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-rw-r--r--drivers/crypto/caam/ctrl.c63
-rw-r--r--drivers/crypto/caam/regs.h7
2 files changed, 52 insertions, 18 deletions
diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 11c7f29..d5fe5f5 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -82,7 +82,7 @@ static int instantiate_rng(struct device *ctrldev)
struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
struct caam_full __iomem *topregs;
unsigned int timeout = 100000;
- u32 *desc;
+ u32 *desc, deco_dbg_reg;
int i, ret = 0;
desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL | GFP_DMA);
@@ -112,9 +112,17 @@ static int instantiate_rng(struct device *ctrldev)
wr_reg32(&topregs->deco.jr_ctl_hi, DECO_JQCR_WHL | DECO_JQCR_FOUR);
timeout = 10000000;
- while ((rd_reg32(&topregs->deco.desc_dbg) & DECO_DBG_VALID) &&
- --timeout)
+ do {
+ deco_dbg_reg = rd_reg32(&topregs->deco.desc_dbg);
+ /*
+ * If an error occured in the descriptor, then
+ * the DECO status field will be set to 0x0D
+ */
+ if ((deco_dbg_reg & DESC_DBG_DECO_STAT_MASK) ==
+ DESC_DBG_DECO_STAT_HOST_ERR)
+ break;
cpu_relax();
+ } while ((deco_dbg_reg & DESC_DBG_DECO_STAT_VALID) && --timeout);
if (!timeout) {
dev_err(ctrldev, "failed to instantiate RNG\n");
@@ -128,10 +136,12 @@ out:
}
/*
- * By default, the TRNG runs for 200 clocks per sample;
- * 1600 clocks per sample generates better entropy.
+ * kick_trng - sets the various parameters for enabling the initialization
+ * of the RNG4 block in CAAM
+ * @pdev - pointer to the platform device
+ * @ent_delay - Defines the length (in system clocks) of each entropy sample.
*/
-static void kick_trng(struct platform_device *pdev)
+static void kick_trng(struct platform_device *pdev, int ent_delay)
{
struct device *ctrldev = &pdev->dev;
struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
@@ -144,14 +154,31 @@ static void kick_trng(struct platform_device *pdev)
/* put RNG4 into program mode */
setbits32(&r4tst->rtmctl, RTMCTL_PRGM);
- /* 1600 clocks per sample */
+
+ /*
+ * Performance-wise, it does not make sense to
+ * set the delay to a value that is lower
+ * than the last one that worked (i.e. the state handles
+ * were instantiated properly. Thus, instead of wasting
+ * time trying to set the values controlling the sample
+ * frequency, the function simply returns.
+ */
+ val = (rd_reg32(&r4tst->rtsdctl) & RTSDCTL_ENT_DLY_MASK)
+ >> RTSDCTL_ENT_DLY_SHIFT;
+ if (ent_delay <= val) {
+ /* put RNG4 into run mode */
+ clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);
+ return;
+ }
+
val = rd_reg32(&r4tst->rtsdctl);
- val = (val & ~RTSDCTL_ENT_DLY_MASK) | (1600 << RTSDCTL_ENT_DLY_SHIFT);
+ val = (val & ~RTSDCTL_ENT_DLY_MASK) |
+ (ent_delay << RTSDCTL_ENT_DLY_SHIFT);
wr_reg32(&r4tst->rtsdctl, val);
- /* min. freq. count */
- wr_reg32(&r4tst->rtfrqmin, 400);
- /* max. freq. count */
- wr_reg32(&r4tst->rtfrqmax, 6400);
+ /* min. freq. count, equal to 1/4 of the entropy sample length */
+ wr_reg32(&r4tst->rtfrqmin, ent_delay >> 2);
+ /* max. freq. count, equal to 8 times the entropy sample length */
+ wr_reg32(&r4tst->rtfrqmax, ent_delay << 3);
/* put RNG4 into run mode */
clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);
}
@@ -192,7 +219,7 @@ EXPORT_SYMBOL(caam_get_era);
/* Probe routine for CAAM top (controller) level */
static int caam_probe(struct platform_device *pdev)
{
- int ret, ring, rspec;
+ int ret, ring, rspec, ent_delay = RTSDCTL_ENT_DLY_MIN;
u64 caam_id;
struct device *dev;
struct device_node *nprop, *np;
@@ -298,13 +325,17 @@ static int caam_probe(struct platform_device *pdev)
/*
* If SEC has RNG version >= 4 and RNG state handle has not been
- * already instantiated ,do RNG instantiation
+ * already instantiated, do RNG instantiation
*/
if ((cha_vid & CHA_ID_RNG_MASK) >> CHA_ID_RNG_SHIFT >= 4 &&
!(rd_reg32(&topregs->ctrl.r4tst[0].rdsta) & RDSTA_IF0)) {
- kick_trng(pdev);
- ret = instantiate_rng(dev);
+ do {
+ kick_trng(pdev, ent_delay);
+ ret = instantiate_rng(dev);
+ ent_delay += 400;
+ } while ((ret == -EIO) && (ent_delay < RTSDCTL_ENT_DLY_MAX));
if (ret) {
+ dev_err(dev, "failed to instantiate RNG");
caam_remove(pdev);
return ret;
}
diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h
index 4455396..9aa9f71 100644
--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@ -255,6 +255,8 @@ struct rng4tst {
};
#define RTSDCTL_ENT_DLY_SHIFT 16
#define RTSDCTL_ENT_DLY_MASK (0xffff << RTSDCTL_ENT_DLY_SHIFT)
+#define RTSDCTL_ENT_DLY_MIN 1200
+#define RTSDCTL_ENT_DLY_MAX 12800
u32 rtsdctl; /* seed control register */
union {
u32 rtsblim; /* PRGM=1: sparse bit limit register */
@@ -706,12 +708,13 @@ struct caam_deco {
u32 rsvd29[48];
u32 descbuf[64]; /* DxDESB - Descriptor buffer */
u32 rscvd30[193];
+#define DESC_DBG_DECO_STAT_HOST_ERR 0x00D00000
+#define DESC_DBG_DECO_STAT_VALID 0x80000000
+#define DESC_DBG_DECO_STAT_MASK 0x00F00000
u32 desc_dbg; /* DxDDR - DECO Debug Register */
u32 rsvd31[126];
};
-/* DECO DBG Register Valid Bit*/
-#define DECO_DBG_VALID 0x80000000
#define DECO_JQCR_WHL 0x20000000
#define DECO_JQCR_FOUR 0x10000000