linux-toradex.git/arch/arc/mm, branch v5.18

ARC: fix typos in comments

2022-04-18T19:20:23+00:00

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall 
Signed-off-by: Vineet Gupta

Merge tag 'arc-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2022-01-18T04:36:35+00:00

Pull ARC fixes from Vineet Gupta:
 "Nothing too exciting for now"

* tag 'arc-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  arc: use swap() to make code cleaner
  arc: perf: Move static structs to where they're really used
  ARC: perf: fix misleading comment about pmu vs counter stop
  arc: Replace lkml.org links with lore
  ARC: perf: Remove redundant initialization of variable idx
  ARC: thread_info.h: correct two typos in a comment

mm: remove redundant check about FAULT_FLAG_ALLOW_RETRY bit

2022-01-15T14:30:27+00:00

Since commit 4064b9827063 ("mm: allow VM_FAULT_RETRY for multiple
times") allowed VM_FAULT_RETRY for multiple times, the
FAULT_FLAG_ALLOW_RETRY bit of fault_flag will not be changed in the page
fault path, so the following check is no longer needed:

	flags & FAULT_FLAG_ALLOW_RETRY

So just remove it.

[akpm@linux-foundation.org: coding style fixes]

Link: https://lkml.kernel.org/r/20211110123358.36511-1-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng 
Cc: Peter Zijlstra 
Cc: Ingo Molnar 
Cc: David Hildenbrand 
Cc: Kirill Shutemov 
Cc: Peter Xu 
Cc: Muchun Song 
Cc: Chengming Zhou 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

arc: Replace lkml.org links with lore

2021-12-29T03:48:49+00:00

As started by commit 05a5f51ca566 ("Documentation: Replace lkml.org
links with lore"), replace lkml.org links with lore to better use a
single source that's more likely to stay available long-term.

Signed-off-by: Kees Cook 
Signed-off-by: Vineet Gupta

memblock: allow to specify flags with memblock_add_node()

2021-11-06T20:30:42+00:00

We want to specify flags when hotplugging memory.  Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.

Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images.  It's important to add the memory
directly to memblock via a single call with the right flags, instead of
adding the memory first and apply flags later: otherwise, concurrent
memblock users might temporarily stumble over memblocks with wrong
flags, which will be important in a follow-up patch that introduces a
new flag to properly handle add_memory_driver_managed().

Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com
Acked-by: Geert Uytterhoeven 
Acked-by: Heiko Carstens 
Signed-off-by: David Hildenbrand 
Acked-by: Shahab Vahedi 	[arch/arc]
Reviewed-by: Mike Rapoport 
Cc: "Aneesh Kumar K . V" 
Cc: Arnd Bergmann 
Cc: Christian Borntraeger 
Cc: Eric Biederman 
Cc: Huacai Chen 
Cc: Jianyong Wu 
Cc: Jiaxun Yang 
Cc: Michal Hocko 
Cc: Oscar Salvador 
Cc: Thomas Bogendoerfer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memblock: rename memblock_free to memblock_phys_free

2021-11-06T20:30:41+00:00

Since memblock_free() operates on a physical range, make its name
reflect it and rename it to memblock_phys_free(), so it will be a
logical counterpart to memblock_phys_alloc().

The callers are updated with the below semantic patch:

    @@
    expression addr;
    expression size;
    @@
    - memblock_free(addr, size);
    + memblock_phys_free(addr, size);

Link: https://lkml.kernel.org/r/20210930185031.18648-6-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Cc: Christophe Leroy 
Cc: Juergen Gross 
Cc: Shahab Vahedi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'arc-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2021-09-05T18:43:03+00:00

Pull ARC updates from Vineet Gupta:
 "Finally a big pile of changes for ARC (atomics/mm). These are from our
  internal arc64 tree, preparing mainline for eventual arc64 support.
  I'm spreading them out to avoid tsunami of patches in one release.

   - MM rework:
       - Implement up to 4 paging levels
       - Enable STRICT_MM_TYPECHECK
       - switch pgtable_t back to 'struct page *'

   - Atomics rework / implement relaxed accessors

   - Retire legacy MMUv1,v2; ARC750 cores

   - A few other build errors, typos"

* tag 'arc-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (33 commits)
  ARC: mm: vmalloc sync from kernel to user table to update PMD ...
  ARC: mm: support 4 levels of page tables
  ARC: mm: support 3 levels of page tables
  ARC: mm: switch to asm-generic/pgalloc.h
  ARC: mm: switch pgtable_t back to struct page *
  ARC: mm: hack to allow 2 level build with 4 level code
  ARC: mm: disintegrate pgtable.h into levels and flags
  ARC: mm: disintegrate mmu.h (arcv2 bits out)
  ARC: mm: move MMU specific bits out of entry code ...
  ARC: mm: move MMU specific bits out of ASID allocator
  ARC: mm: non-functional code movement/cleanup
  ARC: mm: pmd_populate* to use the canonical set_pmd (and drop pmd_set)
  ARC: ioremap: use more commonly used PAGE_KERNEL based uncached flag
  ARC: mm: Enable STRICT_MM_TYPECHECKS
  ARC: mm: Fixes to allow STRICT_MM_TYPECHECKS
  ARC: mm: move mmu/cache externs out to setup.h
  ARC: mm: remove tlb paranoid code
  ARC: mm: use SCRATCH_DATA0 register for caching pgdir in ARCv2 only
  ARC: retire MMUv1 and MMUv2 support
  ARC: retire ARC750 support
  ...

ARC: mm: vmalloc sync from kernel to user table to update PMD ...

2021-08-26T20:43:19+00:00

... not PGD

vmalloc() sets up the kernel page table (starting from @swapper_pg_dir).
But when vmalloc area is accessed in context of a user task, say opening
terminal in n_tty_open(), the user page tables need to be synced from
kernel page tables so that TLB entry is created in "user context".

The old code was doing this incorrectly, as it was updating the user pgd
entry (first level itself) to point to kernel pud table (2nd level),
effectively yanking away the entire user space translation with kernel one.

The correct way to do this is to ONLY update a user space pgd/pud/pmd entry
if it is not popluated already. This ensures that only the missing leaf
pmd entry gets updated to point to relevant kernel pte table.

From code change pov, we are chaging the pattern:

	p4d = p4d_offset(pgd, address);
	p4d_k = p4d_offset(pgd_k, address);
	if (!p4d_present(*p4d_k))
		goto bad_area;
	set_p4d(p4d, *p4d_k);

with
	p4d = p4d_offset(pgd, address);
	p4d_k = p4d_offset(pgd_k, address);
	if (p4d_none(*p4d_k))
		goto bad_area;
	if (!p4d_present(*p4d))
		set_p4d(p4d, *p4d_k);

Signed-off-by: Vineet Gupta

ARC: mm: support 4 levels of page tables

2021-08-26T20:43:19+00:00

Acked-by: Mike Rapoport 
Signed-off-by: Vineet Gupta

ARC: mm: support 3 levels of page tables

2021-08-26T20:43:19+00:00

ARCv2 MMU is software walked and Linux implements 2 levels of paging: pgd/pte.
Forthcoming hw will have multiple levels, so this change preps mm code
for same. It is also fun to try multi levels even on soft-walked code to
ensure generic mm code is robust to handle.

overview
________

2 levels {pgd, pte} : pmd is folded but pmd_* macros are valid and operate on pgd
3 levels {pgd, pmd, pte}:
  - pud is folded and pud_* macros point to pgd
  - pmd_* macros operate on actual pmd

code changes
____________

1. #include 

2. Define CONFIG_PGTABLE_LEVELS 3

3a. Define PMD_SHIFT, PMD_SIZE, PMD_MASK, pmd_t
3b. Define pmd_val() which actually deals with pmd
    (pmd_offset(), pmd_index() are provided by generic code)
3c. pmd_alloc_one()/pmd_free() also provided by generic code
    (pmd_populate/pmd_free already exist)

4. Define pud_none(), pud_bad() macros based on generic pud_val() which
   internally pertains to pgd now.
4b. define pud_populate() to just setup pgd

Acked-by: Mike Rapoport 
Signed-off-by: Vineet Gupta