powerpc/mm/trace: convert trace event to trace event class

A follow-up patch will add a pud variant for this same event. Using event
class makes that addition simpler.

No functional change in this patch.

Link: https://lkml.kernel.org/r/20230724190759.483013-9-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc/64s: Fix hash__change_memory_range preemption warning

stop_machine_cpuslocked takes a mutex so it must be called in a
preemptible context, so it can't simply be fixed by disabling
preemption.

This is not a bug, because CPU hotplug is locked, so this processor will
call in to the stop machine function. So raw_smp_processor_id() could be
used. This leaves a small chance that this thread will be migrated to
another CPU, so the master work would be done by a CPU from a different
context. Better for test coverage to make that a common case by just
having the first CPU to call in become the master.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221013151647.1857994-2-npiggin@gmail.com

powerpc/mm/book3s/hash: Rename flush_tlb_pmd_range

This function does the hash page table update. Hence rename it to
indicate this better to avoid confusion with flush_pmd_tlb_range()

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Drop unnecessary extern]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220907081941.209501-1-aneesh.kumar@linux.ibm.com

powerpc: move __end_rodata to cover arch read-only sections

powerpc has a number of read-only sections and tables that are put after
RO_DATA(). Move the __end_rodata symbol to cover these as well.

Setting memory to read-only at boot is done using __init_begin, change
that to use __end_rodata.

This makes is_kernel_rodata() exactly cover the read-only region, as
well as other things using __end_rodata (e.g., kernel/dma/debug.c).
Boot dmesg also prints the rodata size more accurately.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220916040755.2398112-2-npiggin@gmail.com

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

Trying to remove asm/ppc_asm.h from all places that don't need it
leads to several failures linked to firmware_has_feature().

To fix it, include asm/firmware.h in all files using
firmware_has_feature()

All users found with:

git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("`

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu

powerpc: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220430185654.5855-1-Julia.Lawall@inria.fr

powerpc/64s: move THP trace point creation out of hash specific file

In preparation for making hash MMU support configurable, move THP
trace point function definitions out of an otherwise hash-specific
file.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211201144153.2456614-8-npiggin@gmail.com

powerpc/mm/64s/hash: Add real-mode change_memory_range() for hash LPAR

When we enabled STRICT_KERNEL_RWX we received some reports of boot
failures when using the Hash MMU and running under phyp. The crashes
are intermittent, and often exhibit as a completely unresponsive
system, or possibly an oops.

One example, which was caught in xmon:

[ 14.068327][ T1] devtmpfs: mounted
[ 14.069302][ T1] Freeing unused kernel memory: 5568K
[ 14.142060][ T347] BUG: Unable to handle kernel instruction fetch
[ 14.142063][ T1] Run /sbin/init as init process
[ 14.142074][ T347] Faulting instruction address: 0xc000000000004400
cpu 0x2: Vector: 400 (Instruction Access) at [c00000000c7475e0]
pc: c000000000004400: exc_virt_0x4400_instruction_access+0x0/0x80
lr: c0000000001862d4: update_rq_clock+0x44/0x110
sp: c00000000c747880
msr: 8000000040001031
current = 0xc00000000c60d380
paca = 0xc00000001ec9de80 irqmask: 0x03 irq_happened: 0x01
pid = 347, comm = kworker/2:1
...
enter ? for help
[c00000000c747880] c0000000001862d4 update_rq_clock+0x44/0x110 (unreliable)
[c00000000c7478f0] c000000000198794 update_blocked_averages+0xb4/0x6d0
[c00000000c7479f0] c000000000198e40 update_nohz_stats+0x90/0xd0
[c00000000c747a20] c0000000001a13b4 _nohz_idle_balance+0x164/0x390
[c00000000c747b10] c0000000001a1af8 newidle_balance+0x478/0x610
[c00000000c747be0] c0000000001a1d48 pick_next_task_fair+0x58/0x480
[c00000000c747c40] c000000000eaab5c __schedule+0x12c/0x950
[c00000000c747cd0] c000000000eab3e8 schedule+0x68/0x120
[c00000000c747d00] c00000000016b730 worker_thread+0x130/0x640
[c00000000c747da0] c000000000174d50 kthread+0x1a0/0x1b0
[c00000000c747e10] c00000000000e0f0 ret_from_kernel_thread+0x5c/0x6c

This shows that CPU 2, which was idle, woke up and then appears to
randomly take an instruction fault on a completely valid area of
kernel text.

The cause turns out to be the call to hash__mark_rodata_ro(), late in
boot. Due to the way we layout text and rodata, that function actually
changes the permissions for all of text and rodata to read-only plus
execute.

To do the permission change we use a hypervisor call, H_PROTECT. On
phyp that appears to be implemented by briefly removing the mapping of
the kernel text, before putting it back with the updated permissions.
If any other CPU is executing during that window, it will see spurious
faults on the kernel text and/or data, leading to crashes.

To fix it we use stop machine to collect all other CPUs, and then have
them drop into real mode (MMU off), while we change the mapping. That
way they are unaffected by the mapping temporarily disappearing.

We don't see this bug on KVM because KVM always use VPM=1, where
faults are directed to the hypervisor, and the fault will be
serialised vs the h_protect() by HPTE_V_HVLOCK.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210331003845.216246-5-mpe@ellerman.id.au

powerpc/mm/64s/hash: Factor out change_memory_range()

Pull the loop calling hpte_updateboltedpp() out of
hash__change_memory_range() into a helper function. We need it to be a
separate function for the next patch.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210331003845.216246-4-mpe@ellerman.id.au

powerpc/64s: Use htab_convert_pte_flags() in hash__mark_rodata_ro()

In hash__mark_rodata_ro() we pass the raw PP_RXXX value to
hash__change_memory_range(). That has the effect of setting the key to
zero, because PP_RXXX contains no key value.

Fix it by using htab_convert_pte_flags(), which knows how to convert a
pgprot into a pp value, including the key.

Fixes: d94b827e89dc ("powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Link: https://lore.kernel.org/r/20210331003845.216246-3-mpe@ellerman.id.au

powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation

This patch updates kernel hash page table entries to use storage key 3
for its mapping. This implies all kernel access will now use key 3 to
control READ/WRITE. The patch also prevents the allocation of key 3 from
userspace and UAMOR value is updated such that userspace cannot modify key 3.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-9-aneesh.kumar@linux.ibm.com

mm: remove unneeded includes of <asm/pgalloc.h>

Patch series "mm: cleanup usage of <asm/pgalloc.h>"

Most architectures have very similar versions of pXd_alloc_one() and
pXd_free_one() for intermediate levels of page table. These patches add
generic versions of these functions in <asm-generic/pgalloc.h> and enable
use of the generic functions where appropriate.

In addition, functions declared and defined in <asm/pgalloc.h> headers are
used mostly by core mm and early mm initialization in arch and there is no
actual reason to have the <asm/pgalloc.h> included all over the place.
The first patch in this series removes unneeded includes of
<asm/pgalloc.h>

In the end it didn't work out as neatly as I hoped and moving
pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require
unnecessary changes to arches that have custom page table allocations, so
I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local
to mm/.

This patch (of 8):

In most cases <asm/pgalloc.h> header is required only for allocations of
page table memory. Most of the .c files that include that header do not
use symbols declared in <asm/pgalloc.h> and do not require that header.

As for the other header files that used to include <asm/pgalloc.h>, it is
possible to move that include into the .c file that actually uses symbols
from <asm/pgalloc.h> and drop the include from the header file.

The process was somewhat automated using

sed -i -E '/[<"]asm\/pgalloc\.h/d' \
$(grep -L -w -f /tmp/xx \
$(git grep -E -l '[<"]asm/pgalloc\.h'))

where /tmp/xx contains all the symbols defined in
arch/*/include/asm/pgalloc.h.

[rppt@linux.ibm.com: fix powerpc warning]

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mmap locking API: convert mmap_sem comments

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: don't include asm/pgtable.h if linux/mm.h is already included

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate and replace 5level-fixup.h with pgtable-nop4d.h.

[rppt@linux.ibm.com: powerpc/xmon: drop unused pgdir varialble in show_pte() function]
Link: http://lkml.kernel.org/r/20200519181454.GI1059226@linux.ibm.com
[rppt@linux.ibm.com; build fix]
Link: http://lkml.kernel.org/r/20200423141845.GI13521@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # 8xx and 83xx
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: James Morse <james.morse@arm.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200414153455.21744-9-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/mm/book3s64: Avoid sending IPI on clearing PMD

Now that all the lockless page table walk is careful w.r.t the PTE
address returned, we can now revert
commit: 13bd817bb884 ("powerpc/thp: Serialize pmd clear against a linux page table walk.")

We also drop the equivalent IPI from other pte updates routines. We still keep
IPI in hash pmdp collapse and that is to take care of parallel hash page table
insert. The radix pmdp collapse flush can possibly be removed once I am sure
generic code doesn't have the any expectations around parallel gup walk.

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:
munmap start: timer = 196449 ms, PID=6681
munmap finish: timer = 196488 ms, PID=6681 - delta = 39ms

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/20200505071729.54912-21-aneesh.kumar@linux.ibm.com

powerpc/book3s64: Export has_transparent_hugepage() related functions.

In later patch, we want to use hash_transparent_hugepage() in a kernel module.
Export two related functions.

Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Link: https://lore.kernel.org/r/20190924042440.27946-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/mm: Move book3s64 specifics in subdirectory mm/book3s64

Many files in arch/powerpc/mm are only for book3S64. This patch
creates a subdirectory for them.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Update the selftest sym links, shorten new filenames, cleanup some
whitespace and formatting in the new files.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>