linux.git/arch/csky/include/asm/pgalloc.h, branch v6.14

asm-generic: pgalloc: provide generic __pgd_{alloc,free}

2025-01-26T04:22:24+00:00

We already have a generic implementation of alloc/free up to P4D level, as
well as pgd_free().  Let's finish the work and add a generic PGD-level
alloc helper as well.

Unlike at lower levels, almost all architectures need some specific magic
at PGD level (typically initialising PGD entries), so introducing a
generic pgd_alloc() isn't worth it.  Instead we introduce two new helpers,
__pgd_alloc() and __pgd_free(), and make use of them in the arch-specific
pgd_alloc() and pgd_free() wherever possible.  To accommodate as many arch
as possible, __pgd_alloc() takes a page allocation order.

Because pagetable_alloc() allocates zeroed pages, explicit zeroing in
pgd_alloc() becomes redundant and we can get rid of it.  Some trivial
implementations of pgd_free() also become unnecessary once __pgd_alloc()
is used; remove them.

Another small improvement is consistent accounting of PGD pages by using
GFP_PGTABLE_{USER,KERNEL} as appropriate.

Not all PGD allocations can be handled by the generic helpers.  In
particular, multiple architectures allocate PGDs from a kmem_cache, and
those PGDs may not be page-sized.

Link: https://lkml.kernel.org/r/20250103184415.2744423-6-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky 
Acked-by: Dave Hansen 
Acked-by: Qi Zheng 
Cc: Andy Lutomirski 
Cc: Catalin Marinas 
Cc: Ingo Molnar 
Cc: Linus Walleij 
Cc: Matthew Wilcox (Oracle) 
Cc: Mike Rapoport (Microsoft) 
Cc: Peter Zijlstra 
Cc: Ryan Roberts 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

mm: pgtable: introduce pagetable_dtor()

2025-01-26T04:22:22+00:00

The pagetable_p*_dtor() are exactly the same except for the handling of
ptlock.  If we make ptlock_free() handle the case where ptdesc->ptl is
NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify
pagetable_p*_dtor() into one function.  Let's introduce pagetable_dtor()
to do this.

Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that
ptlock and page table pages can be freed together (regardless of whether
RCU is used).  This prevents the use-after-free problem where the ptlock
is freed immediately but the page table pages is freed later via RCU.

Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng 
Originally-by: Peter Zijlstra (Intel) 
Reviewed-by: Kevin Brodsky 
Acked-by: Alexander Gordeev 	[s390]
Cc: Alexandre Ghiti 
Cc: Alexandre Ghiti 
Cc: Andreas Larsson 
Cc: Aneesh Kumar K.V (Arm) 
Cc: Arnd Bergmann 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jann Horn 
Cc: Lorenzo Stoakes 
Cc: Matthew Wilcox (Oracle) 
Cc: Mike Rapoport (Microsoft) 
Cc: Muchun Song 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Ryan Roberts 
Cc: Thomas Gleixner 
Cc: Vishal Moola (Oracle) 
Cc: Will Deacon 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton

csky: convert __pte_free_tlb() to use ptdescs

2023-08-21T20:37:55+00:00

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.

Link: https://lkml.kernel.org/r/20230807230513.102486-20-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) 
Acked-by: Guo Ren 
Acked-by: Mike Rapoport (IBM) 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Christophe Leroy 
Cc: Claudio Imbrenda 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: "David S. Miller" 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Geert Uytterhoeven 
Cc: Huacai Chen 
Cc: Hugh Dickins 
Cc: John Paul Adrian Glaubitz 
Cc: Jonas Bonn 
Cc: Matthew Wilcox 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Thomas Bogendoerfer 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

csky: drop definition of PGD_ORDER

2022-07-18T00:14:42+00:00

This is the order of the page table allocation, not the order of a PGD. 
Since its always hardwired to 0, simply drop it.

Link: https://lkml.kernel.org/r/20220703141203.147893-3-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Cc: Arnd Bergmann 
Cc: Dinh Nguyen 
Cc: Guo Ren 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: James Bottomley 
Cc: "Matthew Wilcox (Oracle)" 
Cc: Max Filippov 
Cc: Thomas Bogendoerfer 
Cc: Xuerui Wang 
Signed-off-by: Andrew Morton

mm/thp: define default pmd_pgtable()

2021-07-01T18:06:03+00:00

Currently most platforms define pmd_pgtable() as pmd_page() duplicating
the same code all over.  Instead just define a default value i.e
pmd_page() for pmd_pgtable() and let platforms override when required via
.  All the existing platform that override pmd_pgtable()
have been moved into their respective  header in order to
precede before the new generic definition.  This makes it much cleaner
with reduced code.

Link: https://lkml.kernel.org/r/1623646133-20306-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual 
Acked-by: Geert Uytterhoeven 
Acked-by: Mike Rapoport 
Cc: Nick Hu 
Cc: Richard Henderson 
Cc: Vineet Gupta 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Guo Ren 
Cc: Brian Cain 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Thomas Bogendoerfer 
Cc: Ley Foon Tan 
Cc: Jonas Bonn 
Cc: Stefan Kristiansson 
Cc: Stafford Horne 
Cc: "James E.J. Bottomley" 
Cc: Michael Ellerman 
Cc: Christophe Leroy 
Cc: Paul Walmsley 
Cc: Palmer Dabbelt 
Cc: Heiko Carstens 
Cc: Yoshinori Sato 
Cc: "David S. Miller" 
Cc: Jeff Dike 
Cc: Thomas Gleixner 
Cc: Chris Zankel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

csky: Fixup compile error

2021-02-27T14:04:14+00:00

: error: C++ style comments are not allowed in ISO C90
 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
 ^
error: (this will be reported only once per input file)

Signed-off-by: Guo Ren

csky: Add memory layout 2.5G(user):1.5G(kernel)

2021-01-12T01:52:40+00:00

There are two ways for translating va to pa for csky:
 - Use TLB(Translate Lookup Buffer) and PTW (Page Table Walk)
 - Use SSEG0/1 (Simple Segment Mapping)

We use tlb mapping 0-2G and 3G-4G virtual address area and SSEG0/1
are for 2G-2.5G and 2.5G-3G translation. We could disable SSEG0
to use 2G-2.5G as TLB user mapping.

Signed-off-by: Guo Ren

asm-generic: pgalloc: provide generic pgd_free()

2020-08-07T18:33:26+00:00

Most architectures define pgd_free() as a wrapper for free_page().

Provide a generic version in asm-generic/pgalloc.h and enable its use for
most architectures.

Signed-off-by: Mike Rapoport 
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: Joerg Roedel 
Cc: Max Filippov 
Cc: Peter Zijlstra (Intel) 
Cc: Satheesh Rajendran 
Cc: Stafford Horne 
Cc: Stephen Rothwell 
Cc: Steven Rostedt 
Cc: Matthew Wilcox 
Link: http://lkml.kernel.org/r/20200627143453.31835-7-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming

2019-09-26T17:10:44+00:00

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland 
Reviewed-by: Mike Rapoport 
Acked-by: Geert Uytterhoeven 	[m68k]
Cc: Anshuman Khandual 
Cc: Matthew Wilcox 
Cc: Michal Hocko 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove quicklist page table caches

2019-09-24T22:54:09+00:00

Patch series "mm: remove quicklist page table caches".

A while ago Nicholas proposed to remove quicklist page table caches [1].

I've rebased his patch on the curren upstream and switched ia64 and sh to
use generic versions of PTE allocation.

[1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com

This patch (of 3):

Remove page table allocator "quicklists".  These have been around for a
long time, but have not got much traction in the last decade and are only
used on ia64 and sh architectures.

The numbers in the initial commit look interesting but probably don't
apply anymore.  If anybody wants to resurrect this it's in the git
history, but it's unhelpful to have this code and divergent allocator
behaviour for minor archs.

Also it might be better to instead make more general improvements to page
allocator if this is still so slow.

Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Nicholas Piggin 
Signed-off-by: Mike Rapoport 
Cc: Tony Luck 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds