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[HWRNG]: move status polling loop to data_present callbacks

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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>
This commit is contained in:
Patrick McHardy 2007-11-21 12:24:45 +08:00 committed by Herbert Xu
parent 2407d60872
commit 984e976f53
8 changed files with 71 additions and 36 deletions
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12
drivers/char/hw_random/amd-rng.c
View File

@ -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)

24
drivers/char/hw_random/core.c
View File

@ -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);

12
drivers/char/hw_random/geode-rng.c
View File

@ -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;
}

13
drivers/char/hw_random/intel-rng.c
View File

@ -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;
int data, i;
return !!(readb(mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT);
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)

13
drivers/char/hw_random/omap-rng.c
View File

@ -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)

12
drivers/char/hw_random/pasemi-rng.c
View File

@ -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;
int data, i;
return (in_le32(rng_regs + SDCRNG_CTL_REG)
& SDCRNG_CTL_FVLD_M) ? 1 : 0;
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)

19
drivers/char/hw_random/via-rng.c
View File

@ -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)

2
include/linux/hw_random.h
View File

@ -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;