Files
linux/lib/raid/xor/powerpc/xor_vmx.c
Christoph Hellwig 80dcf0a783 xor: pass the entire operation to the low-level ops
Currently the high-level xor code chunks up all operations into small
units for only up to 1 + 4 vectors, and passes it to four different
methods.  This means the FPU/vector context is entered and left a lot for
wide stripes, and a lot of indirect expensive indirect calls are
performed.  Switch to passing the entire gen_xor request to the low-level
ops, and provide a macro to dispatch it to the existing helper.

This reduce the number of indirect calls and FPU/vector context switches
by a factor approaching nr_stripes / 4, and also reduces source and binary
code size.

Link: https://lkml.kernel.org/r/20260327061704.3707577-27-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Tested-by: Eric Biggers <ebiggers@kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Borislav Petkov (AMD)" <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Sterba <dsterba@suse.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Li Nan <linan122@huawei.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-02 23:36:21 -07:00

161 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
*
* 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.
*/
#include "xor_impl.h"
#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)
static void __xor_altivec_2(unsigned long bytes,
unsigned long * __restrict v1_in,
const unsigned long * __restrict 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);
}
static void __xor_altivec_3(unsigned long bytes,
unsigned long * __restrict v1_in,
const unsigned long * __restrict v2_in,
const unsigned long * __restrict 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);
}
static void __xor_altivec_4(unsigned long bytes,
unsigned long * __restrict v1_in,
const unsigned long * __restrict v2_in,
const unsigned long * __restrict v3_in,
const unsigned long * __restrict 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);
}
static void __xor_altivec_5(unsigned long bytes,
unsigned long * __restrict v1_in,
const unsigned long * __restrict v2_in,
const unsigned long * __restrict v3_in,
const unsigned long * __restrict v4_in,
const unsigned long * __restrict 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);
}
__DO_XOR_BLOCKS(altivec_inner, __xor_altivec_2, __xor_altivec_3,
__xor_altivec_4, __xor_altivec_5);