[PATCH v3 2/2] crypto: sun4i-ss: enable pm_runtime

Corentin Labbe
2019-09-24T08:09:22Z

This patch enables power management on the Security System.
sun4i-ss now depends on PM because it simplify code and prevent some ifdef.
But this is not a problem since arch maintainer want ARCH_SUNXI to
depend on PM in the future.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
---
drivers/crypto/Kconfig | 1 +
drivers/crypto/sunxi-ss/sun4i-ss-cipher.c | 10 +++
drivers/crypto/sunxi-ss/sun4i-ss-core.c | 82 ++++++++++++++++++-----
drivers/crypto/sunxi-ss/sun4i-ss-hash.c | 12 ++++
drivers/crypto/sunxi-ss/sun4i-ss-prng.c | 9 ++-
drivers/crypto/sunxi-ss/sun4i-ss.h | 2 +
6 files changed, 97 insertions(+), 19 deletions(-)

diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 980b0844918b..ee53660b532c 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -662,6 +662,7 @@ config CRYPTO_DEV_IMGTEC_HASH
config CRYPTO_DEV_SUN4I_SS
tristate "Support for Allwinner Security System cryptographic accelerator"
depends on ARCH_SUNXI && !64BIT
+ depends on PM
select CRYPTO_MD5
select CRYPTO_SHA1
select CRYPTO_AES
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
index fa4b1b47822e..93acec22e42f 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-cipher.c
@@ -480,6 +480,7 @@ int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
struct sun4i_ss_alg_template *algt;
const char *name = crypto_tfm_alg_name(tfm);
+ int err;

memset(op, 0, sizeof(struct sun4i_tfm_ctx));

@@ -497,13 +498,22 @@ int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
return PTR_ERR(op->fallback_tfm);
}

+ err = pm_runtime_get_sync(op->ss->dev);
+ if (err < 0)
+ goto error_pm;
+
return 0;
+error_pm:
+ crypto_free_sync_skcipher(op->fallback_tfm);
+ return err;
}

void sun4i_ss_cipher_exit(struct crypto_tfm *tfm)
{
struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
+
crypto_free_sync_skcipher(op->fallback_tfm);
+ pm_runtime_put(op->ss->dev);
}

/* check and set the AES key, prepare the mode to be used */
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-core.c b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
index 6c2db5d83b06..814cd12149a9 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-core.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-core.c
@@ -44,7 +44,8 @@ static struct sun4i_ss_alg_template ss_algs[] = {
.cra_blocksize = MD5_HMAC_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct sun4i_req_ctx),
.cra_module = THIS_MODULE,
- .cra_init = sun4i_hash_crainit
+ .cra_init = sun4i_hash_crainit,
+ .cra_exit = sun4i_hash_craexit,
}
}
}
@@ -70,7 +71,8 @@ static struct sun4i_ss_alg_template ss_algs[] = {
.cra_blocksize = SHA1_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct sun4i_req_ctx),
.cra_module = THIS_MODULE,
- .cra_init = sun4i_hash_crainit
+ .cra_init = sun4i_hash_crainit,
+ .cra_exit = sun4i_hash_craexit,
}
}
}
@@ -223,17 +225,26 @@ static struct sun4i_ss_alg_template ss_algs[] = {
#endif
};

-static void sun4i_ss_disable(struct sun4i_ss_ctx *ss)
+/*
+ * Power management strategy: The device is suspended unless a TFM exists for
+ * one of the algorithms proposed by this driver.
+ */
+static int sun4i_ss_pm_suspend(struct device *dev)
{
+ struct sun4i_ss_ctx *ss = dev_get_drvdata(dev);
+
if (ss->reset)
reset_control_assert(ss->reset);

clk_disable_unprepare(ss->ssclk);
clk_disable_unprepare(ss->busclk);
+ return 0;
}

-static int sun4i_ss_enable(struct sun4i_ss_ctx *ss)
+static int sun4i_ss_pm_resume(struct device *dev)
{
+ struct sun4i_ss_ctx *ss = dev_get_drvdata(dev);
+
int err;

err = clk_prepare_enable(ss->busclk);
@@ -258,10 +269,38 @@ static int sun4i_ss_enable(struct sun4i_ss_ctx *ss)

return err;
err_enable:
- sun4i_ss_disable(ss);
+ sun4i_ss_pm_suspend(dev);
+ return err;
+}
+
+const struct dev_pm_ops sun4i_ss_pm_ops = {
+ SET_RUNTIME_PM_OPS(sun4i_ss_pm_suspend, sun4i_ss_pm_resume, NULL)
+};
+
+/*
+ * When power management is enabled, this function enables the PM and set the
+ * device as suspended
+ * When power management is disabled, this function just enables the device
+ */
+static int sun4i_ss_pm_init(struct sun4i_ss_ctx *ss)
+{
+ int err;
+
+ pm_runtime_use_autosuspend(ss->dev);
+ pm_runtime_set_autosuspend_delay(ss->dev, 2000);
+
+ err = pm_runtime_set_suspended(ss->dev);
+ if (err)
+ return err;
+ pm_runtime_enable(ss->dev);
return err;
}

+static void sun4i_ss_pm_exit(struct sun4i_ss_ctx *ss)
+{
+ pm_runtime_disable(ss->dev);
+}
+
static int sun4i_ss_probe(struct platform_device *pdev)
{
u32 v;
@@ -308,10 +347,6 @@ static int sun4i_ss_probe(struct platform_device *pdev)
ss->reset = NULL;
}

- err = sun4i_ss_enable(ss);
- if (err)
- goto error_enable;
-
/*
* Check that clock have the correct rates given in the datasheet
* Try to set the clock to the maximum allowed
@@ -319,7 +354,7 @@ static int sun4i_ss_probe(struct platform_device *pdev)
err = clk_set_rate(ss->ssclk, cr_mod);
if (err) {
dev_err(&pdev->dev, "Cannot set clock rate to ssclk\n");
- goto error_enable;
+ return err;
}

/*
@@ -347,12 +382,26 @@ static int sun4i_ss_probe(struct platform_device *pdev)
dev_warn(&pdev->dev, "Clock ss is at %lu (%lu MHz) (must be <= %lu)\n",
cr, cr / 1000000, cr_mod);

+ ss->dev = &pdev->dev;
+ platform_set_drvdata(pdev, ss);
+
+ spin_lock_init(&ss->slock);
+
+ err = sun4i_ss_pm_init(ss);
+ if (err)
+ return err;
+
/*
* Datasheet named it "Die Bonding ID"
* I expect to be a sort of Security System Revision number.
* Since the A80 seems to have an other version of SS
* this info could be useful
*/
+
+ err = pm_runtime_get_sync(ss->dev);
+ if (err < 0)
+ goto error_pm;
+
writel(SS_ENABLED, ss->base + SS_CTL);
v = readl(ss->base + SS_CTL);
v >>= 16;
@@ -360,9 +409,7 @@ static int sun4i_ss_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "Die ID %d\n", v);
writel(0, ss->base + SS_CTL);

- ss->dev = &pdev->dev;
-
- spin_lock_init(&ss->slock);
+ pm_runtime_put_sync(ss->dev);

for (i = 0; i < ARRAY_SIZE(ss_algs); i++) {
ss_algs[i].ss = ss;
@@ -392,7 +439,6 @@ static int sun4i_ss_probe(struct platform_device *pdev)
break;
}
}
- platform_set_drvdata(pdev, ss);
return 0;
error_alg:
i--;
@@ -409,8 +455,8 @@ static int sun4i_ss_probe(struct platform_device *pdev)
break;
}
}
-error_enable:
- sun4i_ss_disable(ss);
+error_pm:
+ sun4i_ss_pm_exit(ss);
return err;
}

@@ -433,8 +479,7 @@ static int sun4i_ss_remove(struct platform_device *pdev)
}
}

- writel(0, ss->base + SS_CTL);
- sun4i_ss_disable(ss);
+ sun4i_ss_pm_exit(ss);
return 0;
}

@@ -449,6 +494,7 @@ static struct platform_driver sun4i_ss_driver = {
.remove = sun4i_ss_remove,
.driver = {
.name = "sun4i-ss",
+ .pm = &sun4i_ss_pm_ops,
.of_match_table = a20ss_crypto_of_match_table,
},
};
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
index fcffba5ef927..9930c9ce8971 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
@@ -19,17 +19,29 @@ int sun4i_hash_crainit(struct crypto_tfm *tfm)
struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
struct ahash_alg *alg = __crypto_ahash_alg(tfm->__crt_alg);
struct sun4i_ss_alg_template *algt;
+ int err;

memset(op, 0, sizeof(struct sun4i_tfm_ctx));

algt = container_of(alg, struct sun4i_ss_alg_template, alg.hash);
op->ss = algt->ss;

+ err = pm_runtime_get_sync(op->ss->dev);
+ if (err < 0)
+ return err;
+
crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
sizeof(struct sun4i_req_ctx));
return 0;
}

+void sun4i_hash_craexit(struct crypto_tfm *tfm)
+{
+ struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
+
+ pm_runtime_put(op->ss->dev);
+}
+
/* sun4i_hash_init: initialize request context */
int sun4i_hash_init(struct ahash_request *areq)
{
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-prng.c b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
index 63d636424161..729aafdbea84 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-prng.c
@@ -17,7 +17,7 @@ int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
{
struct sun4i_ss_alg_template *algt;
struct rng_alg *alg = crypto_rng_alg(tfm);
- int i;
+ int i, err;
u32 v;
u32 *data = (u32 *)dst;
const u32 mode = SS_OP_PRNG | SS_PRNG_CONTINUE | SS_ENABLED;
@@ -28,6 +28,10 @@ int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,
algt = container_of(alg, struct sun4i_ss_alg_template, alg.rng);
ss = algt->ss;

+ err = pm_runtime_get_sync(ss->dev);
+ if (err < 0)
+ return err;
+
spin_lock_bh(&ss->slock);

writel(mode, ss->base + SS_CTL);
@@ -52,5 +56,8 @@ int sun4i_ss_prng_generate(struct crypto_rng *tfm, const u8 *src,

writel(0, ss->base + SS_CTL);
spin_unlock_bh(&ss->slock);
+
+ pm_runtime_put(ss->dev);
+
return 0;
}
diff --git a/drivers/crypto/sunxi-ss/sun4i-ss.h b/drivers/crypto/sunxi-ss/sun4i-ss.h
index 35a27a7145f8..60425ac75d90 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss.h
+++ b/drivers/crypto/sunxi-ss/sun4i-ss.h
@@ -22,6 +22,7 @@
#include <linux/scatterlist.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
+#include <linux/pm_runtime.h>
#include <crypto/md5.h>
#include <crypto/skcipher.h>
#include <crypto/sha.h>
@@ -177,6 +178,7 @@ struct sun4i_req_ctx {
};

int sun4i_hash_crainit(struct crypto_tfm *tfm);
+void sun4i_hash_craexit(struct crypto_tfm *tfm);
int sun4i_hash_init(struct ahash_request *areq);
int sun4i_hash_update(struct ahash_request *areq);
int sun4i_hash_final(struct ahash_request *areq);