sh: Fixup various PAGE_SIZE == 4096 assumptions.

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 commit is contained in:
Paul Mundt
2006-11-27 12:06:26 +09:00
parent 1dc41e58a5
commit 510c72ad2d
11 changed files with 37 additions and 45 deletions

View File

@@ -23,8 +23,9 @@
#ifdef CONFIG_HAS_SR_RB
stc r7_bank, \ti
#else
mov #((THREAD_SIZE - 1)>> 8) ^ 0xff, \tmp
mov #((THREAD_SIZE - 1) >> 10) ^ 0xff, \tmp
shll8 \tmp
shll2 \tmp
mov r15, \ti
and \tmp, \ti
#endif