linux-stable.git/arch/mips/kernel/setup.c, branch linux-5.15.y

mips: Fix incorrect max_low_pfn adjustment

2024-01-25T22:52:50+00:00

[ Upstream commit 0f5cc249ff73552d3bd864e62f85841dafaa107d ]

max_low_pfn variable is incorrectly adjusted if the kernel is built with
high memory support and the later is detected in a running system, so the
memory which actually can be directly mapped is getting into the highmem
zone. See the ZONE_NORMAL range on my MIPS32r5 system:

> Zone ranges:
>   DMA      [mem 0x0000000000000000-0x0000000000ffffff]
>   Normal   [mem 0x0000000001000000-0x0000000007ffffff]
>   HighMem  [mem 0x0000000008000000-0x000000020fffffff]

while the zones are supposed to look as follows:

> Zone ranges:
>   DMA      [mem 0x0000000000000000-0x0000000000ffffff]
>   Normal   [mem 0x0000000001000000-0x000000001fffffff]
>   HighMem  [mem 0x0000000020000000-0x000000020fffffff]

Even though the physical memory within the range [0x08000000;0x20000000]
belongs to MMIO on our system, we don't really want it to be considered as
high memory since on MIPS32 that range still can be directly mapped.

Note there might be other problems caused by the max_low_pfn variable
misconfiguration. For instance high_memory variable is initialize with
virtual address corresponding to the max_low_pfn PFN, and by design it
must define the upper bound on direct map memory, then end of the normal
zone. That in its turn potentially may cause problems in accessing the
memory by means of the /dev/mem and /dev/kmem devices.

Let's fix the discovered misconfiguration then. It turns out the commit
a94e4f24ec83 ("MIPS: init: Drop boot_mem_map") didn't introduce the
max_low_pfn adjustment quite correct. If the kernel is built with high
memory support and the system is equipped with high memory, the
max_low_pfn variable will need to be initialized with PFN of the most
upper directly reachable memory address so the zone normal would be
correctly setup. On MIPS that PFN corresponds to PFN_DOWN(HIGHMEM_START).
If the system is built with no high memory support and one is detected in
the running system, we'll just need to adjust the max_pfn variable to
discard the found high memory from the system and leave the max_low_pfn as
is, since the later will be less than PFN_DOWN(HIGHMEM_START) anyway by
design of the for_each_memblock() loop performed a bit early in the
bootmem_init() method.

Fixes: a94e4f24ec83 ("MIPS: init: Drop boot_mem_map")
Signed-off-by: Serge Semin 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

mips/cpu: Switch to arch_cpu_finalize_init()

2023-08-08T17:58:30+00:00

commit 7f066a22fe353a827a402ee2835e81f045b1574d upstream

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Link: https://lore.kernel.org/r/20230613224545.312438573@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

mips: Move initrd_start check after initrd address sanitisation.

2023-06-21T13:59:13+00:00

[ Upstream commit 4897a898a216058dec55e5e5902534e6e224fcdf ]

PAGE_OFFSET is technically a virtual address so when checking the value of
initrd_start against it we should make sure that it has been sanitised from
the values passed by the bootloader. Without this change, even with a bootloader
that passes correct addresses for an initrd, we are failing to load it on MT7621
boards, for example.

Signed-off-by: Liviu Dudau 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

mips: setup: fix setnocoherentio() boolean setting

2022-03-08T18:12:48+00:00

commit 1e6ae0e46e32749b130f1823da30cea9aa2a59a0 upstream.

Correct a typo/pasto: setnocoherentio() should set
dma_default_coherent to false, not true.

Fixes: 14ac09a65e19 ("MIPS: refactor the runtime coherent vs noncoherent DMA indicators")
Signed-off-by: Randy Dunlap 
Cc: Christoph Hellwig 
Cc: Thomas Bogendoerfer 
Cc: linux-mips@vger.kernel.org
Reviewed-by: Christoph Hellwig 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

memblock: make memblock_find_in_range method private

2021-09-03T16:58:17+00:00

There are a lot of uses of memblock_find_in_range() along with
memblock_reserve() from the times memblock allocation APIs did not exist.

memblock_find_in_range() is the very core of memblock allocations, so any
future changes to its internal behaviour would mandate updates of all the
users outside memblock.

Replace the calls to memblock_find_in_range() with an equivalent calls to
memblock_phys_alloc() and memblock_phys_alloc_range() and make
memblock_find_in_range() private method of memblock.

This simplifies the callers, ensures that (unlikely) errors in
memblock_reserve() are handled and improves maintainability of
memblock_find_in_range().

Link: https://lkml.kernel.org/r/20210816122622.30279-1-rppt@kernel.org
Signed-off-by: Mike Rapoport 
Reviewed-by: Catalin Marinas 		[arm64]
Acked-by: Kirill A. Shutemov 
Acked-by: Rafael J. Wysocki 	[ACPI]
Acked-by: Russell King (Oracle) 
Acked-by: Nick Kossifidis 			[riscv]
Tested-by: Guenter Roeck 
Acked-by: Rob Herring 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MIPS: kernel: setup.c: fix compilation error

2021-03-30T12:51:23+00:00

With ath79_defconfig enabling CONFIG_MIPS_ELF_APPENDED_DTB gives a
compilation error. This patch fixes it.

Build log:
...
  CC      kernel/locking/percpu-rwsem.o
../arch/mips/kernel/setup.c:46:39: error: conflicting types for
'__appended_dtb'
 const char __section(".appended_dtb") __appended_dtb[0x100000];
                                       ^~~~~~~~~~~~~~
In file included from ../arch/mips/kernel/setup.c:34:
../arch/mips/include/asm/bootinfo.h:118:13: note: previous declaration
of '__appended_dtb' was here
 extern char __appended_dtb[];
             ^~~~~~~~~~~~~~
  CC      fs/attr.o
make[4]: *** [../scripts/Makefile.build:271: arch/mips/kernel/setup.o]
 Error 1
...

Root cause seems to be:
Fixes: b83ba0b9df56 ("MIPS: of: Introduce helper function to get DTB")

Signed-off-by: Mauri Sandberg 
Reviewed-by: Thomas Bogendoerfer 
Cc: trivial@kernel.org
Signed-off-by: Thomas Bogendoerfer

MIPS: Use common way to parse elfcorehdr

2021-02-13T08:57:22+00:00

"elfcorehdr" can be parsed at kernel/crash_dump.c

Signed-off-by: Jinyang He 
Signed-off-by: Thomas Bogendoerfer

MIPS: remove CONFIG_DMA_MAYBE_COHERENT

2021-02-13T08:51:45+00:00

CONFIG_DMA_MAYBE_COHERENT just guards two early init options now.  Just
enable them unconditionally for CONFIG_DMA_NONCOHERENT.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Thomas Bogendoerfer

driver core: lift dma_default_coherent into common code

2021-02-13T08:51:45+00:00

Lift the dma_default_coherent variable from the mips architecture code
to the driver core.  This allows an architecture to sdefault all device
to be DMA coherent at run time, even if the kernel is build with support
for DMA noncoherent device.  By allowing device_initialize to set the
->dma_coherent field to this default the amount of arch hooks required
for this behavior can be greatly reduced.

Signed-off-by: Christoph Hellwig 
Acked-by: Greg Kroah-Hartman 
Signed-off-by: Thomas Bogendoerfer

MIPS: refactor the runtime coherent vs noncoherent DMA indicators

2021-02-13T08:51:45+00:00

Replace the global coherentio enum, and the hw_coherentio (fake) boolean
variables with a single boolean dma_default_coherent flag.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Thomas Bogendoerfer