linux.git/arch/powerpc/kernel/setup-common.c, branch v5.10.258

powerpc/mm: Fix boot warning with hugepages and CONFIG_DEBUG_VIRTUAL

2024-10-17T13:07:31+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

2023-11-08T16:30:49+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/64: Set up a kernel stack for secondaries before cpu_restore()

2020-12-30T10:53:01+00:00

[ Upstream commit 3c0b976bf20d236c57adcefa80f86a0a1d737727 ]

Currently in generic_secondary_smp_init(), cur_cpu_spec->cpu_restore()
is called before a stack has been set up in r1. This was previously fine
as the cpu_restore() functions were implemented in assembly and did not
use a stack. However commit 5a61ef74f269 ("powerpc/64s: Support new
device tree binding for discovering CPU features") used
__restore_cpu_cpufeatures() as the cpu_restore() function for a
device-tree features based cputable entry. This is a C function and
hence uses a stack in r1.

generic_secondary_smp_init() is entered on the secondary cpus via the
primary cpu using the OPAL call opal_start_cpu(). In OPAL, each hardware
thread has its own stack. The OPAL call is ran in the primary's hardware
thread. During the call, a job is scheduled on a secondary cpu that will
start executing at the address of generic_secondary_smp_init().  Hence
the value that will be left in r1 when the secondary cpu enters the
kernel is part of that secondary cpu's individual OPAL stack. This means
that __restore_cpu_cpufeatures() will write to that OPAL stack. This is
not horribly bad as each hardware thread has its own stack and the call
that enters the kernel from OPAL never returns, but it is still wrong
and should be corrected.

Create the temp kernel stack before calling cpu_restore().

As noted by mpe, for a kexec boot, the secondary CPUs are released from
the spin loop at address 0x60 by smp_release_cpus() and then jump to
generic_secondary_smp_init(). The call to smp_release_cpus() is in
setup_arch(), and it comes before the call to emergency_stack_init().
emergency_stack_init() allocates an emergency stack in the PACA for each
CPU.  This address in the PACA is what is used to set up the temp kernel
stack in generic_secondary_smp_init(). Move releasing the secondary CPUs
to after the PACAs have been allocated an emergency stack, otherwise the
PACA stack pointer will contain garbage and hence the temp kernel stack
created from it will be broken.

Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Signed-off-by: Jordan Niethe 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20201014072837.24539-1-jniethe5@gmail.com
Signed-off-by: Sasha Levin

powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores

2020-08-17T03:11:22+00:00

On POWER10 bit 12 in the PVR indicates if the core is SMT4 or SMT8.
Bit 12 is set for SMT4.

Without this patch, /proc/cpuinfo on a SMT4 DD1 POWER10 looks like
this:
  cpu             : POWER10, altivec supported
  revision        : 17.0 (pvr 0080 1100)

Fixes: a3ea40d5c736 ("powerpc: Add POWER10 architected mode")
Cc: stable@vger.kernel.org # v5.8
Signed-off-by: Michael Neuling 
Reviewed-by: Vaidyanathan Srinivasan 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200803035600.1820371-1-mikey@neuling.org

powerpc/hugetlb/cma: Allocate gigantic hugetlb pages using CMA

2020-07-29T11:09:37+00:00

commit: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages using cma")
added support for allocating gigantic hugepages using CMA. This patch
enables the same for powerpc

Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200713150749.25245-1-aneesh.kumar@linux.ibm.com

mm: reorder includes after introduction of linux/pgtable.h

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

The replacement of  with  made the include
of the latter in the middle of asm includes.  Fix this up with the aid of
the below script and manual adjustments here and there.

	import sys
	import re

	if len(sys.argv) is not 3:
	    print "USAGE: %s  " % (sys.argv[0])
	    sys.exit(1)

	hdr_to_move="#include " % sys.argv[2]
	moved = False
	in_hdrs = False

	with open(sys.argv[1], "r") as f:
	    lines = f.readlines()
	    for _line in lines:
		line = _line.rstrip('
')
		if line == hdr_to_move:
		    continue
		if line.startswith("#include 
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: 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/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds

mm: introduce include/linux/pgtable.h

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

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

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: 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/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds

powerpc/40x: Remove support for IBM 403GCX

2020-05-28T13:24:35+00:00

CONFIG_403GCX is not user selectable and is not
selected by any platform.

Remove it.

Signed-off-by: Christophe Leroy 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/635f8f5ce9d1f761b3bd8dc3e8ddad500cea26c4.1590079968.git.christophe.leroy@csgroup.eu

powerpc/kernel: no need to check return value of debugfs_create functions

2020-03-04T11:44:25+00:00

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20200209105901.1620958-1-gregkh@linuxfoundation.org

arch/powerpc/setup: Drop dummy_con initialization

2020-01-14T14:29:17+00:00

con_init in tty/vt.c will now set conswitchp to dummy_con if it's unset.
Drop it from arch setup code.

Signed-off-by: Arvind Sankar 
Link: https://lore.kernel.org/r/20191218214506.49252-18-nivedita@alum.mit.edu
Signed-off-by: Greg Kroah-Hartman