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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/sh64/lib/page_clear.S | |
download | talos-obmc-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz talos-obmc-linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
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!
Diffstat (limited to 'arch/sh64/lib/page_clear.S')
-rw-r--r-- | arch/sh64/lib/page_clear.S | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/sh64/lib/page_clear.S b/arch/sh64/lib/page_clear.S new file mode 100644 index 000000000000..ac0111d669a3 --- /dev/null +++ b/arch/sh64/lib/page_clear.S @@ -0,0 +1,54 @@ +/* + Copyright 2003 Richard Curnow, SuperH (UK) Ltd. + + This file is subject to the terms and conditions of the GNU General Public + License. See the file "COPYING" in the main directory of this archive + for more details. + + Tight version of memset for the case of just clearing a page. It turns out + that having the alloco's spaced out slightly due to the increment/branch + pair causes them to contend less for access to the cache. Similarly, + keeping the stores apart from the allocos causes less contention. => Do two + separate loops. Do multiple stores per loop to amortise the + increment/branch cost a little. + + Parameters: + r2 : source effective address (start of page) + + Always clears 4096 bytes. + + Note : alloco guarded by synco to avoid TAKum03020 erratum + +*/ + + .section .text..SHmedia32,"ax" + .little + + .balign 8 + .global sh64_page_clear +sh64_page_clear: + pta/l 1f, tr1 + pta/l 2f, tr2 + ptabs/l r18, tr0 + + movi 4096, r7 + add r2, r7, r7 + add r2, r63, r6 +1: + alloco r6, 0 + synco ! TAKum03020 + addi r6, 32, r6 + bgt/l r7, r6, tr1 + + add r2, r63, r6 +2: + st.q r6, 0, r63 + st.q r6, 8, r63 + st.q r6, 16, r63 + st.q r6, 24, r63 + addi r6, 32, r6 + bgt/l r7, r6, tr2 + + blink tr0, r63 + + |