From: David Hildenbrand <david@redhat.com>
To: Mike Rapoport <rppt@linux.ibm.com>
Cc: Mike Rapoport <rppt@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Christopher Lameter <cl@linux.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Elena Reshetova <elena.reshetova@intel.com>,
"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@redhat.com>,
James Bottomley <jejb@linux.ibm.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>,
Matthew Wilcox <willy@infradead.org>,
Mark Rutland <mark.rutland@arm.com>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Peter Zijlstra <peterz@infradead.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Roman Gushchin <guro@fb.com>, Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Tycho Andersen <tycho@tycho.ws>, Will Deacon <will@kernel.org>,
linux-api@vger.kernel.org, linux-arch@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
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linux-nvdimm@lists.01.org, linux-riscv@lists.infradead.org,
x86@kernel.org
Subject: Re: [PATCH v12 04/10] set_memory: allow querying whether set_direct_map_*() is actually enabled
Date: Wed, 25 Nov 2020 13:42:36 +0100 [thread overview]
Message-ID: <bb27ab9e-8c74-e297-acc1-a92bcc4087a9@redhat.com> (raw)
In-Reply-To: <20201125121138.GJ123287@linux.ibm.com>
On 25.11.20 13:11, Mike Rapoport wrote:
> On Wed, Nov 25, 2020 at 12:22:52PM +0100, David Hildenbrand wrote:
>>> #include <asm-generic/cacheflush.h>
>>>
>>> #endif /* __ASM_CACHEFLUSH_H */
>>> diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
>>> new file mode 100644
>>> index 000000000000..ecb6b0f449ab
>>> --- /dev/null
>>> +++ b/arch/arm64/include/asm/set_memory.h
>>> @@ -0,0 +1,17 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +
>>> +#ifndef _ASM_ARM64_SET_MEMORY_H
>>> +#define _ASM_ARM64_SET_MEMORY_H
>>> +
>>> +#include <asm-generic/set_memory.h>
>>> +
>>> +bool can_set_direct_map(void);
>>> +#define can_set_direct_map can_set_direct_map
>>
>> Well, that looks weird.
>> [...]
>
> We have a lot of those e.g. in linux/pgtable.h
>
>>> }
>>> +#else /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
>>> +/*
>>> + * Some architectures, e.g. ARM64 can disable direct map modifications at
>>> + * boot time. Let them overrive this query.
>>> + */
>>> +#ifndef can_set_direct_map
>>> +static inline bool can_set_direct_map(void)
>>> +{
>>> + return true;
>>> +}
>>
>> I think we prefer __weak functions for something like that, avoids the
>> ifdefery.
>
> I'd prefer this for two reasons: first, static inline can be optimized
> away and second, there is no really good place to put generic
> implementation.
Fair enough
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-11-25 12:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-25 9:21 [PATCH v12 00/10] mm: introduce memfd_secret system call to create "secret" memory areas Mike Rapoport
2020-11-25 9:21 ` [PATCH v12 01/10] mm: add definition of PMD_PAGE_ORDER Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 02/10] mmap: make mlock_future_check() global Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 03/10] set_memory: allow set_direct_map_*_noflush() for multiple pages Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 04/10] set_memory: allow querying whether set_direct_map_*() is actually enabled Mike Rapoport
2020-11-25 11:22 ` David Hildenbrand
2020-11-25 12:11 ` Mike Rapoport
2020-11-25 12:42 ` David Hildenbrand [this message]
2020-11-25 18:36 ` Catalin Marinas
2020-11-25 9:22 ` [PATCH v12 05/10] mm: introduce memfd_secret system call to create "secret" memory areas Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 06/10] secretmem: use PMD-size pages to amortize direct map fragmentation Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 07/10] secretmem: add memcg accounting Mike Rapoport
2020-11-29 15:53 ` Shakeel Butt
2020-11-29 17:26 ` Mike Rapoport
2020-11-30 20:15 ` Roman Gushchin
2020-11-25 9:22 ` [PATCH v12 08/10] PM: hibernate: disable when there are active secretmem users Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 09/10] arch, mm: wire up memfd_secret system call were relevant Mike Rapoport
2020-11-25 9:22 ` [PATCH v12 10/10] secretmem: test: add basic selftest for memfd_secret(2) Mike Rapoport
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