From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9D283350D7D; Tue, 22 Sep 2026 05:55:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790056510; cv=none; b=BSJNk67nlWg8QW/WI5Fxs7G7eBiRXLqlwdOlWUnRnqUHqYzfK7sertbZHB70QfB7dwBeEhvsrKztgVqE59yCSQlxmzVaa09hOvy0N7h+O2JlbOJeRBLZiD6IAvTtFJoFPTvk7wQ4ZqStwQLVN3sSSQjdAWT+aAVrqiRgy49Hsjk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790056510; c=relaxed/simple; bh=Aqa9mX2RqSKxdgvAwau1o6WmbwcRAGpRhQPj+UCHJ/w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=X7zdzp9jb4tzeF4W58HFoCeMZ7U7Rns60cGf/OdGcdTIaT8XeqIKeR6aq+iuYW1VONv16NnADBl5bUNTsCTeAvYmRlfppKR6mJA1a5dcJSAKzitISujJzJjJSa+10gI9QQC8zvTUVIMeF6ycl/Eg23127m47PyUwcUPzulGVIlA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O0cvYgM8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O0cvYgM8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6941E1F000FF; Tue, 22 Sep 2026 05:55:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790056509; bh=iztKm2JMcpPyD4ogPKgWEoylK7dEWOn5IAjcyxHLqcg=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=O0cvYgM8kt/cMF7FBXrvQkxWgtZ2Glj7e3ADqsEpq3bD6vXdPWL3K2NoyKhbpGVvw EtP8rsjdrAEFvnuhUZ5CBWuEjXK5SUQQynKfcuWnzRRfdVm6bQcFXDTDtQr9ZKgmKb uvsqAQZ251m+AZnrQto2WVFz+y4AxcUH4eRKZg1eTCVDDKudXus8BfpkPm0ehW9SCK AMP1iadYeZENwWQWP+vq2xWiOGqD/zujoBpwJyDYSZtEhl+VvaeyIhKp2r+SOZ/wvi so58HdN8dJGzckKAB/RmLv57qkUHFGJu/G/maafzVT2kOZoa90eShkTUXYDzEcX5uW mLyah6pWuRtuQ== Date: Tue, 22 Sep 2026 08:55:03 +0300 From: Mike Rapoport To: Vincent Donnefort Cc: catalin.marinas@arm.com, will@kernel.org, rafael@kernel.org, mark.rutland@arm.com, lenb@kernel.org, pavel@kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, thierry.reding@kernel.org Subject: Re: [PATCH v1 1/4] PM: hibernate: Add arch specific hooks for hibernate_map/unmap_page Message-ID: References: <20260918131656.3710047-1-vdonnefort@google.com> <20260918131656.3710047-2-vdonnefort@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260918131656.3710047-2-vdonnefort@google.com> Hi Vincent, On Fri, Sep 18, 2026 at 02:16:53PM +0100, Vincent Donnefort wrote: > hibernate_map_page() is called from an atomic context. This is > problematic for Arm BBML3 systems where the linear map may contain > blocks and is allowed to split as splitting is a sleepable operation. > > Add arch hook so arm64 can define its own implementation without relying > on the direct map. I posted patches that remove set_direct_map usage from hibernation: https://lore.kernel.org/all/20260917-hibernation-v1-0-7f7dfae3dbe0@kernel.org So I really hope this patch won't be needed :) > Signed-off-by: Vincent Donnefort > --- > include/linux/suspend.h | 2 ++ > kernel/power/snapshot.c | 10 ++++++---- > 2 files changed, 8 insertions(+), 4 deletions(-) > > diff --git a/include/linux/suspend.h b/include/linux/suspend.h > index b02876f1ae38..10fe2298d94e 100644 > --- a/include/linux/suspend.h > +++ b/include/linux/suspend.h > @@ -401,6 +401,8 @@ int hibernate_quiet_exec(int (*func)(void *data), void *data); > int hibernate_resume_nonboot_cpu_disable(void); > int arch_hibernation_header_save(void *addr, unsigned int max_size); > int arch_hibernation_header_restore(void *addr); > +void *hibernate_map_page(struct page *page); > +void hibernate_unmap_page(struct page *page); > > #else /* CONFIG_HIBERNATION */ > static inline void register_nosave_region(unsigned long b, unsigned long e) {} > diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c > index b209712cb2c3..b41952f1de2a 100644 > --- a/kernel/power/snapshot.c > +++ b/kernel/power/snapshot.c > @@ -85,7 +85,7 @@ static inline int hibernate_restore_unprotect_page(void *page_address) {return 0 > * It is still worth to have a warning here if something changes and this > * will no longer be the case. > */ > -static inline void hibernate_map_page(struct page *page) > +void * __weak hibernate_map_page(struct page *page) > { > if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { > int ret = set_direct_map_default_noflush(page); > @@ -95,9 +95,10 @@ static inline void hibernate_map_page(struct page *page) > } else { > debug_pagealloc_map_pages(page, 1); > } > + return page_address(page); > } > > -static inline void hibernate_unmap_page(struct page *page) > +void __weak hibernate_unmap_page(struct page *page) > { > if (IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) { > unsigned long addr = (unsigned long)page_address(page); > @@ -1456,8 +1457,9 @@ static bool safe_copy_page(void *dst, struct page *s_page) > if (kernel_page_present(s_page)) { > zeros_only = do_copy_page(dst, page_address(s_page)); > } else { > - hibernate_map_page(s_page); > - zeros_only = do_copy_page(dst, page_address(s_page)); > + void *src = hibernate_map_page(s_page); > + > + zeros_only = do_copy_page(dst, src); > hibernate_unmap_page(s_page); > } > return zeros_only; > -- > 2.55.0.1082.g2b9226bbc0-goog > -- Sincerely yours, Mike.