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 B35313F4825 for ; Fri, 5 Jun 2026 18:35:44 +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=1780684547; cv=none; b=YOa0FF7AFOv/dqJd3WXgNqfYP3qvaBt3wZ+nnj4oWI++mUV+3EeWvNMjLLXR85xeP5y4pZZ8Sg8DQ0DxeupbZvrqEQ/i6VcIMBAMufQ+b0qiAaEIlnxswYPwG0hWiPNTLMTP3HwTDElHdPp6uNPorSsfZbzvauRUZja8DTK3v0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780684547; c=relaxed/simple; bh=lw+5TYsAVHh2euhs/gGmR+V1YcnV1T1/1LFm92fmVsc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gzUY+mphuKP3mOrAyQ+WvXDSlqJTXhWIVUX0LQn54P0TWYszjgTFNw+Xbc+8G8O+KjWXmYNA/RxmWQK34vbCXzT7EUrpmsbOBYRab45XbG3E5y6APY2IECUPpdKeAygoe6e+yjwPVXh4nmji5XCmipC1lUl2dMqRhjk2NBgEhnQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BydKaYKs; 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="BydKaYKs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A1941F0089B; Fri, 5 Jun 2026 18:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780684544; bh=MPgTzFffYY8+ZzNyhPkuE1ZkvrAANKQQVvr8ndIw9wg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BydKaYKsPPMaQYb1m+R//+fdgzANeeVCNM2zxeJ3Ypk4tYKIYwwCiv9GLWp4ulG1h Hc0purKydXxPZ3b9Mx47+4HFBVaDU+3r7gQGNx/2yAa3EfqD+rQdVRvVDlrHpMsPDW bW5KJdUUu3EF28QEw65ZeOfcTPHx3ZyqRN2Pl8WUd/c8pPfpC41wFOsOqYPfXs7Flb vtRghhCn81f64hN8Gbj0kumucDSXUFDTX5zyeWyDBkFFc30dUcc9meDdHNPc18VGId U5YcKmUUpNpAS/Tl6BvmYi4/U4k/iJw2G0iQX3Y1aSUT/0sF1Cwo+Cv0Bi7hTXg2nV 3wRBscIKlW1Bw== 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 v2 13/18] kho: initialize kho_scratch pointer earlier in boot Date: Fri, 5 Jun 2026 20:34:46 +0200 Message-ID: <20260605183501.3884950-14-pratyush@kernel.org> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog In-Reply-To: <20260605183501.3884950-1-pratyush@kernel.org> References: <20260605183501.3884950-1-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 | 12 ++++++++++-- mm/mm_init.c | 1 + 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 3740c14d970d..9e961032e06b 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -37,6 +37,7 @@ 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); @@ -114,6 +115,8 @@ 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 a66f23a35389..af22086ca2d6 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1535,8 +1535,6 @@ 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 @@ -1757,6 +1755,16 @@ static __init int kho_init(void) } fs_initcall(kho_init); +void __init kho_memory_init_early(void) +{ + /* + * kho_scratch_overlap() needs kho_scratch to be initialized. It is used + * by free_area_init() on KHO boots, so initialize it early. + */ + if (kho_in.scratch_phys) + 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 eddc0f03a779..0675837bbfc9 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2688,6 +2688,7 @@ void __init __weak mem_init(void) void __init mm_core_init_early(void) { + kho_memory_init_early(); hugetlb_cma_reserve(); hugetlb_bootmem_alloc(); -- 2.54.0.1032.g2f8565e1d1-goog