Merge branches 'x86/apic', 'x86/asm', 'x86/mm' and 'x86/platform' into x86/core, to merge last updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar
2015-06-22 09:15:03 +02:00
643 changed files with 9093 additions and 5866 deletions

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@@ -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

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@@ -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

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@@ -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

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@@ -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.