public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Michael Ellerman <mpe@ellerman•id.au>
To: Nicholas Piggin <npiggin@gmail•com>,
	linuxppc-dev@ozlabs•org, Paul Mackerras <paulus@ozlabs•org>
Subject: Re: [PATCH 07/11] powerpc: Add support for microwatt's hardware random number generator
Date: Wed, 16 Jun 2021 23:16:02 +1000	[thread overview]
Message-ID: <87bl86rlv1.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <1623720368.eqmkro3mgw.astroid@bobo.none>

Nicholas Piggin <npiggin@gmail•com> writes:
> Excerpts from Paul Mackerras's message of June 15, 2021 9:02 am:
>> This is accessed using the DARN instruction and should probably be
>> done more generically.
>> 
>> Signed-off-by: Paul Mackerras <paulus@ozlabs•org>
>> ---
>>  arch/powerpc/include/asm/archrandom.h     | 12 +++++-
>>  arch/powerpc/platforms/microwatt/Kconfig  |  1 +
>>  arch/powerpc/platforms/microwatt/Makefile |  2 +-
>>  arch/powerpc/platforms/microwatt/rng.c    | 48 +++++++++++++++++++++++
>>  4 files changed, 61 insertions(+), 2 deletions(-)
>>  create mode 100644 arch/powerpc/platforms/microwatt/rng.c
>> 
>> diff --git a/arch/powerpc/include/asm/archrandom.h b/arch/powerpc/include/asm/archrandom.h
>> index 9a53e29680f4..e8ae0f7740f9 100644
>> --- a/arch/powerpc/include/asm/archrandom.h
>> +++ b/arch/powerpc/include/asm/archrandom.h
>> @@ -8,12 +8,22 @@
>>  
>>  static inline bool __must_check arch_get_random_long(unsigned long *v)
>>  {
>> +	if (ppc_md.get_random_seed)
>> +		return ppc_md.get_random_seed(v);
>> +
>>  	return false;
>>  }
>>  
>>  static inline bool __must_check arch_get_random_int(unsigned int *v)
>>  {
>> -	return false;
>> +	unsigned long val;
>> +	bool rc;
>> +
>> +	rc = arch_get_random_long(&val);
>> +	if (rc)
>> +		*v = val;
>> +
>> +	return rc;
>>  }
>>  
>
> I would be happier if you didn't change this (or at least put it in its 
> own patch explaining why it's not going to slow down other platforms).

It would essentially be a revert of 01c9348c7620 ("powerpc: Use hardware
RNG for arch_get_random_seed_* not arch_get_random_*")

Which would be ironic :)

cheers

  reply	other threads:[~2021-06-16 13:16 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-14 22:56 [PATCH 00/11] powerpc: Add support for Microwatt soft-core Paul Mackerras
2021-06-14 22:57 ` [PATCH 01/11] powerpc: Add Microwatt platform Paul Mackerras
2021-06-16 18:40   ` Segher Boessenkool
2021-06-16 22:24     ` Paul Mackerras
2021-06-14 22:58 ` [PATCH 02/11] powerpc: Add Microwatt device tree Paul Mackerras
2021-06-17  4:41   ` Michael Ellerman
2021-06-18  2:58     ` Paul Mackerras
2021-06-14 22:59 ` [PATCH 03/11] powerpc/radix: Add support for microwatt's PRTBL SPR Paul Mackerras
2021-06-15  1:12   ` Nicholas Piggin
2021-06-14 23:00 ` [PATCH 04/11] powerpc/microwatt: Populate platform bus from device-tree Paul Mackerras
2021-06-14 23:00 ` [PATCH 05/11] powerpc/xics: Add a native ICS backend for microwatt Paul Mackerras
2021-06-14 23:01 ` [PATCH 06/11] powerpc: microwatt: Use standard 16550 UART for console Paul Mackerras
2021-06-16 20:42   ` Segher Boessenkool
2021-06-14 23:02 ` [PATCH 07/11] powerpc: Add support for microwatt's hardware random number generator Paul Mackerras
2021-06-15  1:40   ` Nicholas Piggin
2021-06-16 13:16     ` Michael Ellerman [this message]
2021-06-16 22:22       ` Paul Mackerras
2021-06-14 23:02 ` [PATCH 08/11] powerpc/microwatt: Add microwatt_defconfig Paul Mackerras
2021-06-14 23:03 ` [PATCH 10/11] powerpc/microwatt: Add a boot wrapper for Microwatt Paul Mackerras
2021-06-14 23:04 ` [PATCH 09/11] powerpc: boot: Fixup device-tree on little endian Paul Mackerras
2021-06-14 23:05 ` [PATCH 11/11] powerpc/microwatt: Disable interrupts in boot wrapper main program Paul Mackerras
2021-06-15  1:21   ` Nicholas Piggin
2021-06-16 23:37   ` Segher Boessenkool
2021-06-17  1:40     ` Nicholas Piggin
2021-06-17  4:06       ` Michael Ellerman
2021-06-17 16:54       ` Segher Boessenkool

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87bl86rlv1.fsf@mpe.ellerman.id.au \
    --to=mpe@ellerman$(echo .)id.au \
    --cc=linuxppc-dev@ozlabs$(echo .)org \
    --cc=npiggin@gmail$(echo .)com \
    --cc=paulus@ozlabs$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox