18 Nov, 2020
1 commit
-
Signed-off-by: Flavio Suligoi
Signed-off-by: Vineet Gupta
21 Oct, 2020
1 commit
-
Pull ARC updates from Vineet Gupta:
"The bulk of ARC pull request is removal of EZChip NPS platform which
was suffering from constant bitrot. In recent years EZChip has gone
though multiple successive acquisitions and I guess things and people
move on. I would like to take this opportunity to recognize and thank
all those good folks (Gilad, Noam, Ofer...) for contributing major
bits to ARC port (SMP, Big Endian).Summary:
- drop support for EZChip NPS platform
- misc other fixes"
* tag 'arc-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
arc: include/asm: fix typos of "themselves"
ARC: SMP: fix typo and use "come up" instead of "comeup"
ARC: [dts] fix the errors detected by dtbs_check
arc: plat-hsdk: fix kconfig dependency warning when !RESET_CONTROLLER
ARC: [plat-eznps]: Drop support for EZChip NPS platform
06 Oct, 2020
3 commits
-
Move more nitty gritty DMA implementation details into the common
internal header.Signed-off-by: Christoph Hellwig
-
Split out all the bits that are purely for dma_map_ops implementations
and related code into a new header so that they
don't get pulled into all the drivers. That also means the architecture
specific is not pulled in by
any more, which leads to a missing includes that were pulled in by the
x86 or arm versions in a few not overly portable drivers.Signed-off-by: Christoph Hellwig
-
NPS customers are no longer doing active development, as evident from
rand config build failures reported in recent times, so drop support
for NPS platform.Tested-by: kernel test robot
Signed-off-by: Vineet Gupta
02 Sep, 2020
1 commit
-
Rework of memory map initialization broke initialization of ARC systems
with two memory banks. Before these changes, memblock was not aware of
nodes configuration and the memory map was always allocated from the
"lowmem" bank. After the addition of node information to memblock, the core
mm attempts to allocate the memory map for the "highmem" bank from its
node. The access to this memory using __va() fails because it can be only
accessed using kmap.Anther problem that was uncovered is that {min,max}_high_pfn are calculated
from u64 high_mem_start variable which prevents truncation to 32-bit
physical address and the PFN values are above the node and zone boundaries.Use phys_addr_t type for high_mem_start and high_mem_size to ensure
correspondence between PFNs and highmem zone boundaries and reserve the
entire highmem bank until mem_init() to avoid accesses to it before highmem
is enabled.To test this:
1. Enable HIGHMEM in ARC config
2. Enable 2 memory banks in haps_hs.dts (uncomment the 2nd bank)Fixes: 51930df5801e ("mm: free_area_init: allow defining max_zone_pfn in descending order")
Cc: stable@vger.kernel.org [5.8]
Signed-off-by: Mike Rapoport
Signed-off-by: Vineet Gupta
[vgupta: added instructions to test highmem]
13 Aug, 2020
2 commits
-
Use the general page fault accounting by passing regs into
handle_mm_fault(). It naturally solve the issue of multiple page fault
accounting when page fault retry happened.Fix PERF_COUNT_SW_PAGE_FAULTS perf event manually for page fault retries,
by moving it before taking mmap_sem.Signed-off-by: Peter Xu
Signed-off-by: Andrew Morton
Cc: Vineet Gupta
Link: http://lkml.kernel.org/r/20200707225021.200906-4-peterx@redhat.com
Signed-off-by: Linus Torvalds -
Patch series "mm: Page fault accounting cleanups", v5.
This is v5 of the pf accounting cleanup series. It originates from Gerald
Schaefer's report on an issue a week ago regarding to incorrect page fault
accountings for retried page fault after commit 4064b9827063 ("mm: allow
VM_FAULT_RETRY for multiple times"):https://lore.kernel.org/lkml/20200610174811.44b94525@thinkpad/
What this series did:
- Correct page fault accounting: we do accounting for a page fault
(no matter whether it's from #PF handling, or gup, or anything else)
only with the one that completed the fault. For example, page fault
retries should not be counted in page fault counters. Same to the
perf events.- Unify definition of PERF_COUNT_SW_PAGE_FAULTS: currently this perf
event is used in an adhoc way across different archs.Case (1): for many archs it's done at the entry of a page fault
handler, so that it will also cover e.g. errornous faults.Case (2): for some other archs, it is only accounted when the page
fault is resolved successfully.Case (3): there're still quite some archs that have not enabled
this perf event.Since this series will touch merely all the archs, we unify this
perf event to always follow case (1), which is the one that makes most
sense. And since we moved the accounting into handle_mm_fault, the
other two MAJ/MIN perf events are well taken care of naturally.- Unify definition of "major faults": the definition of "major
fault" is slightly changed when used in accounting (not
VM_FAULT_MAJOR). More information in patch 1.- Always account the page fault onto the one that triggered the page
fault. This does not matter much for #PF handlings, but mostly for
gup. More information on this in patch 25.Patchset layout:
Patch 1: Introduced the accounting in handle_mm_fault(), not enabled.
Patch 2-23: Enable the new accounting for arch #PF handlers one by one.
Patch 24: Enable the new accounting for the rest outliers (gup, iommu, etc.)
Patch 25: Cleanup GUP task_struct pointer since it's not needed any moreThis patch (of 25):
This is a preparation patch to move page fault accountings into the
general code in handle_mm_fault(). This includes both the per task
flt_maj/flt_min counters, and the major/minor page fault perf events. To
do this, the pt_regs pointer is passed into handle_mm_fault().PERF_COUNT_SW_PAGE_FAULTS should still be kept in per-arch page fault
handlers.So far, all the pt_regs pointer that passed into handle_mm_fault() is
NULL, which means this patch should have no intented functional change.Suggested-by: Linus Torvalds
Signed-off-by: Peter Xu
Signed-off-by: Andrew Morton
Cc: Albert Ou
Cc: Alexander Gordeev
Cc: Andy Lutomirski
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Brian Cain
Cc: Catalin Marinas
Cc: Christian Borntraeger
Cc: Chris Zankel
Cc: Dave Hansen
Cc: David S. Miller
Cc: Geert Uytterhoeven
Cc: Gerald Schaefer
Cc: Greentime Hu
Cc: Guo Ren
Cc: Heiko Carstens
Cc: Helge Deller
Cc: H. Peter Anvin
Cc: Ingo Molnar
Cc: Ivan Kokshaysky
Cc: James E.J. Bottomley
Cc: John Hubbard
Cc: Jonas Bonn
Cc: Ley Foon Tan
Cc: "Luck, Tony"
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Nick Hu
Cc: Palmer Dabbelt
Cc: Paul Mackerras
Cc: Paul Walmsley
Cc: Pekka Enberg
Cc: Peter Zijlstra
Cc: Richard Henderson
Cc: Rich Felker
Cc: Russell King
Cc: Stafford Horne
Cc: Stefan Kristiansson
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Cc: Vasily Gorbik
Cc: Vincent Chen
Cc: Vineet Gupta
Cc: Will Deacon
Cc: Yoshinori Sato
Link: http://lkml.kernel.org/r/20200707225021.200906-1-peterx@redhat.com
Link: http://lkml.kernel.org/r/20200707225021.200906-2-peterx@redhat.com
Signed-off-by: Linus Torvalds
08 Aug, 2020
1 commit
-
Patch series "mm: cleanup usage of "
Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in and enable
use of the generic functions where appropriate.In addition, functions declared and defined in headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the included all over the place.
The first patch in this series removes unneeded includes ofIn the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.This patch (of 8):
In most cases header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in and do not require that header.As for the other header files that used to include , it is
possible to move that include into the .c file that actually uses symbols
from and drop the include from the header file.The process was somewhat automated using
sed -i -E '/[
Signed-off-by: Andrew Morton
Reviewed-by: Pekka Enberg
Acked-by: Geert Uytterhoeven [m68k]
Cc: Abdul Haleem
Cc: Andy Lutomirski
Cc: Arnd Bergmann
Cc: Christophe Leroy
Cc: Joerg Roedel
Cc: Max Filippov
Cc: Peter Zijlstra
Cc: Satheesh Rajendran
Cc: Stafford Horne
Cc: Stephen Rothwell
Cc: Steven Rostedt
Cc: Joerg Roedel
Cc: Matthew Wilcox
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds
10 Jun, 2020
5 commits
-
Convert comments that reference mmap_sem to reference mmap_lock instead.
[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Vlastimil Babka
Reviewed-by: Daniel Jordan
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Laurent Dufour
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds -
This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.The change is generated using coccinelle with the following rule:
// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .
@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)Signed-off-by: Michel Lespinasse
Signed-off-by: Andrew Morton
Reviewed-by: Daniel Jordan
Reviewed-by: Laurent Dufour
Reviewed-by: Vlastimil Babka
Cc: Davidlohr Bueso
Cc: David Rientjes
Cc: Hugh Dickins
Cc: Jason Gunthorpe
Cc: Jerome Glisse
Cc: John Hubbard
Cc: Liam Howlett
Cc: Matthew Wilcox
Cc: Peter Zijlstra
Cc: Ying Han
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds -
The powerpc 32-bit implementation of pgtable has nice shortcuts for
accessing kernel PMD and PTE for a given virtual address. Make these
helpers available for all architectures.[rppt@linux.ibm.com: microblaze: fix page table traversal in setup_rt_frame()]
Link: http://lkml.kernel.org/r/20200518191511.GD1118872@kernel.org
[akpm@linux-foundation.org: s/pmd_ptr_k/pmd_off_k/ in various powerpc places]Signed-off-by: Mike Rapoport
Signed-off-by: Andrew Morton
Cc: Arnd Bergmann
Cc: Borislav Petkov
Cc: Brian Cain
Cc: Catalin Marinas
Cc: Chris Zankel
Cc: "David S. Miller"
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Ungerer
Cc: Guan Xuetao
Cc: Guo Ren
Cc: Heiko Carstens
Cc: Helge Deller
Cc: Ingo Molnar
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Matthew Wilcox
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Nick Hu
Cc: Paul Walmsley
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Stafford Horne
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vincent Chen
Cc: Vineet Gupta
Cc: Will Deacon
Cc: Yoshinori Sato
Link: http://lkml.kernel.org/r/20200514170327.31389-9-rppt@kernel.org
Signed-off-by: Linus Torvalds -
The replacement of with made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.import sys
import reif len(sys.argv) is not 3:
print "USAGE: %s " % (sys.argv[0])
sys.exit(1)hdr_to_move="#include " % sys.argv[2]
moved = False
in_hdrs = Falsewith open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Ungerer
Cc: Guan Xuetao
Cc: Guo Ren
Cc: Heiko Carstens
Cc: Helge Deller
Cc: Ingo Molnar
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Matthew Wilcox
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Nick Hu
Cc: Paul Walmsley
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Stafford Horne
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vincent Chen
Cc: Vineet Gupta
Cc: Will Deacon
Cc: Yoshinori Sato
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds -
The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.Signed-off-by: Mike Rapoport
Signed-off-by: Andrew Morton
Cc: Arnd Bergmann
Cc: Borislav Petkov
Cc: Brian Cain
Cc: Catalin Marinas
Cc: Chris Zankel
Cc: "David S. Miller"
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Ungerer
Cc: Guan Xuetao
Cc: Guo Ren
Cc: Heiko Carstens
Cc: Helge Deller
Cc: Ingo Molnar
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Matthew Wilcox
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Simek
Cc: Nick Hu
Cc: Paul Walmsley
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Stafford Horne
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Cc: Tony Luck
Cc: Vincent Chen
Cc: Vineet Gupta
Cc: Will Deacon
Cc: Yoshinori Sato
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds
05 Jun, 2020
5 commits
-
To support kmap_atomic_prot(), all architectures need to support
protections passed to their kmap_atomic_high() function. Pass protections
into kmap_atomic_high() and change the name to kmap_atomic_high_prot() to
match.Then define kmap_atomic_prot() as a core function which calls
kmap_atomic_high_prot() when needed.Finally, redefine kmap_atomic() as a wrapper of kmap_atomic_prot() with
the default kmap_prot exported by the architectures.Signed-off-by: Ira Weiny
Signed-off-by: Andrew Morton
Reviewed-by: Christoph Hellwig
Cc: Al Viro
Cc: Andy Lutomirski
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Christian König
Cc: Chris Zankel
Cc: Daniel Vetter
Cc: Dan Williams
Cc: Dave Hansen
Cc: "David S. Miller"
Cc: Helge Deller
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Max Filippov
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/20200507150004.1423069-11-ira.weiny@intel.com
Signed-off-by: Linus Torvalds -
Every single architecture (including !CONFIG_HIGHMEM) calls...
pagefault_enable();
preempt_enable();... before returning from __kunmap_atomic(). Lift this code into the
kunmap_atomic() macro.While we are at it rename __kunmap_atomic() to kunmap_atomic_high() to
be consistent.[ira.weiny@intel.com: don't enable pagefault/preempt twice]
Link: http://lkml.kernel.org/r/20200518184843.3029640-1-ira.weiny@intel.com
[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: Ira Weiny
Signed-off-by: Andrew Morton
Reviewed-by: Christoph Hellwig
Cc: Al Viro
Cc: Andy Lutomirski
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Christian König
Cc: Chris Zankel
Cc: Daniel Vetter
Cc: Dan Williams
Cc: Dave Hansen
Cc: "David S. Miller"
Cc: Helge Deller
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Max Filippov
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Cc: Guenter Roeck
Link: http://lkml.kernel.org/r/20200507150004.1423069-8-ira.weiny@intel.com
Signed-off-by: Linus Torvalds -
Every arch has the same code to ensure atomic operations and a check for
!HIGHMEM page.Remove the duplicate code by defining a core kmap_atomic() which only
calls the arch specific kmap_atomic_high() when the page is high memory.[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: Ira Weiny
Signed-off-by: Andrew Morton
Reviewed-by: Christoph Hellwig
Cc: Al Viro
Cc: Andy Lutomirski
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Christian König
Cc: Chris Zankel
Cc: Daniel Vetter
Cc: Dan Williams
Cc: Dave Hansen
Cc: "David S. Miller"
Cc: Helge Deller
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Max Filippov
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/20200507150004.1423069-7-ira.weiny@intel.com
Signed-off-by: Linus Torvalds -
The kmap code for all the architectures is almost 100% identical.
Lift the common code to the core. Use ARCH_HAS_KMAP_FLUSH_TLB to indicate
if an arch defines kmap_flush_tlb() and call if if needed.This also has the benefit of changing kmap() on a number of architectures
to be an inline call rather than an actual function.Signed-off-by: Ira Weiny
Signed-off-by: Andrew Morton
Reviewed-by: Christoph Hellwig
Cc: Al Viro
Cc: Andy Lutomirski
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Christian König
Cc: Chris Zankel
Cc: Daniel Vetter
Cc: Dan Williams
Cc: Dave Hansen
Cc: "David S. Miller"
Cc: Helge Deller
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: "James E.J. Bottomley"
Cc: Max Filippov
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Thomas Bogendoerfer
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/20200507150004.1423069-4-ira.weiny@intel.com
Signed-off-by: Linus Torvalds -
Patch series "Remove duplicated kmap code", v3.
The kmap infrastructure has been copied almost verbatim to every
architecture. This series consolidates obvious duplicated code by
defining core functions which call into the architectures only when
needed.Some of the k[un]map_atomic() implementations have some similarities but
the similarities were not sufficient to warrant further changes.In addition we remove a duplicate implementation of kmap() in DRM.
This patch (of 15):
Replace the use of BUG_ON(in_interrupt()) in the kmap() and kunmap() in
favor of might_sleep().Besides the benefits of might_sleep(), this normalizes the implementations
such that they can be made generic in subsequent patches.Signed-off-by: Ira Weiny
Signed-off-by: Andrew Morton
Reviewed-by: Dan Williams
Reviewed-by: Christoph Hellwig
Cc: Al Viro
Cc: Christian König
Cc: Daniel Vetter
Cc: Thomas Bogendoerfer
Cc: "James E.J. Bottomley"
Cc: Helge Deller
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: "David S. Miller"
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: Borislav Petkov
Cc: "H. Peter Anvin"
Cc: Dave Hansen
Cc: Andy Lutomirski
Cc: Peter Zijlstra
Cc: Chris Zankel
Cc: Max Filippov
Link: http://lkml.kernel.org/r/20200507150004.1423069-1-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20200507150004.1423069-2-ira.weiny@intel.com
Signed-off-by: Linus Torvalds
04 Jun, 2020
1 commit
-
Some architectures (e.g. ARC) have the ZONE_HIGHMEM zone below the
ZONE_NORMAL. Allowing free_area_init() parse max_zone_pfn array even it
is sorted in descending order allows using free_area_init() on such
architectures.Add top -> down traversal of max_zone_pfn array in free_area_init() and
use the latter in ARC node/zone initialization.[rppt@kernel.org: ARC fix]
Link: http://lkml.kernel.org/r/20200504153901.GM14260@kernel.org
[rppt@linux.ibm.com: arc: free_area_init(): take into account PAE40 mode]
Link: http://lkml.kernel.org/r/20200507205900.GH683243@linux.ibm.com
[akpm@linux-foundation.org: declare arch_has_descending_max_zone_pfns()]
Signed-off-by: Mike Rapoport
Signed-off-by: Andrew Morton
Tested-by: Hoan Tran [arm64]
Reviewed-by: Baoquan He
Cc: Brian Cain
Cc: Catalin Marinas
Cc: "David S. Miller"
Cc: Geert Uytterhoeven
Cc: Greentime Hu
Cc: Greg Ungerer
Cc: Guan Xuetao
Cc: Guo Ren
Cc: Heiko Carstens
Cc: Helge Deller
Cc: "James E.J. Bottomley"
Cc: Jonathan Corbet
Cc: Ley Foon Tan
Cc: Mark Salter
Cc: Matt Turner
Cc: Max Filippov
Cc: Michael Ellerman
Cc: Michal Hocko
Cc: Michal Simek
Cc: Nick Hu
Cc: Paul Walmsley
Cc: Richard Weinberger
Cc: Rich Felker
Cc: Russell King
Cc: Stafford Horne
Cc: Thomas Bogendoerfer
Cc: Tony Luck
Cc: Vineet Gupta
Cc: Yoshinori Sato
Cc: Guenter Roeck
Link: http://lkml.kernel.org/r/20200412194859.12663-18-rppt@kernel.org
Signed-off-by: Linus Torvalds
03 Apr, 2020
3 commits
-
The idea comes from a discussion between Linus and Andrea [1].
Before this patch we only allow a page fault to retry once. We achieved
this by clearing the FAULT_FLAG_ALLOW_RETRY flag when doing
handle_mm_fault() the second time. This was majorly used to avoid
unexpected starvation of the system by looping over forever to handle the
page fault on a single page. However that should hardly happen, and after
all for each code path to return a VM_FAULT_RETRY we'll first wait for a
condition (during which time we should possibly yield the cpu) to happen
before VM_FAULT_RETRY is really returned.This patch removes the restriction by keeping the FAULT_FLAG_ALLOW_RETRY
flag when we receive VM_FAULT_RETRY. It means that the page fault handler
now can retry the page fault for multiple times if necessary without the
need to generate another page fault event. Meanwhile we still keep the
FAULT_FLAG_TRIED flag so page fault handler can still identify whether a
page fault is the first attempt or not.Then we'll have these combinations of fault flags (only considering
ALLOW_RETRY flag and TRIED flag):- ALLOW_RETRY and !TRIED: this means the page fault allows to
retry, and this is the first try- ALLOW_RETRY and TRIED: this means the page fault allows to
retry, and this is not the first try- !ALLOW_RETRY and !TRIED: this means the page fault does not allow
to retry at all- !ALLOW_RETRY and TRIED: this is forbidden and should never be used
In existing code we have multiple places that has taken special care of
the first condition above by checking against (fault_flags &
FAULT_FLAG_ALLOW_RETRY). This patch introduces a simple helper to detect
the first retry of a page fault by checking against both (fault_flags &
FAULT_FLAG_ALLOW_RETRY) and !(fault_flag & FAULT_FLAG_TRIED) because now
even the 2nd try will have the ALLOW_RETRY set, then use that helper in
all existing special paths. One example is in __lock_page_or_retry(), now
we'll drop the mmap_sem only in the first attempt of page fault and we'll
keep it in follow up retries, so old locking behavior will be retained.This will be a nice enhancement for current code [2] at the same time a
supporting material for the future userfaultfd-writeprotect work, since in
that work there will always be an explicit userfault writeprotect retry
for protected pages, and if that cannot resolve the page fault (e.g., when
userfaultfd-writeprotect is used in conjunction with swapped pages) then
we'll possibly need a 3rd retry of the page fault. It might also benefit
other potential users who will have similar requirement like userfault
write-protection.GUP code is not touched yet and will be covered in follow up patch.
Please read the thread below for more information.
[1] https://lore.kernel.org/lkml/20171102193644.GB22686@redhat.com/
[2] https://lore.kernel.org/lkml/20181230154648.GB9832@redhat.com/Suggested-by: Linus Torvalds
Suggested-by: Andrea Arcangeli
Signed-off-by: Peter Xu
Signed-off-by: Andrew Morton
Tested-by: Brian Geffon
Cc: Bobby Powers
Cc: David Hildenbrand
Cc: Denis Plotnikov
Cc: "Dr . David Alan Gilbert"
Cc: Hugh Dickins
Cc: Jerome Glisse
Cc: Johannes Weiner
Cc: "Kirill A . Shutemov"
Cc: Martin Cracauer
Cc: Marty McFadden
Cc: Matthew Wilcox
Cc: Maya Gokhale
Cc: Mel Gorman
Cc: Mike Kravetz
Cc: Mike Rapoport
Cc: Pavel Emelyanov
Link: http://lkml.kernel.org/r/20200220160246.9790-1-peterx@redhat.com
Signed-off-by: Linus Torvalds -
Although there're tons of arch-specific page fault handlers, most of them
are still sharing the same initial value of the page fault flags. Say,
merely all of the page fault handlers would allow the fault to be retried,
and they also allow the fault to respond to SIGKILL.Let's define a default value for the fault flags to replace those initial
page fault flags that were copied over. With this, it'll be far easier to
introduce new fault flag that can be used by all the architectures instead
of touching all the archs.Signed-off-by: Peter Xu
Signed-off-by: Andrew Morton
Tested-by: Brian Geffon
Reviewed-by: David Hildenbrand
Cc: Andrea Arcangeli
Cc: Bobby Powers
Cc: Denis Plotnikov
Cc: "Dr . David Alan Gilbert"
Cc: Hugh Dickins
Cc: Jerome Glisse
Cc: Johannes Weiner
Cc: "Kirill A . Shutemov"
Cc: Martin Cracauer
Cc: Marty McFadden
Cc: Matthew Wilcox
Cc: Maya Gokhale
Cc: Mel Gorman
Cc: Mike Kravetz
Cc: Mike Rapoport
Cc: Pavel Emelyanov
Link: http://lkml.kernel.org/r/20200220160238.9694-1-peterx@redhat.com
Signed-off-by: Linus Torvalds -
Let ARC to use the new helper fault_signal_pending() by moving the signal
check out of the retry logic as standalone. This should also helps to
simplify the code a bit.Signed-off-by: Peter Xu
Signed-off-by: Andrew Morton
Tested-by: Brian Geffon
Cc: Andrea Arcangeli
Cc: Bobby Powers
Cc: David Hildenbrand
Cc: Denis Plotnikov
Cc: "Dr . David Alan Gilbert"
Cc: Hugh Dickins
Cc: Jerome Glisse
Cc: Johannes Weiner
Cc: "Kirill A . Shutemov"
Cc: Martin Cracauer
Cc: Marty McFadden
Cc: Matthew Wilcox
Cc: Maya Gokhale
Cc: Mel Gorman
Cc: Mike Kravetz
Cc: Mike Rapoport
Cc: Pavel Emelyanov
Link: http://lkml.kernel.org/r/20200220155843.9172-1-peterx@redhat.com
Signed-off-by: Linus Torvalds
05 Dec, 2019
1 commit
-
Pull ARC updates from Vineet Gupta
- Jump Label support for ARC
- kmemleak enabled
- arc mm backend TLB Miss / flush optimizations
- nSIM platform switching to dwuart (vs. arcuart) and ensuing defconfig
updates and cleanups- axs platform pll / video-mode updates
* tag 'arc-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: add kmemleak support
ARC: [plat-axs10x]: remove hardcoded video mode from bootargs
ARC: [plat-axs10x]: use pgu pll instead of fixed clock
ARC: ARCv2: jump label: implement jump label patching
ARC: mm: tlb flush optim: elide redundant uTLB invalidates for MMUv3
ARC: mm: tlb flush optim: elide repeated uTLB invalidate in loop
ARC: mm: tlb flush optim: Make TLBWriteNI fallback to TLBWrite if not available
ARC: mm: TLB Miss optim: avoid re-reading ECR
ARCv2: mm: TLB Miss optim: Use double world load/stores LDD/STD
ARCv2: mm: TLB Miss optim: SMP builds can cache pgd pointer in mmu scratch reg
ARC: nSIM_700: remove unused network options
ARC: nSIM_700: switch to DW UART usage
ARC: merge HAPS-HS with nSIM-HS configs
ARC: HAPS: cleanup defconfigs from unused ETH drivers
ARC: HAPS: add HIGHMEM memory zone to DTS
ARC: HAPS: use same UART configuration everywhere
ARC: HAPS: cleanup defconfigs from unused IO-related options
ARC: regenerate nSIM and HAPS defconfigs
01 Dec, 2019
1 commit
-
Patch series "elide extraneous generated code for folded p4d/pud/pmd", v3.
This series came out of seemingly benign excursion into
understanding/removing __ARCH_USE_5LEVEL_HACK from ARC port showing some
extraneous code being generated despite folded p4d/pud/pmd| bloat-o-meter2 vmlinux-[AB]*
| add/remove: 0/0 grow/shrink: 3/0 up/down: 130/0 (130)
| function old new delta
| free_pgd_range 548 660 +112
| p4d_clear_bad 2 20 +18The patches here address that
| bloat-o-meter2 vmlinux-[BF]*
| add/remove: 0/2 grow/shrink: 0/1 up/down: 0/-386 (-386)
| function old new delta
| pud_clear_bad 20 - -20
| p4d_clear_bad 20 - -20
| free_pgd_range 660 314 -346The code savings are not a whole lot, but still worthwhile IMHO.
This patch (of 5):
With paging code made 5-level compliant, this is no longer needed. ARC
has software page walker with 2 lookup levels (pgd -> pte)This was expected to be non functional change but ended with slight
code bloat due to needless inclusions of p*d_free_tlb() macros which
will be addressed in further patches.| bloat-o-meter2 vmlinux-[AB]*
| add/remove: 0/0 grow/shrink: 2/0 up/down: 128/0 (128)
| function old new delta
| free_pgd_range 546 656 +110
| p4d_clear_bad 2 20 +18
| Total: Before=4137148, After=4137276, chg 0.000000%Link: http://lkml.kernel.org/r/20191016162400.14796-2-vgupta@synopsys.com
Signed-off-by: Vineet Gupta
Acked-by: Kirill A. Shutemov
Cc: "Aneesh Kumar K . V"
Cc: Arnd Bergmann
Cc: Nick Piggin
Cc: Peter Zijlstra
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Nov, 2019
1 commit
-
These are pure cache maintainance routines, so drop the unused
struct device argument.Signed-off-by: Christoph Hellwig
Suggested-by: Daniel Vetter
29 Oct, 2019
6 commits
-
For MMUv3 (and prior) the flush_tlb_{range,mm,page} API use the MMU
TLBWrite cmd which already nukes the entire uTLB, so NO need for
additional IVUTLB cmd from utlb_invalidate() - hence this patchlocal_flush_tlb_all() is special since it uses a weaker TLBWriteNI
cmd (prec commit) to shoot down JTLB, hence we retain the explicit
uTLB flushSigned-off-by: Vineet Gupta
-
The unconditional full TLB flush (on say ASID rollover) iterates over each
entry and uses TLBWrite to zero it out. TLBWrite by design also invalidates
the uTLBs thus we end up invalidating it as many times as numbe rof
entries (512 or 1k)Optimize this by using a weaker TLBWriteNI cmd in loop, which doesn't
tinker with uTLBs and an explicit one time IVUTLB, outside the loop to
invalidate them all once.And given the optimiztion, the IVUTLB is now needed on MMUv4 too where
the uTLBs and JTLBs are otherwise coherent given the TLBInsertEntry /
TLBDeleteEntry commandsSigned-off-by: Vineet Gupta
-
TLBWriteNI was introduced in MMUv2 (to not invalidate uTLBs in Fast Path
TLB Refill Handler). To avoid #ifdef'ery make it fallback to TLBWrite availabel on all MMUs. This will also help with next changeSigned-off-by: Vineet Gupta
-
For setting PTE Dirty bit, reuse the prior test for ST miss.
No need to reload ECR and test for ST cause code as the prev
condition code is still valid (uncloberred)Signed-off-by: Vineet Gupta
-
Signed-off-by: Vineet Gupta
-
ARC700 exception (and intr handling) didn't have auto stack switching
thus had to rely on stashing a reg temporarily (to free it up) at a
known place in memory, allowing to code up the low level stack switching.
This however was not re-entrant in SMP which thus had to repurpose the
per-cpu MMU SCRATCH DATA register otherwise used to "cache" the task pdg
pointer (vs. reading it from mm struct)The newer HS cores do have auto-stack switching and thus even SMP builds
can use the MMU SCRATCH reg as originally intended.This patch fixes the restriction to ARC700 SMP builds only
Signed-off-by: Vineet Gupta
20 Sep, 2019
1 commit
-
Pull dma-mapping updates from Christoph Hellwig:
- add dma-mapping and block layer helpers to take care of IOMMU merging
for mmc plus subsequent fixups (Yoshihiro Shimoda)- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask
(me)- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
mmc: queue: Fix bigger segments usage
arm64: use asm-generic/dma-mapping.h
swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
swiotlb-xen: simplify cache maintainance
swiotlb-xen: use the same foreign page check everywhere
swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
xen: remove the exports for xen_{create,destroy}_contiguous_region
xen/arm: remove xen_dma_ops
xen/arm: simplify dma_cache_maint
xen/arm: use dev_is_dma_coherent
xen/arm: consolidate page-coherent.h
xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
arm: remove wrappers for the generic dma remap helpers
dma-mapping: introduce a dma_common_find_pages helper
dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
vmalloc: lift the arm flag for coherent mappings to common code
dma-mapping: provide a better default ->get_required_mask
dma-mapping: remove the dma_declare_coherent_memory export
remoteproc: don't allow modular build
...
29 Aug, 2019
1 commit
-
The memory allocated for the atomic pool needs to have the same
mapping attributes that we use for remapping, so use
pgprot_dmacoherent instead of open coding it. Also deduct a
suitable zone to allocate the memory from based on the presence
of the DMA zones.Signed-off-by: Christoph Hellwig
05 Aug, 2019
1 commit
-
Signed-off-by: Eugeniy Paltsev
Signed-off-by: Vineet Gupta
17 Jul, 2019
1 commit
-
Pull ARC updates from Vineet Gupta:
- long due rewrite of do_page_fault
- refactoring of entry/exit code to utilize the double load/store
instructions- hsdk platform updates
* tag 'arc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: [plat-hsdk]: Enable AXI DW DMAC in defconfig
ARC: [plat-hsdk]: enable DW SPI controller
ARC: hide unused function unw_hdr_alloc
ARC: [haps] Add Virtio support
ARCv2: entry: simplify return to Delay Slot via interrupt
ARC: entry: EV_Trap expects r10 (vs. r9) to have exception cause
ARCv2: entry: rewrite to enable use of double load/stores LDD/STD
ARCv2: entry: avoid a branch
ARCv2: entry: push out the Z flag unclobber from common EXCEPTION_PROLOGUE
ARCv2: entry: comments about hardware auto-save on taken interrupts
ARC: mm: do_page_fault refactor #8: release mmap_sem sooner
ARC: mm: do_page_fault refactor #7: fold the various error handling
ARC: mm: do_page_fault refactor #6: error handlers to use same pattern
ARC: mm: do_page_fault refactor #5: scoot no_context to end
ARC: mm: do_page_fault refactor #4: consolidate retry related logic
ARC: mm: do_page_fault refactor #3: tidyup vma access permission code
ARC: mm: do_page_fault refactor #2: remove short lived variable
ARC: mm: do_page_fault refactor #1: remove label @good_area
13 Jul, 2019
1 commit
-
Pull dma-mapping updates from Christoph Hellwig:
- move the USB special case that bounced DMA through a device bar into
the USB code instead of handling it in the common DMA code (Laurentiu
Tudor and Fredrik Noring)- don't dip into the global CMA pool for single page allocations
(Nicolin Chen)- fix a crash when allocating memory for the atomic pool failed during
boot (Florian Fainelli)- move support for MIPS-style uncached segments to the common code and
use that for MIPS and nios2 (me)- make support for DMA_ATTR_NON_CONSISTENT and
DMA_ATTR_NO_KERNEL_MAPPING generic (me)- convert nds32 to the generic remapping allocator (me)
* tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping: (29 commits)
dma-mapping: mark dma_alloc_need_uncached as __always_inline
MIPS: only select ARCH_HAS_UNCACHED_SEGMENT for non-coherent platforms
usb: host: Fix excessive alignment restriction for local memory allocations
lib/genalloc.c: Add algorithm, align and zeroed family of DMA allocators
nios2: use the generic uncached segment support in dma-direct
nds32: use the generic remapping allocator for coherent DMA allocations
arc: use the generic remapping allocator for coherent DMA allocations
dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code
dma-direct: handle DMA_ATTR_NON_CONSISTENT in common code
dma-mapping: add a dma_alloc_need_uncached helper
openrisc: remove the partial DMA_ATTR_NON_CONSISTENT support
arc: remove the partial DMA_ATTR_NON_CONSISTENT support
arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support
ARM: dma-mapping: allow larger DMA mask than supported
dma-mapping: truncate dma masks to what dma_addr_t can hold
iommu/dma: Apply dma_{alloc,free}_contiguous functions
dma-remap: Avoid de-referencing NULL atomic_pool
MIPS: use the generic uncached segment support in dma-direct
dma-direct: provide generic support for uncached kernel segments
au1100fb: fix DMA API abuse
...
09 Jul, 2019
1 commit
-
…iederm/user-namespace
Pull force_sig() argument change from Eric Biederman:
"A source of error over the years has been that force_sig has taken a
task parameter when it is only safe to use force_sig with the current
task.The force_sig function is built for delivering synchronous signals
such as SIGSEGV where the userspace application caused a synchronous
fault (such as a page fault) and the kernel responded with a signal.Because the name force_sig does not make this clear, and because the
force_sig takes a task parameter the function force_sig has been
abused for sending other kinds of signals over the years. Slowly those
have been fixed when the oopses have been tracked down.This set of changes fixes the remaining abusers of force_sig and
carefully rips out the task parameter from force_sig and friends
making this kind of error almost impossible in the future"* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
signal: Remove the signal number and task parameters from force_sig_info
signal: Factor force_sig_info_to_task out of force_sig_info
signal: Generate the siginfo in force_sig
signal: Move the computation of force into send_signal and correct it.
signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
signal: Remove the task parameter from force_sig_fault
signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
signal: Explicitly call force_sig_fault on current
signal/unicore32: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from ptrace_break
signal/nds32: Remove tsk parameter from send_sigtrap
signal/riscv: Remove tsk parameter from do_trap
signal/sh: Remove tsk parameter from force_sig_info_fault
signal/um: Remove task parameter from send_sigtrap
signal/x86: Remove task parameter from send_sigtrap
signal: Remove task parameter from force_sig_mceerr
signal: Remove task parameter from force_sig
signal: Remove task parameter from force_sigsegv
...
02 Jul, 2019
2 commits
-
Upon a taken interrupt/exception from User mode, HS hardware auto sets Z flag.
This helps shave a few instructions from EXCEPTION_PROLOGUE by eliding
re-reading ERSTATUS and some bit fiddling.However TLB Miss Exception handler can clobber the CPU flags and still end
up in EXCEPTION_PROLOGUE in the slow path handling TLB handling case:EV_TLBMissD
do_slow_path_pf
EV_TLBProtV (aliased to call_do_page_fault)
EXCEPTION_PROLOGUEAs a result, EXCEPTION_PROLOGUE need to "unclobber" the Z flag which this
patch changes. It is now pushed out to TLB Miss Exception handler.
The reasons beings:- The flag restoration is only needed for slowpath TLB Miss Exception
handling, but currently being in EXCEPTION_PROLOGUE penalizes all
exceptions such as ProtV and syscall Trap, where Z flag is already
as expected.- Pushing unclobber out to where it was clobbered is much cleaner and
also serves to document the fact.- Makes EXCEPTION_PROLGUE similar to INTERRUPT_PROLOGUE so easier to
refactor the common parts which is what this series aims to doSigned-off-by: Vineet Gupta
-
In case of successful page fault handling, this patch releases mmap_sem
before updating the perf stat event for major/minor faults. So even
though the contention reduction is NOT super high, it is still an
improvement.There's an additional code size improvement as we only have 2 up_read()
calls now.Note to myself:
--------------1. Given the way it is done, we are forced to move @bad_area label earlier
causing the various "goto bad_area" cases to hit perf stat code.- PERF_COUNT_SW_PAGE_FAULTS is NOW updated for access errors which is what
arm/arm64 seem to be doing as well (with slightly different code)
- PERF_COUNT_SW_PAGE_FAULTS_{MAJ,MIN} must NOT be updated for the
error case which is guarded by now setting @fault initial value
to VM_FAULT_ERROR which serves both cases when handle_mm_fault()
returns error or is not called at all.2. arm/arm64 use two homebrew fault flags VM_FAULT_BAD{MAP,MAPACCESS}
which I was inclined to add too but seems not needed for ARC- given that we have everything is 1 function we can still use goto
- we setup si_code at the right place (arm* do that in the end)
- we init fault already to error value which guards entry into perf
stats event updateCc: Peter Zijlstra
Signed-off-by: Vineet Gupta