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authorPatrick McHardy <kaber@trash.net>2007-11-21 12:24:45 +0800
committerHerbert Xu <herbert@gondor.apana.org.au>2008-01-11 08:16:16 +1100
commit984e976f5382ff09351ddd3b023937611396d739 (patch)
tree2fcce0de19b06547772f015b8409efc3d2c8d52a
parent[CRYPTO] salsa20: Salsa20 stream cipher (diff)
downloadlinux-dev-984e976f5382ff09351ddd3b023937611396d739.tar.xz
linux-dev-984e976f5382ff09351ddd3b023937611396d739.zip
[HWRNG]: move status polling loop to data_present callbacks
Handle waiting for new random within the drivers themselves, this allows to use better suited timeouts for the individual rngs. Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Michael Buesch <mb@bu3sch.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
-rw-r--r--drivers/char/hw_random/amd-rng.c12
-rw-r--r--drivers/char/hw_random/core.c24
-rw-r--r--drivers/char/hw_random/geode-rng.c12
-rw-r--r--drivers/char/hw_random/intel-rng.c15
-rw-r--r--drivers/char/hw_random/omap-rng.c13
-rw-r--r--drivers/char/hw_random/pasemi-rng.c14
-rw-r--r--drivers/char/hw_random/via-rng.c19
-rw-r--r--include/linux/hw_random.h2
8 files changed, 73 insertions, 38 deletions
diff --git a/drivers/char/hw_random/amd-rng.c b/drivers/char/hw_random/amd-rng.c
index 556fd81fa815..c422e870dc52 100644
--- a/drivers/char/hw_random/amd-rng.c
+++ b/drivers/char/hw_random/amd-rng.c
@@ -28,6 +28,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -52,11 +53,18 @@ MODULE_DEVICE_TABLE(pci, pci_tbl);
static struct pci_dev *amd_pdev;
-static int amd_rng_data_present(struct hwrng *rng)
+static int amd_rng_data_present(struct hwrng *rng, int wait)
{
u32 pmbase = (u32)rng->priv;
+ int data, i;
- return !!(inl(pmbase + 0xF4) & 1);
+ for (i = 0; i < 20; i++) {
+ data = !!(inl(pmbase + 0xF4) & 1);
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int amd_rng_data_read(struct hwrng *rng, u32 *data)
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index 26a860adcb38..0118b9817a95 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -66,11 +66,11 @@ static inline void hwrng_cleanup(struct hwrng *rng)
rng->cleanup(rng);
}
-static inline int hwrng_data_present(struct hwrng *rng)
+static inline int hwrng_data_present(struct hwrng *rng, int wait)
{
if (!rng->data_present)
return 1;
- return rng->data_present(rng);
+ return rng->data_present(rng, wait);
}
static inline int hwrng_data_read(struct hwrng *rng, u32 *data)
@@ -94,8 +94,7 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
{
u32 data;
ssize_t ret = 0;
- int i, err = 0;
- int data_present;
+ int err = 0;
int bytes_read;
while (size) {
@@ -107,21 +106,10 @@ static ssize_t rng_dev_read(struct file *filp, char __user *buf,
err = -ENODEV;
goto out;
}
- if (filp->f_flags & O_NONBLOCK) {
- data_present = hwrng_data_present(current_rng);
- } else {
- /* Some RNG require some time between data_reads to gather
- * new entropy. Poll it.
- */
- for (i = 0; i < 20; i++) {
- data_present = hwrng_data_present(current_rng);
- if (data_present)
- break;
- udelay(10);
- }
- }
+
bytes_read = 0;
- if (data_present)
+ if (hwrng_data_present(current_rng,
+ !(filp->f_flags & O_NONBLOCK)))
bytes_read = hwrng_data_read(current_rng, &data);
mutex_unlock(&rng_mutex);
diff --git a/drivers/char/hw_random/geode-rng.c b/drivers/char/hw_random/geode-rng.c
index 8e8658dcd2e3..fed4ef5569f5 100644
--- a/drivers/char/hw_random/geode-rng.c
+++ b/drivers/char/hw_random/geode-rng.c
@@ -28,6 +28,7 @@
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -61,11 +62,18 @@ static int geode_rng_data_read(struct hwrng *rng, u32 *data)
return 4;
}
-static int geode_rng_data_present(struct hwrng *rng)
+static int geode_rng_data_present(struct hwrng *rng, int wait)
{
void __iomem *mem = (void __iomem *)rng->priv;
+ int data, i;
- return !!(readl(mem + GEODE_RNG_STATUS_REG));
+ for (i = 0; i < 20; i++) {
+ data = !!(readl(mem + GEODE_RNG_STATUS_REG));
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
diff --git a/drivers/char/hw_random/intel-rng.c b/drivers/char/hw_random/intel-rng.c
index 753f46052b87..5cc651ef75eb 100644
--- a/drivers/char/hw_random/intel-rng.c
+++ b/drivers/char/hw_random/intel-rng.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/stop_machine.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -162,11 +163,19 @@ static inline u8 hwstatus_set(void __iomem *mem,
return hwstatus_get(mem);
}
-static int intel_rng_data_present(struct hwrng *rng)
+static int intel_rng_data_present(struct hwrng *rng, int wait)
{
void __iomem *mem = (void __iomem *)rng->priv;
-
- return !!(readb(mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT);
+ int data, i;
+
+ for (i = 0; i < 20; i++) {
+ data = !!(readb(mem + INTEL_RNG_STATUS) &
+ INTEL_RNG_DATA_PRESENT);
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int intel_rng_data_read(struct hwrng *rng, u32 *data)
diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index 3f35a1c562b1..7e319951fa41 100644
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -29,6 +29,7 @@
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
@@ -65,9 +66,17 @@ static void omap_rng_write_reg(int reg, u32 val)
}
/* REVISIT: Does the status bit really work on 16xx? */
-static int omap_rng_data_present(struct hwrng *rng)
+static int omap_rng_data_present(struct hwrng *rng, int wait)
{
- return omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1;
+ int data, i;
+
+ for (i = 0; i < 20; i++) {
+ data = omap_rng_read_reg(RNG_STAT_REG) ? 0 : 1;
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int omap_rng_data_read(struct hwrng *rng, u32 *data)
diff --git a/drivers/char/hw_random/pasemi-rng.c b/drivers/char/hw_random/pasemi-rng.c
index fa6040b6c8f2..621adf25e580 100644
--- a/drivers/char/hw_random/pasemi-rng.c
+++ b/drivers/char/hw_random/pasemi-rng.c
@@ -23,6 +23,7 @@
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/of_platform.h>
#include <asm/io.h>
@@ -44,9 +45,16 @@
static int pasemi_rng_data_present(struct hwrng *rng)
{
void __iomem *rng_regs = (void __iomem *)rng->priv;
-
- return (in_le32(rng_regs + SDCRNG_CTL_REG)
- & SDCRNG_CTL_FVLD_M) ? 1 : 0;
+ int data, i;
+
+ for (i = 0; i < 20; i++) {
+ data = (in_le32(rng_regs + SDCRNG_CTL_REG)
+ & SDCRNG_CTL_FVLD_M) ? 1 : 0;
+ if (data || !wait)
+ break;
+ udelay(10);
+ }
+ return data;
}
static int pasemi_rng_data_read(struct hwrng *rng, u32 *data)
diff --git a/drivers/char/hw_random/via-rng.c b/drivers/char/hw_random/via-rng.c
index ec435cb25c4f..868e39fd42e4 100644
--- a/drivers/char/hw_random/via-rng.c
+++ b/drivers/char/hw_random/via-rng.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hw_random.h>
+#include <linux/delay.h>
#include <asm/io.h>
#include <asm/msr.h>
#include <asm/cpufeature.h>
@@ -77,10 +78,11 @@ static inline u32 xstore(u32 *addr, u32 edx_in)
return eax_out;
}
-static int via_rng_data_present(struct hwrng *rng)
+static int via_rng_data_present(struct hwrng *rng, int wait)
{
u32 bytes_out;
u32 *via_rng_datum = (u32 *)(&rng->priv);
+ int i;
/* We choose the recommended 1-byte-per-instruction RNG rate,
* for greater randomness at the expense of speed. Larger
@@ -95,12 +97,15 @@ static int via_rng_data_present(struct hwrng *rng)
* completes.
*/
- *via_rng_datum = 0; /* paranoia, not really necessary */
- bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
- bytes_out &= VIA_XSTORE_CNT_MASK;
- if (bytes_out == 0)
- return 0;
- return 1;
+ for (i = 0; i < 20; i++) {
+ *via_rng_datum = 0; /* paranoia, not really necessary */
+ bytes_out = xstore(via_rng_datum, VIA_RNG_CHUNK_1);
+ bytes_out &= VIA_XSTORE_CNT_MASK;
+ if (bytes_out || !wait)
+ break;
+ udelay(10);
+ }
+ return bytes_out ? 1 : 0;
}
static int via_rng_data_read(struct hwrng *rng, u32 *data)
diff --git a/include/linux/hw_random.h b/include/linux/hw_random.h
index 21ea7610e177..85d11916e9ea 100644
--- a/include/linux/hw_random.h
+++ b/include/linux/hw_random.h
@@ -33,7 +33,7 @@ struct hwrng {
const char *name;
int (*init)(struct hwrng *rng);
void (*cleanup)(struct hwrng *rng);
- int (*data_present)(struct hwrng *rng);
+ int (*data_present)(struct hwrng *rng, int wait);
int (*data_read)(struct hwrng *rng, u32 *data);
unsigned long priv;