Hi,
This is a follow up of my questions around exynos-rng [1].
Changes since v4:
=================
1. Patch 2/2: Use "stdrng" name, as suggested by Herbert.
2. Patch 2/2: Add Bartlomiej's reviewed-by.
Changes since v3:
=================
1. New patch: 1/2 for ALIGN_DOWN macro. The change in metag architecture
was not compiled. Please test it.
2. Dropped patches touching ARM defconfig as they are not changing and
they pollute this submission.
3. Utilize all seed provided by kcapi (suggested by Stephan Müller).
4. Drop dev->ctx (suggested by PrasannaKumar Muralidharan).
5. Remove any printks from set_seed callback as this might be a way
for unprivileged user to pollute the log (suggested by Stephan).
6. Minor cleanups: initialize 'read' variable in exynos_rng_reseed()
for readability (it is not strictly required).
7. Add review tags from Stephen and PrasannaKumar.
Changes since v2:
=================
1. Do not re-use random numbers for re-seed (neither for system resume
nor for periodic re-seed). Instead the driver will just generate new
random numbers (suggested by Stephan Müller).
Suspend path tested with suspend-to-freeze, not real suspend. Testing
on Trats2 would be welcomed.
Changes since v1:
=================
1. Re-work the code for seeding after system resume, following suggestions
and review by Stephan Müller.
2. Re-seed itself from time to time (every 100 ms), suggested by Stephan
Müller.
3. Use a define for retries (Bartlomiej Zolnierkiewicz).
4. Add some docs.
Description:
============
The existing exynos-rng has many issues. The most important one is that
it is a pseudo RNG device but uses hw_random interface which does not allow
proper seeding.
The RNG module on Exynos4 requires seeding. On newer SoCs (like Exynos5420)
it can seed itself from a true RNG. Converting the existing driver
to use TRNG would effectively drop support for Exynos4 and break
compatibility with existing users.
Instead I decided to convert it to crypto API. In the future I hope
to add support for seeding from TRNG module.
Tested with app [2].
Patches are independent. I will take the defconfig changes (2/3 and 3/3)
through samsung-soc tree.
Best regards,
Krzysztof
[1] https://www.spinics.net/lists/arm-kernel/msg569641.html
[2] https://www.spinics.net/lists/arm-kernel/msg571184.html
Krzysztof Kozlowski (2):
linux/kernel.h: Add ALIGN_DOWN macro
crypto: hw_random - Add new Exynos RNG driver
MAINTAINERS | 8 +
arch/metag/kernel/stacktrace.c | 2 -
drivers/char/hw_random/Kconfig | 14 --
drivers/char/hw_random/Makefile | 1 -
drivers/char/hw_random/exynos-rng.c | 231 ---------------------
drivers/crypto/Kconfig | 15 ++
drivers/crypto/Makefile | 1 +
drivers/crypto/exynos-rng.c | 389 ++++++++++++++++++++++++++++++++++++
drivers/gpu/drm/udl/udl_fb.c | 2 +-
include/linux/kernel.h | 1 +
include/video/udlfb.h | 2 +-
11 files changed, 416 insertions(+), 250 deletions(-)
delete mode 100644 drivers/char/hw_random/exynos-rng.c
create mode 100644 drivers/crypto/exynos-rng.c
--
2.9.3
Few parts of kernel define their own macro for aligning down so provide
a common define for this, with the same usage and assumptions as existing
ALIGN.
Convert also three existing implementations to this one.
Signed-off-by: Krzysztof Kozlowski <[email protected]>
---
The metag change was not even compiled due to lack of cross compiler.
---
arch/metag/kernel/stacktrace.c | 2 --
drivers/gpu/drm/udl/udl_fb.c | 2 +-
include/linux/kernel.h | 1 +
include/video/udlfb.h | 2 +-
4 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/metag/kernel/stacktrace.c b/arch/metag/kernel/stacktrace.c
index 91ffc4b75c33..09d67b7f51ca 100644
--- a/arch/metag/kernel/stacktrace.c
+++ b/arch/metag/kernel/stacktrace.c
@@ -31,8 +31,6 @@ static void tbi_boing_init(void)
}
#endif
-#define ALIGN_DOWN(addr, size) ((addr)&(~((size)-1)))
-
/*
* Unwind the current stack frame and store the new register values in the
* structure passed as argument. Unwinding is equivalent to a function return,
diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
index d05abc69e305..4a6500362564 100644
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@@ -37,7 +37,7 @@ struct udl_fbdev {
};
#define DL_ALIGN_UP(x, a) ALIGN(x, a)
-#define DL_ALIGN_DOWN(x, a) ALIGN(x-(a-1), a)
+#define DL_ALIGN_DOWN(x, a) ALIGN_DOWN(x, a)
/** Read the red component (0..255) of a 32 bpp colour. */
#define DLO_RGB_GETRED(col) (uint8_t)((col) & 0xFF)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 4c26dc3a8295..3d9f8420f973 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -47,6 +47,7 @@
/* @a is a power of 2 value */
#define ALIGN(x, a) __ALIGN_KERNEL((x), (a))
+#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a))
#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask))
#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a)))
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0)
diff --git a/include/video/udlfb.h b/include/video/udlfb.h
index f9466fa54ba4..3ea90aea5617 100644
--- a/include/video/udlfb.h
+++ b/include/video/udlfb.h
@@ -92,6 +92,6 @@ struct dlfb_data {
/* remove these once align.h patch is taken into kernel */
#define DL_ALIGN_UP(x, a) ALIGN(x, a)
-#define DL_ALIGN_DOWN(x, a) ALIGN(x-(a-1), a)
+#define DL_ALIGN_DOWN(x, a) ALIGN_DOWN(x, a)
#endif
--
2.9.3
On Tue, Apr 11, 2017 at 08:08:33PM +0200, Krzysztof Kozlowski wrote:
> Hi,
>
> This is a follow up of my questions around exynos-rng [1].
>
> Changes since v4:
> =================
> 1. Patch 2/2: Use "stdrng" name, as suggested by Herbert.
> 2. Patch 2/2: Add Bartlomiej's reviewed-by.
All applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt