[PATCH v2 0/2] Add dm_rng_read_default() helper
Hello!
This patchset adds dm_rng_read_default() helper function, that selects the first rng device and uses it to obtain random bytes.
V2:
- Move platform_get_rng_device() to rng-uclass.c. - Re-implement it to get first successfully probed device. - Use it in dm_rng_read_default().
Alexey Romanov (2): rng: move platform_get_rng_device() to rng-uclass.c rng: add dm_rng_read_default() helper
drivers/rng/rng-uclass.c | 34 ++++++++++++++++++++++++++++++++++ include/efi_rng.h | 2 -- include/rng.h | 21 +++++++++++++++++++++ lib/efi_loader/efi_rng.c | 27 --------------------------- 4 files changed, 55 insertions(+), 29 deletions(-)
The correct declaration place for platform_get_rng_device() function is here. Also, this function is re-implemented to provide the first successfully probed RNG device.
Signed-off-by: Alexey Romanov avromanov@salutedevices.com --- drivers/rng/rng-uclass.c | 16 ++++++++++++++++ include/efi_rng.h | 2 -- include/rng.h | 11 +++++++++++ lib/efi_loader/efi_rng.c | 27 --------------------------- 4 files changed, 27 insertions(+), 29 deletions(-)
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c index 53108e1b31..d7236b9335 100644 --- a/drivers/rng/rng-uclass.c +++ b/drivers/rng/rng-uclass.c @@ -9,6 +9,22 @@ #include <dm.h> #include <rng.h>
+int platform_get_rng_device(struct udevice **dev) +{ + int ret; + struct udevice *devp; + + ret = uclass_first_device_check(UCLASS_RNG, &devp); + if (ret) { + pr_err("Unable to get RNG device (%d)\n", ret); + return -ENODEV; + } + + *dev = devp; + + return 0; +} + int dm_rng_read(struct udevice *dev, void *buffer, size_t size) { const struct dm_rng_ops *ops = device_get_ops(dev); diff --git a/include/efi_rng.h b/include/efi_rng.h index 3c622381cb..f22e54adb0 100644 --- a/include/efi_rng.h +++ b/include/efi_rng.h @@ -23,6 +23,4 @@ struct efi_rng_protocol { efi_uintn_t rng_value_length, uint8_t *rng_value); };
-efi_status_t platform_get_rng_device(struct udevice **dev); - #endif /* _EFI_RNG_H_ */ diff --git a/include/rng.h b/include/rng.h index 37af554363..255c85d3e8 100644 --- a/include/rng.h +++ b/include/rng.h @@ -20,6 +20,17 @@ struct udevice; */ int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+/** + * platform_get_rng_device() - retrieve random number generator + * + * This function retrieves the first udevice implementing a hardware + * random number generator. Device is already probed. + * + * @dev: udevice + * Return: status code + */ +int platform_get_rng_device(struct udevice **dev); + /** * struct dm_rng_ops - operations for the hwrng uclass * diff --git a/lib/efi_loader/efi_rng.c b/lib/efi_loader/efi_rng.c index bb11d8d0e0..0d8bf770f5 100644 --- a/lib/efi_loader/efi_rng.c +++ b/lib/efi_loader/efi_rng.c @@ -17,33 +17,6 @@ DECLARE_GLOBAL_DATA_PTR;
const efi_guid_t efi_guid_rng_protocol = EFI_RNG_PROTOCOL_GUID;
-/** - * platform_get_rng_device() - retrieve random number generator - * - * This function retrieves the udevice implementing a hardware random - * number generator. - * - * This function may be overridden if special initialization is needed. - * - * @dev: udevice - * Return: status code - */ -__weak efi_status_t platform_get_rng_device(struct udevice **dev) -{ - int ret; - struct udevice *devp; - - ret = uclass_get_device(UCLASS_RNG, 0, &devp); - if (ret) { - debug("Unable to get rng device\n"); - return EFI_DEVICE_ERROR; - } - - *dev = devp; - - return EFI_SUCCESS; -} - /** * rng_getinfo() - get information about random number generation *
On 11/2/23 11:16, Alexey Romanov wrote:
The correct declaration place for platform_get_rng_device() function is here. Also, this function is re-implemented to provide the first successfully probed RNG device.
Signed-off-by: Alexey Romanov avromanov@salutedevices.com
drivers/rng/rng-uclass.c | 16 ++++++++++++++++ include/efi_rng.h | 2 -- include/rng.h | 11 +++++++++++ lib/efi_loader/efi_rng.c | 27 --------------------------- 4 files changed, 27 insertions(+), 29 deletions(-)
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c index 53108e1b31..d7236b9335 100644 --- a/drivers/rng/rng-uclass.c +++ b/drivers/rng/rng-uclass.c @@ -9,6 +9,22 @@ #include <dm.h> #include <rng.h>
+int platform_get_rng_device(struct udevice **dev)
You are dropping __weak here. The rationale behind this change should be provided in the commit message.
Best regards
Heinrich
+{
- int ret;
- struct udevice *devp;
- ret = uclass_first_device_check(UCLASS_RNG, &devp);
- if (ret) {
pr_err("Unable to get RNG device (%d)\n", ret);return -ENODEV;- }
- *dev = devp;
- return 0;
+}
- int dm_rng_read(struct udevice *dev, void *buffer, size_t size) { const struct dm_rng_ops *ops = device_get_ops(dev);
diff --git a/include/efi_rng.h b/include/efi_rng.h index 3c622381cb..f22e54adb0 100644 --- a/include/efi_rng.h +++ b/include/efi_rng.h @@ -23,6 +23,4 @@ struct efi_rng_protocol { efi_uintn_t rng_value_length, uint8_t *rng_value); };
-efi_status_t platform_get_rng_device(struct udevice **dev);
- #endif /* _EFI_RNG_H_ */
diff --git a/include/rng.h b/include/rng.h index 37af554363..255c85d3e8 100644 --- a/include/rng.h +++ b/include/rng.h @@ -20,6 +20,17 @@ struct udevice; */ int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+/**
- platform_get_rng_device() - retrieve random number generator
- This function retrieves the first udevice implementing a hardware
- random number generator. Device is already probed.
- @dev: udevice
- Return: status code
- */
+int platform_get_rng_device(struct udevice **dev);
- /**
- struct dm_rng_ops - operations for the hwrng uclass
diff --git a/lib/efi_loader/efi_rng.c b/lib/efi_loader/efi_rng.c index bb11d8d0e0..0d8bf770f5 100644 --- a/lib/efi_loader/efi_rng.c +++ b/lib/efi_loader/efi_rng.c @@ -17,33 +17,6 @@ DECLARE_GLOBAL_DATA_PTR;
const efi_guid_t efi_guid_rng_protocol = EFI_RNG_PROTOCOL_GUID;
-/**
- platform_get_rng_device() - retrieve random number generator
- This function retrieves the udevice implementing a hardware random
- number generator.
- This function may be overridden if special initialization is needed.
- @dev: udevice
- Return: status code
- */
-__weak efi_status_t platform_get_rng_device(struct udevice **dev) -{
- int ret;
- struct udevice *devp;
- ret = uclass_get_device(UCLASS_RNG, 0, &devp);
- if (ret) {
debug("Unable to get rng device\n");return EFI_DEVICE_ERROR;- }
- *dev = devp;
- return EFI_SUCCESS;
-}
- /**
- rng_getinfo() - get information about random number generation
Hi Alexey,
On Thu, 2 Nov 2023 at 12:58, Alexey Romanov avromanov@salutedevices.com wrote:
The correct declaration place for platform_get_rng_device() function is here. Also, this function is re-implemented to provide the first successfully probed RNG device.
Signed-off-by: Alexey Romanov avromanov@salutedevices.com
drivers/rng/rng-uclass.c | 16 ++++++++++++++++ include/efi_rng.h | 2 -- include/rng.h | 11 +++++++++++ lib/efi_loader/efi_rng.c | 27 --------------------------- 4 files changed, 27 insertions(+), 29 deletions(-)
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c index 53108e1b31..d7236b9335 100644 --- a/drivers/rng/rng-uclass.c +++ b/drivers/rng/rng-uclass.c @@ -9,6 +9,22 @@ #include <dm.h> #include <rng.h>
+int platform_get_rng_device(struct udevice **dev) +{
int ret;struct udevice *devp;ret = uclass_first_device_check(UCLASS_RNG, &devp);if (ret) {pr_err("Unable to get RNG device (%d)\n", ret);return -ENODEV;}*dev = devp;return 0;+}
Why not delete this function? It doesn't seem to do anything useful except return the wrong error code if something goes wrong :-)
I worry that people might add other logic to it.
Also you might consider using rng0, rng1 aliases so people can actually choose the device to use? If you want that you could uclass_get_device_by_seq()
int dm_rng_read(struct udevice *dev, void *buffer, size_t size) { const struct dm_rng_ops *ops = device_get_ops(dev); diff --git a/include/efi_rng.h b/include/efi_rng.h index 3c622381cb..f22e54adb0 100644 --- a/include/efi_rng.h +++ b/include/efi_rng.h @@ -23,6 +23,4 @@ struct efi_rng_protocol { efi_uintn_t rng_value_length, uint8_t *rng_value); };
-efi_status_t platform_get_rng_device(struct udevice **dev);
#endif /* _EFI_RNG_H_ */ diff --git a/include/rng.h b/include/rng.h index 37af554363..255c85d3e8 100644 --- a/include/rng.h +++ b/include/rng.h @@ -20,6 +20,17 @@ struct udevice; */ int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+/**
- platform_get_rng_device() - retrieve random number generator
- This function retrieves the first udevice implementing a hardware
- random number generator. Device is already probed.
- @dev: udevice
- Return: status code
- */
+int platform_get_rng_device(struct udevice **dev);
Better naming (if you do keep this) is rng_get_first()
There is no such thing as a 'platform' in U-Boot.
/**
- struct dm_rng_ops - operations for the hwrng uclass
diff --git a/lib/efi_loader/efi_rng.c b/lib/efi_loader/efi_rng.c index bb11d8d0e0..0d8bf770f5 100644 --- a/lib/efi_loader/efi_rng.c +++ b/lib/efi_loader/efi_rng.c @@ -17,33 +17,6 @@ DECLARE_GLOBAL_DATA_PTR;
const efi_guid_t efi_guid_rng_protocol = EFI_RNG_PROTOCOL_GUID;
-/**
- platform_get_rng_device() - retrieve random number generator
- This function retrieves the udevice implementing a hardware random
- number generator.
- This function may be overridden if special initialization is needed.
- @dev: udevice
- Return: status code
- */
-__weak efi_status_t platform_get_rng_device(struct udevice **dev) -{
int ret;struct udevice *devp;ret = uclass_get_device(UCLASS_RNG, 0, &devp);if (ret) {debug("Unable to get rng device\n");return EFI_DEVICE_ERROR;}*dev = devp;return EFI_SUCCESS;-}
/**
- rng_getinfo() - get information about random number generation
-- 2.30.1
Regards, Simon
Add dm_rng_read_default() function, which obtain a series of random bytes. In some cases, such function would be useful because it allows the caller to abstract away from RNG device.
Signed-off-by: Alexey Romanov avromanov@salutedevices.com --- drivers/rng/rng-uclass.c | 18 ++++++++++++++++++ include/rng.h | 10 ++++++++++ 2 files changed, 28 insertions(+)
diff --git a/drivers/rng/rng-uclass.c b/drivers/rng/rng-uclass.c index d7236b9335..e298623e1d 100644 --- a/drivers/rng/rng-uclass.c +++ b/drivers/rng/rng-uclass.c @@ -35,6 +35,24 @@ int dm_rng_read(struct udevice *dev, void *buffer, size_t size) return ops->read(dev, buffer, size); }
+int dm_rng_read_default(void *buffer, size_t size) +{ + struct udevice *rng; + int ret; + + ret = platform_get_rng_device(&rng); + if (ret) + return ret; + + ret = dm_rng_read(rng, buffer, size); + if (ret) { + pr_err("Can't read from RNG device (%d)\n", ret); + return ret; + } + + return 0; +} + UCLASS_DRIVER(rng) = { .name = "rng", .id = UCLASS_RNG, diff --git a/include/rng.h b/include/rng.h index 255c85d3e8..6412fedad2 100644 --- a/include/rng.h +++ b/include/rng.h @@ -20,6 +20,16 @@ struct udevice; */ int dm_rng_read(struct udevice *dev, void *buffer, size_t size);
+/** + * dm_rng_read_default() - same as dm_rng_read(), except that caller + * don't need to pass an argument with RNG udevice. + * @buffer: input buffer to put the read random seed into + * @size: number of bytes of random seed read + * + * Return: 0 if OK, -ve on error + */ +int dm_rng_read_default(void *buffer, size_t size); + /** * platform_get_rng_device() - retrieve random number generator *
Hi Alexey,
On Thu, 2 Nov 2023 at 12:57, Alexey Romanov avromanov@salutedevices.com wrote:
Add dm_rng_read_default() function, which obtain a series of random bytes. In some cases, such function would be useful because it allows the caller to abstract away from RNG device.
It should not do that. It should create a RNG device for its needs.
Signed-off-by: Alexey Romanov avromanov@salutedevices.com
drivers/rng/rng-uclass.c | 18 ++++++++++++++++++ include/rng.h | 10 ++++++++++ 2 files changed, 28 insertions(+)
Regards, Simon
participants (3)
-
Alexey Romanov -
Heinrich Schuchardt -
Simon Glass