The current memory hotplug implementation relies on having all the
struct pages associate with a zone/node during the physical hotplug
phase (arch_add_memory->__add_pages->__add_section->__add_zone). In the
vast majority of cases this means that they are added to ZONE_NORMAL.
This has been so since 9d99aaa31f ("[PATCH] x86_64: Support memory
hotadd without sparsemem") and it wasn't a big deal back then because
movable onlining didn't exist yet.
Much later memory hotplug wanted to (ab)use ZONE_MOVABLE for movable
onlining 511c2aba8f ("mm, memory-hotplug: dynamic configure movable
memory and portion memory") and then things got more complicated.
Rather than reconsidering the zone association which was no longer
needed (because the memory hotplug already depended on SPARSEMEM) a
convoluted semantic of zone shifting has been developed. Only the
currently last memblock or the one adjacent to the zone_movable can be
onlined movable. This essentially means that the online type changes as
the new memblocks are added.
Let's simulate memory hot online manually
$ echo 0x100000000 > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory32/valid_zones
Normal Movable
$ echo $((0x100000000+(128<<20))) > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
$ echo $((0x100000000+2*(128<<20))) > /sys/devices/system/memory/probe
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
$ echo online_movable > /sys/devices/system/memory/memory34/state
$ grep . /sys/devices/system/memory/memory3?/valid_zones
/sys/devices/system/memory/memory32/valid_zones:Normal
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable Normal
This is an awkward semantic because an udev event is sent as soon as the
block is onlined and an udev handler might want to online it based on
some policy (e.g. association with a node) but it will inherently race
with new blocks showing up.
This patch changes the physical online phase to not associate pages with
any zone at all. All the pages are just marked reserved and wait for
the onlining phase to be associated with the zone as per the online
request. There are only two requirements
- existing ZONE_NORMAL and ZONE_MOVABLE cannot overlap
- ZONE_NORMAL precedes ZONE_MOVABLE in physical addresses
the latter one is not an inherent requirement and can be changed in the
future. It preserves the current behavior and made the code slightly
simpler. This is subject to change in future.
This means that the same physical online steps as above will lead to the
following state: Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Normal Movable
/sys/devices/system/memory/memory32/valid_zones:Normal Movable
/sys/devices/system/memory/memory33/valid_zones:Normal Movable
/sys/devices/system/memory/memory34/valid_zones:Movable
Implementation:
The current move_pfn_range is reimplemented to check the above
requirements (allow_online_pfn_range) and then updates the respective
zone (move_pfn_range_to_zone), the pgdat and links all the pages in the
pfn range with the zone/node. __add_pages is updated to not require the
zone and only initializes sections in the range. This allowed to
simplify the arch_add_memory code (s390 could get rid of quite some of
code).
devm_memremap_pages is the only user of arch_add_memory which relies on
the zone association because it only hooks into the memory hotplug only
half way. It uses it to associate the new memory with ZONE_DEVICE but
doesn't allow it to be {on,off}lined via sysfs. This means that this
particular code path has to call move_pfn_range_to_zone explicitly.
The original zone shifting code is kept in place and will be removed in
the follow up patch for an easier review.
Please note that this patch also changes the original behavior when
offlining a memory block adjacent to another zone (Normal vs. Movable)
used to allow to change its movable type. This will be handled later.
[richard.weiyang@gmail.com: simplify zone_intersects()]
Link: http://lkml.kernel.org/r/20170616092335.5177-1-richard.weiyang@gmail.com
[richard.weiyang@gmail.com: remove duplicate call for set_page_links]
Link: http://lkml.kernel.org/r/20170616092335.5177-2-richard.weiyang@gmail.com
[akpm@linux-foundation.org: remove unused local `i']
Link: http://lkml.kernel.org/r/20170515085827.16474-12-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # For s390 bits
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Device memory hotplug hooks into regular memory hotplug only half way.
It needs memory sections to track struct pages but there is no
need/desire to associate those sections with memory blocks and export
them to the userspace via sysfs because they cannot be onlined anyway.
This is currently expressed by for_device argument to arch_add_memory
which then makes sure to associate the given memory range with
ZONE_DEVICE. register_new_memory then relies on is_zone_device_section
to distinguish special memory hotplug from the regular one. While this
works now, later patches in this series want to move __add_zone outside
of arch_add_memory path so we have to come up with something else.
Add want_memblock down the __add_pages path and use it to control
whether the section->memblock association should be done.
arch_add_memory then just trivially want memblock for everything but
for_device hotplug.
remove_memory_section doesn't need is_zone_device_section either. We
can simply skip all the memblock specific cleanup if there is no
memblock for the given section.
This shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Reasonably busy this cycle, but perhaps not as busy as in the 4.12
merge window:
1) Several optimizations for UDP processing under high load from
Paolo Abeni.
2) Support pacing internally in TCP when using the sch_fq packet
scheduler for this is not practical. From Eric Dumazet.
3) Support mutliple filter chains per qdisc, from Jiri Pirko.
4) Move to 1ms TCP timestamp clock, from Eric Dumazet.
5) Add batch dequeueing to vhost_net, from Jason Wang.
6) Flesh out more completely SCTP checksum offload support, from
Davide Caratti.
7) More plumbing of extended netlink ACKs, from David Ahern, Pablo
Neira Ayuso, and Matthias Schiffer.
8) Add devlink support to nfp driver, from Simon Horman.
9) Add RTM_F_FIB_MATCH flag to RTM_GETROUTE queries, from Roopa
Prabhu.
10) Add stack depth tracking to BPF verifier and use this information
in the various eBPF JITs. From Alexei Starovoitov.
11) Support XDP on qed device VFs, from Yuval Mintz.
12) Introduce BPF PROG ID for better introspection of installed BPF
programs. From Martin KaFai Lau.
13) Add bpf_set_hash helper for TC bpf programs, from Daniel Borkmann.
14) For loads, allow narrower accesses in bpf verifier checking, from
Yonghong Song.
15) Support MIPS in the BPF selftests and samples infrastructure, the
MIPS eBPF JIT will be merged in via the MIPS GIT tree. From David
Daney.
16) Support kernel based TLS, from Dave Watson and others.
17) Remove completely DST garbage collection, from Wei Wang.
18) Allow installing TCP MD5 rules using prefixes, from Ivan
Delalande.
19) Add XDP support to Intel i40e driver, from Björn Töpel
20) Add support for TC flower offload in nfp driver, from Simon
Horman, Pieter Jansen van Vuuren, Benjamin LaHaise, Jakub
Kicinski, and Bert van Leeuwen.
21) IPSEC offloading support in mlx5, from Ilan Tayari.
22) Add HW PTP support to macb driver, from Rafal Ozieblo.
23) Networking refcount_t conversions, From Elena Reshetova.
24) Add sock_ops support to BPF, from Lawrence Brako. This is useful
for tuning the TCP sockopt settings of a group of applications,
currently via CGROUPs"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1899 commits)
net: phy: dp83867: add workaround for incorrect RX_CTRL pin strap
dt-bindings: phy: dp83867: provide a workaround for incorrect RX_CTRL pin strap
cxgb4: Support for get_ts_info ethtool method
cxgb4: Add PTP Hardware Clock (PHC) support
cxgb4: time stamping interface for PTP
nfp: default to chained metadata prepend format
nfp: remove legacy MAC address lookup
nfp: improve order of interfaces in breakout mode
net: macb: remove extraneous return when MACB_EXT_DESC is defined
bpf: add missing break in for the TCP_BPF_SNDCWND_CLAMP case
bpf: fix return in load_bpf_file
mpls: fix rtm policy in mpls_getroute
net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t
net, ax25: convert ax25_route.refcount from atomic_t to refcount_t
net, ax25: convert ax25_uid_assoc.refcount from atomic_t to refcount_t
net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_transport.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_chunk.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_datamsg.refcnt from atomic_t to refcount_t
net, sctp: convert sctp_auth_bytes.refcnt from atomic_t to refcount_t
...
Pull pstore updates from Kees Cook:
"Various fixes and tweaks for the pstore subsystem.
Highlights:
- use memdup_user() instead of open-coded copies (Geliang Tang)
- fix record memory leak during initialization (Douglas Anderson)
- avoid confused compressed record warning (Ankit Kumar)
- prepopulate record timestamp and remove redundant logic from
backends"
* tag 'pstore-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
powerpc/nvram: use memdup_user
pstore: use memdup_user
pstore: Fix format string to use %u for record id
pstore: Populate pstore record->time field
pstore: Create common record initializer
efi-pstore: Refactor erase routine
pstore: Avoid potential infinite loop
pstore: Fix leaked pstore_record in pstore_get_backend_records()
pstore: Don't warn if data is uncompressed and type is not PSTORE_TYPE_DMESG
Pull driver core updates from Greg KH:
"Here is the big driver core update for 4.13-rc1.
The large majority of this is a lot of cleanup of old fields in the
driver core structures and their remaining usages in random drivers.
All of those fixes have been reviewed by the various subsystem
maintainers. There's also some small firmware updates in here, a new
kobject uevent api interface that makes userspace interaction easier,
and a few other minor things.
All of these have been in linux-next for a long while with no reported
issues"
* tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (56 commits)
arm: mach-rpc: ecard: fix build error
zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()
driver-core: remove struct bus_type.dev_attrs
powerpc: vio_cmo: use dev_groups and not dev_attrs for bus_type
powerpc: vio: use dev_groups and not dev_attrs for bus_type
USB: usbip: convert to use DRIVER_ATTR_RW
s390: drivers: convert to use DRIVER_ATTR_RO/WO
platform: thinkpad_acpi: convert to use DRIVER_ATTR_RO/RW
pcmcia: ds: convert to use DRIVER_ATTR_RO
wireless: ipw2x00: convert to use DRIVER_ATTR_RW
net: ehea: convert to use DRIVER_ATTR_RO
net: caif: convert to use DRIVER_ATTR_RO
TTY: hvc: convert to use DRIVER_ATTR_RW
PCI: pci-driver: convert to use DRIVER_ATTR_WO
IB: nes: convert to use DRIVER_ATTR_RW
HID: hid-core: convert to use DRIVER_ATTR_RO and drv_groups
arm: ecard: fix dev_groups patch typo
tty: serdev: use dev_groups and not dev_attrs for bus_type
sparc: vio: use dev_groups and not dev_attrs for bus_type
hid: intel-ish-hid: use dev_groups and not dev_attrs for bus_type
...
Pull tty/serial updates from Greg KH:
"Here is the large tty/serial patchset for 4.13-rc1.
A lot of tty and serial driver updates are in here, along with some
fixups for some __get/put_user usages that were reported. Nothing
huge, just lots of development by a number of different developers,
full details in the shortlog.
All of these have been in linux-next for a while"
* tag 'tty-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (71 commits)
tty: serial: lpuart: add a more accurate baud rate calculation method
tty: serial: lpuart: add earlycon support for imx7ulp
tty: serial: lpuart: add imx7ulp support
dt-bindings: serial: fsl-lpuart: add i.MX7ULP support
tty: serial: lpuart: add little endian 32 bit register support
tty: serial: lpuart: refactor lpuart32_{read|write} prototype
tty: serial: lpuart: introduce lpuart_soc_data to represent SoC property
serial: imx-serial - move DMA buffer configuration to DT
serial: imx: Enable RTSD only when needed
serial: imx: Remove unused members from imx_port struct
serial: 8250: 8250_omap: Fix race b/w dma completion and RX timeout
serial: 8250: Fix THRE flag usage for CAP_MINI
tty/serial: meson_uart: update to stable bindings
dt-bindings: serial: Add bindings for the Amlogic Meson UARTs
serial: Delete dead code for CIR serial ports
serial: sirf: make of_device_ids const
serial/mpsc: switch to dma_alloc_attrs
tty: serial: Add Actions Semi Owl UART earlycon
dt-bindings: serial: Document Actions Semi Owl UARTs
tty/serial: atmel: make the driver DT only
...
All code that patches kernel text has been moved over to using
patch_instruction() and patch_instruction() is able to cope with the
kernel text being read only.
The linker script has been updated to ensure the read only data ends
on a large page boundary, so it and the preceding kernel text can be
marked R_X. We also have implementations of mark_rodata_ro() for Hash
and Radix MMU modes.
There are some corner-cases missing when the kernel is built
relocatable, so for now make it depend on !RELOCATABLE.
There's also a temporary workaround to depend on !HIBERNATION to avoid
a build failure, that will be removed once we've merged with the PM
tree.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Make it depend on !RELOCATABLE, munge change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The Radix linear mapping code (create_physical_mapping()) tries to use
the largest page size it can at each step. Currently the only reason
it steps down to a smaller page size is if the start addr is
unaligned (never happens in practice), or the end of memory is not
aligned to a huge page boundary.
To support STRICT_RWX we need to break the mapping at __init_begin,
so that the text and rodata prior to that can be marked R_X and the
regular pages after can be marked RW.
Having done that we can now implement mark_rodata_ro() for Radix,
knowing that we won't need to split any mappings.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Split down to PAGE_SIZE, not 2MB, rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With hash we update the bolted pte to mark it read-only. We rely
on the MMU_FTR_KERNEL_RO to generate the correct permissions
for read-only text. The radix implementation just prints a warning
in this implementation
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Make the warning louder when we don't have MMU_FTR_KERNEL_RO]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Pull SMP hotplug updates from Thomas Gleixner:
"This update is primarily a cleanup of the CPU hotplug locking code.
The hotplug locking mechanism is an open coded RWSEM, which allows
recursive locking. The main problem with that is the recursive nature
as it evades the full lockdep coverage and hides potential deadlocks.
The rework replaces the open coded RWSEM with a percpu RWSEM and
establishes full lockdep coverage that way.
The bulk of the changes fix up recursive locking issues and address
the now fully reported potential deadlocks all over the place. Some of
these deadlocks have been observed in the RT tree, but on mainline the
probability was low enough to hide them away."
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
cpu/hotplug: Constify attribute_group structures
powerpc: Only obtain cpu_hotplug_lock if called by rtasd
ARM/hw_breakpoint: Fix possible recursive locking for arch_hw_breakpoint_init
cpu/hotplug: Remove unused check_for_tasks() function
perf/core: Don't release cred_guard_mutex if not taken
cpuhotplug: Link lock stacks for hotplug callbacks
acpi/processor: Prevent cpu hotplug deadlock
sched: Provide is_percpu_thread() helper
cpu/hotplug: Convert hotplug locking to percpu rwsem
s390: Prevent hotplug rwsem recursion
arm: Prevent hotplug rwsem recursion
arm64: Prevent cpu hotplug rwsem recursion
kprobes: Cure hotplug lock ordering issues
jump_label: Reorder hotplug lock and jump_label_lock
perf/tracing/cpuhotplug: Fix locking order
ACPI/processor: Use cpu_hotplug_disable() instead of get_online_cpus()
PCI: Replace the racy recursion prevention
PCI: Use cpu_hotplug_disable() instead of get_online_cpus()
perf/x86/intel: Drop get_online_cpus() in intel_snb_check_microcode()
x86/perf: Drop EXPORT of perf_check_microcode
...
Pull x86 mm updates from Ingo Molnar:
"The main changes in this cycle were:
- Continued work to add support for 5-level paging provided by future
Intel CPUs. In particular we switch the x86 GUP code to the generic
implementation. (Kirill A. Shutemov)
- Continued work to add PCID CPU support to native kernels as well.
In this round most of the focus is on reworking/refreshing the TLB
flush infrastructure for the upcoming PCID changes. (Andy
Lutomirski)"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
x86/mm: Delete a big outdated comment about TLB flushing
x86/mm: Don't reenter flush_tlb_func_common()
x86/KASLR: Fix detection 32/64 bit bootloaders for 5-level paging
x86/ftrace: Exclude functions in head64.c from function-tracing
x86/mmap, ASLR: Do not treat unlimited-stack tasks as legacy mmap
x86/mm: Remove reset_lazy_tlbstate()
x86/ldt: Simplify the LDT switching logic
x86/boot/64: Put __startup_64() into .head.text
x86/mm: Add support for 5-level paging for KASLR
x86/mm: Make kernel_physical_mapping_init() support 5-level paging
x86/mm: Add sync_global_pgds() for configuration with 5-level paging
x86/boot/64: Add support of additional page table level during early boot
x86/boot/64: Rename init_level4_pgt and early_level4_pgt
x86/boot/64: Rewrite startup_64() in C
x86/boot/compressed: Enable 5-level paging during decompression stage
x86/boot/efi: Define __KERNEL32_CS GDT on 64-bit configurations
x86/boot/efi: Fix __KERNEL_CS definition of GDT entry on 64-bit configurations
x86/boot/efi: Cleanup initialization of GDT entries
x86/asm: Fix comment in return_from_SYSCALL_64()
x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation
...
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Add the SYSTEM_SCHEDULING bootup state to move various scheduler
debug checks earlier into the bootup. This turns silent and
sporadically deadly bugs into nice, deterministic splats. Fix some
of the splats that triggered. (Thomas Gleixner)
- A round of restructuring and refactoring of the load-balancing and
topology code (Peter Zijlstra)
- Another round of consolidating ~20 of incremental scheduler code
history: this time in terms of wait-queue nomenclature. (I didn't
get much feedback on these renaming patches, and we can still
easily change any names I might have misplaced, so if anyone hates
a new name, please holler and I'll fix it.) (Ingo Molnar)
- sched/numa improvements, fixes and updates (Rik van Riel)
- Another round of x86/tsc scheduler clock code improvements, in hope
of making it more robust (Peter Zijlstra)
- Improve NOHZ behavior (Frederic Weisbecker)
- Deadline scheduler improvements and fixes (Luca Abeni, Daniel
Bristot de Oliveira)
- Simplify and optimize the topology setup code (Lauro Ramos
Venancio)
- Debloat and decouple scheduler code some more (Nicolas Pitre)
- Simplify code by making better use of llist primitives (Byungchul
Park)
- ... plus other fixes and improvements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
sched/cputime: Refactor the cputime_adjust() code
sched/debug: Expose the number of RT/DL tasks that can migrate
sched/numa: Hide numa_wake_affine() from UP build
sched/fair: Remove effective_load()
sched/numa: Implement NUMA node level wake_affine()
sched/fair: Simplify wake_affine() for the single socket case
sched/numa: Override part of migrate_degrades_locality() when idle balancing
sched/rt: Move RT related code from sched/core.c to sched/rt.c
sched/deadline: Move DL related code from sched/core.c to sched/deadline.c
sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled
sched/fair: Spare idle load balancing on nohz_full CPUs
nohz: Move idle balancer registration to the idle path
sched/loadavg: Generalize "_idle" naming to "_nohz"
sched/core: Drop the unused try_get_task_struct() helper function
sched/fair: WARN() and refuse to set buddy when !se->on_rq
sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well
sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming
sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c
sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h>
sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h>
...
For CONFIG_STRICT_KERNEL_RWX align __init_begin to 16M. We use 16M
since its the larger of 2M on radix and 16M on hash for our linear
mapping. The plan is to have .text, .rodata and everything upto
__init_begin marked as RX. Note we still have executable read only
data. We could further align rodata to another 16M boundary. I've used
keeping text plus rodata as read-only-executable as a trade-off to
doing read-only-executable for text and read-only for rodata.
We don't use multi PT_LOAD in PHDRS because we are not sure if all
bootloaders support them. This patch keeps PHDRS in vmlinux.lds.S as
the same they are with just one PT_LOAD for all of the kernel marked
as RWX (7).
mpe: What this means is the added alignment bloats the resulting
binary on disk, a powernv kernel goes from 17M to 22M.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch creates the window using text_poke_area, allocated via
get_vm_area(). text_poke_area is per CPU to avoid locking.
text_poke_area for each cpu is setup using late_initcall, prior to
setup of these alternate mapping areas, we continue to use direct
write to change/modify kernel text. With the ability to use alternate
mappings to write to kernel text, it provides us the freedom to then
turn text read-only and implement CONFIG_STRICT_KERNEL_RWX.
This code is CPU hotplug aware to ensure that the we have mappings for
any new cpus as they come online and tear down mappings for any CPUs
that go offline.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move from mwrite() to patch_instruction() for xmon for
breakpoint addition and removal.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
So that we can implement STRICT_RWX, use patch_instruction() in
optprobes.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch_arm/disarm_probe() use direct assignment for copying
instructions, replace them with patch_instruction(). We don't need to
call flush_icache_range() because patch_instruction() does it for us.
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 9abcc981de ("powerpc/mm/radix: Only add X for pages
overlapping kernel text") changed the linear mapping on Radix to only
mark the kernel text executable.
However if the kernel is run relocated, for example as a kdump kernel,
then the exception vectors are split from the kernel text, ie. they
remain at real address 0.
We tend to get away with it, because the kernel itself will usually be
below 1G, which means the 1G page at 0-1G is marked executable and
everything works OK. However if the kernel is loaded above 1G, or the
system has less than 1G in total (meaning we can't use a 1G page),
then the exception vectors will not be marked executable and the
kernel will fail to boot.
Fix it by also checking if the address range overlaps the exception
vectors when deciding if we should add PAGE_KERNEL_X.
Fixes: 9abcc981de ("powerpc/mm/radix: Only add X for pages overlapping kernel text")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Combine with the existing check, rewrite change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Once upon a time there were only two PP (page protection) bits. In ISA
2.03 an additional PP bit was added, but because of the layout of the
HPTE it could not be made contiguous with the existing PP bits.
The result is that we now have three PP bits, named pp0, pp1, pp2,
where pp0 occupies bit 63 of dword 1 of the HPTE and pp1 and pp2
occupy bits 1 and 0 respectively. Until recently Linux hasn't used
pp0, however with the addition of _PAGE_KERNEL_RO we started using it.
The problem arises in the LPAR code, where we need to translate the PP
bits into the argument for the H_PROTECT hypercall. Currently the code
only passes bits 0-2 of newpp, which covers pp1, pp2 and N (no
execute), meaning pp0 is not passed to the hypervisor at all.
We can't simply pass it through in bit 63, as that would collide with a
different field in the flags argument, as defined in PAPR. Instead we
have to shift it down to bit 8 (IBM bit 55).
Fixes: e58e87adc8 ("powerpc/mm: Update _PAGE_KERNEL_RO")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[mpe: Simplify the test, rework change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
We can't take traps with relocation off, so blacklist enter_rtas() and
rtas_return_loc(). However, instead of blacklisting all of enter_rtas(),
introduce a new symbol __enter_rtas from where on we can't take a trap
and blacklist that.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Blacklist all functions involved while handling a trap. We:
- convert some of the symbols into private symbols, and
- blacklist most functions involved while handling a trap.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It is actually safe to probe system_call() in entry_64.S, but only till
we unset MSR_RI. To allow this, add a new symbol system_call_exit()
after the mtmsrd and blacklist that.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It is common to get a PMU interrupt right after the mtmsr instruction that
enables interrupts. Due to this, the stack trace profile gets needlessly split
across system_call_common() and system_call().
Previously, system_call() symbol was at the current place to hide a few
earlier symbols which have since been made private or removed entirely.
So, let's move system_call() slightly higher up, right after the mtmsr
instruction that enables interrupts. Convert existing references to
system_call to a local syscall symbol.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Convert some of the symbols into private symbols and blacklist
system_call_common() and system_call() from kprobes. We can't take a
trap at parts of these functions as either MSR_RI is unset or the
kernel stack pointer is not yet setup.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Don't convert system_call_common to _GLOBAL()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit b48bbb82e2 ("powerpc/64s: Don't unbalance the return branch
predictor in __replay_interrupt()") introduced __replay_interrupt_return
symbol with '.L' prefix in hopes of keeping it private. However, due to
the use of LOAD_REG_ADDR(), the assembler kept this symbol visible. Fix
the same by instead using the local label '1'.
Fixes: Commit b48bbb82e2 ("powerpc/64s: Don't unbalance the return branch
predictor in __replay_interrupt()")
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, we assume that the function pointer we receive in
ppc_function_entry() points to a function descriptor. However, this is
not always the case. In particular, assembly symbols without the right
annotation do not have an associated function descriptor. Some of these
symbols are added to the kprobe blacklist using _ASM_NOKPROBE_SYMBOL().
When such addresses are subsequently processed through
arch_deref_entry_point() in populate_kprobe_blacklist(), we see the
below errors during bootup:
[ 0.663963] Failed to find blacklist at 7d9b02a648029b6c
[ 0.663970] Failed to find blacklist at a14d03d0394a0001
[ 0.663972] Failed to find blacklist at 7d5302a6f94d0388
[ 0.663973] Failed to find blacklist at 48027d11e8610178
[ 0.663974] Failed to find blacklist at f8010070f8410080
[ 0.663976] Failed to find blacklist at 386100704801f89d
[ 0.663977] Failed to find blacklist at 7d5302a6f94d00b0
Fix this by checking if the function pointer we receive in
ppc_function_entry() already points to kernel text. If so, we just
return it as is. If not, we assume that this is a function descriptor
and proceed to dereference it.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This patch exports a in-kernel 'library' API which can be called by
other drivers to help interacting with an IBM XSL on a POWER9 system.
The XSL (Translation Service Layer) is a stripped down version of the
PSL (Power Service Layer) used in some cards such as the Mellanox CX5.
Like the PSL, it implements the CAIA architecture, but has a number
of differences, mostly in it's implementation dependent registers.
The XSL also uses a special DMA cxl mode, which uses a slightly
different init sequence for the CAPP and PHB.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge our fixes branch, a few of them are tripping people up while
working on top of next, and we also have a dependency between the CXL
fixes and new CXL code we want to merge into next.
Most of DT files in PowerPC use #include "..." to make pre-processor
include DT in the same directory, but we have 3 exceptional files
that use #include <...> for that.
Fix them to remove -I$(srctree)/arch/$(SRCARCH)/boot/dts path from
dtc_cpp_flags.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Better machine check handling for HV KVM
- Ability to support guests with threads=2, 4 or 8 on POWER9
- Fix for a race that could cause delayed recognition of signals
- Fix for a bug where POWER9 guests could sleep with interrupts
pending.
On POWER9 SMT8 the 24x7 API returns two result elements for physical core
and virtual CPU events and we need to add their counts to get the final
result.
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 introduces a new version of the hypervisor API to access the 24x7
perf counters. The new version changed some of the structures used for
requests and results.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There's an H24x7_DATA_BUFFER_SIZE constant, so use it in init_24x7_request.
There's also an HV_PERF_DOMAIN_MAX constant, so use it in
h_24x7_event_init. This makes the comment above the check redundant,
so remove it.
In add_event_to_24x7_request, a statement is terminated with a comma
instead of a semicolon. Fix it.
In hv-24x7.h, improve comments in struct hv_24x7_result.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The H_GET_24X7_CATALOG_PAGE hcall can return a signed error code, so fix
this in the code.
The H_GET_24X7_DATA hcall can return a signed error code, so fix this in
the code. Also, don't truncate it to 32 bit to use as return value for
make_24x7_request. In case of error h_24x7_event_commit_txn passes that
return value to generic code, so it should be a proper errno. The other
caller of make_24x7_request is single_24x7_request, whose callers don't
actually care which error code is returned so they are not affected by this
change.
Finally, h_24x7_get_value doesn't use the error code from
single_24x7_request, so there's no need to store it.
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
make_24x7_request already calls log_24x7_hcall if it fails, so callers
don't have to do it again.
In fact, since the latter is now only called from the former, there's no
need for a separate log_24x7_hcall anymore so remove it.
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hv-24x7.h has a comment mentioning that result_buffer->results can't be
indexed as a normal array because it may contain results of variable sizes,
so fix the loop in h_24x7_event_commit_txn to take the variation into
account when iterating through results.
Another problem in that loop is that it sets h24x7hw->events[i] to NULL.
This assumes that only the i'th result maps to the i'th request, but that
is not guaranteed to be true. We need to leave the event in the array so
that we don't dereference a NULL pointer in case more than one result maps
to one request.
We still assume that each result has only one result element, so warn if
that assumption is violated.
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
request_buffer can hold 254 requests, so if it already has that number of
entries we can't add a new one.
Also, define constant to show where the number comes from.
Fixes: e3ee15dc5d ("powerpc/perf/hv-24x7: Define add_event_to_24x7_request()")
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
H_GET_24X7_CATALOG_PAGE needs to be passed the version number obtained from
the first catalog page obtained previously. This is a 64 bit number, but
create_events_from_catalog truncates it to 32-bit.
This worked on POWER8, but POWER9 actually uses the upper bits so the call
fails with H_P3 because the hypervisor doesn't recognize the version.
This patch also adds the hcall return code to the error message, which is
helpful when debugging the problem.
Fixes: 5c5cd7b502 ("powerpc/perf/hv-24x7: parse catalog and populate sysfs with events")
Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Flip the switch. Running around and screaming "IT'S ALIVE" is optional,
but recommended.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Adds support for removing bolted (i.e kernel linear mapping) mappings on
powernv. This is needed to support memory hot unplug operations which
are required for the teardown of DAX/PMEM devices.
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add support for the devmap bit on PTEs and PMDs for PPC64 Book3S. This
is used to differentiate device backed memory from transparent huge
pages since they are handled in more or less the same manner by the core
mm code.
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Adds support to powerpc for the altmap feature of ZONE_DEVICE memory. An
altmap is a driver provided region that is used to provide the backing
storage for the struct pages of ZONE_DEVICE memory. In situations where
large amount of ZONE_DEVICE memory is being added to the system the
altmap reduces pressure on main system memory by allowing the mm/
metadata to be stored on the device itself rather in main memory.
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Removes an indentation level and shuffles some code around to make the
following patch cleaner. No functional changes.
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Export it so it can be referenced inside a module.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use the different spin loop primitives in some simple powerpc
spin loops, including those which will spin as a common case.
This will help to test the spin loop primitives before more
conversions are done.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Add some includes of <linux/processor.h>]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
At present, interrupts are hard-disabled fairly late in the guest
entry path, in the assembly code. Since we check for pending signals
for the vCPU(s) task(s) earlier in the guest entry path, it is
possible for a signal to be delivered before we enter the guest but
not be noticed until after we exit the guest for some other reason.
Similarly, it is possible for the scheduler to request a reschedule
while we are in the guest entry path, and we won't notice until after
we have run the guest, potentially for a whole timeslice.
Furthermore, with a radix guest on POWER9, we can take the interrupt
with the MMU on. In this case we end up leaving interrupts
hard-disabled after the guest exit, and they are likely to stay
hard-disabled until we exit to userspace or context-switch to
another process. This was masking the fact that we were also not
setting the RI (recoverable interrupt) bit in the MSR, meaning
that if we had taken an interrupt, it would have crashed the host
kernel with an unrecoverable interrupt message.
To close these races, we need to check for signals and reschedule
requests after hard-disabling interrupts, and then keep interrupts
hard-disabled until we enter the guest. If there is a signal or a
reschedule request from another CPU, it will send an IPI, which will
cause a guest exit.
This puts the interrupt disabling before we call kvmppc_start_thread()
for all the secondary threads of this core that are going to run vCPUs.
The reason for that is that once we have started the secondary threads
there is no easy way to back out without going through at least part
of the guest entry path. However, kvmppc_start_thread() includes some
code for radix guests which needs to call smp_call_function(), which
must be called with interrupts enabled. To solve this problem, this
patch moves that code into a separate function that is called earlier.
When the guest exit is caused by an external interrupt, a hypervisor
doorbell or a hypervisor maintenance interrupt, we now handle these
using the replay facility. __kvmppc_vcore_entry() now returns the
trap number that caused the exit on this thread, and instead of the
assembly code jumping to the handler entry, we return to C code with
interrupts still hard-disabled and set the irq_happened flag in the
PACA, so that when we do local_irq_enable() the appropriate handler
gets called.
With all this, we now have the interrupt soft-enable flag clear while
we are in the guest. This is useful because code in the real-mode
hypercall handlers that checks whether interrupts are enabled will
now see that they are disabled, which is correct, since interrupts
are hard-disabled in the real-mode code.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Since commit b009031f74 ("KVM: PPC: Book3S HV: Take out virtual
core piggybacking code", 2016-09-15), we only have at most one
vcore per subcore. Previously, the fact that there might be more
than one vcore per subcore meant that we had the notion of a
"master vcore", which was the vcore that controlled thread 0 of
the subcore. We also needed a list per subcore in the core_info
struct to record which vcores belonged to each subcore. Now that
there can only be one vcore in the subcore, we can replace the
list with a simple pointer and get rid of the notion of the
master vcore (and in fact treat every vcore as a master vcore).
We can also get rid of the subcore_vm[] field in the core_info
struct since it is never read.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
