linux-stable.git/arch/powerpc/kernel/setup-common.c, branch linux-5.15.y

powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL

2024-10-17T13:10:32+00:00

[ Upstream commit e7e846dc6c73fbc94ae8b4ec20d05627646416f2 ]

Booting with CONFIG_DEBUG_VIRTUAL leads to following warning when
passing hugepage reservation on command line:

  Kernel command line: hugepagesz=1g hugepages=1 hugepagesz=64m hugepages=1 hugepagesz=256m hugepages=1 noreboot
  HugeTLB: allocating 1 of page size 1.00 GiB failed.  Only allocated 0 hugepages.
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at arch/powerpc/include/asm/io.h:948 __alloc_bootmem_huge_page+0xd4/0x284
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted 6.10.0-rc6-00396-g6b0e82791bd0-dirty #936
  Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
  NIP:  c1020240 LR: c10201d0 CTR: 00000000
  REGS: c13fdd30 TRAP: 0700   Not tainted  (6.10.0-rc6-00396-g6b0e82791bd0-dirty)
  MSR:  00021000   CR: 44084288  XER: 20000000

  GPR00: c10201d0 c13fde20 c130b560 e8000000 e8001000 00000000 00000000 c1420000
  GPR08: 00000000 00028001 00000000 00000004 44084282 01066ac0 c0eb7c9c efffe149
  GPR16: c0fc4228 0000005f ffffffff c0eb7d0c c0eb7cc0 c0eb7ce0 ffffffff 00000000
  GPR24: c1441cec efffe153 e8001000 c14240c0 00000000 c1441d64 00000000 e8000000
  NIP [c1020240] __alloc_bootmem_huge_page+0xd4/0x284
  LR [c10201d0] __alloc_bootmem_huge_page+0x64/0x284
  Call Trace:
  [c13fde20] [c10201d0] __alloc_bootmem_huge_page+0x64/0x284 (unreliable)
  [c13fde50] [c10207b8] hugetlb_hstate_alloc_pages+0x8c/0x3e8
  [c13fdeb0] [c1021384] hugepages_setup+0x240/0x2cc
  [c13fdef0] [c1000574] unknown_bootoption+0xfc/0x280
  [c13fdf30] [c0078904] parse_args+0x200/0x4c4
  [c13fdfa0] [c1000d9c] start_kernel+0x238/0x7d0
  [c13fdff0] [c0000434] set_ivor+0x12c/0x168
  Code: 554aa33e 7c042840 3ce0c142 80a7427c 5109a016 50caa016 7c9a2378 7fdcf378 4180000c 7c052040 41810160 7c095040 <0fe00000> 38c00000 40800108 3c60c0eb
  ---[ end trace 0000000000000000 ]---

This is due to virt_addr_valid() using high_memory before it is set.

high_memory is set in mem_init() using max_low_pfn, but max_low_pfn
is available long before, it is set in mem_topology_setup(). So just
like commit daa9ada2093e ("powerpc/mm: Fix boot crash with FLATMEM")
moved the setting of max_mapnr immediately after the call to
mem_topology_setup(), the same can be done for high_memory.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/62b69c4baad067093f39e7e60df0fe27a86b8d2a.1723100702.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin

powerpc/mm: Fix boot crash with FLATMEM

2023-11-08T16:26:48+00:00

[ Upstream commit daa9ada2093ed23d52b4c1fe6e13cf78f55cc85f ]

Erhard reported that his G5 was crashing with v6.6-rc kernels:

  mpic: Setting up HT PICs workarounds for U3/U4
  BUG: Unable to handle kernel data access at 0xfeffbb62ffec65fe
  Faulting instruction address: 0xc00000000005dc40
  Oops: Kernel access of bad area, sig: 11 [#1]
  BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 PowerMac
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Tainted: G                T  6.6.0-rc3-PMacGS #1
  Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac
  NIP:  c00000000005dc40 LR: c000000000066660 CTR: c000000000007730
  REGS: c0000000022bf510 TRAP: 0380   Tainted: G                T (6.6.0-rc3-PMacGS)
  MSR:  9000000000001032   CR: 44004242  XER: 00000000
  IRQMASK: 3
  GPR00: 0000000000000000 c0000000022bf7b0 c0000000010c0b00 00000000000001ac
  GPR04: 0000000003c80000 0000000000000300 c0000000f20001ae 0000000000000300
  GPR08: 0000000000000006 feffbb62ffec65ff 0000000000000001 0000000000000000
  GPR12: 9000000000001032 c000000002362000 c000000000f76b80 000000000349ecd8
  GPR16: 0000000002367ba8 0000000002367f08 0000000000000006 0000000000000000
  GPR20: 00000000000001ac c000000000f6f920 c0000000022cd985 000000000000000c
  GPR24: 0000000000000300 00000003b0a3691d c0003e008030000e 0000000000000000
  GPR28: c00000000000000c c0000000f20001ee feffbb62ffec65fe 00000000000001ac
  NIP hash_page_do_lazy_icache+0x50/0x100
  LR  __hash_page_4K+0x420/0x590
  Call Trace:
    hash_page_mm+0x364/0x6f0
    do_hash_fault+0x114/0x2b0
    data_access_common_virt+0x198/0x1f0
  --- interrupt: 300 at mpic_init+0x4bc/0x10c4
  NIP:  c000000002020a5c LR: c000000002020a04 CTR: 0000000000000000
  REGS: c0000000022bf9f0 TRAP: 0300   Tainted: G                T (6.6.0-rc3-PMacGS)
  MSR:  9000000000001032   CR: 24004248  XER: 00000000
  DAR: c0003e008030000e DSISR: 40000000 IRQMASK: 1
  ...
  NIP mpic_init+0x4bc/0x10c4
  LR  mpic_init+0x464/0x10c4
  --- interrupt: 300
    pmac_setup_one_mpic+0x258/0x2dc
    pmac_pic_init+0x28c/0x3d8
    init_IRQ+0x90/0x140
    start_kernel+0x57c/0x78c
    start_here_common+0x1c/0x20

A bisect pointed to the breakage beginning with commit 9fee28baa601 ("powerpc:
implement the new page table range API").

Analysis of the oops pointed to a struct page with a corrupted
compound_head being loaded via page_folio() -> _compound_head() in
hash_page_do_lazy_icache().

The access by the mpic code is to an MMIO address, so the expectation
is that the struct page for that address would be initialised by
init_unavailable_range(), as pointed out by Aneesh.

Instrumentation showed that was not the case, which eventually lead to
the realisation that pfn_valid() was returning false for that address,
causing the struct page to not be initialised.

Because the system is using FLATMEM, the version of pfn_valid() in
memory_model.h is used:

static inline int pfn_valid(unsigned long pfn)
{
	...
	return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
}

Which relies on max_mapnr being initialised. Early in boot max_mapnr is
zero meaning no PFNs are valid.

max_mapnr is initialised in mem_init() called via:

  start_kernel()
    mm_core_init()  # init/main.c:928
      mem_init()

But that is too late for the usage in init_unavailable_range() called via:

  start_kernel()
    setup_arch()    # init/main.c:893
      paging_init()
        free_area_init()
          init_unavailable_range()

Although max_mapnr is currently set in mem_init(), the value is actually
already available much earlier, as soon as mem_topology_setup() has
completed, which is also before paging_init() is called. So move the
initialisation there, which causes paging_init() to correctly initialise
the struct page and fixes the bug.

This bug seems to have been lurking for years, but went unnoticed
because the pre-folio code was inspecting the uninitialised page->flags
but not dereferencing it.

Thanks to Erhard and Aneesh for help debugging.

Reported-by: Erhard Furtner 
Closes: https://lore.kernel.org/all/20230929132750.3cd98452@yea/
Signed-off-by: Michael Ellerman 
Link: https://msgid.link/20231023112500.1550208-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin

powerpc: rename powerpc_debugfs_root to arch_debugfs_dir

2021-08-13T12:04:26+00:00

No functional change in this patch. arch_debugfs_dir is the generic kernel
name declared in linux/debugfs.h for arch-specific debugfs directory.
Architectures like x86/s390 already use the name. Rename powerpc
specific powerpc_debugfs_root to arch_debugfs_dir.

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210812132831.233794-2-aneesh.kumar@linux.ibm.com

powerpc: convert to setup_initial_init_mm()

2021-07-08T18:48:21+00:00

Use setup_initial_init_mm() helper to simplify code.

Link: https://lkml.kernel.org/r/20210608083418.137226-12-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Souptick Joarder 
Cc: Christophe Leroy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-07-02T19:54:34+00:00

Pull powerpc updates from Michael Ellerman:

 - A big series refactoring parts of our KVM code, and converting some
   to C.

 - Support for ARCH_HAS_SET_MEMORY, and ARCH_HAS_STRICT_MODULE_RWX on
   some CPUs.

 - Support for the Microwatt soft-core.

 - Optimisations to our interrupt return path on 64-bit.

 - Support for userspace access to the NX GZIP accelerator on PowerVM on
   Power10.

 - Enable KUAP and KUEP by default on 32-bit Book3S CPUs.

 - Other smaller features, fixes & cleanups.

Thanks to: Andy Shevchenko, Aneesh Kumar K.V, Arnd Bergmann, Athira
Rajeev, Baokun Li, Benjamin Herrenschmidt, Bharata B Rao, Christophe
Leroy, Daniel Axtens, Daniel Henrique Barboza, Finn Thain, Geoff Levand,
Haren Myneni, Jason Wang, Jiapeng Chong, Joel Stanley, Jordan Niethe,
Kajol Jain, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas
Piggin, Nick Desaulniers, Paul Mackerras, Russell Currey, Sathvika
Vasireddy, Shaokun Zhang, Stephen Rothwell, Sudeep Holla, Suraj Jitindar
Singh, Tom Rix, Vaibhav Jain, YueHaibing, Zhang Jianhua, and Zhen Lei.

* tag 'powerpc-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (218 commits)
  powerpc: Only build restart_table.c for 64s
  powerpc/64s: move ret_from_fork etc above __end_soft_masked
  powerpc/64s/interrupt: clean up interrupt return labels
  powerpc/64/interrupt: add missing kprobe annotations on interrupt exit symbols
  powerpc/64: enable MSR[EE] in irq replay pt_regs
  powerpc/64s/interrupt: preserve regs->softe for NMI interrupts
  powerpc/64s: add a table of implicit soft-masked addresses
  powerpc/64e: remove implicit soft-masking and interrupt exit restart logic
  powerpc/64e: fix CONFIG_RELOCATABLE build warnings
  powerpc/64s: fix hash page fault interrupt handler
  powerpc/4xx: Fix setup_kuep() on SMP
  powerpc/32s: Fix setup_{kuap/kuep}() on SMP
  powerpc/interrupt: Use names in check_return_regs_valid()
  powerpc/interrupt: Also use exit_must_hard_disable() on PPC32
  powerpc/sysfs: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE
  powerpc/ptrace: Refactor regs_set_return_{msr/ip}
  powerpc/ptrace: Move set_return_regs_changed() before regs_set_return_{msr/ip}
  powerpc/stacktrace: Fix spurious "stale" traces in raise_backtrace_ipi()
  powerpc/pseries/vas: Include irqdomain.h
  powerpc: mark local variables around longjmp as volatile
  ...

kernel.h: split out panic and oops helpers

2021-07-01T18:06:04+00:00

kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.

There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain

At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
  Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko 
Reviewed-by: Bjorn Andersson 
Co-developed-by: Andrew Morton 
Acked-by: Mike Rapoport 
Acked-by: Corey Minyard 
Acked-by: Christian Brauner 
Acked-by: Arnd Bergmann 
Acked-by: Kees Cook 
Acked-by: Wei Liu 
Acked-by: Rasmus Villemoes 
Signed-off-by: Andrew Morton 
Acked-by: Sebastian Reichel 
Acked-by: Luis Chamberlain 
Acked-by: Stephen Boyd 
Acked-by: Thomas Bogendoerfer 
Acked-by: Helge Deller  # parisc
Signed-off-by: Linus Torvalds

powerpc: Remove klimit

2021-06-24T14:07:10+00:00

klimit is a global variable initialised at build time with the
value of _end.

This variable is never modified, so _end symbol can be used directly.

Remove klimit.

Signed-off-by: Christophe Leroy 
Reviewed-by: Kefeng Wang 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/9fa9ba6807c17f93f35a582c199c646c4a8bfd9c.1622800638.git.christophe.leroy@csgroup.eu

powerpc: Fix section mismatch warning in smp_setup_pacas()

2021-03-29T02:22:14+00:00

Section mismatch in reference from the function .smp_setup_pacas() to
the function .init.text:.allocate_paca()

The only caller of smp_setup_pacas() is setup_arch() which is __init,
so mark smp_setup_pacas() __init.

Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20210314093333.132657-1-mpe@ellerman.id.au

powerpc: Remove duplicate includes

2021-03-24T03:09:30+00:00

asm/tm.h included in traps.c is duplicated. It is also included on
the 62nd line.

asm/udbg.h included in setup-common.c is duplicated. It is also
included on the 61st line.

asm/bug.h included in arch/powerpc/include/asm/book3s/64/mmu-hash.h
is duplicated. It is also included on the 12th line.

asm/tlbflush.h included in arch/powerpc/include/asm/pgtable.h is
duplicated. It is also included on the 11th line.

asm/page.h included in arch/powerpc/include/asm/thread_info.h is
duplicated. It is also included on the 13th line.

Signed-off-by: Zhang Yunkai 
[mpe: Squash together from multiple commits]
Signed-off-by: Michael Ellerman

powerpc/setup: Adjust six seq_printf() calls in show_cpuinfo()

2021-01-31T11:35:50+00:00

A bit of information should be put into a sequence.
Thus improve the execution speed for this data output by better usage
of corresponding functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/5b62379e-a35f-4f56-f1b5-6350f76007e7@web.de