linux.git/arch/um/kernel/physmem.c, branch v7.0

um: Remove file-based iomem emulation support

2025-10-27T15:37:12+00:00

The file-based iomem emulation was introduced to support writing
paravirtualized drivers based on emulated iomem regions. However,
the only driver that makes use of it is an example driver called
mmapper, which was written over two decades ago.

We now have several modern device emulation mechanisms, such as
vhost-user-based virtio-uml. Remove the file-based iomem emulation
support to reduce the maintenance burden.

Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20251027054519.1996090-5-tiwei.bie@linux.dev
Signed-off-by: Johannes Berg

arch, mm: set max_mapnr when allocating memory map for FLATMEM

2025-03-18T05:06:52+00:00

max_mapnr is essentially the size of the memory map for systems that use
FLATMEM. There is no reason to calculate it in each and every architecture
when it's anyway calculated in alloc_node_mem_map().

Drop setting of max_mapnr from architecture code and set it once in
alloc_node_mem_map().

While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so
there won't be two copies for MMU and !MMU variants.

Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) 
Acked-by: Dave Hansen 	[x86]
Tested-by: Mark Brown 
Cc: Alexander Gordeev 
Cc: Andreas Larsson 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Arnd Bergmann 
Cc: Borislav Betkov 
Cc: Catalin Marinas 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Gerald Schaefer 
Cc: Guo Ren (csky) 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiaxun Yang 
Cc: Johannes Berg 
Cc: John Paul Adrian Glaubitz 
Cc: Madhavan Srinivasan 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michael Ellerman 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Russel King 
Cc: Stafford Horne 
Cc: Thomas Bogendoerfer 
Cc: Thomas Gleinxer 
Cc: Vasily Gorbik 
Cc: Vineet Gupta 
Cc: Will Deacon 
Signed-off-by: Andrew Morton

um: remove file sync for stub data

2024-11-07T16:36:30+00:00

There is no need to sync the stub code to "disk" for the other process
to see the correct memory. Drop the fsync there and remove the helper
function.

Signed-off-by: Benjamin Berg 
Link: https://patch.msgid.link/20241103150506.1367695-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg

um: Do not propagate mem parameter to kernel

2024-10-23T07:52:48+00:00

This parameter is UML specific and is unknown to kernel. It should not
be propagated to kernel, otherwise it will be passed to user space as
an environment option by kernel with a warning like:

Unknown kernel command line parameters "mem=2G", will be passed to user space.

Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20241011040441.1586345-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg

um: Fix the definition for physmem_size

2024-10-10T10:02:13+00:00

Currently physmem_size is defined as long long but declared locally
as unsigned long long before using it in separate .c files. Make them
match by defining physmem_size as unsigned long long and also move
the declaration to a common header to allow the compiler to check it.

Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20240916045950.508910-5-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg

um: Remove highmem leftovers

2024-10-10T10:02:13+00:00

Highmem was only supported on UML/i386. And the support has been
removed by commit a98a6d864d3b ("um: Remove broken highmem support").
Remove the leftovers and stop UML from trying to setup highmem when
the sum of physmem_size and iomem_size exceeds max_physmem.

Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20240916045950.508910-4-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg

um: Fix potential integer overflow during physmem setup

2024-10-10T10:02:13+00:00

This issue happens when the real map size is greater than LONG_MAX,
which can be easily triggered on UML/i386.

Fixes: fe205bdd1321 ("um: Print minimum physical memory requirement")
Signed-off-by: Tiwei Bie 
Link: https://patch.msgid.link/20240916045950.508910-3-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg

um: Move declarations to proper headers

2024-04-22T19:58:48+00:00

This will address below -Wmissing-prototypes warnings:

arch/um/kernel/initrd.c:18:12: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:15:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:101:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:153:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/tls_32.c:184:5: warning: no previous prototype for ‘arch_switch_tls’ [-Wmissing-prototypes]

Signed-off-by: Tiwei Bie 
Signed-off-by: Richard Weinberger

um: Fix comment typo

2022-09-19T21:05:46+00:00

The double `in' is duplicated in line 172, remove one.

Signed-off-by: Jason Wang 
Signed-off-by: Richard Weinberger

um: Add SPDX headers to files in arch/um/kernel/

2019-09-15T19:37:17+00:00

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

Signed-off-by: Alex Dewar 
Signed-off-by: Richard Weinberger