linux-toradex.git/mm/sparse.c, branch v5.11-rc5

mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG

2020-10-16T18:11:18+00:00

We soon want to pass flags via a new type to add_memory() and friends.
That revealed that we currently don't guard some declarations by
CONFIG_MEMORY_HOTPLUG.

While some definitions could be moved to different places, let's keep it
minimal for now and use CONFIG_MEMORY_HOTPLUG for all functions only
compiled with CONFIG_MEMORY_HOTPLUG.

Wrap sparse_decode_mem_map() into CONFIG_MEMORY_HOTPLUG, it's only called
from CONFIG_MEMORY_HOTPLUG code.

While at it, remove allow_online_pfn_range(), which is no longer around,
and mhp_notimplemented(), which is unused.

Signed-off-by: David Hildenbrand 
Signed-off-by: Andrew Morton 
Cc: Michal Hocko 
Cc: Dan Williams 
Cc: Pankaj Gupta 
Cc: Baoquan He 
Cc: Wei Yang 
Cc: Anton Blanchard 
Cc: Ard Biesheuvel 
Cc: Benjamin Herrenschmidt 
Cc: Boris Ostrovsky 
Cc: Christian Borntraeger 
Cc: Dave Jiang 
Cc: Eric Biederman 
Cc: Greg Kroah-Hartman 
Cc: Haiyang Zhang 
Cc: Heiko Carstens 
Cc: Jason Gunthorpe 
Cc: Jason Wang 
Cc: Juergen Gross 
Cc: Julien Grall 
Cc: Kees Cook 
Cc: "K. Y. Srinivasan" 
Cc: Len Brown 
Cc: Leonardo Bras 
Cc: Libor Pechacek 
Cc: Michael Ellerman 
Cc: "Michael S. Tsirkin" 
Cc: Nathan Lynch 
Cc: "Oliver O'Halloran" 
Cc: Paul Mackerras 
Cc: Pingfan Liu 
Cc: "Rafael J. Wysocki" 
Cc: Roger Pau Monné 
Cc: Stefano Stabellini 
Cc: Stephen Hemminger 
Cc: Thomas Gleixner 
Cc: Vasily Gorbik 
Cc: Vishal Verma 
Cc: Wei Liu 
Link: https://lkml.kernel.org/r/20200911103459.10306-4-david@redhat.com
Signed-off-by: Linus Torvalds

arch, mm: replace for_each_memblock() with for_each_mem_pfn_range()

2020-10-14T01:38:35+00:00

There are several occurrences of the following pattern:

	for_each_memblock(memory, reg) {
		start_pfn = memblock_region_memory_base_pfn(reg);
		end_pfn = memblock_region_memory_end_pfn(reg);

		/* do something with start_pfn and end_pfn */
	}

Rather than iterate over all memblock.memory regions and each time query
for their start and end PFNs, use for_each_mem_pfn_range() iterator to get
simpler and clearer code.

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Reviewed-by: Baoquan He 
Acked-by: Miguel Ojeda 	[.clang-format]
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Borislav Petkov 
Cc: Catalin Marinas 
Cc: Christoph Hellwig 
Cc: Daniel Axtens 
Cc: Dave Hansen 
Cc: Emil Renner Berthing 
Cc: Hari Bathini 
Cc: Ingo Molnar 
Cc: Ingo Molnar 
Cc: Jonathan Cameron 
Cc: Marek Szyprowski 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Paul Mackerras 
Cc: Paul Walmsley 
Cc: Peter Zijlstra 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Link: https://lkml.kernel.org/r/20200818151634.14343-12-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm/sparse: cleanup the code surrounding memory_present()

2020-08-07T18:33:27+00:00

After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent
functions that call memory_present() for each region in memblock.memory:
sparse_memory_present_with_active_regions() and membocks_present().

Moreover, all architectures have a call to either of these functions
preceding the call to sparse_init() and in the most cases they are called
one after the other.

Mark the regions from memblock.memory as present during sparce_init() by
making sparse_init() call memblocks_present(), make memblocks_present()
and memory_present() functions static and remove redundant
sparse_memory_present_with_active_regions() function.

Also remove no longer required HAVE_MEMORY_PRESENT configuration option.

Signed-off-by: Mike Rapoport 
Signed-off-by: Andrew Morton 
Link: http://lkml.kernel.org/r/20200712083130.22919-1-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm/sparse: never partially remove memmap for early section

2020-08-07T18:33:27+00:00

For early sections, its memmap is handled specially even sub-section is
enabled.  The memmap could only be populated as a whole.

Quoted from the comment of section_activate():

    * The early init code does not consider partially populated
    * initial sections, it simply assumes that memory will never be
    * referenced.  If we hot-add memory into such a section then we
    * do not need to populate the memmap and can simply reuse what
    * is already there.

While current section_deactivate() breaks this rule.  When hot-remove a
sub-section, section_deactivate() would depopulate its memmap.  The
consequence is if we hot-add this subsection again, its memmap never get
proper populated.

We can reproduce the case by following steps:

1. Hacking qemu to allow sub-section early section

:   diff --git a/hw/i386/pc.c b/hw/i386/pc.c
:   index 51b3050d01..c6a78d83c0 100644
:   --- a/hw/i386/pc.c
:   +++ b/hw/i386/pc.c
:   @@ -1010,7 +1010,7 @@ void pc_memory_init(PCMachineState *pcms,
:            }
:
:            machine->device_memory->base =
:   -            ROUND_UP(0x100000000ULL + x86ms->above_4g_mem_size, 1 * GiB);
:   +            0x100000000ULL + x86ms->above_4g_mem_size;
:
:            if (pcmc->enforce_aligned_dimm) {
:                /* size device region assuming 1G page max alignment per slot */

2. Bootup qemu with PSE disabled and a sub-section aligned memory size

   Part of the qemu command would look like this:

   sudo x86_64-softmmu/qemu-system-x86_64 \
       --enable-kvm -cpu host,pse=off \
       -m 4160M,maxmem=20G,slots=1 \
       -smp sockets=2,cores=16 \
       -numa node,nodeid=0,cpus=0-1 -numa node,nodeid=1,cpus=2-3 \
       -machine pc,nvdimm \
       -nographic \
       -object memory-backend-ram,id=mem0,size=8G \
       -device nvdimm,id=vm0,memdev=mem0,node=0,addr=0x144000000,label-size=128k

3. Re-config a pmem device with sub-section size in guest

   ndctl create-namespace --force --reconfig=namespace0.0 --mode=devdax --size=16M

Then you would see the following call trace:

   pmem0: detected capacity change from 0 to 16777216
   BUG: unable to handle page fault for address: ffffec73c51000b4
   #PF: supervisor write access in kernel mode
   #PF: error_code(0x0002) - not-present page
   PGD 81ff8067 P4D 81ff8067 PUD 81ff7067 PMD 1437cb067 PTE 0
   Oops: 0002 [#1] SMP NOPTI
   CPU: 16 PID: 1348 Comm: ndctl Kdump: loaded Tainted: G        W         5.8.0-rc2+ #24
   Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.4
   RIP: 0010:memmap_init_zone+0x154/0x1c2
   Code: 77 16 f6 40 10 02 74 10 48 03 48 08 48 89 cb 48 c1 eb 0c e9 3a ff ff ff 48 89 df 48 c1 e7 06 48f
   RSP: 0018:ffffbdc7011a39b0 EFLAGS: 00010282
   RAX: ffffec73c5100088 RBX: 0000000000144002 RCX: 0000000000144000
   RDX: 0000000000000004 RSI: 007ffe0000000000 RDI: ffffec73c5100080
   RBP: 027ffe0000000000 R08: 0000000000000001 R09: ffff9f8d38f6d708
   R10: ffffec73c0000000 R11: 0000000000000000 R12: 0000000000000004
   R13: 0000000000000001 R14: 0000000000144200 R15: 0000000000000000
   FS:  00007efe6b65d780(0000) GS:ffff9f8d3f780000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: ffffec73c51000b4 CR3: 000000007d718000 CR4: 0000000000340ee0
   Call Trace:
    move_pfn_range_to_zone+0x128/0x150
    memremap_pages+0x4e4/0x5a0
    devm_memremap_pages+0x1e/0x60
    dev_dax_probe+0x69/0x160 [device_dax]
    really_probe+0x298/0x3c0
    driver_probe_device+0xe1/0x150
    ? driver_allows_async_probing+0x50/0x50
    bus_for_each_drv+0x7e/0xc0
    __device_attach+0xdf/0x160
    bus_probe_device+0x8e/0xa0
    device_add+0x3b9/0x740
    __devm_create_dev_dax+0x127/0x1c0
    __dax_pmem_probe+0x1f2/0x219 [dax_pmem_core]
    dax_pmem_probe+0xc/0x1b [dax_pmem]
    nvdimm_bus_probe+0x69/0x1c0 [libnvdimm]
    really_probe+0x147/0x3c0
    driver_probe_device+0xe1/0x150
    device_driver_attach+0x53/0x60
    bind_store+0xd1/0x110
    kernfs_fop_write+0xce/0x1b0
    vfs_write+0xb6/0x1a0
    ksys_write+0x5f/0xe0
    do_syscall_64+0x4d/0x90
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: Wei Yang 
Signed-off-by: Andrew Morton 
Acked-by: David Hildenbrand 
Cc: Oscar Salvador 
Cc: Dan Williams 
Link: http://lkml.kernel.org/r/20200625223534.18024-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds

mm: remove unneeded includes of

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

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 of


In 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 '/[<"]asm\/pgalloc\.h/d' \
                $(grep -L -w -f /tmp/xx \
                        $(git grep -E -l '[<"]asm/pgalloc\.h'))

where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.

[rppt@linux.ibm.com: fix powerpc warning]

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: 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

mm: don't include asm/pgtable.h if linux/mm.h is already included

2020-06-09T16:39:13+00:00

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once.  For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
        return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
        return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes  to allow inlining of the
functions involving page table manipulations, e.g.  pte_alloc() and
pmd_alloc().  So, there is no point to explicitly include 
in the files that include .

The include statements in such cases are remove with a simple loop:

	for f in $(git grep -l "include ") ; do
		sed -i -e '/include / d' $f
	done

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: Mike Rapoport 
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/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm/sparse: fix a typo in comment "convienence"->"convenience"

2020-06-05T02:06:24+00:00

There is a typo in comment, fix it.

Signed-off-by: Ethon Paul 
Signed-off-by: Andrew Morton 
Link: http://lkml.kernel.org/r/20200411002955.14545-1-ethp@qq.com
Signed-off-by: Linus Torvalds

mm/sparse.c: move subsection_map related functions together

2020-04-07T17:43:40+00:00

No functional change.

[bhe@redhat.com: move functions into CONFIG_MEMORY_HOTPLUG ifdeffery scope]
  Link: http://lkml.kernel.org/r/20200316045804.GC3486@MiWiFi-R3L-srv
Signed-off-by: Baoquan He 
Signed-off-by: Andrew Morton 
Cc: Michal Hocko 
Cc: David Hildenbrand 
Cc: Wei Yang 
Cc: Dan Williams 
Cc: Pankaj Gupta 
Cc: Stephen Rothwell 
Link: http://lkml.kernel.org/r/20200312124414.439-6-bhe@redhat.com
Signed-off-by: Linus Torvalds

mm/sparse.c: add note about only VMEMMAP supporting sub-section hotplug

2020-04-07T17:43:40+00:00

And tell check_pfn_span() gating the porper alignment and size of hot
added memory region.

And also move the code comments from inside section_deactivate() to being
above it.  The code comments are reasonable for the whole function, and
the moving makes code cleaner.

Signed-off-by: Baoquan He 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Acked-by: Michal Hocko 
Cc: Dan Williams 
Cc: Pankaj Gupta 
Cc: Wei Yang 
Link: http://lkml.kernel.org/r/20200312124414.439-5-bhe@redhat.com
Signed-off-by: Linus Torvalds

mm/sparse.c: only use subsection map in VMEMMAP case

2020-04-07T17:43:40+00:00

Currently, to support subsection aligned memory region adding for pmem,
subsection map is added to track which subsection is present.

However, config ZONE_DEVICE depends on SPARSEMEM_VMEMMAP.  It means
subsection map only makes sense when SPARSEMEM_VMEMMAP enabled.  For the
classic sparse, it's meaningless.  Even worse, it may confuse people when
checking code related to the classic sparse.

About the classic sparse which doesn't support subsection hotplug, Dan
said it's more because the effort and maintenance burden outweighs the
benefit.  Besides, the current 64 bit ARCHes all enable
SPARSEMEM_VMEMMAP_ENABLE by default.

Combining the above reasons, no need to provide subsection map and the
relevant handling for the classic sparse.  Let's remove them.

Signed-off-by: Baoquan He 
Signed-off-by: Andrew Morton 
Reviewed-by: David Hildenbrand 
Cc: Dan Williams 
Cc: Michal Hocko 
Cc: Pankaj Gupta 
Cc: Wei Yang 
Link: http://lkml.kernel.org/r/20200312124414.439-4-bhe@redhat.com
Signed-off-by: Linus Torvalds