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>
diff --git a/arch/sh/kernel/head.S b/arch/sh/kernel/head.S
index b5ff232..6aca4bc 100644
--- a/arch/sh/kernel/head.S
+++ b/arch/sh/kernel/head.S
@@ -33,7 +33,7 @@
.long 0x00360000 /* INITRD_START */
.long 0x000a0000 /* INITRD_SIZE */
.long 0
- .balign 4096,0,4096
+ .balign PAGE_SIZE,0,PAGE_SIZE
.text
/*
@@ -70,8 +70,9 @@
!
mov.l 2f, r0
mov r0, r15 ! Set initial r15 (stack pointer)
- mov #(THREAD_SIZE >> 8), r1
+ mov #(THREAD_SIZE >> 10), r1
shll8 r1 ! r1 = THREAD_SIZE
+ shll2 r1
sub r1, r0 !
#ifdef CONFIG_CPU_HAS_SR_RB
ldc r0, r7_bank ! ... and initial thread_info