07 Jun, 2015
1 commit
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Add ioremap_wt() for creating Write-Through mappings on x86. It
follows the same model as ioremap_wc() for multi-arch support.
Define ARCH_HAS_IOREMAP_WT in the x86 version of io.h to
indicate that ioremap_wt() is implemented on x86.Also update the PAT documentation file to cover ioremap_wt().
Signed-off-by: Toshi Kani
Signed-off-by: Borislav Petkov
Cc: Andrew Morton
Cc: Andy Lutomirski
Cc: Elliott@hp.com
Cc: H. Peter Anvin
Cc: Linus Torvalds
Cc: Luis R. Rodriguez
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar
11 May, 2015
1 commit
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ioremap_nocache() currently uses UC- by default. Our goal is to
eventually make UC the default. Linux maps UC- to PCD=1, PWT=0
page attributes on non-PAT systems. Linux maps UC to PCD=1,
PWT=1 page attributes on non-PAT systems. On non-PAT and PAT
systems a WC MTRR has different effects on pages with either of
these attributes. In order to help with a smooth transition its
best to enable use of UC (PCD,1, PWT=1) on a region as that
ensures a WC MTRR will have no effect on a region, this however
requires us to have an way to declare a region as UC and we
currently do not have a way to do this.WC MTRR on non-PAT system with PCD=1, PWT=0 (UC-) yields WC.
WC MTRR on non-PAT system with PCD=1, PWT=1 (UC) yields UC.WC MTRR on PAT system with PCD=1, PWT=0 (UC-) yields WC.
WC MTRR on PAT system with PCD=1, PWT=1 (UC) yields UC.A flip of the default ioremap_nocache() behaviour from UC- to UC
can therefore regress a memory region from effective memory type
WC to UC if MTRRs are used. Use of MTRRs should be phased out
and in the best case only arch_phys_wc_add() use will remain,
even if this happens arch_phys_wc_add() will have an effect on
non-PAT systems and changes to default ioremap_nocache()
behaviour could regress drivers.Now, ideally we'd use ioremap_nocache() on the regions in which
we'd need uncachable memory types and avoid any MTRRs on those
regions. There are however some restrictions on MTRRs use, such
as the requirement of having the base and size of variable sized
MTRRs to be powers of two, which could mean having to use a WC
MTRR over a large area which includes a region in which
write-combining effects are undesirable.Add ioremap_uc() to help with the both phasing out of MTRR use
and also provide a way to blacklist small WC undesirable regions
in devices with mixed regions which are size-implicated to use
large WC MTRRs. Use of ioremap_uc() helps phase out MTRR use by
avoiding regressions with an eventual flip of default behaviour
or ioremap_nocache() from UC- to UC.Drivers working with WC MTRRs can use the below table to review
and consider the use of ioremap*() and similar helpers to ensure
appropriate behaviour long term even if default
ioremap_nocache() behaviour changes from UC- to UC.Although ioremap_uc() is being added we leave set_memory_uc() to
use UC- as only initial memory type setup is required to be able
to accommodate existing device drivers and phase out MTRR use.
It should also be clarified that set_memory_uc() cannot be used
with IO memory, even though its use will not return any errors,
it really has no effect.----------------------------------------------------------------------
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* | WC
WC 011 UC _PAGE_CACHE_MODE_UC UC | UC
----------------------------------------------------------------------Signed-off-by: Luis R. Rodriguez
Signed-off-by: Borislav Petkov
Acked-by: H. Peter Anvin
Cc: Andy Lutomirski
Cc: Antonino Daplas
Cc: Bjorn Helgaas
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: Daniel Vetter
Cc: Dave Airlie
Cc: Davidlohr Bueso
Cc: Denys Vlasenko
Cc: Jean-Christophe Plagniol-Villard
Cc: Juergen Gross
Cc: Linus Torvalds
Cc: Mel Gorman
Cc: Mike Travis
Cc: Peter Zijlstra
Cc: Suresh Siddha
Cc: Thierry Reding
Cc: Thomas Gleixner
Cc: Tomi Valkeinen
Cc: Toshi Kani
Cc: Ville Syrjälä
Cc: Vlastimil Babka
Cc: Will Deacon
Cc: linux-fbdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1430343851-967-2-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1431332153-18566-9-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar
12 Nov, 2014
1 commit
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* 'io' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
documentation: memory-barriers: clarify relaxed io accessor semantics
x86: io: implement dummy relaxed accessor macros for writes
tile: io: implement dummy relaxed accessor macros for writes
sparc: io: implement dummy relaxed accessor macros for writes
powerpc: io: implement dummy relaxed accessor macros for writes
parisc: io: implement dummy relaxed accessor macros for writes
mn10300: io: implement dummy relaxed accessor macros for writes
m68k: io: implement dummy relaxed accessor macros for writes
m32r: io: implement dummy relaxed accessor macros for writes
ia64: io: implement dummy relaxed accessor macros for writes
cris: io: implement dummy relaxed accessor macros for writes
frv: io: implement dummy relaxed accessor macros for writes
xtensa: io: remove dummy relaxed accessor macros for reads
s390: io: remove dummy relaxed accessor macros for reads
microblaze: io: remove dummy relaxed accessor macros
asm-generic: io: implement relaxed accessor macros as conditional wrappersConflicts:
include/asm-generic/io.hSigned-off-by: Arnd Bergmann
10 Nov, 2014
2 commits
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Currently driver writers need to use io{read,write}{8,16,32}_rep() when
accessing FIFO registers portably. This is bad for two reasons: it is
inconsistent with how other registers are accessed using the standard
{read,write}{b,w,l}() functions, which can lead to confusion. On some
architectures the io{read,write}*() functions also need to perform some
extra checks to determine whether an address is memory-mapped or refers
to I/O space. Drivers which can be expected to never use I/O can safely
use the {read,write}s{b,w,l,q}(), just like they use their non-string
variants and there's no need for these extra checks.This patch implements generic versions of readsb(), readsw(), readsl(),
readsq(), writesb(), writesw(), writesl() and writesq(). Variants of
these string functions for I/O accesses (ins*() and outs*() as well as
ioread*_rep() and iowrite*_rep()) are now implemented in terms of the
new functions.Going forward, {read,write}{,s}{b,w,l,q}() should be used consistently
by drivers for devices that will only ever be memory-mapped and hence
don't need to access I/O space, whereas io{read,write}{8,16,32}_rep()
should be used by drivers for devices that can be either memory-mapped
or I/O-mapped.Signed-off-by: Thierry Reding
-
Overriding I/O accessors and helpers is currently very inconsistent.
This commit introduces a homogeneous way to override functions by
checking for the existence of a macro with the same of the function.
Architectures can provide their own implementations and communicate this
to the generic header by defining the appropriate macro. Doing this will
also help prevent the implementations from being subsequently
overridden.While at it, also turn a lot of macros into static inline functions for
better type checking and to provide a canonical signature for overriding
architectures to copy. Also reorder functions by logical groups.Signed-off-by: Thierry Reding
21 Oct, 2014
1 commit
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{read,write}{b,w,l,q}_relaxed are implemented by some architectures in
order to permit memory-mapped I/O accesses with weaker barrier semantics
than the non-relaxed variants.This patch adds wrappers to asm-generic so that drivers can rely on the
relaxed accessors being available, even if they don't always provide
weaker ordering guarantees. Since some architectures both include
asm-generic/io.h and define some relaxed accessors, the definitions here
are conditional for the time being.Cc: Arnd Bergmann
Signed-off-by: Will Deacon
30 Sep, 2014
1 commit
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The !CONFIG_GENERIC_IOMAP version of ioport_map() is wrong. It returns a
mapped, i.e., virtual, address that can start from zero and completely
ignores the PCI_IOBASE and IO_SPACE_LIMIT that most architectures that use
!CONFIG_GENERIC_MAP define.Tested-by: Tanmay Inamdar
Signed-off-by: Liviu Dudau
Signed-off-by: Bjorn Helgaas
Reviewed-by: Catalin Marinas
Acked-by: Arnd Bergmann
08 Apr, 2014
1 commit
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If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally. So
HAS_IOPORT_MAP is the better name for this.Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.
The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available. I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.The changes in this commit were done using:
$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: Uwe Kleine-König
Acked-by: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 May, 2013
1 commit
-
On s390 the prefix page and absolute zero pages are not correctly
returned when reading /dev/mem. The reason is that the s390 asm/io.h
file includes the asm-generic/io.h file which then defines
xlate_dev_mem_ptr() and therefore overwrites the s390 specific
version that does the correct swap operation for prefix and absolute
zero pages. The problem is a regression that was introduced with git
commit cd248341 (s390/pci: base support).To fix the problem add "#ifndef xlate_dev_mem_ptr" in asm-generic/io.h
and "#define xlate_dev_mem_ptr" in asm/io.h. This ensures that the
s390 version is used. For completeness also add the "#ifndef"
construct for xlate_dev_kmem_ptr().Signed-off-by: Michael Holzheu
Signed-off-by: Martin Schwidefsky
04 Mar, 2013
1 commit
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Pull new ImgTec Meta architecture from James Hogan:
"This adds core architecture support for Imagination's Meta processor
cores, followed by some later miscellaneous arch/metag cleanups and
fixes which I kept separate to ease review:- Support for basic Meta 1 (ATP) and Meta 2 (HTP) core architecture
- A few fixes all over, particularly for symbol prefixes
- A few privilege protection fixes
- Several cleanups (setup.c includes, split out a lot of
metag_ksyms.c)
- Fix some missing exports
- Convert hugetlb to use vm_unmapped_area()
- Copy device tree to non-init memory
- Provide dma_get_sgtable()"* tag 'metag-v3.9-rc1-v4' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: (61 commits)
metag: Provide dma_get_sgtable()
metag: prom.h: remove declaration of metag_dt_memblock_reserve()
metag: copy devicetree to non-init memory
metag: cleanup metag_ksyms.c includes
metag: move mm/init.c exports out of metag_ksyms.c
metag: move usercopy.c exports out of metag_ksyms.c
metag: move setup.c exports out of metag_ksyms.c
metag: move kick.c exports out of metag_ksyms.c
metag: move traps.c exports out of metag_ksyms.c
metag: move irq enable out of irqflags.h on SMP
genksyms: fix metag symbol prefix on crc symbols
metag: hugetlb: convert to vm_unmapped_area()
metag: export clear_page and copy_page
metag: export metag_code_cache_flush_all
metag: protect more non-MMU memory regions
metag: make TXPRIVEXT bits explicit
metag: kernel/setup.c: sort includes
perf: Enable building perf tools for Meta
metag: add boot time LNKGET/LNKSET check
metag: add __init to metag_cache_probe()
...
03 Mar, 2013
1 commit
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Make asm-generic/io.h check CONFIG_VIRT_TO_BUS before defining
virt_to_bus() and bus_to_virt(), otherwise it's easy to accidentally
have a silently failing incorrect direct mapped definition rather then
no definition at all.Signed-off-by: James Hogan
Acked-by: Arnd Bergmann
27 Feb, 2013
1 commit
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Pull microblaze update from Michal Simek:
"Microblaze changes.After my discussion with Arnd I have also added there asm-generic io
patch which is Acked by him and Geert."* 'next' of git://git.monstr.eu/linux-2.6-microblaze:
asm-generic: io: Fix ioread16/32be and iowrite16/32be
microblaze: Do not use module.h in files which are not modules
microblaze: Fix coding style issues
microblaze: Add missing return from debugfs_tlb
microblaze: Makefile clean
microblaze: Add .gitignore entries for auto-generated files
microblaze: Fix strncpy_from_user macro
14 Feb, 2013
1 commit
-
E.g. readl is defined like this
#define readl(addr) __le32_to_cpu(__raw_readl(addr))
If a there is a readl() call that doesn't check the return value
this will cause a compile warning on big endian machines due to
the __le32_to_cpu macro magic.E.g. code like this:
readl(addr);
will generate the following compile warning:
warning: value computed is not used [-Wunused-value]
With this patch we get rid of dozens of compile warnings on s390.
Signed-off-by: Heiko Carstens
Acked-by: Arnd Bergmann
Signed-off-by: Martin Schwidefsky
12 Feb, 2013
1 commit
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Fix ioreadXXbe and iowriteXXbe functions which did
additional little endian conversion on native big endian systems.
Using be_to_cpu (cpu_to_be) conversions with __raw_read/write
functions have resolved it.Signed-off-by: Michal Simek
Acked-by: Arnd Bergmann
Acked-by: Geert Uytterhoeven
CC: Benjamin Herrenschmidt
CC: Will Deacon
CC: linux-arch@vger.kernel.org
22 Dec, 2012
1 commit
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Pull asm-generic cleanup from Arnd Bergmann:
"These are a few cleanups for asm-generic:- a set of patches from Lars-Peter Clausen to generalize asm/mmu.h
and use it in the architectures that don't need any special
handling.
- A patch from Will Deacon to remove the {read,write}s{b,w,l} as
discussed during the arm64 review
- A patch from James Hogan that helps with the meta architecture
series."* tag 'asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
xtensa: Use generic asm/mmu.h for nommu
h8300: Use generic asm/mmu.h
c6x: Use generic asm/mmu.h
asm-generic/mmu.h: Add support for FDPIC
asm-generic/mmu.h: Remove unused vmlist field from mm_context_t
asm-generic: io: remove {read,write} string functions
asm-generic/io.h: remove asm/cacheflush.h include
18 Dec, 2012
1 commit
-
The {in,out}s{b,w,l} functions are designed to operate on a stream of
bytes and therefore should not perform any byte-swapping, regardless of
the CPU byte order.This patch fixes the generic IO header so that {in,out}s{b,w,l} call the
__raw_{read,write} functions directly rather than going via the
endian-correcting accessors.Signed-off-by: Will Deacon
Cc: Mike Frysinger
Acked-by: Arnd Bergmann
Acked-by: Ben Herrenschmidt
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Nov, 2012
1 commit
-
Add PCI support for s390, (only 64 bit mode is supported by hardware):
- PCI facility tests
- PCI instructions: pcilg, pcistg, pcistb, stpcifc, mpcifc, rpcit
- map readb/w/l/q and writeb/w/l/q to pcilg and pcistg instructions
- pci_iomap implementation
- memcpy_fromio/toio
- pci_root_ops using special pcilg/pcistg
- device, bus and domain allocationSigned-off-by: Jan Glauber
Signed-off-by: Martin Schwidefsky
26 Oct, 2012
1 commit
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The {read,write}s{b,w,l} functions are not defined across all
architectures and therefore shouldn't be used by portable drivers. We
should encourage driver writers to use the io{read,write}{8,16,32}_rep
functions instead.This patch removes the {read,write} string functions for the generic IO
header as they have no place in a new architecture port.Cc: Arnd Bergmann
Cc: Mike Frysinger
Cc: Ben Herrenschmidt
Signed-off-by: Will Deacon
25 Oct, 2012
1 commit
-
Including from prevents
cacheflush.h being able to use I/O functions like readl and writel due
to circular include dependencies. It doesn't appear as if anything from
cacheflush.h is actually used by the generic io.h, so remove the
include.I've compile tested a defconfig compilation of blackfin, openrisc (which
needed including from it's to get the PAGE_*
definitions), and xtensa.Other architectures which use asm-generic/io.h are score and unicore32,
and looking at their io.h I don't see any obvious problems.Signed-off-by: James Hogan
Acked-by: Jonas Bonn
Cc: Chris Zankel
Cc: Max Filippov
Cc: Mike Frysinger
Cc: Chen Liqin
Cc: Lennox Wu
Cc: Guan Xuetao
Signed-off-by: Arnd Bergmann
11 Jan, 2012
1 commit
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lib: use generic pci_iomap on all architectures
Many architectures don't want to pull in iomap.c,
so they ended up duplicating pci_iomap from that file.
That function isn't trivial, and we are going to modify it
https://lkml.org/lkml/2011/11/14/183
so the duplication hurts.This reduces the scope of the problem significantly,
by moving pci_iomap to a separate file and
referencing that from all architectures.* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
alpha: drop pci_iomap/pci_iounmap from pci-noop.c
mn10300: switch to GENERIC_PCI_IOMAP
mn10300: add missing __iomap markers
frv: switch to GENERIC_PCI_IOMAP
tile: switch to GENERIC_PCI_IOMAP
tile: don't panic on iomap
sparc: switch to GENERIC_PCI_IOMAP
sh: switch to GENERIC_PCI_IOMAP
powerpc: switch to GENERIC_PCI_IOMAP
parisc: switch to GENERIC_PCI_IOMAP
mips: switch to GENERIC_PCI_IOMAP
microblaze: switch to GENERIC_PCI_IOMAP
arm: switch to GENERIC_PCI_IOMAP
alpha: switch to GENERIC_PCI_IOMAP
lib: add GENERIC_PCI_IOMAP
lib: move GENERIC_IOMAP to lib/KconfigFix up trivial conflicts due to changes nearby in arch/{m68k,score}/Kconfig
29 Nov, 2011
1 commit
-
Many architectures want a generic pci_iomap but
not the rest of iomap.c. Split that to a separate .c
file and add a new config symbol. select automatically
by GENERIC_IOMAP.Signed-off-by: Michael S. Tsirkin
07 Oct, 2011
1 commit
-
Signed-off-by: Mark Salter
Acked-by: Arnd Bergmann
23 Jul, 2011
2 commits
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Use the CONFIG_HAS_IOPORT and CONFIG_PCI options to decide whether or
not functions for mapping these areas are provided.Signed-off-by: Jonas Bonn
Acked-by: Arnd Bergmann -
Some of the implementations, in particular the ioremap variants, in
asm-generic/io.h are for systems without an MMU. In order to be able to
use the generic header file for systems with an MMU, this patch wraps
these implementations in checks for CONFIG_MMU.Tested on OpenRISC.
Signed-off-by: Jonas Bonn
Cc: liqin.chen@sunplusct.com
Cc: gxt@mprc.pku.edu.cn
Acked-by: Mike Frysinger
Acked-by: Arnd Bergmann
17 Mar, 2011
1 commit
-
The definitions for the PC-style PIO functions in asm-generic/io.h were
meant as dummies so you could compile code on architectures without
ISA and PCI buses. However, unicore32 actually wants to use them
with a real PCI bus, so they need to be defined to actually address
the register window holding the I/O ports.Signed-off-by: Arnd Bergmann
10 Jan, 2011
1 commit
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A bunch of arches define reads[bwl]/writes[bwl] helpers for accessing
memory mapped registers. Since the Blackfin ones aren't specific to
Blackfin code, move them to the common asm-generic/io.h for people.Acked-by: Arnd Bergmann
Signed-off-by: Mike Frysinger
18 Oct, 2010
1 commit
-
For the Blackfin port, we can use much of the asm-generic/io.h header,
but we still need to declare some of our own versions of functions.
Like the __raw_read* and in/out "string" helpers. So let people do
this easily for many of these funcs.Signed-off-by: Mike Frysinger
Signed-off-by: Arnd Bergmann
10 Aug, 2010
1 commit
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The asm-generic/iomap.h provides these functions already, but the
non-generic fallback defines do not.Signed-off-by: Mike Frysinger
Cc: Arnd Bergmann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jun, 2009
1 commit
-
atomic.h and io.h are based on the mn10300 architecture,
which is already pretty generic and can be used by
other architectures that do not have hardware support
for atomic operations or out-of-order I/O access.Signed-off-by: Arnd Bergmann