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 E82CA3F5BEF for ; Sat, 25 Jul 2026 17:22:21 +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=1785000143; cv=none; b=kAPXkj0H5rQgrbF1bdHs3PXBFJy9dtVKwGeEeq4t3f5KswQ/crM5d31k2eX7zmR/YVLBtJgAs0PzKHMu8Cjff5zdjQWEgx3e8x92KAIAE7iXGrF7KtI30is8O9BryJyaWfRcHar3OElFDhJ7Fzev8Q1E46EmAI7WQBr1jHxRVbk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785000143; c=relaxed/simple; bh=L6vFJLR+nhO1HC4/6SwDyU6/C6d9F6KvOOk+iRVPr/A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m3eO7Ms+Pbj6VO1cxdOQXHYPpI8k+dVq4/PirpbjA8/Xv/gFUZCOBe0m1gm0NCvTzYgp8ZlLJQNowxOQGUjTdNAn+Zp09ctyjVzKGRI4tG/Qg6UrFtzzPEkmgtGxFaKR/e0P7B1MFnKD10gX5UdypPlyHLV4BL3yYfCWz42/i9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=B9fIEhVy; 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="B9fIEhVy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6279A1F00A3A; Sat, 25 Jul 2026 17:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785000141; bh=fxTUe+ZTLtTyF8qsexavFqzxBST5EZcJ5kz9myxc9Sw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=B9fIEhVydg6PY66G5SZ0FhttHr1YhtNNHJKxH0h2mFtMAbyKlqkL5PW7eOEv2rKjv dZkcGLvn6Rl1hAKsQUUzhpAKChMNb69cWHFmFNYNtORBvx6Ow0Io9GUzdq5/xaRRp9 F+WHVGUX+GVyUzqhXFto80lD6y7pA+NwXBZU2gd+uk3Hj136r/ubZcBwdPYQKGRH1W LPzqmPKOFiR1VWBf4VGfS2x73W9MSc+y2nqVELe8GCDECi1qy6xq13UdCZ9VnsT266 l0K50AHf/o2BjXR22Maf4aTMKh+3xULWlXzJNWBv5kaVfzuXWUwWQN+79L6k0xXEaX 2bgAxSu70qccA== 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 v4 14/21] kho: initialize kho_scratch pointer earlier in boot Date: Sat, 25 Jul 2026 19:21:14 +0200 Message-ID: <20260725172133.4018491-15-pratyush@kernel.org> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog In-Reply-To: <20260725172133.4018491-1-pratyush@kernel.org> References: <20260725172133.4018491-1-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(); -- 2.55.0.229.g6434b31f56-goog