mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 05:32:00 +00:00
f718d426d7
The xor_vmx.c file is used for the RAID5 xor operations. In these functions altivec is enabled to run the operation and then disabled. The code uses enable_kernel_altivec() around the core of the algorithm, however the whole file is built with -maltivec, so the compiler is within its rights to generate altivec code anywhere. This has been seen at least once in the wild: 0:mon> di $xor_altivec_2 c0000000000b97d0 3c4c01d9 addis r2,r12,473 c0000000000b97d4 3842db30 addi r2,r2,-9424 c0000000000b97d8 7c0802a6 mflr r0 c0000000000b97dc f8010010 std r0,16(r1) c0000000000b97e0 60000000 nop c0000000000b97e4 7c0802a6 mflr r0 c0000000000b97e8 faa1ffa8 std r21,-88(r1) ... c0000000000b981c f821ff41 stdu r1,-192(r1) c0000000000b9820 7f8101ce stvx v28,r1,r0 <-- POP c0000000000b9824 38000030 li r0,48 c0000000000b9828 7fa101ce stvx v29,r1,r0 ... c0000000000b984c 4bf6a06d bl c0000000000238b8 # enable_kernel_altivec This patch splits the non-altivec code into xor_vmx_glue.c which calls the altivec functions in xor_vmx.c. By compiling xor_vmx_glue.c without -maltivec we can guarantee that altivec instruction will not be executed outside of the enable/disable block. Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> [mpe: Rework change log and include disassembly] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
161 lines
3.2 KiB
C
161 lines
3.2 KiB
C
/*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* Copyright (C) IBM Corporation, 2012
|
|
*
|
|
* Author: Anton Blanchard <anton@au.ibm.com>
|
|
*/
|
|
|
|
/*
|
|
* Sparse (as at v0.5.0) gets very, very confused by this file.
|
|
* Make it a bit simpler for it.
|
|
*/
|
|
#if !defined(__CHECKER__)
|
|
#include <altivec.h>
|
|
#else
|
|
#define vec_xor(a, b) a ^ b
|
|
#define vector __attribute__((vector_size(16)))
|
|
#endif
|
|
|
|
#include "xor_vmx.h"
|
|
|
|
typedef vector signed char unative_t;
|
|
|
|
#define DEFINE(V) \
|
|
unative_t *V = (unative_t *)V##_in; \
|
|
unative_t V##_0, V##_1, V##_2, V##_3
|
|
|
|
#define LOAD(V) \
|
|
do { \
|
|
V##_0 = V[0]; \
|
|
V##_1 = V[1]; \
|
|
V##_2 = V[2]; \
|
|
V##_3 = V[3]; \
|
|
} while (0)
|
|
|
|
#define STORE(V) \
|
|
do { \
|
|
V[0] = V##_0; \
|
|
V[1] = V##_1; \
|
|
V[2] = V##_2; \
|
|
V[3] = V##_3; \
|
|
} while (0)
|
|
|
|
#define XOR(V1, V2) \
|
|
do { \
|
|
V1##_0 = vec_xor(V1##_0, V2##_0); \
|
|
V1##_1 = vec_xor(V1##_1, V2##_1); \
|
|
V1##_2 = vec_xor(V1##_2, V2##_2); \
|
|
V1##_3 = vec_xor(V1##_3, V2##_3); \
|
|
} while (0)
|
|
|
|
void __xor_altivec_2(unsigned long bytes, unsigned long *v1_in,
|
|
unsigned long *v2_in)
|
|
{
|
|
DEFINE(v1);
|
|
DEFINE(v2);
|
|
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
|
|
|
|
do {
|
|
LOAD(v1);
|
|
LOAD(v2);
|
|
XOR(v1, v2);
|
|
STORE(v1);
|
|
|
|
v1 += 4;
|
|
v2 += 4;
|
|
} while (--lines > 0);
|
|
}
|
|
|
|
void __xor_altivec_3(unsigned long bytes, unsigned long *v1_in,
|
|
unsigned long *v2_in, unsigned long *v3_in)
|
|
{
|
|
DEFINE(v1);
|
|
DEFINE(v2);
|
|
DEFINE(v3);
|
|
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
|
|
|
|
do {
|
|
LOAD(v1);
|
|
LOAD(v2);
|
|
LOAD(v3);
|
|
XOR(v1, v2);
|
|
XOR(v1, v3);
|
|
STORE(v1);
|
|
|
|
v1 += 4;
|
|
v2 += 4;
|
|
v3 += 4;
|
|
} while (--lines > 0);
|
|
}
|
|
|
|
void __xor_altivec_4(unsigned long bytes, unsigned long *v1_in,
|
|
unsigned long *v2_in, unsigned long *v3_in,
|
|
unsigned long *v4_in)
|
|
{
|
|
DEFINE(v1);
|
|
DEFINE(v2);
|
|
DEFINE(v3);
|
|
DEFINE(v4);
|
|
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
|
|
|
|
do {
|
|
LOAD(v1);
|
|
LOAD(v2);
|
|
LOAD(v3);
|
|
LOAD(v4);
|
|
XOR(v1, v2);
|
|
XOR(v3, v4);
|
|
XOR(v1, v3);
|
|
STORE(v1);
|
|
|
|
v1 += 4;
|
|
v2 += 4;
|
|
v3 += 4;
|
|
v4 += 4;
|
|
} while (--lines > 0);
|
|
}
|
|
|
|
void __xor_altivec_5(unsigned long bytes, unsigned long *v1_in,
|
|
unsigned long *v2_in, unsigned long *v3_in,
|
|
unsigned long *v4_in, unsigned long *v5_in)
|
|
{
|
|
DEFINE(v1);
|
|
DEFINE(v2);
|
|
DEFINE(v3);
|
|
DEFINE(v4);
|
|
DEFINE(v5);
|
|
unsigned long lines = bytes / (sizeof(unative_t)) / 4;
|
|
|
|
do {
|
|
LOAD(v1);
|
|
LOAD(v2);
|
|
LOAD(v3);
|
|
LOAD(v4);
|
|
LOAD(v5);
|
|
XOR(v1, v2);
|
|
XOR(v3, v4);
|
|
XOR(v1, v5);
|
|
XOR(v1, v3);
|
|
STORE(v1);
|
|
|
|
v1 += 4;
|
|
v2 += 4;
|
|
v3 += 4;
|
|
v4 += 4;
|
|
v5 += 4;
|
|
} while (--lines > 0);
|
|
}
|