/*
* Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* =======================================
* BCOPY, MEMCPY, and MEMMOVE for Mac OS X
*
* Version of 6/11/2003, tuned for the IBM 970.
*
- *
* Register usage. Note the rather delicate way we assign multiple uses
* to the same register. Beware.
* r0 = temp (NB: cannot use r0 for any constant such as "c16")
#define vy v11
#define vz v12
-#define ASSEMBLER
#include <sys/appleapiopts.h>
#include <ppc/asm.h>
#include <machine/cpu_capabilities.h>
#include <machine/commpage.h>
.text
- .globl EXT(bcopy_970)
-
+/*
+ * WARNING: this code is written for 32-bit mode, and ported by the kernel if necessary
+ * to 64-bit mode for use in the 64-bit commpage. This "port" consists of the following
+ * simple transformations:
+ * - all word compares are changed to doubleword
+ * - all "srwi[.]" opcodes are changed to "srdi[.]"
+ * Nothing else is done. For this to work, the following rules must be
+ * carefully followed:
+ * - do not use carry or overflow
+ * - only use record mode if you are sure the results are mode-invariant
+ * for example, all "andi." and almost all "rlwinm." are fine
+ * - do not use "slwi", "slw", or "srw"
+ * An imaginative programmer could break the porting model in other ways, but the above
+ * are the most likely problem areas. It is perhaps surprising how well in practice
+ * this simple method works.
+ */
#define kShort 64
#define kVeryLong (128*1024)
beq LFwdMedAligned // source is 8-byte aligned, so use ld/std loop
mfspr rv,vrsave // get bitmap of live vector registers
oris w4,rv,0xFFF8 // we use v0-v12
- li c16,16 // get constants used in lvx
+ li c16,16 // get constant used in lvx
li c32,32
mtspr vrsave,w4 // update mask
lvx v1,0,rs // prefetch 1st source quadword
lis w3,kVeryLong>>16 // cutoff for very-long-operand special case path
cmplw cr1,rc,w3 // very long operand?
rlwinm w3,rc,0,28,31 // move last 0-15 byte count to w3
- bgea-- cr1,_COMM_PAGE_BIGCOPY // handle big copies separately
+ bge-- cr1,LBigCopy // handle big copies separately
mtctr r0 // set up loop count
cmpwi cr6,w3,0 // set cr6 on leftover byte count
oris w4,rv,0xFFF8 // we use v0-v12
bne cr6,LShortReverse16 // handle last 0-15 bytes iff any
blr
- COMMPAGE_DESCRIPTOR(bcopy_970,_COMM_PAGE_BCOPY,k64Bit+kHasAltivec,0,kCommPageMTCRF)
+
+// Very Big Copy Path. Save our return address in the stack for help decoding backtraces.
+// The conditions bigcopy expects are:
+// r0 = return address (also stored in caller's SF)
+// r4 = source ptr
+// r5 = length (at least several pages)
+// r12 = dest ptr
+
+LBigCopy:
+ lis r2,0x4000 // r2 <- 0x40000000
+ mflr r0 // get our return address
+ add. r2,r2,r2 // set cr0_lt if running in 32-bit mode
+ stw r0,8(r1) // save return, assuming 32-bit mode ("crsave" if 64-bit mode)
+ blta _COMM_PAGE_BIGCOPY // 32-bit mode, join big operand copy
+ std r0,16(r1) // save return in correct spot for 64-bit mode
+ ba _COMM_PAGE_BIGCOPY // then join big operand code
+
+
+ COMMPAGE_DESCRIPTOR(bcopy_970,_COMM_PAGE_BCOPY,k64Bit+kHasAltivec,0, \
+ kCommPageMTCRF+kCommPageBoth+kPort32to64)
projects / apple / xnu.git / blobdiff