From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2EB43C55175 for ; Sat, 1 Aug 2026 08:49:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=v3kXUz2Z2rDW9BnKcIvM/TL6/lSSMoYpc0koUm//CXU=; b=AxQNNHJBHG0iBG8Rx9QnwNdSGn B6mYiugNQY1tdHcmsv2YO4Q0JKjfca50u47N1kOlvjA7w7cGjzqNdB/xvDftTLPyj6Weiy6c91ne4 DiW3Y9XyaGkmM0yTpKcG9jvqP/sElg0EyE2tMcFY1QH+hPs4OUpm6nlTaQbNPevfsKcZOsaovpG1D kKph2VdMFYayAz/dw8l/xpHARWtVpHi4zBEAxsF7Tnm9lHC/bJt9U8kXOZRjkN80+uhq/UNB0VmyF PyXWhe9HY6lEDN0pJi4EsjE493E3ZBDX9quaClPxvLetcLHDrpNHeeDgAJzM/sTA8sWjw1+55GNPK Ns2ZhvNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wq5PN-0000000E4qh-1k8J; Sat, 01 Aug 2026 08:49:29 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wq5PM-0000000E4pG-1tDA for kexec@lists.infradead.org; Sat, 01 Aug 2026 08:49:28 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id DECF960AA4; Sat, 1 Aug 2026 08:49:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E5921F00ADE; Sat, 1 Aug 2026 08:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785574167; bh=v3kXUz2Z2rDW9BnKcIvM/TL6/lSSMoYpc0koUm//CXU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IgNuVO3ecZRiZnO66E61fzNWgHjg8+r203fe7t0v1iYhva313WTdnWnUOfZyONHkk i7/aVSiBiapw7W6dmdrvfsnMWFIpglmqg7ccNGjzVDZq1M+t0gGjCwzmkwq7G4n0IB uRthP/MB63J0+6mwIClV4OjKJJeGZ/QWz+BbeiyVcVhpFwRY1lfqRiviRYF9ioQMaL DHGvhIVF0D4n+4ZqebVLqEX9dlL1BgkfkUkZ9Xgf+bW+4T5ACsKlhihPMvlAQ0yjtq YxNnxNwx3tmNjpDLIVGjImpJCP5dLgwFlwPpoZvKvIfkq5UMFk7FQxCngJa5XNs0Vs 65dHIVuRteNbA== 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 v6 14/22] kho: initialize kho_scratch pointer earlier in boot Date: Sat, 1 Aug 2026 10:48:23 +0200 Message-ID: <20260801084833.1897543-15-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.571.g244d577d93-goog In-Reply-To: <20260801084833.1897543-1-pratyush@kernel.org> References: <20260801084833.1897543-1-pratyush@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org 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(); -- 2.55.0.571.g244d577d93-goog