arch: define CONFIG_PAGE_SIZE_*KB on all architectures

Most architectures only support a single hardcoded page size. In order
to ensure that each one of these sets the corresponding Kconfig symbols,
change over the PAGE_SHIFT definition to the common one and allow
only the hardware page size to be selected.

Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

mm, arch: add generic implementation of pfn_valid() for FLATMEM

Every architecture that supports FLATMEM memory model defines its own
version of pfn_valid() that essentially compares a pfn to max_mapnr.

Use mips/powerpc version implemented as static inline as a generic
implementation of pfn_valid() and drop its per-architecture definitions.

[rppt@kernel.org: fix the generic pfn_valid()]
Link: https://lkml.kernel.org/r/Y9lg7R1Yd931C+y5@kernel.org
Link: https://lkml.kernel.org/r/20230129124235.209895-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guo Ren <guoren@kernel.org> [csky]
Acked-by: Huacai Chen <chenhuacai@loongson.cn> [LoongArch]
Acked-by: Stafford Horne <shorne@gmail.com> [OpenRISC]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

um: Replace to_phys() and to_virt() with less generic function names

to_virt() and to_phys() are very generic and may be defined by drivers.
As it turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
did exactly that. This results in build errors such as the following
when trying to build um:allmodconfig.

drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’:
./arch/um/include/asm/page.h:105:20: error:
too few arguments to function ‘to_phys’
105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt))
| ^~~~~~~

Use less generic function names for the um specific to_phys() and to_virt()
functions to fix the problem and to avoid similar problems in the future.

Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: Replace to_phys() and to_virt() with less generic function names

The UML function names to_virt() and to_phys() are exposed by UML
headers, and are very generic and may be defined by drivers. As it
turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
did exactly that.

This results in build errors such as the following when trying to build
um:allmodconfig:

drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’:
./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’
105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt))
| ^~~~~~~

Use less generic function names for the um specific to_phys() and
to_virt() functions to fix the problem and to avoid similar problems in
the future.

Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: Add SPDX headers for files in arch/um/include

Convert files to use SPDX header. All files are licensed under the GPLv2.

Signed-off-by: Alex Dewar <alex.dewar@gmx.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: asm/page.h: remove the pte_high member from struct pte_t

Commit 16da306849d0 ("um: kill pfn_t") introduced a compile warning for
defconfig (SUBARCH=i386):

arch/um/kernel/skas/mmu.c:38:206:
warning: right shift count >= width of type [-Wshift-count-overflow]

Aforementioned patch changes the definition of the phys_to_pfn() macro
from

((pfn_t) ((p) >> PAGE_SHIFT))

to

((p) >> PAGE_SHIFT)

This effectively changes the phys_to_pfn() expansion's type from
unsigned long long to unsigned long.

Through the callchain init_stub_pte() => mk_pte(), the expansion of
phys_to_pfn() is (indirectly) fed into the 'phys' argument of the
pte_set_val(pte, phys, prot) macro, eventually leading to

(pte).pte_high = (phys) >> 32;

This results in the warning from above.

Since UML only deals with 32 bit addresses, the upper 32 bits from
'phys' used to be always zero anyway. Also, all page protection flags
defined by UML don't use any bits beyond bit 9. Since the contents of a
PTE are defined within architecture scope only, the ->pte_high member
can be safely removed.

Remove the ->pte_high member from struct pte_t.
Rename ->pte_low to ->pte.
Adapt the pte helper macros in arch/um/include/asm/page.h.

Noteworthy is the pte_copy() macro where a smp_wmb() gets dropped. This
write barrier doesn't seem to be paired with any read barrier though and
thus, was useless anyway.

Fixes: 16da306849d0 ("um: kill pfn_t")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: kill pfn_t

The core has developed a need for a "pfn_t" type [1]. Convert the usage
of pfn_t by usermode-linux to an unsigned long, and update pfn_to_phys()
to drop its expectation of a typed pfn.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-September/002199.html

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit
UML, and x86_32 have their own code just to disable it. arm, 32-bit UML,
and x86_64 have gate areas, but they have their own implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's now
possible to inline the gate_area functions in the default case.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
Acked-by: Richard Weinberger <richard@nod.at> [for um]
Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

um: get rid of pointless include "..." where include <...> will do

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

um: take vm-flags.h to sys-*/asm

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

asm-generic: rename page.h and uaccess.h

The current asm-generic/page.h only contains the get_order
function, and asm-generic/uaccess.h only implements
unaligned accesses. This renames the file to getorder.h
and uaccess-unaligned.h to make room for new page.h
and uaccess.h file that will be usable by all simple
(e.g. nommu) architectures.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

x86, um: take vm-flags.h to sysdep

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

x86, um: initial part of asm-um move

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>