linux-toradex.git/arch/mips/kernel/setup.c, branch v4.19

MIPS: Fix CONFIG_CMDLINE handling

2018-09-28T19:09:04+00:00

Commit 8ce355cf2e38 ("MIPS: Setup boot_command_line before
plat_mem_setup") fixed a problem for systems which have
CONFIG_CMDLINE_BOOL=y & use a DT with a chosen node that has either no
bootargs property or an empty one. In this configuration
early_init_dt_scan_chosen() copies CONFIG_CMDLINE into
boot_command_line, but the MIPS code doesn't know this so it appends
CONFIG_CMDLINE (via builtin_cmdline) to boot_command_line again. The
result is that boot_command_line contains the arguments from
CONFIG_CMDLINE twice.

That commit took the approach of simply setting up boot_command_line
from the MIPS code before early_init_dt_scan_chosen() runs, causing it
not to copy CONFIG_CMDLINE to boot_command_line if a chosen node with no
bootargs property is found.

Unfortunately this is problematic for systems which do have a non-empty
bootargs property & CONFIG_CMDLINE_BOOL=y. There
early_init_dt_scan_chosen() will overwrite boot_command_line with the
arguments from DT, which means we lose those from CONFIG_CMDLINE
entirely. This breaks CONFIG_MIPS_CMDLINE_DTB_EXTEND. If we have
CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER or
CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND selected and the DT has a bootargs
property which we should ignore, it will instead be honoured breaking
those configurations too.

Fix this by reverting commit 8ce355cf2e38 ("MIPS: Setup
boot_command_line before plat_mem_setup") to restore the former
behaviour, and fixing the CONFIG_CMDLINE duplication issue by
initializing boot_command_line to a non-empty string that
early_init_dt_scan_chosen() will not overwrite with CONFIG_CMDLINE.

This is a little ugly, but cleanup in this area is on its way. In the
meantime this is at least easy to backport & contains the ugliness
within arch/mips/.

Signed-off-by: Paul Burton 
Fixes: 8ce355cf2e38 ("MIPS: Setup boot_command_line before plat_mem_setup")
References: https://patchwork.linux-mips.org/patch/18804/
Patchwork: https://patchwork.linux-mips.org/patch/20813/
Cc: Frank Rowand 
Cc: Jaedon Shin 
Cc: Mathieu Malaterre 
Cc: Rob Herring 
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.16+

MIPS: Allow auto-dection of ARCH_PFN_OFFSET & PHYS_OFFSET

2018-07-30T17:27:32+00:00

On systems where physical memory begins at a non-zero address, defining
PHYS_OFFSET (which influences ARCH_PFN_OFFSET) can save us time & memory
by avoiding book-keeping for pages from address zero to the start of
memory.

Some MIPS platforms already make use of this, but with the definition of
PHYS_OFFSET being compile-time constant it hasn't been possible to
enable this optimization for a kernel which may run on systems with
varying physical memory base addresses.

Introduce a new Kconfig option CONFIG_MIPS_AUTO_PFN_OFFSET which, when
enabled, makes ARCH_PFN_OFFSET a variable & detects it from the boot
memory map (which for example may have been populated from DT). The
relationship with PHYS_OFFSET is reversed, with PHYS_OFFSET now being
based on ARCH_PFN_OFFSET. This is because ARCH_PFN_OFFSET is used far
more often, so avoiding the need for runtime calculation gives us a
smaller impact on kernel text size (0.1% rather than 0.15% for
64r6el_defconfig).

Signed-off-by: Paul Burton 
Suggested-by: Vladimir Kondratiev 
Patchwork: https://patchwork.linux-mips.org/patch/20048/
Cc: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org

MIPS: move coherentio setup to setup.c

2018-06-24T16:26:04+00:00

We want to be able to use it even when not building dma-default.c
in the near future.

Signed-off-by: Christoph Hellwig 
Patchwork: https://patchwork.linux-mips.org/patch/19543/
Signed-off-by: Paul Burton 
Cc: Florian Fainelli 
Cc: David Daney 
Cc: Kevin Cernekee 
Cc: Jiaxun Yang 
Cc: Tom Bogendoerfer 
Cc: Huacai Chen 
Cc: iommu@lists.linux-foundation.org
Cc: linux-mips@linux-mips.org

treewide: use PHYS_ADDR_MAX to avoid type casting ULLONG_MAX

2018-06-14T22:55:25+00:00

With PHYS_ADDR_MAX there is now a type safe variant for all bits set.
Make use of it.

Patch created using a semantic patch as follows:

// 
@@
typedef phys_addr_t;
@@
-(phys_addr_t)ULLONG_MAX
+PHYS_ADDR_MAX
// 

Link: http://lkml.kernel.org/r/20180419214204.19322-1-stefan@agner.ch
Signed-off-by: Stefan Agner 
Reviewed-by: Andrew Morton 
Acked-by: Ard Biesheuvel 
Acked-by: Catalin Marinas 	[arm64]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MIPS: Remove a warning when PHYS_OFFSET is 0x0

2018-02-19T10:55:38+00:00

Rewrite the comparison in `else if` statement, case where `min_low_pfn >
ARCH_PFN_OFFSET` has already been checked in the first `if` statement:

  if (min_low_pfn > ARCH_PFN_OFFSET) {

Fix non-fatal warning during compilation using W=1:

arch/mips/kernel/setup.c: In function ‘bootmem_init’:
arch/mips/kernel/setup.c:461:25: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  } else if (min_low_pfn < ARCH_PFN_OFFSET) {
                         ^

Signed-off-by: Mathieu Malaterre 
Reviewed-by: James Hogan 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18176/
Signed-off-by: James Hogan

MIPS: Make declaration for function `memory_region_available` static

2018-02-19T10:55:38+00:00

Fix non-fatal warning during compilation using W=1:

arch/mips/kernel/setup.c:158:13: warning: no previous prototype for ‘memory_region_available’ [-Wmissing-prototypes]
 bool __init memory_region_available(phys_addr_t start, phys_addr_t size)
             ^~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Mathieu Malaterre 
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18175/
[jhogan@kernel.org: tweak whitespace]
Signed-off-by: James Hogan

MIPS: Fix incorrect mem=X@Y handling

2018-02-13T13:14:41+00:00

Commit 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing") added a
fix to ensure that the memory range between PHYS_OFFSET and low memory
address specified by mem= cmdline argument is not later processed by
free_all_bootmem.  This change was incorrect for systems where the
commandline specifies more than 1 mem argument, as it will cause all
memory between PHYS_OFFSET and each of the memory offsets to be marked
as reserved, which results in parts of the RAM marked as reserved
(Creator CI20's u-boot has a default commandline argument 'mem=256M@0x0
mem=768M@0x30000000').

Change the behaviour to ensure that only the range between PHYS_OFFSET
and the lowest start address of the memories is marked as protected.

This change also ensures that the range is marked protected even if it's
only defined through the devicetree and not only via commandline
arguments.

Reported-by: Mathieu Malaterre 
Signed-off-by: Marcin Nowakowski 
Fixes: 73fbc1eba7ff ("MIPS: fix mem=X@Y commandline processing")
Cc: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Cc:  # v4.11+
Tested-by: Mathieu Malaterre 
Patchwork: https://patchwork.linux-mips.org/patch/18562/
Signed-off-by: James Hogan

MIPS: Setup boot_command_line before plat_mem_setup

2018-01-18T22:06:07+00:00

Platforms using DT will typically call __dt_setup_arch from
plat_mem_setup. This in turn calls early_init_dt_scan. When
CONFIG_CMDLINE is set, this leads to its value being copied into
boot_command_line by early_init_dt_scan_chosen. If this happens before
the code setting up boot_command_line in arch_mem_init runs, that code
will go on to append CONFIG_CMDLINE (via builtin_cmdline) to
boot_command_line again, duplicating it. For some command line
parameters (eg. earlycon) this can be a problem. Set up
boot_command_line before early_init_dt_scan_chosen gets called such that
it will not write CONFIG_CMDLINE in this scenario & the arguments aren't
duplicated.

Signed-off-by: Paul Burton 
Acked-by: Mathieu Malaterre 
Cc: Ralf Baechle 
Cc: Maarten ter Huurne 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18483/
Signed-off-by: James Hogan

MIPS: Add iomem resource for kernel bss section.

2017-11-13T17:40:49+00:00

The kexec/kdump tools need to know where the .bss is so it can be
included in the core dump.  This allows vmcore-dmesg to have access to
the dmesg buffers of the crashed kernel as well as allowing the
debugger to examine variables in the bss section.

Add a request for the bss resource in addition to the already
requested code and data sections.

Signed-off-by: David Daney 
Cc: Ralf Baechle 
Cc: Steven J. Hill ,
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17485/
Signed-off-by: James Hogan

MIPS: cmdline: Add support for 'memmap' parameter

2017-06-29T00:42:23+00:00

Implement support for parsing 'memmap' kernel command line parameter.

This patch covers parsing of the following two formats for 'memmap'
parameter values:

  - nn[KMG]@ss[KMG]
  - nn[KMG]$ss[KMG]

  ([KMG] = K M or G (kilo, mega, giga))

These two allowed formats for parameter value are already documented
in file kernel-parameters.txt in Documentation/admin-guide folder.
Some architectures already support them, but Mips did not prior to
this patch.

Excerpt from Documentation/admin-guide/kernel-parameters.txt:

memmap=nn[KMG]@ss[KMG]
    [KNL] Force usage of a specific region of memory.
    Region of memory to be used is from ss to ss+nn.

memmap=nn[KMG]$ss[KMG]
    Mark specific memory as reserved.
    Region of memory to be reserved is from ss to ss+nn.
    Example: Exclude memory from 0x18690000-0x1869ffff
        memmap=64K$0x18690000
        or
        memmap=0x10000$0x18690000

There is no need to update this documentation file with respect to
this patch.

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16508/
Signed-off-by: Ralf Baechle