Files
linux/arch/powerpc/lib/crc32-glue.c
Eric Biggers 372ff60ac4 powerpc/crc32: expose CRC32 functions through lib
Move the powerpc CRC32C assembly code into the lib directory and wire it
up to the library interface.  This allows it to be used without going
through the crypto API.  It remains usable via the crypto API too via
the shash algorithms that use the library interface.  Thus all the
arch-specific "shash" code becomes unnecessary and is removed.

Note: to see the diff from arch/powerpc/crypto/crc32c-vpmsum_glue.c to
arch/powerpc/lib/crc32-glue.c, view this commit with 'git show -M10'.

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20241202010844.144356-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
2024-12-01 17:23:01 -08:00

93 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/crc32.h>
#include <crypto/internal/simd.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/cpufeature.h>
#include <asm/simd.h>
#include <asm/switch_to.h>
#define VMX_ALIGN 16
#define VMX_ALIGN_MASK (VMX_ALIGN-1)
#define VECTOR_BREAKPOINT 512
static DEFINE_STATIC_KEY_FALSE(have_vec_crypto);
u32 __crc32c_vpmsum(u32 crc, const u8 *p, size_t len);
u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
{
return crc32_le_base(crc, p, len);
}
EXPORT_SYMBOL(crc32_le_arch);
u32 crc32c_le_arch(u32 crc, const u8 *p, size_t len)
{
unsigned int prealign;
unsigned int tail;
if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) ||
!static_branch_likely(&have_vec_crypto) || !crypto_simd_usable())
return crc32c_le_base(crc, p, len);
if ((unsigned long)p & VMX_ALIGN_MASK) {
prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
crc = crc32c_le_base(crc, p, prealign);
len -= prealign;
p += prealign;
}
if (len & ~VMX_ALIGN_MASK) {
preempt_disable();
pagefault_disable();
enable_kernel_altivec();
crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
disable_kernel_altivec();
pagefault_enable();
preempt_enable();
}
tail = len & VMX_ALIGN_MASK;
if (tail) {
p += len & ~VMX_ALIGN_MASK;
crc = crc32c_le_base(crc, p, tail);
}
return crc;
}
EXPORT_SYMBOL(crc32c_le_arch);
u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
{
return crc32_be_base(crc, p, len);
}
EXPORT_SYMBOL(crc32_be_arch);
static int __init crc32_powerpc_init(void)
{
if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
(cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_VEC_CRYPTO))
static_branch_enable(&have_vec_crypto);
return 0;
}
arch_initcall(crc32_powerpc_init);
static void __exit crc32_powerpc_exit(void)
{
}
module_exit(crc32_powerpc_exit);
u32 crc32_optimizations(void)
{
if (static_key_enabled(&have_vec_crypto))
return CRC32C_OPTIMIZATION;
return 0;
}
EXPORT_SYMBOL(crc32_optimizations);
MODULE_AUTHOR("Anton Blanchard <anton@samba.org>");
MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions");
MODULE_LICENSE("GPL");