From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2FB6B4C79 for ; Thu, 26 Sep 2024 04:18:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727324292; cv=none; b=o6P8p2qwUV4s/a/EeYrL4C86HfJwT0sWRjWR23kxqU/d23SSVB+6C1rKSnJAfgIxJpg6WCcldX6qT4U5GK0hxzX6RBZXYgUj8Au/S/3RMa8/VbbQHWO/qVmnXKzHAHm8XBgHE30cCb+4BFnUDkNFsKa1CXObRma2jmVp/8H0K2k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727324292; c=relaxed/simple; bh=0TjdrucShvr7QUbd5OwG9DXgoM0NPmZ8qTPdh6Q0qns=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=htVFQdLuvGQkpaLkIlpJwBPJgdby6sMHIZrHqwMoDuvV0DXamiEpupurntp0G8GALNguCFvLoNvpDyjbyr2Mklb+F+roNTGYnP39mdLC6I9yCpY9JVELUfHUpK5rDs1aCbDZT9YNcfwD2a4EzP8z+a/GnjcQUiz/idJ/P0CyfYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C367615A1; Wed, 25 Sep 2024 21:18:36 -0700 (PDT) Received: from [10.163.35.5] (unknown [10.163.35.5]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1DF693F528; Wed, 25 Sep 2024 21:18:03 -0700 (PDT) Message-ID: <97c9f027-0162-4093-a5d7-0dc561ea28c7@arm.com> Date: Thu, 26 Sep 2024 09:48:00 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: Move set_pxd_safe() helpers from generic to platform To: linux-mm@kvack.org, akpm@linux-foundation.org, Dave Hansen , Palmer Dabbelt Cc: Paul Walmsley , Palmer Dabbelt , Thomas Gleixner , Dave Hansen , David Hildenbrand , Ryan Roberts , x86@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org References: <20240920053017.2514920-1-anshuman.khandual@arm.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20240920053017.2514920-1-anshuman.khandual@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/20/24 11:00, Anshuman Khandual wrote: > set_pxd_safe() helpers that serve a specific purpose for both x86 and riscv > platforms, do not need to be in the common memory code. Otherwise they just > unnecessarily make the common API more complicated. This moves the helpers > from common code to platform instead. > > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Thomas Gleixner > Cc: Dave Hansen > Cc: David Hildenbrand > Cc: Ryan Roberts > Cc: Andrew Morton > Cc: x86@kernel.org > Cc: linux-mm@kvack.org > Cc: linux-riscv@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Suggested-by: David Hildenbrand > Signed-off-by: Anshuman Khandual > --- > arch/riscv/include/asm/pgtable.h | 19 ++++++++++++++++ > arch/x86/include/asm/pgtable.h | 37 +++++++++++++++++++++++++++++++ > include/linux/pgtable.h | 38 -------------------------------- > 3 files changed, 56 insertions(+), 38 deletions(-) > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 089f3c9f56a3..39ca652c5ebe 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -957,6 +957,25 @@ void misc_mem_init(void); > extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > > +/* > + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > + * TLB flush will be required as a result of the "set". For example, use > + * in scenarios where it is known ahead of time that the routine is > + * setting non-present entries, or re-setting an existing entry to the > + * same value. Otherwise, use the typical "set" helpers and flush the > + * TLB. > + */ > +#define set_p4d_safe(p4dp, p4d) \ > +({ \ > + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ > + set_p4d(p4dp, p4d); \ > +}) > + > +#define set_pgd_safe(pgdp, pgd) \ > +({ \ > + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ > + set_pgd(pgdp, pgd); \ > +}) > #endif /* !__ASSEMBLY__ */ > > #endif /* _ASM_RISCV_PGTABLE_H */ > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h > index e39311a89bf4..fefb52bb6b4d 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -1701,6 +1701,43 @@ bool arch_is_platform_page(u64 paddr); > #define arch_is_platform_page arch_is_platform_page > #endif > > +/* > + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > + * TLB flush will be required as a result of the "set". For example, use > + * in scenarios where it is known ahead of time that the routine is > + * setting non-present entries, or re-setting an existing entry to the > + * same value. Otherwise, use the typical "set" helpers and flush the > + * TLB. > + */ > +#define set_pte_safe(ptep, pte) \ > +({ \ > + WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ > + set_pte(ptep, pte); \ > +}) > + > +#define set_pmd_safe(pmdp, pmd) \ > +({ \ > + WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ > + set_pmd(pmdp, pmd); \ > +}) > + > +#define set_pud_safe(pudp, pud) \ > +({ \ > + WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ > + set_pud(pudp, pud); \ > +}) > + > +#define set_p4d_safe(p4dp, p4d) \ > +({ \ > + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ > + set_p4d(p4dp, p4d); \ > +}) > + > +#define set_pgd_safe(pgdp, pgd) \ > +({ \ > + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ > + set_pgd(pgdp, pgd); \ > +}) > #endif /* __ASSEMBLY__ */ > > #endif /* _ASM_X86_PGTABLE_H */ > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 2a6a3cccfc36..0bf88e505aad 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -1050,44 +1050,6 @@ static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b) > } > #endif > > -/* > - * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > - * TLB flush will be required as a result of the "set". For example, use > - * in scenarios where it is known ahead of time that the routine is > - * setting non-present entries, or re-setting an existing entry to the > - * same value. Otherwise, use the typical "set" helpers and flush the > - * TLB. > - */ > -#define set_pte_safe(ptep, pte) \ > -({ \ > - WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ > - set_pte(ptep, pte); \ > -}) > - > -#define set_pmd_safe(pmdp, pmd) \ > -({ \ > - WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ > - set_pmd(pmdp, pmd); \ > -}) > - > -#define set_pud_safe(pudp, pud) \ > -({ \ > - WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ > - set_pud(pudp, pud); \ > -}) > - > -#define set_p4d_safe(p4dp, p4d) \ > -({ \ > - WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ > - set_p4d(p4dp, p4d); \ > -}) > - > -#define set_pgd_safe(pgdp, pgd) \ > -({ \ > - WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ > - set_pgd(pgdp, pgd); \ > -}) > - > #ifndef __HAVE_ARCH_DO_SWAP_PAGE > static inline void arch_do_swap_page_nr(struct mm_struct *mm, > struct vm_area_struct *vma, Hello Dave/Palmer, Unless there is still any more objection from x86 or riscv, could this patch be pulled ? - Anshuman