All of the cached/uncached mapping setup is duplicated for each size, and
also misses out on the 16MB case. Rather than duplicating the same iter
code for that we just consolidate it in to a helper macro that builds an
iter for each size. The 16MB case is then trivially bolted on at the end.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
More and more boards are going to start shipping that boot with the MMU
in 32BIT mode by default. Previously we relied on the bootloader to
setup PMB mappings for use by the kernel but we also need to cater for
boards whose bootloaders don't set them up.
If CONFIG_PMB_LEGACY is not enabled we have full control over our PMB
mappings and can compress our address space. Usually, the distance
between the the cached and uncached mappings of RAM is always 512MB,
however we can compress the distance to be the amount of RAM on the
board.
pmb_init() now becomes much simpler. It no longer has to calculate any
mappings, it just has to synchronise the software PMB table with the
hardware.
Tested on SDK7786 and SH7785LCR.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This introduces some much overdue chainsawing of the fixed PMB support.
fixed PMB was introduced initially to work around the fact that dynamic
PMB mode was relatively broken, though they were never intended to
converge. The main areas where there are differences are whether the
system is booted in 29-bit mode or 32-bit mode, and whether legacy
mappings are to be preserved. Any system booting in true 32-bit mode will
not care about legacy mappings, so these are roughly decoupled.
Regardless of the entry point, PMB and 32BIT are directly related as far
as the kernel is concerned, so we also switch back to having one select
the other.
With legacy mappings iterated through and applied in the initialization
path it's now possible to finally merge the two implementations and
permit dynamic remapping overtop of remaining entries regardless of
whether boot mappings are crafted by hand or inherited from the boot
loader.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
CONFIG_PMB will eventually allow the MMU to be switched between 29-bit
and 32-bit mode dynamically at runtime.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This has the consequence of changing the section name use for head
code from ".text.head" to ".head.text". Since this commit changes all
users in the architecture, this change should be harmless.
Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This enables the same functionality that sh64 has for sh32. When running
on simulated hardware or via remote memory via the debug interface,
memory is gauranteed to be zero on boot already, and skipping the zeroing
of BSS has measurable boot time benefits.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
When using initramfs on systems that don't explicitly clear LOADER_TYPE,
unpack_to_rootfs() tramples tramples the range with the defaults taken
out of .empty_zero_page. This causes kernels with valid initramfs images
to bail out with crc or gzip magic mismatch errors after the second
unpack takes place on certain platform configurations.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Shoves a magic word in to the empty_zero_page section for the
bootloader to work out whether to start the kernel in 29-bit
or 32-bit mode.
[ Renesas CPUs already take care of the initial PMB mappings entirely
in hardware and decide on 29-bit/32-bit physical depending on which
pin powered up the CPU, so this is mostly for ST parts. -- PFM ].
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There was a very preliminary bunch of SMP code scattered around for the
SH7604 microcontrollers from way back when, and it has mostly suffered
bitrot since then. With the tree already having been slowly getting
prepped for SMP, this plugs in most of the remaining platform-independent
bits.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Follow Al Viro's m68k change from l-k:
i.e. tell modpost that entry point code (that has to be outside
of .init.text for external reasons) is OK to refer to .init.*
Shuts up some section mismatch warnings from modpost.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
There were a number of places that made evil PAGE_SIZE == 4k
assumptions that ended up breaking when trying to play with
8k and 64k page sizes, this fixes those up.
The most significant change is the way we load THREAD_SIZE,
previously this was done via:
mov #(THREAD_SIZE >> 8), reg
shll8 reg
to avoid a memory access and allow the immediate load. With
a 64k PAGE_SIZE, we're out of range for the immediate load
size without resorting to special instructions available in
later ISAs (movi20s and so on). The "workaround" for this is
to bump up the shift to 10 and insert a shll2, which gives a
bit more flexibility while still being much cheaper than a
memory access.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This splits out common bits from the existing exception handler for
use between SH-2/SH-2A and SH-3/4, and adds support for the SH-2/2A
exceptions.
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This enables support for 4K stacks on SH.
Currently this depends on DEBUG_KERNEL, but likely all boards
will switch to this as the default in the future.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
A synco is needed before we jump to start_kernel().
While we're at it, also move the sh_cpu_init() jump until after
we've zeroed BSS, as this has caused some undesirable results
in sh_cpu_init().
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
We had a special .stack section in the ld script that
was being used to position r15 initially. This is
nonsensical, as we can just use a THREAD_SIZE offset
from the init_thread_union instead (as every other arch
does).
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Paul Mundt