powerpc: implement the new page table range API

Add set_ptes(), update_mmu_cache_range() and flush_dcache_folio(). Change
the PG_arch_1 (aka PG_dcache_dirty) flag from being per-page to per-folio.

[willy@infradead.org: re-export flush_dcache_icache_folio()]
Link: https://lkml.kernel.org/r/ZMx1daYwvD9EM7Cv@casper.infradead.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-22-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc: Fix all occurences of "the the"

Rather than waiting for the bots to fix these one-by-one, fix all
occurences of "the the" throughout arch/powerpc.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220518142629.513007-1-mpe@ellerman.id.au

powerpc/mem: Use kmap_local_page() in flushing functions

Flushing functions don't rely on preemption being disabled, so
use kmap_local_page() instead of kmap_atomic().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b6a880ea0ec7886b51edbb4979c188be549231c0.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Inline flush_dcache_page()

flush_dcache_page() is only a few lines, it is worth
inlining.

ia64, csky, mips, openrisc and riscv have a similar
flush_dcache_page() and inline it.

On pmac32_defconfig, we get a small size reduction.
On ppc64_defconfig, we get a very small size increase.

In both case that's in the noise (less than 0.1%).

text data bss dec hex filename
18991155 5934744 1497624 26423523 19330e3 vmlinux64.before
18994829 5936732 1497624 26429185 1934701 vmlinux64.after
9150963 2467502 184548 11803013 b41985 vmlinux32.before
9149689 2467302 184548 11801539 b413c3 vmlinux32.after

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/21c417488b70b7629dae316539fb7bb8bdef4fdd.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Help GCC realise __flush_dcache_icache() flushes single pages

'And' the given page address with PAGE_MASK to help GCC.

With the patch:

00000024 <__flush_dcache_icache>:
24: 54 63 00 26 rlwinm r3,r3,0,0,19
28: 39 40 00 40 li r10,64
2c: 7c 69 1b 78 mr r9,r3
30: 7d 49 03 a6 mtctr r10
34: 7c 00 48 6c dcbst 0,r9
38: 39 29 00 20 addi r9,r9,32
3c: 7c 00 48 6c dcbst 0,r9
40: 39 29 00 20 addi r9,r9,32
44: 42 00 ff f0 bdnz 34 <__flush_dcache_icache+0x10>
48: 7c 00 04 ac hwsync
4c: 39 20 00 40 li r9,64
50: 7d 29 03 a6 mtctr r9
54: 7c 00 1f ac icbi 0,r3
58: 38 63 00 20 addi r3,r3,32
5c: 7c 00 1f ac icbi 0,r3
60: 38 63 00 20 addi r3,r3,32
64: 42 00 ff f0 bdnz 54 <__flush_dcache_icache+0x30>
68: 7c 00 04 ac hwsync
6c: 4c 00 01 2c isync
70: 4e 80 00 20 blr

Without the patch:

00000024 <__flush_dcache_icache>:
24: 54 6a 00 34 rlwinm r10,r3,0,0,26
28: 39 23 10 1f addi r9,r3,4127
2c: 7d 2a 48 50 subf r9,r10,r9
30: 55 29 d9 7f rlwinm. r9,r9,27,5,31
34: 41 82 00 94 beq c8 <__flush_dcache_icache+0xa4>
38: 71 28 00 01 andi. r8,r9,1
3c: 38 c9 ff ff addi r6,r9,-1
40: 7d 48 53 78 mr r8,r10
44: 7d 27 4b 78 mr r7,r9
48: 40 82 00 6c bne b4 <__flush_dcache_icache+0x90>
4c: 54 e7 f8 7e rlwinm r7,r7,31,1,31
50: 7c e9 03 a6 mtctr r7
54: 7c 00 40 6c dcbst 0,r8
58: 39 08 00 20 addi r8,r8,32
5c: 7c 00 40 6c dcbst 0,r8
60: 39 08 00 20 addi r8,r8,32
64: 42 00 ff f0 bdnz 54 <__flush_dcache_icache+0x30>
68: 7c 00 04 ac hwsync
6c: 71 28 00 01 andi. r8,r9,1
70: 39 09 ff ff addi r8,r9,-1
74: 40 82 00 2c bne a0 <__flush_dcache_icache+0x7c>
78: 55 29 f8 7e rlwinm r9,r9,31,1,31
7c: 7d 29 03 a6 mtctr r9
80: 7c 00 57 ac icbi 0,r10
84: 39 4a 00 20 addi r10,r10,32
88: 7c 00 57 ac icbi 0,r10
8c: 39 4a 00 20 addi r10,r10,32
90: 42 00 ff f0 bdnz 80 <__flush_dcache_icache+0x5c>
94: 7c 00 04 ac hwsync
98: 4c 00 01 2c isync
9c: 4e 80 00 20 blr
a0: 7c 00 57 ac icbi 0,r10
a4: 2c 08 00 00 cmpwi r8,0
a8: 39 4a 00 20 addi r10,r10,32
ac: 40 82 ff cc bne 78 <__flush_dcache_icache+0x54>
b0: 4b ff ff e4 b 94 <__flush_dcache_icache+0x70>
b4: 7c 00 50 6c dcbst 0,r10
b8: 2c 06 00 00 cmpwi r6,0
bc: 39 0a 00 20 addi r8,r10,32
c0: 40 82 ff 8c bne 4c <__flush_dcache_icache+0x28>
c4: 4b ff ff a4 b 68 <__flush_dcache_icache+0x44>
c8: 7c 00 04 ac hwsync
cc: 7c 00 04 ac hwsync
d0: 4c 00 01 2c isync
d4: 4e 80 00 20 blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/23030822ea5cd0a122948b10226abe56602dc027.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: flush_dcache_icache_phys() is for HIGHMEM pages only

__flush_dcache_icache() is usable for non HIGHMEM pages on
every platform.

It is only for HIGHMEM pages that BOOKE needs kmap() and
BOOK3S needs flush_dcache_icache_phys().

So make flush_dcache_icache_phys() dependent on CONFIG_HIGHMEM and
call it only when it is a HIGHMEM page.

We could make flush_dcache_icache_phys() available at all time,
but as it is declared NOKPROBE_SYMBOL(), GCC doesn't optimise
it out when it is not used.

So define a stub for !CONFIG_HIGHMEM in order to remove the #ifdef in
flush_dcache_icache_page() and use IS_ENABLED() instead.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/79ed5d7914f497cd5fcd681ca2f4d50a91719455.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Optimise flush_dcache_icache_hugepage()

flush_dcache_icache_hugepage() is a static function, with
only one caller. That caller calls it when PageCompound() is true,
so bugging on !PageCompound() is useless if we can trust the
compiler a little. Remove the BUG_ON(!PageCompound()).

The number of elements of a page won't change over time, but
GCC doesn't know about it, so it gets the value at every iteration.

To avoid that, call compound_nr() outside the loop and save it in
a local variable.

Whether the page is a HIGHMEM page or not doesn't change over time.

But GCC doesn't know it so it does the test on every iteration.

Do the test outside the loop.

When the page is not a HIGHMEM page, page_address() will fallback on
lowmem_page_address(), so call lowmem_page_address() directly and
don't suffer the call to page_address() on every iteration.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ab03712b70105fccfceef095aa03007de9295a40.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Call flush_coherent_icache() at higher level

flush_coherent_icache() doesn't need the address anymore,
so it can be called immediately when entering the public
functions and doesn't need to be disseminated among
lower level functions.

And use page_to_phys() instead of open coding the calculation
of phys address to call flush_dcache_icache_phys().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5f063986e325d2efdd404b8f8c5f4bcbd4eb11a6.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Remove address argument to flush_coherent_icache()

flush_coherent_icache() can use any valid address as mentionned
by the comment.

Use PAGE_OFFSET as base address. This allows removing the
user access stuff.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/742b6360ae4f344a1c6ecfadcf3b6645f443fa7a.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Declare __flush_dcache_icache() static

__flush_dcache_icache() is only used in mem.c.

Move it before the functions that use it and declare it static.

And also fix the name of the parameter in the comment.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3fa903eb5a10b2bc7d99a8c559ffdaa05452d8e0.1617895813.git.christophe.leroy@csgroup.eu

powerpc/mem: Move cache flushing functions into mm/cacheflush.c

Cache flushing functions are in the middle of completely
unrelated stuff in mm/mem.c

Create a dedicated mm/cacheflush.c for those functions.

Also cleanup the list of included headers.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7bf6f1600acad146e541a4e220940062f2e5b03d.1617895813.git.christophe.leroy@csgroup.eu