32 SMP
one. Other than the segment register, operand size and the base of
percpu symbols, they behave identical now.
This patch replaces now unnecessary pda->data_offset with a dummy
field which is necessary to keep stack_canary at its place. This
patch also moves per_cpu_offset initialization out of init_gdt() into
setup_per_cpu_areas(). Note that this change also necessitates
explicit per_cpu_offset initializations in voyager_smp.c.
With this change, x86_OP_percpu()'s are as efficient on x86_64 as on
x86_32 and also x86_64 can use assembly PER_CPU macros.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
Currently pdas and percpu areas are allocated separately. %gs points
to local pda and percpu area can be reached using pda->data_offset.
This patch folds pda into percpu area.
Due to strange gcc requirement, pda needs to be at the beginning of
the percpu area so that pda->stack_canary is at %gs:40. To achieve
this, a new percpu output section macro - PERCPU_VADDR_PREALLOC() - is
added and used to reserve pda sized chunk at the start of the percpu
area.
After this change, for boot cpu, %gs first points to pda in the
data.init area and later during setup_per_cpu_areas() gets updated to
point to the actual pda. This means that setup_per_cpu_areas() need
to reload %gs for CPU0 while clearing pda area for other cpus as cpu0
already has modified it when control reaches setup_per_cpu_areas().
This patch also removes now unnecessary get_local_pda() and its call
sites.
A lot of this patch is taken from Mike Travis' "x86_64: Fold pda into
per cpu area" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
_cpu_pda array first uses statically allocated storage in data.init
and then switches to allocated bootmem to conserve space. However,
after folding pda area into percpu area, _cpu_pda array will be
removed completely. Drop the reallocation part to simplify the code
for soon-to-follow changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
CPU startup code in head_64.S loaded address of a zero page into %gs
for temporary use till pda is loaded but address to the actual pda is
available at the point. Load the real address directly instead.
This will help unifying percpu and pda handling later on.
This patch is mostly taken from Mike Travis' "x86_64: Fold pda into
per cpu area" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
This patch makes percpu symbols zerobased on x86_64 SMP by adding
PERCPU_VADDR() to vmlinux.lds.h which helps setting explicit vaddr on
the percpu output section and using it in vmlinux_64.lds.S. A new
PHDR is added as existing ones cannot contain sections near address
zero. PERCPU_VADDR() also adds a new symbol __per_cpu_load which
always points to the vaddr of the loaded percpu data.init region.
The following adjustments have been made to accomodate the address
change.
* code to locate percpu gdt_page in head_64.S is updated to add the
load address to the gdt_page offset.
* __per_cpu_load is used in places where access to the init data area
is necessary.
* pda->data_offset is initialized soon after C code is entered as zero
value doesn't work anymore.
This patch is mostly taken from Mike Travis' "x86_64: Base percpu
variables at zero" patch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make vmlinux_32.lds.S use the generic PERCPU() macro instead of open
coding it. This will ease future changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[ Based on original patch from Christoph Lameter and Mike Travis. ]
* Ruggedize some calls in setup_percpu.c to prevent mishaps
in early calls, particularly for non-critical functions.
* Cleanup DEBUG_PER_CPU_MAPS usages and some comments.
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make early_per_cpu() a lvalue as per_cpu() is and use it where
applicable.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The function uv_wait_completion() spins on reads of a memory-mapped
register, waiting for completion of BAU hardware replies.
It should call "cpu_relax()" between those reads to improve performance
on hyperthreaded configurations.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Acked-by: Jack Steiner <steiner@sgi.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
-tip testing found this crash:
> [ 35.258515] calling acpi_cpufreq_init+0x0/0x127 @ 1
> [ 35.264127] BUG: unable to handle kernel NULL pointer dereference at (null)
> [ 35.267554] IP: [<ffffffff80478092>] __bitmap_intersects+0x48/0x73
> [ 35.267554] PGD 0
> [ 35.267554] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c is still broken: there's no
allocation of the variable mask, so we pass in an uninitialized cmd.mask
field to drv_read(), which then passes it to the scheduler which then
crashes ...
Switch it over to the much simpler constant-cpumask-pointers approach.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: widen the effect of the 'nolapic' boot parameter
"nolapic" should not only suppress SMP and use of the LAPIC, but it
also ought to have the effect of disabling all IO-APIC related activity
as well as PCI MSI and HT-IRQs.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: micro-optimization, memory reduction
On x86_64 flush tlb data is stored in per_cpu variables. This is
unnecessary because only the first NUM_INVALIDATE_TLB_VECTORS entries
are accessed.
This patch aims at making the code less confusing (there's nothing
really "per_cpu") by using a plain array. It also would save some memory
on most distros out there (Ubuntu x86_64 has NR_CPUS=64 by default).
[ Ravikiran G Thirumalai also pointed out that the correct alignment
is ____cacheline_internodealigned_in_smp, so that there's no
bouncing on vsmp. ]
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu>
Acked-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit broke flush_tlb_others_ipi() causing boot hangs on a
16 logical cpu system:
> commit 4595f9620c
> Author: Rusty Russell <rusty@rustcorp.com.au>
> Date: Sat Jan 10 21:58:09 2009 -0800
>
> x86: change flush_tlb_others to take a const struct cpumask
This change resulted in sending the invalidate tlb vector to the
sender itself causing the hang. flush_tlb_others_ipi() should exclude
the sender itself from the destination list.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix potential boot crash on MAXSMP
Remove code left over by:
50c668d: Revert "cpumask: use work_on_cpu in acpi-cpufreq.c for drv_read
That cmd.cpumask is not allocated anymore. No impact on default !MAXSMP
kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
