172 lines
3.9 KiB
C
172 lines
3.9 KiB
C
#include <linux/crc32.h>
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#include <crypto/internal/hash.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/string.h>
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#include <linux/kernel.h>
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#include <linux/cpufeature.h>
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#include <asm/switch_to.h>
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#define CHKSUM_BLOCK_SIZE 1
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#define CHKSUM_DIGEST_SIZE 4
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#define VMX_ALIGN 16
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#define VMX_ALIGN_MASK (VMX_ALIGN-1)
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#define VECTOR_BREAKPOINT 512
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u32 __crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len);
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static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len)
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{
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unsigned int prealign;
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unsigned int tail;
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if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || in_interrupt())
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return __crc32c_le(crc, p, len);
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if ((unsigned long)p & VMX_ALIGN_MASK) {
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prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
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crc = __crc32c_le(crc, p, prealign);
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len -= prealign;
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p += prealign;
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}
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if (len & ~VMX_ALIGN_MASK) {
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preempt_disable();
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pagefault_disable();
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enable_kernel_altivec();
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crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
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disable_kernel_altivec();
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pagefault_enable();
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preempt_enable();
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}
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tail = len & VMX_ALIGN_MASK;
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if (tail) {
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p += len & ~VMX_ALIGN_MASK;
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crc = __crc32c_le(crc, p, tail);
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}
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return crc;
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}
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static int crc32c_vpmsum_cra_init(struct crypto_tfm *tfm)
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{
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u32 *key = crypto_tfm_ctx(tfm);
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*key = ~0;
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return 0;
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}
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/*
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* Setting the seed allows arbitrary accumulators and flexible XOR policy
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* If your algorithm starts with ~0, then XOR with ~0 before you set
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* the seed.
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*/
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static int crc32c_vpmsum_setkey(struct crypto_shash *hash, const u8 *key,
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unsigned int keylen)
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{
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u32 *mctx = crypto_shash_ctx(hash);
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if (keylen != sizeof(u32)) {
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crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
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return -EINVAL;
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}
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*mctx = le32_to_cpup((__le32 *)key);
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return 0;
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}
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static int crc32c_vpmsum_init(struct shash_desc *desc)
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{
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u32 *mctx = crypto_shash_ctx(desc->tfm);
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u32 *crcp = shash_desc_ctx(desc);
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*crcp = *mctx;
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return 0;
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}
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static int crc32c_vpmsum_update(struct shash_desc *desc, const u8 *data,
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unsigned int len)
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{
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u32 *crcp = shash_desc_ctx(desc);
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*crcp = crc32c_vpmsum(*crcp, data, len);
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return 0;
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}
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static int __crc32c_vpmsum_finup(u32 *crcp, const u8 *data, unsigned int len,
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u8 *out)
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{
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*(__le32 *)out = ~cpu_to_le32(crc32c_vpmsum(*crcp, data, len));
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return 0;
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}
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static int crc32c_vpmsum_finup(struct shash_desc *desc, const u8 *data,
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unsigned int len, u8 *out)
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{
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return __crc32c_vpmsum_finup(shash_desc_ctx(desc), data, len, out);
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}
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static int crc32c_vpmsum_final(struct shash_desc *desc, u8 *out)
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{
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u32 *crcp = shash_desc_ctx(desc);
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*(__le32 *)out = ~cpu_to_le32p(crcp);
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return 0;
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}
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static int crc32c_vpmsum_digest(struct shash_desc *desc, const u8 *data,
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unsigned int len, u8 *out)
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{
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return __crc32c_vpmsum_finup(crypto_shash_ctx(desc->tfm), data, len,
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out);
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}
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static struct shash_alg alg = {
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.setkey = crc32c_vpmsum_setkey,
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.init = crc32c_vpmsum_init,
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.update = crc32c_vpmsum_update,
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.final = crc32c_vpmsum_final,
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.finup = crc32c_vpmsum_finup,
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.digest = crc32c_vpmsum_digest,
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.descsize = sizeof(u32),
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.digestsize = CHKSUM_DIGEST_SIZE,
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.base = {
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.cra_name = "crc32c",
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.cra_driver_name = "crc32c-vpmsum",
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.cra_priority = 200,
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.cra_blocksize = CHKSUM_BLOCK_SIZE,
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.cra_ctxsize = sizeof(u32),
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.cra_module = THIS_MODULE,
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.cra_init = crc32c_vpmsum_cra_init,
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}
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};
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static int __init crc32c_vpmsum_mod_init(void)
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{
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if (!cpu_has_feature(CPU_FTR_ARCH_207S))
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return -ENODEV;
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return crypto_register_shash(&alg);
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}
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static void __exit crc32c_vpmsum_mod_fini(void)
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{
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crypto_unregister_shash(&alg);
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}
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module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crc32c_vpmsum_mod_init);
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module_exit(crc32c_vpmsum_mod_fini);
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MODULE_AUTHOR("Anton Blanchard <anton@samba.org>");
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MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_CRYPTO("crc32c");
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MODULE_ALIAS_CRYPTO("crc32c-vpmsum");
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