MFC r338537, r338539:
Bump MAX_HWCNT and MAX_EXCNT.

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r306262, r306267, r310021: (needed to avoid conflicts on later merges)

Remove bus_dma_get_range and bus_dma_get_range_nb on armv6. We only need
this on a few earlier arm SoCs.

Restrict where we need to define fdt_fixup_table to just PowerPC and
Marvell.

Add the missing void to function signatures in much of the arm code.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix a copyright glitch before it gets copy-pasted again. I think this must
have started as collateral damage in a global search-replace, then it got
copied around when I cloned a file to begin creating a new file.

Allow us to be told about memory past the first 4GB point, but ignore it.
This allows, for example, UEFI pass a memory map with some ram in this
region, but for us to ignore it. This is the case when running under the
qemu virt machine type.

Sponsored by: ABT Systems Ltd

Add extra checks to make sure the size is valid. We may get an integer
underflow when we have small blocks of memory at the start and end of the
32-bit address range.

While here, only insert mappings pointing at a non-zero amount of memory.

Sponsored by: ABT Systems Ltd

Reword the comment to better describe what I found while researching the
problem that led to this temporary workaround (and also so I can properly
cite the PR in the commit this time).

In general this is intended to be a temporary workaround until we can figure
out why including any ram from the last megabyte of the physical address
space leads to a NULL pointer deref. Debugging that is made trickier by the
fact that I couldn't even get a backtrace in ddb.

PR: 201614

Work around problems that happen when there is ram at the end of the
physical address space.

Use 64-bit math when processing the lists of physical and excluded memory
to generate the phys_avail and dump_avail arrays.

This is a partial fix for the kernel side of the problem mentioned in the
PR. This part handles the cases where comparing start and end addresses of
a block would fail because 32-bit wrap caused the end address to come out
zero if the end of the region is the end of the address space (0xffffffff
with 32-bit vm_paddr_t, but now the code should also work right if we ever
support LPAE with 36-bit addresses).

More work is necessary to make systems with ram at the end of the physical
address space usable, but at least initially it's going to be more like a
workaround than a fix, so this non-hacky part is being committed first.

PR: 201614

Remove trailing whitespace from sys/arm/arm

Update a comment that had drifted out of date with the last changes.

Add the Maxmem global and set it to the highest physical page number plus 1.

When building the lists of available memory, actually honor the exclusion
flags, like the comment says it does.

Pointy hat: ian
Submitted by: Svatopluk Kraus <onwahe@gmail.com>

Add some extra debugging output when DEBUG is defined.

Fix the exclude-region clipping logic for the edge-trim case.

Use vm_paddr_t, not vm_offset_t, when dealing with physical addresses.

Pointed out by: alc

It turns out a global variable is the only straightforward way to
communicate the kernel's physical load address from where it's known in
initarm() into cpu_mp_start() which is called from non-arm code and
takes no parameters.

This adds the global variable and ensures that all the various copies
of initarm() set it. It uses the variable in cpu_mp_start(), eliminating
the last uses of KERNPHYSADDR outside of locore.S (where we can now
calculate it instead of relying on the constant).

Consolidate code related to setting up physical memory configuration into
a new physmem.c file. The new code provides helper routines that can be
used by legacy SoCs and newer FDT-based systems. There are routines to
add one or more regions of physically contiguous ram, and exclude one or
more physically contiguous regions of ram. Ram can be excluded from crash
dumps, from being given over to the vm system for allocation management,
or both. After all the included and excluded regions have been added,
arm_physmem_init_kernel_globals() processes the regions into the global
dump_avail and phys_avail arrays and realmem and physmem variables that
communicate memory configuration to the rest of the kernel.

Convert all existing SoCs to use the new helper code.