cryp: Session handling for software context

 - Add a session id to the software crypto context in ux500 crypto
   driver.

 - Add a static global session id which is a counter that increases when
   a new job is started (it is ok that this variable loop back to
   zero when it reach the maximum value).

 - These session id's will be used to decide if the hardware registers
   needs be restored or not for continous jobs. As a result we gain
   performance when we don't need to restore hardware registers.

ST-Ericsson ID: 342659
ST-Ericsson Linux next: Not tested, ER 320876
ST-Ericsson FOSS-OUT ID: Trivial

Change-Id: I1a1f508e9969e438204d1b4a803f1d637c1e0d60
Signed-off-by: Joakim Bech <joakim.xx.bech@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/24019
Reviewed-by: QATOOLS
Reviewed-by: QATEST
Reviewed-by: Berne HEBARK <berne.hebark@stericsson.com>

2 files changed, 30 insertions, 9 deletions

diff --git a/drivers/crypto/ux500/cryp/cryp.h b/drivers/crypto/ux500/cryp/cryp.h
index bfa2beb694f..36835a3982e 100644
--- a/drivers/crypto/ux500/cryp/cryp.h
+++ b/drivers/crypto/ux500/cryp/cryp.h
@@ -80,7 +80,6 @@ enum cryp_mode {
 
 /**
  * struct cryp_config -
- * @keyrden: Cryp state enable/disable
  * @keysize: Key size for AES
  * @algomode: AES modes
  * @algodir: Cryp Encryption or Decryption
@@ -88,7 +87,6 @@ enum cryp_mode {
  * CRYP configuration structure to be passed to set configuration
  */
 struct cryp_config {
-	enum cryp_state keyrden;
 	int keysize;
 	enum cryp_algo_mode algomode;
 	enum cryp_algorithm_dir algodir;
diff --git a/drivers/crypto/ux500/cryp/cryp_core.c b/drivers/crypto/ux500/cryp/cryp_core.c
index 051874bff03..9cbfc63ba2b 100644
--- a/drivers/crypto/ux500/cryp/cryp_core.c
+++ b/drivers/crypto/ux500/cryp/cryp_core.c
@@ -42,6 +42,7 @@
 #define BYTES_PER_WORD		4
 
 static int cryp_mode;
+static atomic_t session_id;
 
 static struct stedma40_chan_cfg *mem_to_engine;
 static struct stedma40_chan_cfg *engine_to_mem;
@@ -85,6 +86,7 @@ struct cryp_ctx {
 	u8 updated;
 	struct cryp_device_context dev_ctx;
 	struct cryp_device_data *device;
+	u32 session_id;
 };
 
 static struct cryp_driver_data driver_data;
@@ -176,6 +178,18 @@ static inline void swap_words_in_key_and_bits_in_byte(const u8 *in,
 	}
 }
 
+static void add_session_id(struct cryp_ctx *ctx)
+{
+	/*
+	 * We never want 0 to be a valid value, since this is the default value
+	 * for the software context.
+	 */
+	if (unlikely(atomic_inc_and_test(&session_id)))
+		atomic_inc(&session_id);
+
+	ctx->session_id = atomic_read(&session_id);
+}
+
 static irqreturn_t cryp_interrupt_handler(int irq, void *param)
 {
 	struct cryp_ctx *ctx;
@@ -359,11 +373,10 @@ static int cryp_setup_context(struct cryp_ctx *ctx,
 			      struct cryp_device_data *device_data)
 {
 	u32 control_register = CRYP_CR_DEFAULT;
-	cryp_flush_inoutfifo(device_data);
 
 	switch (cryp_mode) {
 	case CRYP_MODE_INTERRUPT:
-		writel(CRYP_IMSC_DEFAULT,  &device_data->base->imsc);
+		writel(CRYP_IMSC_DEFAULT, &device_data->base->imsc);
 		break;
 
 	case CRYP_MODE_DMA:
@@ -374,10 +387,8 @@ static int cryp_setup_context(struct cryp_ctx *ctx,
 		break;
 	}
 
-	if (ctx->updated) {
-		cryp_restore_device_context(device_data, &ctx->dev_ctx);
-		control_register = ctx->dev_ctx.cr;
-	} else {
+	if (ctx->updated == 0) {
+		cryp_flush_inoutfifo(device_data);
 		if (cfg_keys(ctx) != 0) {
 			dev_err(ctx->device->dev, "[%s]: cfg_keys failed!",
 				__func__);
@@ -394,7 +405,16 @@ static int cryp_setup_context(struct cryp_ctx *ctx,
 
 		cryp_set_configuration(device_data, &ctx->config,
 				       &control_register);
-	}
+		add_session_id(ctx);
+	} else if (ctx->updated == 1 &&
+		   ctx->session_id != atomic_read(&session_id)) {
+		cryp_flush_inoutfifo(device_data);
+		cryp_restore_device_context(device_data, &ctx->dev_ctx);
+
+		add_session_id(ctx);
+		control_register = ctx->dev_ctx.cr;
+	} else
+		control_register = ctx->dev_ctx.cr;
 
 	writel(control_register | (CRYP_CRYPEN_ENABLE << CRYP_CR_CRYPEN_POS),
 	       &device_data->base->cr);
@@ -735,6 +755,7 @@ static int hw_crypt_noxts(struct cryp_ctx *ctx,
 	}
 
 	ret = cryp_setup_context(ctx, device_data);
+
 	if (ret)
 		goto out;
 
@@ -2017,6 +2038,8 @@ static int u8500_cryp_probe(struct platform_device *pdev)
 	/* ... and signal that a new device is available. */
 	up(&driver_data.device_allocation);
 
+	atomic_set(&session_id, 1);
+
 	ret = cryp_algs_register_all();
 	if (ret) {
 		dev_err(dev, "[%s]: cryp_algs_register_all() failed!",