cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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memset.S (2932B)

      1/* SPDX-License-Identifier: GPL-2.0-only */
      2/*
      3 *  linux/arch/arm/lib/memset.S
      4 *
      5 *  Copyright (C) 1995-2000 Russell King
      6 *
      7 *  ASM optimised string functions
      8 */
      9#include <linux/linkage.h>
     10#include <asm/assembler.h>
     11#include <asm/unwind.h>
     12
     13	.text
     14	.align	5
     15
     16ENTRY(__memset)
     17ENTRY(mmioset)
     18WEAK(memset)
     19UNWIND( .fnstart         )
     20	ands	r3, r0, #3		@ 1 unaligned?
     21	mov	ip, r0			@ preserve r0 as return value
     22	bne	6f			@ 1
     23/*
     24 * we know that the pointer in ip is aligned to a word boundary.
     25 */
     261:	orr	r1, r1, r1, lsl #8
     27	orr	r1, r1, r1, lsl #16
     28	mov	r3, r1
     297:	cmp	r2, #16
     30	blt	4f
     31UNWIND( .fnend              )
     32
     33#if ! CALGN(1)+0
     34
     35/*
     36 * We need 2 extra registers for this loop - use r8 and the LR
     37 */
     38UNWIND( .fnstart            )
     39UNWIND( .save {r8, lr}      )
     40	stmfd	sp!, {r8, lr}
     41	mov	r8, r1
     42	mov	lr, r3
     43
     442:	subs	r2, r2, #64
     45	stmiage	ip!, {r1, r3, r8, lr}	@ 64 bytes at a time.
     46	stmiage	ip!, {r1, r3, r8, lr}
     47	stmiage	ip!, {r1, r3, r8, lr}
     48	stmiage	ip!, {r1, r3, r8, lr}
     49	bgt	2b
     50	ldmfdeq	sp!, {r8, pc}		@ Now <64 bytes to go.
     51/*
     52 * No need to correct the count; we're only testing bits from now on
     53 */
     54	tst	r2, #32
     55	stmiane	ip!, {r1, r3, r8, lr}
     56	stmiane	ip!, {r1, r3, r8, lr}
     57	tst	r2, #16
     58	stmiane	ip!, {r1, r3, r8, lr}
     59	ldmfd	sp!, {r8, lr}
     60UNWIND( .fnend              )
     61
     62#else
     63
     64/*
     65 * This version aligns the destination pointer in order to write
     66 * whole cache lines at once.
     67 */
     68
     69UNWIND( .fnstart               )
     70UNWIND( .save {r4-r8, lr}      )
     71	stmfd	sp!, {r4-r8, lr}
     72	mov	r4, r1
     73	mov	r5, r3
     74	mov	r6, r1
     75	mov	r7, r3
     76	mov	r8, r1
     77	mov	lr, r3
     78
     79	cmp	r2, #96
     80	tstgt	ip, #31
     81	ble	3f
     82
     83	and	r8, ip, #31
     84	rsb	r8, r8, #32
     85	sub	r2, r2, r8
     86	movs	r8, r8, lsl #(32 - 4)
     87	stmiacs	ip!, {r4, r5, r6, r7}
     88	stmiami	ip!, {r4, r5}
     89	tst	r8, #(1 << 30)
     90	mov	r8, r1
     91	strne	r1, [ip], #4
     92
     933:	subs	r2, r2, #64
     94	stmiage	ip!, {r1, r3-r8, lr}
     95	stmiage	ip!, {r1, r3-r8, lr}
     96	bgt	3b
     97	ldmfdeq	sp!, {r4-r8, pc}
     98
     99	tst	r2, #32
    100	stmiane	ip!, {r1, r3-r8, lr}
    101	tst	r2, #16
    102	stmiane	ip!, {r4-r7}
    103	ldmfd	sp!, {r4-r8, lr}
    104UNWIND( .fnend                 )
    105
    106#endif
    107
    108UNWIND( .fnstart            )
    1094:	tst	r2, #8
    110	stmiane	ip!, {r1, r3}
    111	tst	r2, #4
    112	strne	r1, [ip], #4
    113/*
    114 * When we get here, we've got less than 4 bytes to set.  We
    115 * may have an unaligned pointer as well.
    116 */
    1175:	tst	r2, #2
    118	strbne	r1, [ip], #1
    119	strbne	r1, [ip], #1
    120	tst	r2, #1
    121	strbne	r1, [ip], #1
    122	ret	lr
    123
    1246:	subs	r2, r2, #4		@ 1 do we have enough
    125	blt	5b			@ 1 bytes to align with?
    126	cmp	r3, #2			@ 1
    127	strblt	r1, [ip], #1		@ 1
    128	strble	r1, [ip], #1		@ 1
    129	strb	r1, [ip], #1		@ 1
    130	add	r2, r2, r3		@ 1 (r2 = r2 - (4 - r3))
    131	b	1b
    132UNWIND( .fnend   )
    133ENDPROC(memset)
    134ENDPROC(mmioset)
    135ENDPROC(__memset)
    136
    137ENTRY(__memset32)
    138UNWIND( .fnstart         )
    139	mov	r3, r1			@ copy r1 to r3 and fall into memset64
    140UNWIND( .fnend   )
    141ENDPROC(__memset32)
    142ENTRY(__memset64)
    143UNWIND( .fnstart         )
    144	mov	ip, r0			@ preserve r0 as return value
    145	b	7b			@ jump into the middle of memset
    146UNWIND( .fnend   )
    147ENDPROC(__memset64)