Re: [PATCH 0/7] microblaze: Define SMP safe operations

Michal Simek
2020-02-13T08:13:21Z

On 13. 02. 20 9:11, Peter Zijlstra wrote:
> On Thu, Feb 13, 2020 at 08:49:40AM +0100, Michal Simek wrote:
>> On 12. 02. 20 17:08, Peter Zijlstra wrote:
>>> On Wed, Feb 12, 2020 at 04:42:22PM +0100, Michal Simek wrote:
>>>
>>>> Microblaze has 32bit exclusive load/store instructions which should be used
>>>> instead of irq enable/disable. For more information take a look at
>>>> https://www.xilinx.com/support/documentation/sw_manuals/xilinx2019_2/ug984-vivado-microblaze-ref.pdf
>>>> starting from page 25.
>>>
>>>> arch/microblaze/include/asm/Kbuild | 1 -
>>>> arch/microblaze/include/asm/atomic.h | 265 ++++++++++++++++++-
>>>> arch/microblaze/include/asm/bitops.h | 189 +++++++++++++
>>>> arch/microblaze/include/asm/cmpxchg.h | 87 ++++++
>>>> arch/microblaze/include/asm/cpuinfo.h | 2 +-
>>>> arch/microblaze/include/asm/pgtable.h | 19 +-
>>>> arch/microblaze/include/asm/spinlock.h | 240 +++++++++++++++++
>>>> arch/microblaze/include/asm/spinlock_types.h | 25 ++
>>>> arch/microblaze/kernel/cpu/cache.c | 154 ++++++-----
>>>> arch/microblaze/kernel/cpu/cpuinfo.c | 38 ++-
>>>> arch/microblaze/kernel/cpu/mb.c | 207 ++++++++-------
>>>> arch/microblaze/kernel/timer.c | 2 +-
>>>> arch/microblaze/mm/consistent.c | 8 +-
>>>> 13 files changed, 1040 insertions(+), 197 deletions(-)
>>>> create mode 100644 arch/microblaze/include/asm/bitops.h
>>>> create mode 100644 arch/microblaze/include/asm/spinlock.h
>>>> create mode 100644 arch/microblaze/include/asm/spinlock_types.h
>>>
>>> I'm missing asm/barrier.h
>>
>> This has been sent in previous patchset. Link was in this email.
>
> lkml.org link, please don't use them. The kernel.org links (example
> below) have the Message-Id in them, which allows me to search for them
> in my local storage without having to use a web browser.
>
> You mean this one, right?
>
> https://lkml.kernel.org/r/be707feb95d65b44435a0d9de946192f1fef30c6.1581497860.git.michal.simek@xilinx.com
>
> So the PDF says this is a completion barrier, needed for DMA. This is a
> very expensive option for smp_mb(), but if it is all you have and is
> required, then yes, that should do.

Yes that's the one.

Thanks,
Michal