diff options
| author | Paul Mundt <lethal@linux-sh.org> | 2006-11-27 12:06:26 +0900 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2006-12-06 10:45:39 +0900 |
| commit | 510c72ad2dd4e05e6908755f51ac89482c6eb987 (patch) | |
| tree | fa2e9e9a674e38dd523d937329627560f0bd6b64 /arch/sh/kernel/cpu/sh3 | |
| parent | 1dc41e58a553e612e3d0349bb60eef08f9462bde (diff) | |
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>
Diffstat (limited to 'arch/sh/kernel/cpu/sh3')
| -rw-r--r-- | arch/sh/kernel/cpu/sh3/entry.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S index 5de99b49873..7ba3dcbe750 100644 --- a/arch/sh/kernel/cpu/sh3/entry.S +++ b/arch/sh/kernel/cpu/sh3/entry.S @@ -335,7 +335,7 @@ general_exception: /* This code makes some assumptions to improve performance. * Make sure they are stil true. */ #if PTRS_PER_PGD != PTRS_PER_PTE -#error PDG and PTE sizes don't match +#error PGD and PTE sizes don't match #endif /* gas doesn't flag impossible values for mov #immediate as an error */ @@ -547,8 +547,9 @@ ENTRY(handle_exception) bt/s 1f ! It's a kernel to kernel transition. mov r15, k0 ! save original stack to k0 /* User space to kernel */ - mov #(THREAD_SIZE >> 8), k1 + mov #(THREAD_SIZE >> 10), k1 shll8 k1 ! k1 := THREAD_SIZE + shll2 k1 add current, k1 mov k1, r15 ! change to kernel stack ! |