crypto: rng - Count error stats differently

Move all stat code specific to rng into the rng code.

While we're at it, change the stats so that bytes and counts
are always incremented even in case of error.  This allows the
reference counting to be removed as we can now increment the
counters prior to the operation.

After the operation we simply increase the error count if necessary.
This is safe as errors can only occur synchronously (or rather,
the existing code already ignored asynchronous errors which are
only visible to the callback function).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 57 insertions, 8 deletions

diff --git a/include/crypto/rng.h b/include/crypto/rng.h
index 17bb3673d3c1..6abe5102e5fb 100644
--- a/include/crypto/rng.h
+++ b/include/crypto/rng.h
@@ -9,10 +9,26 @@
 #ifndef _CRYPTO_RNG_H
 #define _CRYPTO_RNG_H
 
+#include <linux/atomic.h>
+#include <linux/container_of.h>
 #include <linux/crypto.h>
 
 struct crypto_rng;
 
+/*
+ * struct crypto_istat_rng: statistics for RNG algorithm
+ * @generate_cnt:	number of RNG generate requests
+ * @generate_tlen:	total data size of generated data by the RNG
+ * @seed_cnt:		number of times the RNG was seeded
+ * @err_cnt:		number of error for RNG requests
+ */
+struct crypto_istat_rng {
+	atomic64_t generate_cnt;
+	atomic64_t generate_tlen;
+	atomic64_t seed_cnt;
+	atomic64_t err_cnt;
+};
+
 /**
  * struct rng_alg - random number generator definition
  *
@@ -30,6 +46,7 @@ struct crypto_rng;
  *		size of the seed is defined with @seedsize .
  * @set_ent:	Set entropy that would otherwise be obtained from
  *		entropy source.  Internal use only.
+ * @stat:	Statistics for rng algorithm
  * @seedsize:	The seed size required for a random number generator
  *		initialization defined with this variable. Some
  *		random number generators does not require a seed
@@ -46,6 +63,10 @@ struct rng_alg {
 	void (*set_ent)(struct crypto_rng *tfm, const u8 *data,
 			unsigned int len);
 
+#ifdef CONFIG_CRYPTO_STATS
+	struct crypto_istat_rng stat;
+#endif
+
 	unsigned int seedsize;
 
 	struct crypto_alg base;
@@ -94,6 +115,11 @@ static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
 	return &tfm->base;
 }
 
+static inline struct rng_alg *__crypto_rng_alg(struct crypto_alg *alg)
+{
+	return container_of(alg, struct rng_alg, base);
+}
+
 /**
  * crypto_rng_alg - obtain name of RNG
  * @tfm: cipher handle
@@ -104,8 +130,7 @@ static inline struct crypto_tfm *crypto_rng_tfm(struct crypto_rng *tfm)
  */
 static inline struct rng_alg *crypto_rng_alg(struct crypto_rng *tfm)
 {
-	return container_of(crypto_rng_tfm(tfm)->__crt_alg,
-			    struct rng_alg, base);
+	return __crypto_rng_alg(crypto_rng_tfm(tfm)->__crt_alg);
 }
 
 /**
@@ -119,6 +144,26 @@ static inline void crypto_free_rng(struct crypto_rng *tfm)
 	crypto_destroy_tfm(tfm, crypto_rng_tfm(tfm));
 }
 
+static inline struct crypto_istat_rng *rng_get_stat(struct rng_alg *alg)
+{
+#ifdef CONFIG_CRYPTO_STATS
+	return &alg->stat;
+#else
+	return NULL;
+#endif
+}
+
+static inline int crypto_rng_errstat(struct rng_alg *alg, int err)
+{
+	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
+		return err;
+
+	if (err && err != -EINPROGRESS && err != -EBUSY)
+		atomic64_inc(&rng_get_stat(alg)->err_cnt);
+
+	return err;
+}
+
 /**
  * crypto_rng_generate() - get random number
  * @tfm: cipher handle
@@ -137,13 +182,17 @@ static inline int crypto_rng_generate(struct crypto_rng *tfm,
 				      const u8 *src, unsigned int slen,
 				      u8 *dst, unsigned int dlen)
 {
-	struct crypto_alg *alg = tfm->base.__crt_alg;
-	int ret;
+	struct rng_alg *alg = crypto_rng_alg(tfm);
+
+	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
+		struct crypto_istat_rng *istat = rng_get_stat(alg);
+
+		atomic64_inc(&istat->generate_cnt);
+		atomic64_add(dlen, &istat->generate_tlen);
+	}
 
-	crypto_stats_get(alg);
-	ret = crypto_rng_alg(tfm)->generate(tfm, src, slen, dst, dlen);
-	crypto_stats_rng_generate(alg, dlen, ret);
-	return ret;
+	return crypto_rng_errstat(alg,
+				  alg->generate(tfm, src, slen, dst, dlen));
 }
 
 /**