linux-stable.git/arch/powerpc/kernel/setup-common.c, branch v4.14.331

powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used

2019-04-03T04:25:14+00:00

commit 3bc8ea8603ae4c1e09aca8de229ad38b8091fcb3 upstream.

If the user choses not to use the mitigations, replace
the code sequence with nops.

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/64: Call setup_barrier_nospec() from setup_arch()

2019-04-03T04:25:12+00:00

commit af375eefbfb27cbb5b831984e66d724a40d26b5c upstream.

Currently we require platform code to call setup_barrier_nospec(). But
if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case
then we can call it in setup_arch().

Signed-off-by: Diana Craciun 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/mm/slice: Fix hugepage allocation at hint address on 8xx

2018-06-05T09:42:00+00:00

commit aa0ab02ba992eb956934b21373e0138211486ddd upstream.

On the 8xx, the page size is set in the PMD entry and applies to
all pages of the page table pointed by the said PMD entry.

When an app has some regular pages allocated (e.g. see below) and tries
to mmap() a huge page at a hint address covered by the same PMD entry,
the kernel accepts the hint allthough the 8xx cannot handle different
page sizes in the same PMD entry.

10000000-10001000 r-xp 00000000 00:0f 2597 /root/malloc
10010000-10011000 rwxp 00000000 00:0f 2597 /root/malloc

mmap(0x10080000, 524288, PROT_READ|PROT_WRITE,
     MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0) = 0x10080000

This results the app remaining forever in do_page_fault()/hugetlb_fault()
and when interrupting that app, we get the following warning:

[162980.035629] WARNING: CPU: 0 PID: 2777 at arch/powerpc/mm/hugetlbpage.c:354 hugetlb_free_pgd_range+0xc8/0x1e4
[162980.035699] CPU: 0 PID: 2777 Comm: malloc Tainted: G W       4.14.6 #85
[162980.035744] task: c67e2c00 task.stack: c668e000
[162980.035783] NIP:  c000fe18 LR: c00e1eec CTR: c00f90c0
[162980.035830] REGS: c668fc20 TRAP: 0700   Tainted: G W        (4.14.6)
[162980.035854] MSR:  00029032   CR: 24044224 XER: 20000000
[162980.036003]
[162980.036003] GPR00: c00e1eec c668fcd0 c67e2c00 00000010 c6869410 10080000 00000000 77fb4000
[162980.036003] GPR08: ffff0001 0683c001 00000000 ffffff80 44028228 10018a34 00004008 418004fc
[162980.036003] GPR16: c668e000 00040100 c668e000 c06c0000 c668fe78 c668e000 c6835ba0 c668fd48
[162980.036003] GPR24: 00000000 73ffffff 74000000 00000001 77fb4000 100fffff 10100000 10100000
[162980.036743] NIP [c000fe18] hugetlb_free_pgd_range+0xc8/0x1e4
[162980.036839] LR [c00e1eec] free_pgtables+0x12c/0x150
[162980.036861] Call Trace:
[162980.036939] [c668fcd0] [c00f0774] unlink_anon_vmas+0x1c4/0x214 (unreliable)
[162980.037040] [c668fd10] [c00e1eec] free_pgtables+0x12c/0x150
[162980.037118] [c668fd40] [c00eabac] exit_mmap+0xe8/0x1b4
[162980.037210] [c668fda0] [c0019710] mmput.part.9+0x20/0xd8
[162980.037301] [c668fdb0] [c001ecb0] do_exit+0x1f0/0x93c
[162980.037386] [c668fe00] [c001f478] do_group_exit+0x40/0xcc
[162980.037479] [c668fe10] [c002a76c] get_signal+0x47c/0x614
[162980.037570] [c668fe70] [c0007840] do_signal+0x54/0x244
[162980.037654] [c668ff30] [c0007ae8] do_notify_resume+0x34/0x88
[162980.037744] [c668ff40] [c000dae8] do_user_signal+0x74/0xc4
[162980.037781] Instruction dump:
[162980.037821] 7fdff378 81370000 54a3463a 80890020 7d24182e 7c841a14 712a0004 4082ff94
[162980.038014] 2f890000 419e0010 712a0ff0 408200e0 <0fe00000> 54a9000a 7f984840 419d0094
[162980.038216] ---[ end trace c0ceeca8e7a5800a ]---
[162980.038754] BUG: non-zero nr_ptes on freeing mm: 1
[162985.363322] BUG: non-zero nr_ptes on freeing mm: -1

In order to fix this, this patch uses the address space "slices"
implemented for BOOK3S/64 and enhanced to support PPC32 by the
preceding patch.

This patch modifies the context.id on the 8xx to be in the range
[1:16] instead of [0:15] in order to identify context.id == 0 as
not initialised contexts as done on BOOK3S

This patch activates CONFIG_PPC_MM_SLICES when CONFIG_HUGETLB_PAGE is
selected for the 8xx

Alltough we could in theory have as many slices as PMD entries, the
current slices implementation limits the number of low slices to 16.
This limitation is not preventing us to fix the initial issue allthough
it is suboptimal. It will be cured in a subsequent patch.

Fixes: 4b91428699477 ("powerpc/8xx: Implement support of hugepages")
Signed-off-by: Christophe Leroy 
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc: Don't preempt_disable() in show_cpuinfo()

2018-05-22T16:53:57+00:00

commit 349524bc0da698ec77f2057cf4a4948eb6349265 upstream.

This causes warnings from cpufreq mutex code. This is also rather
unnecessary and ineffective. If we really want to prevent concurrent
unplug, we could take the unplug read lock but I don't see this being
critical.

Fixes: cd77b5ce208c ("powerpc/powernv/cpufreq: Fix the frequency read by /proc/cpuinfo")
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Michael Ellerman 
Acked-by: Michal Suchanek 
Signed-off-by: Greg Kroah-Hartman

Revert "powerpc: Do not call ppc_md.panic in fadump panic notifier"

2017-12-14T08:52:57+00:00

commit ab9dbf771ff9b6b7e814e759213ed01d7f0de320 upstream.

This reverts commit a3b2cb30f252b21a6f962e0dd107c8b897ca65e4.

That commit tried to fix problems with panic on powerpc in certain
circumstances, where some output from the generic panic code was being
dropped.

Unfortunately, it breaks things worse in other circumstances. In
particular when running a PAPR guest, it will now attempt to reboot
instead of informing the hypervisor (KVM or PowerVM) that the guest
has crashed. The crash notification is important to some
virtualization management layers.

Revert it for now until we can come up with a better solution.

Fixes: a3b2cb30f252 ("powerpc: Do not call ppc_md.panic in fadump panic notifier")
Signed-off-by: David Gibson 
[mpe: Tweak change log a bit]
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

powerpc/4xx: Fix compile error with 64K pages on 40x, 44x

2017-10-03T10:59:48+00:00

The mmu context on the 40x, 44x does not define pte_frag entry. This
causes gcc abort the compilation due to:

  setup-common.c: In function ‘setup_arch’:
  setup-common.c:908: error: ‘mm_context_t’ has no ‘pte_frag’

This patch fixes the issue by removing the pte_frag initialization in
setup-common.c.

This is possible, because the compiler will do the initialization,
since the mm_context is a sub struct of init_mm. init_mm is declared
in mm_types.h as external linkage.

According to C99 6.2.4.3:
  An object whose identifier is declared with external linkage
  [...] has static storage duration.

C99 defines in 6.7.8.10 that:
  If an object that has static storage duration is not
  initialized explicitly, then:
  - if it has pointer type, it is initialized to a null pointer

Fixes: b1923caa6e64 ("powerpc: Merge 32-bit and 64-bit setup_arch()")
Signed-off-by: Christian Lamparter 
Reviewed-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

treewide: make "nr_cpu_ids" unsigned

2017-09-09T01:26:48+00:00

First, number of CPUs can't be negative number.

Second, different signnnedness leads to suboptimal code in the following
cases:

1)
	kmalloc(nr_cpu_ids * sizeof(X));

"int" has to be sign extended to size_t.

2)
	while (loff_t *pos < nr_cpu_ids)

MOVSXD is 1 byte longed than the same MOV.

Other cases exist as well. Basically compiler is told that nr_cpu_ids
can't be negative which can't be deduced if it is "int".

Code savings on allyesconfig kernel: -3KB

	add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370)
	function                                     old     new   delta
	coretemp_cpu_online                          450     512     +62
	rcu_init_one                                1234    1272     +38
	pci_device_probe                             374     399     +25

				...

	pgdat_reclaimable_pages                      628     556     -72
	select_fallback_rq                           446     369     -77
	task_numa_find_cpu                          1923    1807    -116

Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: Do not call ppc_md.panic in fadump panic notifier

2017-08-31T04:26:01+00:00

If fadump is not registered, and no other crash or debug handlers are
registered, the powerpc panic handler stops the guest before the
generic panic code can push out debug information to the console.

Currently, system reset injection causes the guest to silently stop.

Stop calling ppc_md.panic in the panic notifier. crash_fadump already
does rtas_os_term() to terminate the guest if fadump is registered.

Remove ppc_md.panic. Move fadump panic notifier into fadump code.

Signed-off-by: Nicholas Piggin 
Reviewed-by: Mahesh Salgaonkar 
Signed-off-by: Michael Ellerman

powerpc: Convert to using %pOF instead of full_name

2017-08-23T12:27:04+00:00

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Anatolij Gustschin 
Cc: Scott Wood 
Cc: Kumar Gala 
Cc: Arnd Bergmann 
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Tyrel Datwyler 
Signed-off-by: Michael Ellerman

powerpc/mm/hugetlb: Add support for reserving gigantic huge pages via kernel command line

2017-08-16T04:56:12+00:00

With commit aa888a74977a8 ("hugetlb: support larger than MAX_ORDER") we added
support for allocating gigantic hugepages via kernel command line. Switch
ppc64 arch specific code to use that.

W.r.t FSL support, we now limit our allocation range using BOOTMEM_ALLOC_ACCESSIBLE.

We use the kernel command line to do reservation of hugetlb pages on powernv
platforms. On pseries hash mmu mode the supported gigantic huge page size is
16GB and that can only be allocated with hypervisor assist. For pseries the
command line option doesn't do the allocation. Instead pseries does gigantic
hugepage allocation based on hypervisor hint that is specified via
"ibm,expected#pages" property of the memory node.

Cc: Scott Wood 
Cc: Christophe Leroy 
Signed-off-by: Aneesh Kumar K.V 
Signed-off-by: Michael Ellerman