linux-stable.git/arch/powerpc/include, branch v6.6.78

powerpc/book3s64/hugetlb: Fix disabling hugetlb when fadump is active

2025-02-08T08:51:41+00:00

[ Upstream commit d629d7a8efc33d05d62f4805c0ffb44727e3d99f ]

Commit 8597538712eb ("powerpc/fadump: Do not use hugepages when fadump
is active") disabled hugetlb support when fadump is active by returning
early from hugetlbpage_init():arch/powerpc/mm/hugetlbpage.c and not
populating hpage_shift/HPAGE_SHIFT.

Later, commit 2354ad252b66 ("powerpc/mm: Update default hugetlb size
early") moved the allocation of hpage_shift/HPAGE_SHIFT to early boot,
which inadvertently re-enabled hugetlb support when fadump is active.

Fix this by implementing hugepages_supported() on powerpc. This ensures
that disabling hugetlb for the fadump kernel is independent of
hpage_shift/HPAGE_SHIFT.

Fixes: 2354ad252b66 ("powerpc/mm: Update default hugetlb size early")
Reviewed-by: Ritesh Harjani (IBM) 
Signed-off-by: Sourabh Jain 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/20241217074640.1064510-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static

2024-12-09T09:32:21+00:00

[ Upstream commit a26c4dbb3d9c1821cb0fc11cb2dbc32d5bf3463b ]

These functions are not used outside of sstep.c

Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")
Signed-off-by: Michal Suchanek 
Signed-off-by: Michael Ellerman 
Link: https://patch.msgid.link/20241001130356.14664-1-msuchanek@suse.de
Signed-off-by: Sasha Levin

powerpc/pseries: Fix dtl_access_lock to be a rw_semaphore

2024-12-09T09:32:15+00:00

[ Upstream commit cadae3a45d23aa4f6485938a67cbc47aaaa25e38 ]

The dtl_access_lock needs to be a rw_sempahore, a sleeping lock, because
the code calls kmalloc() while holding it, which can sleep:

  # echo 1 > /proc/powerpc/vcpudispatch_stats
  BUG: sleeping function called from invalid context at include/linux/sched/mm.h:337
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 199, name: sh
  preempt_count: 1, expected: 0
  3 locks held by sh/199:
   #0: c00000000a0743f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x324/0x438
   #1: c0000000028c7058 (dtl_enable_mutex){+.+.}-{3:3}, at: vcpudispatch_stats_write+0xd4/0x5f4
   #2: c0000000028c70b8 (dtl_access_lock){+.+.}-{2:2}, at: vcpudispatch_stats_write+0x220/0x5f4
  CPU: 0 PID: 199 Comm: sh Not tainted 6.10.0-rc4 #152
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,HEAD hv:linux,kvm pSeries
  Call Trace:
    dump_stack_lvl+0x130/0x148 (unreliable)
    __might_resched+0x174/0x410
    kmem_cache_alloc_noprof+0x340/0x3d0
    alloc_dtl_buffers+0x124/0x1ac
    vcpudispatch_stats_write+0x2a8/0x5f4
    proc_reg_write+0xf4/0x150
    vfs_write+0xfc/0x438
    ksys_write+0x88/0x148
    system_call_exception+0x1c4/0x5a0
    system_call_common+0xf4/0x258

Fixes: 06220d78f24a ("powerpc/pseries: Introduce rwlock to gatekeep DTLB usage")
Tested-by: Kajol Jain 
Reviewed-by: Nysal Jan K.A 
Reviewed-by: Kajol Jain 
Signed-off-by: Michael Ellerman 
Link: https://patch.msgid.link/20240819122401.513203-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin

powerpc/fadump: Move fadump_cma_init to setup_arch() after initmem_init()

2024-12-09T09:32:14+00:00

[ Upstream commit 05b94cae1c47f94588c3e7096963c1007c4d9c1d ]

During early init CMA_MIN_ALIGNMENT_BYTES can be PAGE_SIZE,
since pageblock_order is still zero and it gets initialized
later during initmem_init() e.g.
setup_arch() -> initmem_init() -> sparse_init() -> set_pageblock_order()

One such use case where this causes issue is -
early_setup() -> early_init_devtree() -> fadump_reserve_mem() -> fadump_cma_init()

This causes CMA memory alignment check to be bypassed in
cma_init_reserved_mem(). Then later cma_activate_area() can hit
a VM_BUG_ON_PAGE(pfn & ((1 << order) - 1)) if the reserved memory
area was not pageblock_order aligned.

Fix it by moving the fadump_cma_init() after initmem_init(),
where other such cma reservations also gets called.


==============
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10010
flags: 0x13ffff800000000(node=1|zone=0|lastcpupid=0x7ffff) CMA
raw: 013ffff800000000 5deadbeef0000100 5deadbeef0000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: VM_BUG_ON_PAGE(pfn & ((1 << order) - 1))
------------[ cut here ]------------
kernel BUG at mm/page_alloc.c:778!

Call Trace:
__free_one_page+0x57c/0x7b0 (unreliable)
free_pcppages_bulk+0x1a8/0x2c8
free_unref_page_commit+0x3d4/0x4e4
free_unref_page+0x458/0x6d0
init_cma_reserved_pageblock+0x114/0x198
cma_init_reserved_areas+0x270/0x3e0
do_one_initcall+0x80/0x2f8
kernel_init_freeable+0x33c/0x530
kernel_init+0x34/0x26c
ret_from_kernel_user_thread+0x14/0x1c

Fixes: 11ac3e87ce09 ("mm: cma: use pageblock_order as the single alignment")
Suggested-by: David Hildenbrand 
Reported-by: Sachin P Bappalige 
Acked-by: Hari Bathini 
Reviewed-by: Madhavan Srinivasan 
Signed-off-by: Ritesh Harjani (IBM) 
Signed-off-by: Michael Ellerman 
Link: https://patch.msgid.link/3ae208e48c0d9cefe53d2dc4f593388067405b7d.1729146153.git.ritesh.list@gmail.com
Signed-off-by: Sasha Levin

powerpc/vdso: Flag VDSO64 entry points as functions

2024-12-09T09:32:13+00:00

[ Upstream commit 0161bd38c24312853ed5ae9a425a1c41c4ac674a ]

On powerpc64 as shown below by readelf, vDSO functions symbols have
type NOTYPE.

$ powerpc64-linux-gnu-readelf -a arch/powerpc/kernel/vdso/vdso64.so.dbg
ELF Header:
  Magic:   7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF64
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              DYN (Shared object file)
  Machine:                           PowerPC64
  Version:                           0x1
...

Symbol table '.dynsym' contains 12 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
...
     1: 0000000000000524    84 NOTYPE  GLOBAL DEFAULT    8 __[...]@@LINUX_2.6.15
...
     4: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LINUX_2.6.15
     5: 00000000000006c0    48 NOTYPE  GLOBAL DEFAULT    8 __[...]@@LINUX_2.6.15

Symbol table '.symtab' contains 56 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
...
    45: 0000000000000000     0 OBJECT  GLOBAL DEFAULT  ABS LINUX_2.6.15
    46: 00000000000006c0    48 NOTYPE  GLOBAL DEFAULT    8 __kernel_getcpu
    47: 0000000000000524    84 NOTYPE  GLOBAL DEFAULT    8 __kernel_clock_getres

To overcome that, commit ba83b3239e65 ("selftests: vDSO: fix vDSO
symbols lookup for powerpc64") was applied to have selftests also
look for NOTYPE symbols, but the correct fix should be to flag VDSO
entry points as functions.

The original commit that brought VDSO support into powerpc/64 has the
following explanation:

    Note that the symbols exposed by the vDSO aren't "normal" function symbols, apps
    can't be expected to link against them directly, the vDSO's are both seen
    as if they were linked at 0 and the symbols just contain offsets to the
    various functions.  This is done on purpose to avoid a relocation step
    (ppc64 functions normally have descriptors with abs addresses in them).
    When glibc uses those functions, it's expected to use it's own trampolines
    that know how to reach them.

The descriptors it's talking about are the OPD function descriptors
used on ABI v1 (big endian). But it would be more correct for a text
symbol to have type function, even if there's no function descriptor
for it.

glibc has a special case already for handling the VDSO symbols which
creates a fake opd pointing at the kernel symbol. So changing the VDSO
symbol type to function shouldn't affect that.

For ABI v2, there is no function descriptors and VDSO functions can
safely have function type.

So lets flag VDSO entry points as functions and revert the
selftest change.

Link: https://github.com/mpe/linux-fullhistory/commit/5f2dd691b62da9d9cc54b938f8b29c22c93cb805
Fixes: ba83b3239e65 ("selftests: vDSO: fix vDSO symbols lookup for powerpc64")
Signed-off-by: Christophe Leroy 
Reviewed-By: Segher Boessenkool 
Signed-off-by: Michael Ellerman 
Link: https://patch.msgid.link/b6ad2f1ee9887af3ca5ecade2a56f4acda517a85.1728512263.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin

powerpc/vdso: Fix VDSO data access when running in a non-root time namespace

2024-10-10T09:57:42+00:00

[ Upstream commit c73049389e58c01e2e3bbfae900c8daeee177191 ]

When running in a non-root time namespace, the global VDSO data page
is replaced by a dedicated namespace data page and the global data
page is mapped next to it. Detailed explanations can be found at
commit 660fd04f9317 ("lib/vdso: Prepare for time namespace support").

When it happens, __kernel_get_syscall_map and __kernel_get_tbfreq
and __kernel_sync_dicache don't work anymore because they read 0
instead of the data they need.

To address that, clock_mode has to be read. When it is set to
VDSO_CLOCKMODE_TIMENS, it means it is a dedicated namespace data page
and the global data is located on the following page.

Add a macro called get_realdatapage which reads clock_mode and add
PAGE_SIZE to the pointer provided by get_datapage macro when
clock_mode is equal to VDSO_CLOCKMODE_TIMENS. Use this new macro
instead of get_datapage macro except for time functions as they handle
it internally.

Fixes: 74205b3fc2ef ("powerpc/vdso: Add support for time namespaces")
Reported-by: Jason A. Donenfeld 
Closes: https://lore.kernel.org/all/ZtnYqZI-nrsNslwy@zx2c4.com/
Signed-off-by: Christophe Leroy 
Acked-by: Michael Ellerman 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Sasha Levin

powerpc/atomic: Use YZ constraints for DS-form instructions

2024-10-04T14:29:48+00:00

commit 39190ac7cff1fd15135fa8e658030d9646fdb5f2 upstream.

The 'ld' and 'std' instructions require a 4-byte aligned displacement
because they are DS-form instructions. But the "m" asm constraint
doesn't enforce that.

That can lead to build errors if the compiler chooses a non-aligned
displacement, as seen with GCC 14:

  /tmp/ccuSzwiR.s: Assembler messages:
  /tmp/ccuSzwiR.s:2579: Error: operand out of domain (39 is not a multiple of 4)
  make[5]: *** [scripts/Makefile.build:229: net/core/page_pool.o] Error 1

Dumping the generated assembler shows:

  ld 8,39(8)       # MEM[(const struct atomic64_t *)_29].counter, t

Use the YZ constraints to tell the compiler either to generate a DS-form
displacement, or use an X-form instruction, either of which prevents the
build error.

See commit 2d43cc701b96 ("powerpc/uaccess: Fix build errors seen with
GCC 13/14") for more details on the constraint letters.

Fixes: 9f0cbea0d8cc ("[POWERPC] Implement atomic{, 64}_{read, write}() without volatile")
Cc: stable@vger.kernel.org # v2.6.24+
Reported-by: Stephen Rothwell 
Closes: https://lore.kernel.org/all/20240913125302.0a06b4c7@canb.auug.org.au
Tested-by: Mina Almasry 
Reviewed-by: Segher Boessenkool 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240916120510.2017749-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman

powerpc/64e: remove unused IBM HTW code

2024-09-12T09:11:43+00:00

[ Upstream commit 88715b6e5d529f4ef3830ad2a893e4624c6af0b8 ]

Patch series "Reimplement huge pages without hugepd on powerpc (8xx, e500,
book3s/64)", v7.

Unlike most architectures, powerpc 8xx HW requires a two-level pagetable
topology for all page sizes.  So a leaf PMD-contig approach is not
feasible as such.

Possible sizes on 8xx are 4k, 16k, 512k and 8M.

First level (PGD/PMD) covers 4M per entry.  For 8M pages, two PMD entries
must point to a single entry level-2 page table.  Until now that was done
using hugepd.  This series changes it to use standard page tables where
the entry is replicated 1024 times on each of the two pagetables refered
by the two associated PMD entries for that 8M page.

For e500 and book3s/64 there are less constraints because it is not tied
to the HW assisted tablewalk like on 8xx, so it is easier to use leaf PMDs
(and PUDs).

On e500 the supported page sizes are 4M, 16M, 64M, 256M and 1G.  All at
PMD level on e500/32 (mpc85xx) and mix of PMD and PUD for e500/64.  We
encode page size with 4 available bits in PTE entries.  On e300/32 PGD
entries size is increases to 64 bits in order to allow leaf-PMD entries
because PTE are 64 bits on e500.

On book3s/64 only the hash-4k mode is concerned.  It supports 16M pages as
cont-PMD and 16G pages as cont-PUD.  In other modes (radix-4k, radix-6k
and hash-64k) the sizes match with PMD and PUD sizes so that's just leaf
entries.  The hash processing make things a bit more complex.  To ease
things, __hash_page_huge() is modified to bail out when DIRTY or ACCESSED
bits are missing, leaving it to mm core to fix it.

This patch (of 23):

The nohash HTW_IBM (Hardware Table Walk) code is unused since support for
A2 was removed in commit fb5a515704d7 ("powerpc: Remove platforms/ wsp and
associated pieces") (2014).

The remaining supported CPUs use either no HTW (data_tlb_miss_bolted), or
the e6500 HTW (data_tlb_miss_e6500).

Link: https://lkml.kernel.org/r/cover.1719928057.git.christophe.leroy@csgroup.eu
Link: https://lkml.kernel.org/r/820dd1385ecc931f07b0d7a0fa827b1613917ab6.1719928057.git.christophe.leroy@csgroup.eu
Signed-off-by: Michael Ellerman 
Signed-off-by: Christophe Leroy 
Cc: Jason Gunthorpe 
Cc: Nicholas Piggin 
Cc: Oscar Salvador 
Cc: Peter Xu 
Signed-off-by: Andrew Morton 
Stable-dep-of: d92b5cc29c79 ("powerpc/64e: Define mmu_pte_psize static")
Signed-off-by: Sasha Levin

powerpc/topology: Check if a core is online

2024-08-29T15:33:30+00:00

[ Upstream commit 227bbaabe64b6f9cd98aa051454c1d4a194a8c6a ]

topology_is_core_online() checks if the core a CPU belongs to
is online. The core is online if at least one of the sibling
CPUs is online. The first CPU of an online core is also online
in the common case, so this should be fairly quick.

Fixes: 73c58e7e1412 ("powerpc: Add HOTPLUG_SMT support")
Signed-off-by: Nysal Jan K.A 
Reviewed-by: Shrikanth Hegde 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240731030126.956210-3-nysal@linux.ibm.com
Signed-off-by: Sasha Levin

powerpc/64: Set _IO_BASE to POISON_POINTER_DELTA not 0 for CONFIG_PCI=n

2024-07-11T10:49:08+00:00

[ Upstream commit be140f1732b523947425aaafbe2e37b41b622d96 ]

There is code that builds with calls to IO accessors even when
CONFIG_PCI=n, but the actual calls are guarded by runtime checks.

If not those calls would be faulting, because the page at virtual
address zero is (usually) not mapped into the kernel. As Arnd pointed
out, it is possible a large port value could cause the address to be
above mmap_min_addr which would then access userspace, which would be
a bug.

To avoid any such issues, set _IO_BASE to POISON_POINTER_DELTA. That
is a value chosen to point into unmapped space between the kernel and
userspace, so any access will always fault.

Note that on 32-bit POISON_POINTER_DELTA is 0, so the patch only has an
effect on 64-bit.

Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20240503075619.394467-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin