Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Support for userspace to send requests directly to the on-chi

Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Support for userspace to send requests directly to the on-chip GZIP
accelerator on Power9.

- Rework of our lockless page table walking (__find_linux_pte()) to
make it safe against parallel page table manipulations without
relying on an IPI for serialisation.

- A series of fixes & enhancements to make our machine check handling
more robust.

- Lots of plumbing to add support for "prefixed" (64-bit) instructions
on Power10.

- Support for using huge pages for the linear mapping on 8xx (32-bit).

- Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound
driver.

- Removal of some obsolete 40x platforms and associated cruft.

- Initial support for booting on Power10.

- Lots of other small features, cleanups & fixes.

Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent
Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe
JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F.,
Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A.
R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan
Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal
Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai,
Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler,
Wolfram Sang, Xiongfeng Wang.

* tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits)
powerpc/pseries: Make vio and ibmebus initcalls pseries specific
cxl: Remove dead Kconfig options
powerpc: Add POWER10 architected mode
powerpc/dt_cpu_ftrs: Add MMA feature
powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected
powerpc: Add support for ISA v3.1
powerpc: Add new HWCAP bits
powerpc/64s: Don't set FSCR bits in INIT_THREAD
powerpc/64s: Save FSCR to init_task.thread.fscr after feature init
powerpc/64s: Don't let DT CPU features set FSCR_DSCR
powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()
powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG
powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
powerpc/module_64: Consolidate ftrace code
powerpc/32: Disable KASAN with pages bigger than 16k
powerpc/uaccess: Don't set KUEP by default on book3s/32
powerpc/uaccess: Don't set KUAP by default on book3s/32
powerpc/8xx: Reduce time spent in allow_user_access() and friends
...

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Merge branches 'for-5.7/upstream-fixes', 'for-5.8/apple', 'for-5.8/asus', 'for-5.8/core', 'for-5.8/intel-ish', 'for-5.8/logitech', 'for-5.8/mcp2221' and 'for-5.8/multitouch' into for-linus

Merge branch 'for-5.8' into for-linus

Merge branch 'timers/drivers/timer-ti' into timers/drivers/next

Merge branch 'kvm-amd-fixes' into HEAD

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul McKenney:

1. Miscellaneous fixes.
2. kfree_rcu() updates.

Merge branch 'for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu

Pull RCU updates from Paul McKenney:

1. Miscellaneous fixes.
2. kfree_rcu() updates.
3. Remove scheduler locking restriction
4. RCU-tasks update, including addition of RCU Tasks Trace for
BPF use and RCU Tasks Rude. (This branch is on top of #3 due
to overlap of changed code.)
5. RCU CPU stall warning updates.
6. Torture-test updates.

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Merge the lockless page table walk rework into next

This merges the lockless page table walk rework series from Aneesh.
Because it touches powerpc KVM code we are sharing it with the kvm-ppc
tree in

Merge the lockless page table walk rework into next

This merges the lockless page table walk rework series from Aneesh.
Because it touches powerpc KVM code we are sharing it with the kvm-ppc
tree in our topic/ppc-kvm branch.

This is the cover letter from Aneesh:

Avoid IPI while updating page table entries.

Problem Summary:
Slow termination of KVM guest with large guest RAM config due to a
large number of IPIs that were caused by clearing level 1 PTE
entries (THP) entries. This is shown in the stack trace below.

- qemu-system-ppc [kernel.vmlinux] [k] smp_call_function_many
- smp_call_function_many
- 36.09% smp_call_function_many
serialize_against_pte_lookup
radix__pmdp_huge_get_and_clear
zap_huge_pmd
unmap_page_range
unmap_vmas
unmap_region
__do_munmap
__vm_munmap
sys_munmap
system_call
__munmap
qemu_ram_munmap
qemu_anon_ram_free
reclaim_ramblock
call_rcu_thread
qemu_thread_start
start_thread
__clone

Why we need to do IPI when clearing PMD entries:
This was added as part of commit: 13bd817bb884 ("powerpc/thp: Serialize pmd clear against a linux page table walk")

serialize_against_pte_lookup makes sure that all parallel lockless
page table walk completes before we convert a PMD pte entry to regular
pmd entry. We end up doing that conversion in the below scenarios

1) __split_huge_zero_page_pmd
2) do_huge_pmd_wp_page_fallback
3) MADV_DONTNEED running parallel to page faults.

local_irq_disable and lockless page table walk:

The lockless page table walk work with the assumption that we can
dereference the page table contents without holding a lock. For this
to work, we need to make sure we read the page table contents
atomically and page table pages are not going to be freed/released
while we are walking the table pages. We can achieve by using a rcu
based freeing for page table pages or if the architecture implements
broadcast tlbie, we can block the IPI as we walk the page table pages.

To support both the above framework, lockless page table walk is done
with irq disabled instead of rcu_read_lock()

We do have two interface for lockless page table walk, gup fast and
__find_linux_pte. This patch series makes __find_linux_pte table walk
safe against the conversion of PMD PTE to regular PMD.

gup fast:

gup fast is already safe against THP split because kernel now
differentiate between a pmd split and a compound page split. gup fast
can run parallel to a pmd split and we prevent a parallel gup fast to
a hugepage split, by freezing the page refcount and failing the
speculative page ref increment.

Similar to how gup is safe against parallel pmd split, this patch
series updates the __find_linux_pte callers to be safe against a
parallel pmd split. We do that by enforcing the following rules.

1) Don't reload the pte value, because that can be updated in
parallel.
2) Code should be able to work with a stale PTE value and not the
recent one. ie, the pte value that we are looking at may not be the
latest value in the page table.
3) Before looking at pte value check for _PAGE_PTE bit. We now do this
as part of pte_present() check.

Performance:

This speeds up Qemu guest RAM del/unplug time as below
128 core, 496GB guest:

Without patch:
munmap start: timer = 13162 ms, PID=7684
munmap finish: timer = 95312 ms, PID=7684 - delta = 82150 ms

With patch (upto removing IPI)
munmap start: timer = 196449 ms, PID=6681
munmap finish: timer = 196488 ms, PID=6681 - delta = 39ms

With patch (with adding the tlb invalidate in pmdp_huge_get_and_clear_full)
munmap start: timer = 196345 ms, PID=6879
munmap finish: timer = 196714 ms, PID=6879 - delta = 369ms

Link: https://lore.kernel.org/r/20200505071729.54912-1-aneesh.kumar@linux.ibm.com

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powerpc/perf/callchain: Use __get_user_pages_fast in read_user_stack_slow

read_user_stack_slow is called with interrupts soft disabled and it copies contents
from the page which we find mapped to a

powerpc/perf/callchain: Use __get_user_pages_fast in read_user_stack_slow

read_user_stack_slow is called with interrupts soft disabled and it copies contents
from the page which we find mapped to a specific address. To convert
userspace address to pfn, the kernel now uses lockless page table walk.

The kernel needs to make sure the pfn value read remains stable and is not released
and reused for another process while the contents are read from the page. This
can only be achieved by holding a page reference.

One of the first approaches I tried was to check the pte value after the kernel
copies the contents from the page. But as shown below we can still get it wrong

CPU0 CPU1
pte = READ_ONCE(*ptep);
pte_clear(pte);
put_page(page);
page = alloc_page();
memcpy(page_address(page), "secret password", nr);
memcpy(buf, kaddr + offset, nb);
put_page(page);
handle_mm_fault()
page = alloc_page();
set_pte(pte, page);
if (pte_val(pte) != pte_val(*ptep))

Hence switch to __get_user_pages_fast.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200505071729.54912-8-aneesh.kumar@linux.ibm.com

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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI changes for v5.8 from Ard Biesheuvel:

"- preliminary changes for RISC-V
- add support for setti

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI changes for v5.8 from Ard Biesheuvel:

"- preliminary changes for RISC-V
- add support for setting the resolution on the EFI framebuffer
- simplify kernel image loading for arm64
- Move .bss into .data via the linker script instead of relying on symbol
annotations.
- Get rid of __pure getters to access global variables
- Clean up the config table matching arrays"

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Merge branch 'topic/nhlt' into for-next

Merge NHLT init cleanup.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge tag 'tegra-for-5.7-asoc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into asoc-5.7

ASoC: tegra: Fixes for v5.7-rc3

This contains a couple of fixes that are needed to properly

Merge tag 'tegra-for-5.7-asoc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into asoc-5.7

ASoC: tegra: Fixes for v5.7-rc3

This contains a couple of fixes that are needed to properly reconfigure
the audio clocks on older Tegra devices.

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Merge branch 'fixes-v5.7' into fixes

Merge tag 'kvm-s390-master-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master

KVM: s390: Fix for 5.7 and maintainer update

- Silence false positive lockdep warnin

Merge tag 'kvm-s390-master-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master

KVM: s390: Fix for 5.7 and maintainer update

- Silence false positive lockdep warning
- add Claudio as reviewer

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Merge drm/drm-next into drm-misc-next

Backmerging required to pull topic/phy-compliance.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge drm/drm-next into drm-intel-next-queued

Backmerging in order to pull "topic/phy-compliance".

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

Merge v5.7-rc1 into drm-misc-fixes

Start the new drm-misc-fixes cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refresh

Resolve these conflicts:

arch/x86/Kconfig
arch/x86/kernel/Makefile

Do a minor "evil merge" to move the KCSAN entry up a

Merge tag 'v5.7-rc1' into locking/kcsan, to resolve conflicts and refresh

Resolve these conflicts:

arch/x86/Kconfig
arch/x86/kernel/Makefile

Do a minor "evil merge" to move the KCSAN entry up a bit by a few lines
in the Kconfig to reduce the probability of future conflicts.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

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Merge tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull more powerpc updates from Michael Ellerman:
"The bulk of this is the series to make CONFIG_COMPAT user-

Merge tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull more powerpc updates from Michael Ellerman:
"The bulk of this is the series to make CONFIG_COMPAT user-selectable,
it's been around for a long time but was blocked behind the
syscall-in-C series.

Plus there's also a few fixes and other minor things.

Summary:

- A fix for a crash in machine check handling on pseries (ie. guests)

- A small series to make it possible to disable CONFIG_COMPAT, and
turn it off by default for ppc64le where it's not used.

- A few other miscellaneous fixes and small improvements.

Thanks to: Alexey Kardashevskiy, Anju T Sudhakar, Arnd Bergmann,
Christophe Leroy, Dan Carpenter, Ganesh Goudar, Geert Uytterhoeven,
Geoff Levand, Mahesh Salgaonkar, Markus Elfring, Michal Suchanek,
Nicholas Piggin, Stephen Boyd, Wen Xiong"

* tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Always build the tm-poison test 64-bit
powerpc: Improve ppc_save_regs()
Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled"
powerpc/time: Replace <linux/clk-provider.h> by <linux/of_clk.h>
powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory
powerpc/perf: split callchain.c by bitness
powerpc/64: Make COMPAT user-selectable disabled on littleendian by default.
powerpc/64: make buildable without CONFIG_COMPAT
powerpc/perf: consolidate valid_user_sp -> invalid_user_sp
powerpc/perf: consolidate read_user_stack_32
powerpc: move common register copy functions from signal_32.c to signal.c
powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro
powerpc/ps3: Set CONFIG_UEVENT_HELPER=y in ps3_defconfig
powerpc/ps3: Remove an unneeded NULL check
powerpc/ps3: Remove duplicate error message
powerpc/powernv: Re-enable imc trace-mode in kernel
powerpc/perf: Implement a global lock to avoid races between trace, core and thread imc events.
powerpc/pseries: Fix MCE handling on pseries
selftests/eeh: Skip ahci adapters
powerpc/64s: Fix doorbell wakeup msgclr optimisation

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powerpc/perf: split callchain.c by bitness

Building callchain.c with !COMPAT proved quite ugly with all the
defines. Splitting out the 32bit and 64bit parts looks better.

No code change intended.

powerpc/perf: split callchain.c by bitness

Building callchain.c with !COMPAT proved quite ugly with all the
defines. Splitting out the 32bit and 64bit parts looks better.

No code change intended.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a20027bf1074935a7934ee2a6757c99ea047e70d.1584699455.git.msuchanek@suse.de

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