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Subject[PATCH v9 3/9] crypto: caam - drop global context pointer and init_done
Date
Leverage devres to get rid of code storing global context as well as
init_done flag.

Original code also has a circular deallocation dependency where
unregister_algs() -> caam_rng_exit() -> caam_jr_free() chain would
only happen if all of JRs were freed. Fix this by moving
caam_rng_exit() outside of unregister_algs() and doing it specifically
for JR that instantiated HWRNG.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Iuliana Prodan <iuliana.prodan@nxp.com>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-imx@nxp.com
---
drivers/crypto/caam/caamrng.c | 67 +++++++++++++++++------------------
drivers/crypto/caam/intern.h | 7 ++--
drivers/crypto/caam/jr.c | 13 ++++---
3 files changed, 44 insertions(+), 43 deletions(-)

diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
index 69a02ac5de54..753625f2b2c0 100644
--- a/drivers/crypto/caam/caamrng.c
+++ b/drivers/crypto/caam/caamrng.c
@@ -70,6 +70,7 @@ struct buf_data {

/* rng per-device context */
struct caam_rng_ctx {
+ struct hwrng rng;
struct device *jrdev;
dma_addr_t sh_desc_dma;
u32 sh_desc[DESC_RNG_LEN];
@@ -78,13 +79,10 @@ struct caam_rng_ctx {
struct buf_data bufs[2];
};

-static struct caam_rng_ctx *rng_ctx;
-
-/*
- * Variable used to avoid double free of resources in case
- * algorithm registration was unsuccessful
- */
-static bool init_done;
+static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r)
+{
+ return (struct caam_rng_ctx *)r->priv;
+}

static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd)
{
@@ -143,7 +141,7 @@ static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)

static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
- struct caam_rng_ctx *ctx = rng_ctx;
+ struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
struct buf_data *bd = &ctx->bufs[ctx->current_buf];
int next_buf_idx, copied_idx;
int err;
@@ -246,17 +244,18 @@ static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id)

static void caam_cleanup(struct hwrng *rng)
{
+ struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
int i;
struct buf_data *bd;

for (i = 0; i < 2; i++) {
- bd = &rng_ctx->bufs[i];
+ bd = &ctx->bufs[i];
if (atomic_read(&bd->empty) == BUF_PENDING)
wait_for_completion(&bd->filled);
}

- rng_unmap_ctx(rng_ctx);
- caam_jr_free(rng_ctx->jrdev);
+ rng_unmap_ctx(ctx);
+ caam_jr_free(ctx->jrdev);
}

static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)
@@ -277,7 +276,7 @@ static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)

static int caam_init(struct hwrng *rng)
{
- struct caam_rng_ctx *ctx = rng_ctx;
+ struct caam_rng_ctx *ctx = to_caam_rng_ctx(rng);
int err;

ctx->jrdev = caam_jr_alloc();
@@ -309,28 +308,19 @@ static int caam_init(struct hwrng *rng)
return err;
}

-static struct hwrng caam_rng = {
- .name = "rng-caam",
- .init = caam_init,
- .cleanup = caam_cleanup,
- .read = caam_read,
-};
+int caam_rng_init(struct device *ctrldev);

-void caam_rng_exit(void)
+void caam_rng_exit(struct device *ctrldev)
{
- if (!init_done)
- return;
-
- hwrng_unregister(&caam_rng);
- kfree(rng_ctx);
+ devres_release_group(ctrldev, caam_rng_init);
}

int caam_rng_init(struct device *ctrldev)
{
+ struct caam_rng_ctx *ctx;
u32 rng_inst;
struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
- int err;
- init_done = false;
+ int ret;

/* Check for an instantiated RNG before registration */
if (priv->era < 10)
@@ -342,18 +332,27 @@ int caam_rng_init(struct device *ctrldev)
if (!rng_inst)
return 0;

- rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA | GFP_KERNEL);
- if (!rng_ctx)
+ if (!devres_open_group(ctrldev, caam_rng_init, GFP_KERNEL))
+ return -ENOMEM;
+
+ ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_DMA | GFP_KERNEL);
+ if (!ctx)
return -ENOMEM;

+ ctx->rng.name = "rng-caam";
+ ctx->rng.init = caam_init;
+ ctx->rng.cleanup = caam_cleanup;
+ ctx->rng.read = caam_read;
+ ctx->rng.priv = (unsigned long)ctx;
+
dev_info(ctrldev, "registering rng-caam\n");

- err = hwrng_register(&caam_rng);
- if (!err) {
- init_done = true;
- return err;
+ ret = devm_hwrng_register(ctrldev, &ctx->rng);
+ if (ret) {
+ caam_rng_exit(ctrldev);
+ return ret;
}

- kfree(rng_ctx);
- return err;
+ devres_close_group(ctrldev, caam_rng_init);
+ return 0;
}
diff --git a/drivers/crypto/caam/intern.h b/drivers/crypto/caam/intern.h
index 230ea88184f5..402d6a362e8c 100644
--- a/drivers/crypto/caam/intern.h
+++ b/drivers/crypto/caam/intern.h
@@ -47,6 +47,7 @@ struct caam_drv_private_jr {
struct caam_job_ring __iomem *rregs; /* JobR's register space */
struct tasklet_struct irqtask;
int irq; /* One per queue */
+ bool hwrng;

/* Number of scatterlist crypt transforms active on the JobR */
atomic_t tfm_count ____cacheline_aligned;
@@ -163,7 +164,7 @@ static inline void caam_pkc_exit(void)
#ifdef CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API

int caam_rng_init(struct device *dev);
-void caam_rng_exit(void);
+void caam_rng_exit(struct device *dev);

#else

@@ -172,9 +173,7 @@ static inline int caam_rng_init(struct device *dev)
return 0;
}

-static inline void caam_rng_exit(void)
-{
-}
+static inline void caam_rng_exit(struct device *dev) {}

#endif /* CONFIG_CRYPTO_DEV_FSL_CAAM_RNG_API */

diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index 88aff2aefd5d..4af22e7ceb4f 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -27,7 +27,8 @@ static struct jr_driver_data driver_data;
static DEFINE_MUTEX(algs_lock);
static unsigned int active_devs;

-static void register_algs(struct device *dev)
+static void register_algs(struct caam_drv_private_jr *jrpriv,
+ struct device *dev)
{
mutex_lock(&algs_lock);

@@ -37,7 +38,7 @@ static void register_algs(struct device *dev)
caam_algapi_init(dev);
caam_algapi_hash_init(dev);
caam_pkc_init(dev);
- caam_rng_init(dev);
+ jrpriv->hwrng = !caam_rng_init(dev);
caam_qi_algapi_init(dev);

algs_unlock:
@@ -53,7 +54,6 @@ static void unregister_algs(void)

caam_qi_algapi_exit();

- caam_rng_exit();
caam_pkc_exit();
caam_algapi_hash_exit();
caam_algapi_exit();
@@ -135,6 +135,9 @@ static int caam_jr_remove(struct platform_device *pdev)
jrdev = &pdev->dev;
jrpriv = dev_get_drvdata(jrdev);

+ if (jrpriv->hwrng)
+ caam_rng_exit(jrdev->parent);
+
/*
* Return EBUSY if job ring already allocated.
*/
@@ -514,7 +517,7 @@ static int caam_jr_probe(struct platform_device *pdev)
int error;

jrdev = &pdev->dev;
- jrpriv = devm_kmalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
+ jrpriv = devm_kzalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
if (!jrpriv)
return -ENOMEM;

@@ -590,7 +593,7 @@ static int caam_jr_probe(struct platform_device *pdev)

atomic_set(&jrpriv->tfm_count, 0);

- register_algs(jrdev->parent);
+ register_algs(jrpriv, jrdev->parent);

return 0;
}
--
2.21.0
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