0f89f6e188
In crct10dif_vpmsum() we call enable_kernel_altivec() without first disabling preemption, which is not allowed. It used to be sufficient just to call pagefault_disable(), because that also disabled preemption. But the two were decoupled in commit8222dbe21e("sched/preempt, mm/fault: Decouple preemption from the page fault logic") in mid 2015. The crct10dif-vpmsum code inherited this bug from the crc32c-vpmsum code on which it was modelled. So add the missing preempt_disable/enable(). We should also call disable_kernel_fp(), although it does nothing by default, there is a debug switch to make it active and all enables should be paired with disables. Fixes:b01df1c16c("crypto: powerpc - Add CRC-T10DIF acceleration") Acked-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
129 lines
3.0 KiB
C
129 lines
3.0 KiB
C
/*
|
|
* Calculate a CRC T10-DIF with vpmsum acceleration
|
|
*
|
|
* Copyright 2017, Daniel Axtens, IBM Corporation.
|
|
* [based on crc32c-vpmsum_glue.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.
|
|
*/
|
|
|
|
#include <linux/crc-t10dif.h>
|
|
#include <crypto/internal/hash.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/string.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/cpufeature.h>
|
|
#include <asm/switch_to.h>
|
|
|
|
#define VMX_ALIGN 16
|
|
#define VMX_ALIGN_MASK (VMX_ALIGN-1)
|
|
|
|
#define VECTOR_BREAKPOINT 64
|
|
|
|
u32 __crct10dif_vpmsum(u32 crc, unsigned char const *p, size_t len);
|
|
|
|
static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len)
|
|
{
|
|
unsigned int prealign;
|
|
unsigned int tail;
|
|
u32 crc = crci;
|
|
|
|
if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || in_interrupt())
|
|
return crc_t10dif_generic(crc, p, len);
|
|
|
|
if ((unsigned long)p & VMX_ALIGN_MASK) {
|
|
prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
|
|
crc = crc_t10dif_generic(crc, p, prealign);
|
|
len -= prealign;
|
|
p += prealign;
|
|
}
|
|
|
|
if (len & ~VMX_ALIGN_MASK) {
|
|
crc <<= 16;
|
|
preempt_disable();
|
|
pagefault_disable();
|
|
enable_kernel_altivec();
|
|
crc = __crct10dif_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
|
|
disable_kernel_altivec();
|
|
pagefault_enable();
|
|
preempt_enable();
|
|
crc >>= 16;
|
|
}
|
|
|
|
tail = len & VMX_ALIGN_MASK;
|
|
if (tail) {
|
|
p += len & ~VMX_ALIGN_MASK;
|
|
crc = crc_t10dif_generic(crc, p, tail);
|
|
}
|
|
|
|
return crc & 0xffff;
|
|
}
|
|
|
|
static int crct10dif_vpmsum_init(struct shash_desc *desc)
|
|
{
|
|
u16 *crc = shash_desc_ctx(desc);
|
|
|
|
*crc = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int crct10dif_vpmsum_update(struct shash_desc *desc, const u8 *data,
|
|
unsigned int length)
|
|
{
|
|
u16 *crc = shash_desc_ctx(desc);
|
|
|
|
*crc = crct10dif_vpmsum(*crc, data, length);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int crct10dif_vpmsum_final(struct shash_desc *desc, u8 *out)
|
|
{
|
|
u16 *crcp = shash_desc_ctx(desc);
|
|
|
|
*(u16 *)out = *crcp;
|
|
return 0;
|
|
}
|
|
|
|
static struct shash_alg alg = {
|
|
.init = crct10dif_vpmsum_init,
|
|
.update = crct10dif_vpmsum_update,
|
|
.final = crct10dif_vpmsum_final,
|
|
.descsize = CRC_T10DIF_DIGEST_SIZE,
|
|
.digestsize = CRC_T10DIF_DIGEST_SIZE,
|
|
.base = {
|
|
.cra_name = "crct10dif",
|
|
.cra_driver_name = "crct10dif-vpmsum",
|
|
.cra_priority = 200,
|
|
.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
|
|
.cra_module = THIS_MODULE,
|
|
}
|
|
};
|
|
|
|
static int __init crct10dif_vpmsum_mod_init(void)
|
|
{
|
|
if (!cpu_has_feature(CPU_FTR_ARCH_207S))
|
|
return -ENODEV;
|
|
|
|
return crypto_register_shash(&alg);
|
|
}
|
|
|
|
static void __exit crct10dif_vpmsum_mod_fini(void)
|
|
{
|
|
crypto_unregister_shash(&alg);
|
|
}
|
|
|
|
module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crct10dif_vpmsum_mod_init);
|
|
module_exit(crct10dif_vpmsum_mod_fini);
|
|
|
|
MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
|
|
MODULE_DESCRIPTION("CRCT10DIF using vector polynomial multiply-sum instructions");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_CRYPTO("crct10dif");
|
|
MODULE_ALIAS_CRYPTO("crct10dif-vpmsum");
|