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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 17:59:09 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-06-22 17:59:09 -0700 |
commit | d70b3ef54ceaf1c7c92209f5a662a670d04cbed9 (patch) | |
tree | 0f38109c1cabe9e2df028041c1e30f36c803ec5b /Documentation | |
parent | 650ec5a6bd5df4ab0c9ef38d05b94cd82fb99ad8 (diff) | |
parent | 7ef3d7d58d9dc73ee3d4f8f56d0024c8cca8163f (diff) |
Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 core updates from Ingo Molnar:
"There were so many changes in the x86/asm, x86/apic and x86/mm topics
in this cycle that the topical separation of -tip broke down somewhat -
so the result is a more traditional architecture pull request,
collected into the 'x86/core' topic.
The topics were still maintained separately as far as possible, so
bisectability and conceptual separation should still be pretty good -
but there were a handful of merge points to avoid excessive
dependencies (and conflicts) that would have been poorly tested in the
end.
The next cycle will hopefully be much more quiet (or at least will
have fewer dependencies).
The main changes in this cycle were:
* x86/apic changes, with related IRQ core changes: (Jiang Liu, Thomas
Gleixner)
- This is the second and most intrusive part of changes to the x86
interrupt handling - full conversion to hierarchical interrupt
domains:
[IOAPIC domain] -----
|
[MSI domain] --------[Remapping domain] ----- [ Vector domain ]
| (optional) |
[HPET MSI domain] ----- |
|
[DMAR domain] -----------------------------
|
[Legacy domain] -----------------------------
This now reflects the actual hardware and allowed us to distangle
the domain specific code from the underlying parent domain, which
can be optional in the case of interrupt remapping. It's a clear
separation of functionality and removes quite some duct tape
constructs which plugged the remap code between ioapic/msi/hpet
and the vector management.
- Intel IOMMU IRQ remapping enhancements, to allow direct interrupt
injection into guests (Feng Wu)
* x86/asm changes:
- Tons of cleanups and small speedups, micro-optimizations. This
is in preparation to move a good chunk of the low level entry
code from assembly to C code (Denys Vlasenko, Andy Lutomirski,
Brian Gerst)
- Moved all system entry related code to a new home under
arch/x86/entry/ (Ingo Molnar)
- Removal of the fragile and ugly CFI dwarf debuginfo annotations.
Conversion to C will reintroduce many of them - but meanwhile
they are only getting in the way, and the upstream kernel does
not rely on them (Ingo Molnar)
- NOP handling refinements. (Borislav Petkov)
* x86/mm changes:
- Big PAT and MTRR rework: making the code more robust and
preparing to phase out exposing direct MTRR interfaces to drivers -
in favor of using PAT driven interfaces (Toshi Kani, Luis R
Rodriguez, Borislav Petkov)
- New ioremap_wt()/set_memory_wt() interfaces to support
Write-Through cached memory mappings. This is especially
important for good performance on NVDIMM hardware (Toshi Kani)
* x86/ras changes:
- Add support for deferred errors on AMD (Aravind Gopalakrishnan)
This is an important RAS feature which adds hardware support for
poisoned data. That means roughly that the hardware marks data
which it has detected as corrupted but wasn't able to correct, as
poisoned data and raises an APIC interrupt to signal that in the
form of a deferred error. It is the OS's responsibility then to
take proper recovery action and thus prolonge system lifetime as
far as possible.
- Add support for Intel "Local MCE"s: upcoming CPUs will support
CPU-local MCE interrupts, as opposed to the traditional system-
wide broadcasted MCE interrupts (Ashok Raj)
- Misc cleanups (Borislav Petkov)
* x86/platform changes:
- Intel Atom SoC updates
... and lots of other cleanups, fixlets and other changes - see the
shortlog and the Git log for details"
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (222 commits)
x86/hpet: Use proper hpet device number for MSI allocation
x86/hpet: Check for irq==0 when allocating hpet MSI interrupts
x86/mm/pat, drivers/infiniband/ipath: Use arch_phys_wc_add() and require PAT disabled
x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled
x86/platform/intel/baytrail: Add comments about why we disabled HPET on Baytrail
genirq: Prevent crash in irq_move_irq()
genirq: Enhance irq_data_to_desc() to support hierarchy irqdomain
iommu, x86: Properly handle posted interrupts for IOMMU hotplug
iommu, x86: Provide irq_remapping_cap() interface
iommu, x86: Setup Posted-Interrupts capability for Intel iommu
iommu, x86: Add cap_pi_support() to detect VT-d PI capability
iommu, x86: Avoid migrating VT-d posted interrupts
iommu, x86: Save the mode (posted or remapped) of an IRTE
iommu, x86: Implement irq_set_vcpu_affinity for intel_ir_chip
iommu: dmar: Provide helper to copy shared irte fields
iommu: dmar: Extend struct irte for VT-d Posted-Interrupts
iommu: Add new member capability to struct irq_remap_ops
x86/asm/entry/64: Disentangle error_entry/exit gsbase/ebx/usermode code
x86/asm/entry/32: Shorten __audit_syscall_entry() args preparation
x86/asm/entry/32: Explain reloading of registers after __audit_syscall_entry()
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
-rw-r--r-- | Documentation/x86/entry_64.txt | 4 | ||||
-rw-r--r-- | Documentation/x86/mtrr.txt | 18 | ||||
-rw-r--r-- | Documentation/x86/pat.txt | 48 | ||||
-rw-r--r-- | Documentation/x86/x86_64/boot-options.txt | 3 |
5 files changed, 69 insertions, 10 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 705ad8e66703..7bd4501f0cf9 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -746,6 +746,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system + cpu_init_udelay=N + [X86] Delay for N microsec between assert and de-assert + of APIC INIT to start processors. This delay occurs + on every CPU online, such as boot, and resume from suspend. + Default: 10000 + cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver Format: <first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>] diff --git a/Documentation/x86/entry_64.txt b/Documentation/x86/entry_64.txt index 9132b86176a3..33884d156125 100644 --- a/Documentation/x86/entry_64.txt +++ b/Documentation/x86/entry_64.txt @@ -18,10 +18,10 @@ Some of these entries are: - system_call: syscall instruction from 64-bit code. - - ia32_syscall: int 0x80 from 32-bit or 64-bit code; compat syscall + - entry_INT80_compat: int 0x80 from 32-bit or 64-bit code; compat syscall either way. - - ia32_syscall, ia32_sysenter: syscall and sysenter from 32-bit + - entry_INT80_compat, ia32_sysenter: syscall and sysenter from 32-bit code - interrupt: An array of entries. Every IDT vector that doesn't diff --git a/Documentation/x86/mtrr.txt b/Documentation/x86/mtrr.txt index cc071dc333c2..860bc3adc223 100644 --- a/Documentation/x86/mtrr.txt +++ b/Documentation/x86/mtrr.txt @@ -1,7 +1,19 @@ MTRR (Memory Type Range Register) control -3 Jun 1999 -Richard Gooch -<rgooch@atnf.csiro.au> + +Richard Gooch <rgooch@atnf.csiro.au> - 3 Jun 1999 +Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015 + +=============================================================================== +Phasing out MTRR use + +MTRR use is replaced on modern x86 hardware with PAT. Over time the only type +of effective MTRR that is expected to be supported will be for write-combining. +As MTRR use is phased out device drivers should use arch_phys_wc_add() to make +MTRR effective on non-PAT systems while a no-op on PAT enabled systems. + +For details refer to Documentation/x86/pat.txt. + +=============================================================================== On Intel P6 family processors (Pentium Pro, Pentium II and later) the Memory Type Range Registers (MTRRs) may be used to control diff --git a/Documentation/x86/pat.txt b/Documentation/x86/pat.txt index cf08c9fff3cd..54944c71b819 100644 --- a/Documentation/x86/pat.txt +++ b/Documentation/x86/pat.txt @@ -12,7 +12,7 @@ virtual addresses. PAT allows for different types of memory attributes. The most commonly used ones that will be supported at this time are Write-back, Uncached, -Write-combined and Uncached Minus. +Write-combined, Write-through and Uncached Minus. PAT APIs @@ -34,16 +34,23 @@ ioremap | -- | UC- | UC- | | | | | ioremap_cache | -- | WB | WB | | | | | +ioremap_uc | -- | UC | UC | + | | | | ioremap_nocache | -- | UC- | UC- | | | | | ioremap_wc | -- | -- | WC | | | | | +ioremap_wt | -- | -- | WT | + | | | | set_memory_uc | UC- | -- | -- | set_memory_wb | | | | | | | | set_memory_wc | WC | -- | -- | set_memory_wb | | | | | | | | +set_memory_wt | WT | -- | -- | + set_memory_wb | | | | + | | | | pci sysfs resource | -- | -- | UC- | | | | | pci sysfs resource_wc | -- | -- | WC | @@ -102,7 +109,38 @@ wants to export a RAM region, it has to do set_memory_uc() or set_memory_wc() as step 0 above and also track the usage of those pages and use set_memory_wb() before the page is freed to free pool. - +MTRR effects on PAT / non-PAT systems +------------------------------------- + +The following table provides the effects of using write-combining MTRRs when +using ioremap*() calls on x86 for both non-PAT and PAT systems. Ideally +mtrr_add() usage will be phased out in favor of arch_phys_wc_add() which will +be a no-op on PAT enabled systems. The region over which a arch_phys_wc_add() +is made, should already have been ioremapped with WC attributes or PAT entries, +this can be done by using ioremap_wc() / set_memory_wc(). Devices which +combine areas of IO memory desired to remain uncacheable with areas where +write-combining is desirable should consider use of ioremap_uc() followed by +set_memory_wc() to white-list effective write-combined areas. Such use is +nevertheless discouraged as the effective memory type is considered +implementation defined, yet this strategy can be used as last resort on devices +with size-constrained regions where otherwise MTRR write-combining would +otherwise not be effective. + +---------------------------------------------------------------------- +MTRR Non-PAT PAT Linux ioremap value Effective memory type +---------------------------------------------------------------------- + Non-PAT | PAT + PAT + |PCD + ||PWT + ||| +WC 000 WB _PAGE_CACHE_MODE_WB WC | WC +WC 001 WC _PAGE_CACHE_MODE_WC WC* | WC +WC 010 UC- _PAGE_CACHE_MODE_UC_MINUS WC* | UC +WC 011 UC _PAGE_CACHE_MODE_UC UC | UC +---------------------------------------------------------------------- + +(*) denotes implementation defined and is discouraged Notes: @@ -115,8 +153,8 @@ can be more restrictive, in case of any existing aliasing for that address. For example: If there is an existing uncached mapping, a new ioremap_wc can return uncached mapping in place of write-combine requested. -set_memory_[uc|wc] and set_memory_wb should be used in pairs, where driver will -first make a region uc or wc and switch it back to wb after use. +set_memory_[uc|wc|wt] and set_memory_wb should be used in pairs, where driver +will first make a region uc, wc or wt and switch it back to wb after use. Over time writes to /proc/mtrr will be deprecated in favor of using PAT based interfaces. Users writing to /proc/mtrr are suggested to use above interfaces. @@ -124,7 +162,7 @@ interfaces. Users writing to /proc/mtrr are suggested to use above interfaces. Drivers should use ioremap_[uc|wc] to access PCI BARs with [uc|wc] access types. -Drivers should use set_memory_[uc|wc] to set access type for RAM ranges. +Drivers should use set_memory_[uc|wc|wt] to set access type for RAM ranges. PAT debugging diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index 5223479291a2..68ed3114c363 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -31,6 +31,9 @@ Machine check (e.g. BIOS or hardware monitoring applications), conflicting with OS's error handling, and you cannot deactivate the agent, then this option will be a help. + mce=no_lmce + Do not opt-in to Local MCE delivery. Use legacy method + to broadcast MCEs. mce=bootlog Enable logging of machine checks left over from booting. Disabled by default on AMD because some BIOS leave bogus ones. |