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 6A3CB4D9915 for ; Thu, 9 Jul 2026 17:39:08 +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=1783618749; cv=none; b=jXS59B4GlESBBK9Nz4swEFjP7T9QKDbeu5tT2hmNXoicn+eXdIXqG1ajlld79AM92lm7R8k3S0ZB3dmhSdnJa7dls6xb1HkfZowvIjCo+9raca/sJblK9lFGi6PMmGgY6OHwYGpUdoLCbLgEau5pqD5y4CrUojKDjKMkVonE2zk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783618749; c=relaxed/simple; bh=MMzWTU2n8aMFB/5WPpBBKzP8aftHbeGqK72GzCcE26k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Qs2EkHU12sAaZrtvsYh1H01QbyQwm5cdWxOx3zHnUdD8AMPueDAt1QHpXBAW+V2p1wRSVGd21kH3a50Nn+SzF8RQKRdsnKXd9rzWS70sRPzT6QnBimyfWbV4ozxbdta1BBtD7yXoNHHgLqK/lfT1NYvPGrtMGkXrpgJwokjrGlE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NP7n7JZ9; 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="NP7n7JZ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9E181F00A3A; Thu, 9 Jul 2026 17:39:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783618748; bh=XRWHX7zMVtBNXHZRqDliEz73l607WKYgb2CCZt52nTM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NP7n7JZ9Rsq1UO8wAMpyzD3u7hK4XgRdKJqYMf3NGmnjFDasuqjeoZBnMCWUoF6GB f1ci5JPw4rwRrGPTvwjC/dTnPw1s4Mh6ye2rrl9Y6YuMjGIL7NQGIQvtrkrEKz8gtK EK8kmQgMLm6sgLnfpRjJ5bME6hQrtCrg6ZCYyXX/l0T8PStyNZ9/w+FstjBK+NxU/W RuBck4m0VsEySc92EWwrojZeHbI+WgQGyRsbY5RGT66kNe4377F/QDerVTGDHXtDHb n1s1omuYv14J7fgIi4wf4bCdSiICgQEKHmpBB1xOIukRhMjCt4MzgFDKwM5UtpgfhO aqnx/ryim+bTg== From: Pratyush Yadav To: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu , Jork Loeser Cc: kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 14/21] kho: initialize kho_scratch pointer earlier in boot Date: Thu, 9 Jul 2026 19:38:03 +0200 Message-ID: <20260709173821.429921-15-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.141.g00534a21ce-goog In-Reply-To: <20260709173821.429921-1-pratyush@kernel.org> References: <20260709173821.429921-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Pratyush Yadav (Google)" In a future patch, mm init will use kho_scratch_overlap() for deciding the migrate type of pageblocks it initializes. The earliest user currently is free_area_init(). kho_scratch_overlap() relies on kho_scratch pointer being initialized. Introduce kho_memory_init_early() to do this. kho_populate() would normally be a good place to do this, but unfortunately, phys_to_virt() does not work at that point on ARM64. So we need yet another initialization function. Signed-off-by: Pratyush Yadav (Google) --- include/linux/kexec_handover.h | 3 +++ kernel/liveupdate/kexec_handover.c | 15 +++++++++++++-- mm/mm_init.c | 1 + 3 files changed, 17 insertions(+), 2 deletions(-) diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 40cb95a80981..18ba417f1ada 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -33,6 +33,7 @@ void kho_remove_subtree(void *blob); int kho_retrieve_subtree(const char *name, phys_addr_t *phys, size_t *size); void kho_memory_init(void); +void kho_memory_init_early(void); void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len); @@ -110,6 +111,8 @@ static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys, static inline void kho_memory_init(void) { } +static inline void kho_memory_init_early(void) { } + static inline void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len) { diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index b3b97a6ff9c8..2ddfc804cdf7 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1534,8 +1534,6 @@ static void __init kho_mem_retrieve(void) const void *fdt = kho_get_fdt(); int err; - kho_scratch = phys_to_virt(kho_in.scratch_phys); - /* * kho_get_mem_map() should always succeed. If it fails, kho_populate() * catches that and never sets kho_in.scratch_phys, which stops memory @@ -1756,6 +1754,19 @@ static __init int kho_init(void) } fs_initcall(kho_init); +void __init kho_memory_init_early(void) +{ + if (!is_kho_boot()) + return; + + /* + * kho_scratch_overlap() needs kho_scratch to be initialized. It + * is used by free_area_init() on KHO boots, so initialize it + * early. + */ + kho_scratch = phys_to_virt(kho_in.scratch_phys); +} + void __init kho_memory_init(void) { if (kho_in.scratch_phys) diff --git a/mm/mm_init.c b/mm/mm_init.c index 0f64909e8d20..84d4b1c997bc 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2687,6 +2687,7 @@ void __init __weak mem_init(void) void __init mm_core_init_early(void) { + kho_memory_init_early(); hugetlb_cma_reserve(); hugetlb_bootmem_alloc(); -- 2.55.0.141.g00534a21ce-goog