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authorLinus Torvalds <torvalds@linux-foundation.org>2008-01-29 08:52:50 +1100
committerLinus Torvalds <torvalds@linux-foundation.org>2008-01-29 08:52:50 +1100
commite189f3495c4e30fc84fc9241096edf3932e23439 (patch)
tree5916c89ace81537a02ae01869386ba6caafdab9c /arch/sh/lib64/clear_page.S
parentf4798748dee00c807a63f5518f08b3df161e0f6d (diff)
parent6582d7b7376aa587d74b08c74457dc28abc1a9fa (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (197 commits) sh: add spi header and r2d platform data V3 sh: update r7780rp interrupt code sh: remove consistent alloc stuff from the machine vector sh: use declared coherent memory for dreamcast pci ethernet adapter sh: declared coherent memory support V2 sh: Add support for SDK7780 board. sh: constify function pointer tables sh: Kill off -traditional for linker script. cdrom: Add support for Sega Dreamcast GD-ROM. sh: Kill off hs7751rvoip reference from arch/sh/Kconfig. sh: Drop r7780rp_defconfig, use r7780mp_defconfig as kbuild default. sh: Kill off dead HS771RVoIP board support. sh: r7785rp: Fix up DECLARE_INTC_DESC() arg mismatch. sh: r7785rp: Hook up the rest of the HL7785 FPGA IRQ vectors. sh: r2d - enable sm501 usb host function sh: remove voyagergx sh: r2d - add lcd planel timings to sm501 platform data sh: Add OHCI and UDC platform devices for SH7720. sh: intc - remove default interrupt priority tables sh: Correct pte size mismatch for X2 TLB. ...
Diffstat (limited to 'arch/sh/lib64/clear_page.S')
-rw-r--r--arch/sh/lib64/clear_page.S54
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/sh/lib64/clear_page.S b/arch/sh/lib64/clear_page.S
new file mode 100644
index 00000000000..007ab48ecc1
--- /dev/null
+++ b/arch/sh/lib64/clear_page.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 clear_page
+clear_page:
+ 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
+
+