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| /* SPDX-License-Identifier: GPL-2.0-or-later */
| /*
| * User Space Access Routines
| *
| * Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
| * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
| * Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
| * Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
| * Copyright (C) 2017 Helge Deller <deller@gmx.de>
| * Copyright (C) 2017 John David Anglin <dave.anglin@bell.net>
| */
|
| /*
| * These routines still have plenty of room for optimization
| * (word & doubleword load/store, dual issue, store hints, etc.).
| */
|
| /*
| * The following routines assume that space register 3 (sr3) contains
| * the space id associated with the current users address space.
| */
|
|
| .text
|
| #include <asm/assembly.h>
| #include <asm/errno.h>
| #include <linux/linkage.h>
|
| /*
| * get_sr gets the appropriate space value into
| * sr1 for kernel/user space access, depending
| * on the flag stored in the task structure.
| */
|
| .macro get_sr
| mfctl %cr30,%r1
| ldw TI_SEGMENT(%r1),%r22
| mfsp %sr3,%r1
| or,<> %r22,%r0,%r0
| copy %r0,%r1
| mtsp %r1,%sr1
| .endm
|
| /*
| * unsigned long lclear_user(void *to, unsigned long n)
| *
| * Returns 0 for success.
| * otherwise, returns number of bytes not transferred.
| */
|
| ENTRY_CFI(lclear_user)
| comib,=,n 0,%r25,$lclu_done
| get_sr
| $lclu_loop:
| addib,<> -1,%r25,$lclu_loop
| 1: stbs,ma %r0,1(%sr1,%r26)
|
| $lclu_done:
| bv %r0(%r2)
| copy %r25,%r28
|
| 2: b $lclu_done
| ldo 1(%r25),%r25
|
| ASM_EXCEPTIONTABLE_ENTRY(1b,2b)
| ENDPROC_CFI(lclear_user)
|
|
| /*
| * long lstrnlen_user(char *s, long n)
| *
| * Returns 0 if exception before zero byte or reaching N,
| * N+1 if N would be exceeded,
| * else strlen + 1 (i.e. includes zero byte).
| */
|
| ENTRY_CFI(lstrnlen_user)
| comib,= 0,%r25,$lslen_nzero
| copy %r26,%r24
| get_sr
| 1: ldbs,ma 1(%sr1,%r26),%r1
| $lslen_loop:
| comib,=,n 0,%r1,$lslen_done
| addib,<> -1,%r25,$lslen_loop
| 2: ldbs,ma 1(%sr1,%r26),%r1
| $lslen_done:
| bv %r0(%r2)
| sub %r26,%r24,%r28
|
| $lslen_nzero:
| b $lslen_done
| ldo 1(%r26),%r26 /* special case for N == 0 */
|
| 3: b $lslen_done
| copy %r24,%r26 /* reset r26 so 0 is returned on fault */
|
| ASM_EXCEPTIONTABLE_ENTRY(1b,3b)
| ASM_EXCEPTIONTABLE_ENTRY(2b,3b)
|
| ENDPROC_CFI(lstrnlen_user)
|
|
| /*
| * unsigned long pa_memcpy(void *dstp, const void *srcp, unsigned long len)
| *
| * Inputs:
| * - sr1 already contains space of source region
| * - sr2 already contains space of destination region
| *
| * Returns:
| * - number of bytes that could not be copied.
| * On success, this will be zero.
| *
| * This code is based on a C-implementation of a copy routine written by
| * Randolph Chung, which in turn was derived from the glibc.
| *
| * Several strategies are tried to try to get the best performance for various
| * conditions. In the optimal case, we copy by loops that copy 32- or 16-bytes
| * at a time using general registers. Unaligned copies are handled either by
| * aligning the destination and then using shift-and-write method, or in a few
| * cases by falling back to a byte-at-a-time copy.
| *
| * Testing with various alignments and buffer sizes shows that this code is
| * often >10x faster than a simple byte-at-a-time copy, even for strangely
| * aligned operands. It is interesting to note that the glibc version of memcpy
| * (written in C) is actually quite fast already. This routine is able to beat
| * it by 30-40% for aligned copies because of the loop unrolling, but in some
| * cases the glibc version is still slightly faster. This lends more
| * credibility that gcc can generate very good code as long as we are careful.
| *
| * Possible optimizations:
| * - add cache prefetching
| * - try not to use the post-increment address modifiers; they may create
| * additional interlocks. Assumption is that those were only efficient on old
| * machines (pre PA8000 processors)
| */
|
| dst = arg0
| src = arg1
| len = arg2
| end = arg3
| t1 = r19
| t2 = r20
| t3 = r21
| t4 = r22
| srcspc = sr1
| dstspc = sr2
|
| t0 = r1
| a1 = t1
| a2 = t2
| a3 = t3
| a0 = t4
|
| save_src = ret0
| save_dst = ret1
| save_len = r31
|
| ENTRY_CFI(pa_memcpy)
| /* Last destination address */
| add dst,len,end
|
| /* short copy with less than 16 bytes? */
| cmpib,COND(>>=),n 15,len,.Lbyte_loop
|
| /* same alignment? */
| xor src,dst,t0
| extru t0,31,2,t1
| cmpib,<>,n 0,t1,.Lunaligned_copy
|
| #ifdef CONFIG_64BIT
| /* only do 64-bit copies if we can get aligned. */
| extru t0,31,3,t1
| cmpib,<>,n 0,t1,.Lalign_loop32
|
| /* loop until we are 64-bit aligned */
| .Lalign_loop64:
| extru dst,31,3,t1
| cmpib,=,n 0,t1,.Lcopy_loop_16_start
| 20: ldb,ma 1(srcspc,src),t1
| 21: stb,ma t1,1(dstspc,dst)
| b .Lalign_loop64
| ldo -1(len),len
|
| ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
|
| .Lcopy_loop_16_start:
| ldi 31,t0
| .Lcopy_loop_16:
| cmpb,COND(>>=),n t0,len,.Lword_loop
|
| 10: ldd 0(srcspc,src),t1
| 11: ldd 8(srcspc,src),t2
| ldo 16(src),src
| 12: std,ma t1,8(dstspc,dst)
| 13: std,ma t2,8(dstspc,dst)
| 14: ldd 0(srcspc,src),t1
| 15: ldd 8(srcspc,src),t2
| ldo 16(src),src
| 16: std,ma t1,8(dstspc,dst)
| 17: std,ma t2,8(dstspc,dst)
|
| ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy16_fault)
| ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy16_fault)
| ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done)
|
| b .Lcopy_loop_16
| ldo -32(len),len
|
| .Lword_loop:
| cmpib,COND(>>=),n 3,len,.Lbyte_loop
| 20: ldw,ma 4(srcspc,src),t1
| 21: stw,ma t1,4(dstspc,dst)
| b .Lword_loop
| ldo -4(len),len
|
| ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
|
| #endif /* CONFIG_64BIT */
|
| /* loop until we are 32-bit aligned */
| .Lalign_loop32:
| extru dst,31,2,t1
| cmpib,=,n 0,t1,.Lcopy_loop_8
| 20: ldb,ma 1(srcspc,src),t1
| 21: stb,ma t1,1(dstspc,dst)
| b .Lalign_loop32
| ldo -1(len),len
|
| ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
|
|
| .Lcopy_loop_8:
| cmpib,COND(>>=),n 15,len,.Lbyte_loop
|
| 10: ldw 0(srcspc,src),t1
| 11: ldw 4(srcspc,src),t2
| 12: stw,ma t1,4(dstspc,dst)
| 13: stw,ma t2,4(dstspc,dst)
| 14: ldw 8(srcspc,src),t1
| 15: ldw 12(srcspc,src),t2
| ldo 16(src),src
| 16: stw,ma t1,4(dstspc,dst)
| 17: stw,ma t2,4(dstspc,dst)
|
| ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(11b,.Lcopy8_fault)
| ASM_EXCEPTIONTABLE_ENTRY(12b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(13b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(14b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(15b,.Lcopy8_fault)
| ASM_EXCEPTIONTABLE_ENTRY(16b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(17b,.Lcopy_done)
|
| b .Lcopy_loop_8
| ldo -16(len),len
|
| .Lbyte_loop:
| cmpclr,COND(<>) len,%r0,%r0
| b,n .Lcopy_done
| 20: ldb 0(srcspc,src),t1
| ldo 1(src),src
| 21: stb,ma t1,1(dstspc,dst)
| b .Lbyte_loop
| ldo -1(len),len
|
| ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
|
| .Lcopy_done:
| bv %r0(%r2)
| sub end,dst,ret0
|
|
| /* src and dst are not aligned the same way. */
| /* need to go the hard way */
| .Lunaligned_copy:
| /* align until dst is 32bit-word-aligned */
| extru dst,31,2,t1
| cmpib,=,n 0,t1,.Lcopy_dstaligned
| 20: ldb 0(srcspc,src),t1
| ldo 1(src),src
| 21: stb,ma t1,1(dstspc,dst)
| b .Lunaligned_copy
| ldo -1(len),len
|
| ASM_EXCEPTIONTABLE_ENTRY(20b,.Lcopy_done)
| ASM_EXCEPTIONTABLE_ENTRY(21b,.Lcopy_done)
|
| .Lcopy_dstaligned:
|
| /* store src, dst and len in safe place */
| copy src,save_src
| copy dst,save_dst
| copy len,save_len
|
| /* len now needs give number of words to copy */
| SHRREG len,2,len
|
| /*
| * Copy from a not-aligned src to an aligned dst using shifts.
| * Handles 4 words per loop.
| */
|
| depw,z src,28,2,t0
| subi 32,t0,t0
| mtsar t0
| extru len,31,2,t0
| cmpib,= 2,t0,.Lcase2
| /* Make src aligned by rounding it down. */
| depi 0,31,2,src
|
| cmpiclr,<> 3,t0,%r0
| b,n .Lcase3
| cmpiclr,<> 1,t0,%r0
| b,n .Lcase1
| .Lcase0:
| cmpb,COND(=) %r0,len,.Lcda_finish
| nop
|
| 1: ldw,ma 4(srcspc,src), a3
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| 1: ldw,ma 4(srcspc,src), a0
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| b,n .Ldo3
| .Lcase1:
| 1: ldw,ma 4(srcspc,src), a2
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| 1: ldw,ma 4(srcspc,src), a3
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| ldo -1(len),len
| cmpb,COND(=),n %r0,len,.Ldo0
| .Ldo4:
| 1: ldw,ma 4(srcspc,src), a0
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| shrpw a2, a3, %sar, t0
| 1: stw,ma t0, 4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
| .Ldo3:
| 1: ldw,ma 4(srcspc,src), a1
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| shrpw a3, a0, %sar, t0
| 1: stw,ma t0, 4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
| .Ldo2:
| 1: ldw,ma 4(srcspc,src), a2
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| shrpw a0, a1, %sar, t0
| 1: stw,ma t0, 4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
| .Ldo1:
| 1: ldw,ma 4(srcspc,src), a3
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| shrpw a1, a2, %sar, t0
| 1: stw,ma t0, 4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
| ldo -4(len),len
| cmpb,COND(<>) %r0,len,.Ldo4
| nop
| .Ldo0:
| shrpw a2, a3, %sar, t0
| 1: stw,ma t0, 4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcopy_done)
|
| .Lcda_rdfault:
| .Lcda_finish:
| /* calculate new src, dst and len and jump to byte-copy loop */
| sub dst,save_dst,t0
| add save_src,t0,src
| b .Lbyte_loop
| sub save_len,t0,len
|
| .Lcase3:
| 1: ldw,ma 4(srcspc,src), a0
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| 1: ldw,ma 4(srcspc,src), a1
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| b .Ldo2
| ldo 1(len),len
| .Lcase2:
| 1: ldw,ma 4(srcspc,src), a1
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| 1: ldw,ma 4(srcspc,src), a2
| ASM_EXCEPTIONTABLE_ENTRY(1b,.Lcda_rdfault)
| b .Ldo1
| ldo 2(len),len
|
|
| /* fault exception fixup handlers: */
| #ifdef CONFIG_64BIT
| .Lcopy16_fault:
| b .Lcopy_done
| 10: std,ma t1,8(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
| #endif
|
| .Lcopy8_fault:
| b .Lcopy_done
| 10: stw,ma t1,4(dstspc,dst)
| ASM_EXCEPTIONTABLE_ENTRY(10b,.Lcopy_done)
| ENDPROC_CFI(pa_memcpy)
|
| .end
|
|
