Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1407981

[PATCH v2 4/4] hwrng: bcm2835: Read as much data as available

Show all headers | View raw

Read the requested number of data from the fifo

Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
---
 drivers/char/hw_random/bcm2835-rng.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/bcm2835-rng.c b/drivers/char/hw_random/bcm2835-rng.c
index b1e8b78..75ca820 100644
--- a/drivers/char/hw_random/bcm2835-rng.c
+++ b/drivers/char/hw_random/bcm2835-rng.c
@@ -43,6 +43,8 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 			       bool wait)
 {
 	void __iomem *rng_base = (void __iomem *)rng->priv;
+	u32 max_words = max / sizeof(u32);
+	u32 num_words, count;
 
 	while ((__raw_readl(rng_base + RNG_STATUS) >> 24) == 0) {
 		if (!wait)
@@ -50,8 +52,14 @@ static int bcm2835_rng_read(struct hwrng *rng, void *buf, size_t max,
 		cpu_relax();
 	}
 
-	*(u32 *)buf = __raw_readl(rng_base + RNG_DATA);
-	return sizeof(u32);
+	num_words = readl(rng_base + RNG_STATUS) >> 24;
+	if (num_words > max_words)
+		num_words = max_words;
+
+	for (count = 0; count < num_words; count++)
+		((u32 *)buf)[count] = readl(rng_base + RNG_DATA);
+
+	return num_words * sizeof(u32);
 }
 
 static struct hwrng bcm2835_rng_ops = {
-- 
2.1.0

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH v2 0/4] hw rng support for NSP SoC Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200
  [PATCH v2 3/4] ARM: dts: nsp: Add rng device tree entry Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200
  [PATCH v2 4/4] hwrng: bcm2835: Read as much data as available Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> - 2016-05-27 12:20 +0200

csiph-web