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 42DE0C54FCD for ; Sat, 1 Aug 2026 08:49:28 +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=GA/494sNcrbhXmU+JtLyr3LcrZHS+XbcfR8p0tV2EoY=; b=B7btmnqfBiZKYD5mtn7Gxc/+WT vB0LUeKcOjjuugy41hsbZx8bozxPImSoGtyjCkI2SoW324RGUVzJrknLv02okzDP8nvkeeBBjvvQ3 JYD8P8DQIO5OxDnEWbI0KeUEKQRr6i8MXMcN1Bx3RaE25ExdsrkAHPKcqAFvv84mMa4jpKiiZqnjE 9NA96cPLJMW24Svj0fJ5XA43PulhpoGGwU39hfrrfTUEqH4/i7PPxwPRamzHPzbHhbDRVabPpH2Jk feDQHuhI4g5iPn3hiJLy3TtTkqdV6fEYcWGCMvLwa4F3b9nMlszySNTws2+8Pe8cQjRe6vY0TqCxg faQ6B2bg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wq5PL-0000000E4oS-0Ztf; Sat, 01 Aug 2026 08:49:27 +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 1wq5PJ-0000000E4nK-3oTF for kexec@lists.infradead.org; Sat, 01 Aug 2026 08:49:26 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 57A7660AA8; Sat, 1 Aug 2026 08:49:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB6421F00AC4; Sat, 1 Aug 2026 08:49:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785574165; bh=GA/494sNcrbhXmU+JtLyr3LcrZHS+XbcfR8p0tV2EoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Izkr+3BSvz3jsRWtis72ekvU3JOBU04LIrcrLSpVnx/m3omZ+eAvoDeifAb/MSX0a zfgzwp5kqwRB4tKQk6R18H+2u5bXO0/ngJADnH4oJ/MEUQLfkUA1xs7b3PiIrprmKR z6hRJScx2zLauaPeMtQda7ILCNqxxMjvY/mxNuWym8LBWuS1q/UH6du+vzIZKwS1V5 MstPHLTvyq283ezKSx2J2UjRbEhoHfPDkt5LijVPLR9WFAfJRKp5FZ/8n3PMTxHqwV m87O2fJNjba/BIPaXq84tfH+ndIAZIin6ovyZb/41wnnxKPoHIk8Cwitf0q72/u7PN 26ydEsyZHl8HQ== 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 13/22] kho: expose kho_scratch_overlap() to kexec_handover.h Date: Sat, 1 Aug 2026 10:48:22 +0200 Message-ID: <20260801084833.1897543-14-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)" Support for discovering memory blocks with no preserved memory will be added in coming patches. These areas will also be marked as scratch to allow allocations from them. Memblock will switch to looking through the scratch array to decide the right migratetype. Expose kho_scratch_overlap() to KHO users. Since it is now used by non-debug code, move it out of kexec_handover_debug.c and into kexec_handover.c. Gate the overlap checks in kho_preserve_folio() and kho_preserve_pages() by IS_ENABLED(CONFIG_KEXEC_HANDOVER_DEBUG) instead. Since kexec_handover_debug.c is now empty, delete it. Add a stub for kho_scratch_overlap() to memblock tests to make sure it compiles. It will be used in memblock by a coming commit. No functional changes. Signed-off-by: Pratyush Yadav (Google) --- include/linux/kexec_handover.h | 7 ++++++ kernel/liveupdate/Makefile | 1 - kernel/liveupdate/kexec_handover.c | 22 ++++++++++++++++-- kernel/liveupdate/kexec_handover_debug.c | 25 --------------------- kernel/liveupdate/kexec_handover_internal.h | 9 -------- tools/testing/memblock/internal.h | 5 +++++ 6 files changed, 32 insertions(+), 37 deletions(-) delete mode 100644 kernel/liveupdate/kexec_handover_debug.c diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h index 48a9793c2b76..40cb95a80981 100644 --- a/include/linux/kexec_handover.h +++ b/include/linux/kexec_handover.h @@ -36,6 +36,8 @@ void kho_memory_init(void); void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len); + +bool kho_scratch_overlap(phys_addr_t phys, size_t size); #else static inline bool kho_is_enabled(void) { @@ -112,6 +114,11 @@ static inline void kho_populate(phys_addr_t fdt_phys, u64 fdt_len, phys_addr_t scratch_phys, u64 scratch_len) { } + +static inline bool kho_scratch_overlap(phys_addr_t phys, size_t size) +{ + return false; +} #endif /* CONFIG_KEXEC_HANDOVER */ #endif /* LINUX_KEXEC_HANDOVER_H */ diff --git a/kernel/liveupdate/Makefile b/kernel/liveupdate/Makefile index eec9d3ae07eb..d9f469462556 100644 --- a/kernel/liveupdate/Makefile +++ b/kernel/liveupdate/Makefile @@ -8,7 +8,6 @@ luo-y := \ luo_session.o obj-$(CONFIG_KEXEC_HANDOVER) += kexec_handover.o -obj-$(CONFIG_KEXEC_HANDOVER_DEBUG) += kexec_handover_debug.o obj-$(CONFIG_KEXEC_HANDOVER_DEBUGFS) += kexec_handover_debugfs.o obj-$(CONFIG_LIVEUPDATE) += luo.o diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 04bfcbf9cc55..b3b97a6ff9c8 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -765,6 +765,22 @@ static phys_addr_t __init scratch_size_node(int nid) return round_up(size, CMA_MIN_ALIGNMENT_BYTES); } +bool kho_scratch_overlap(phys_addr_t phys, size_t size) +{ + phys_addr_t scratch_start, scratch_end; + unsigned int i; + + for (i = 0; i < kho_scratch_cnt; i++) { + scratch_start = kho_scratch[i].addr; + scratch_end = kho_scratch[i].addr + kho_scratch[i].size; + + if (phys < scratch_end && (phys + size) > scratch_start) + return true; + } + + return false; +} + /** * kho_reserve_scratch - Reserve a contiguous chunk of memory for kexec * @@ -962,7 +978,8 @@ int kho_preserve_folio(struct folio *folio) const unsigned long pfn = folio_pfn(folio); const unsigned int order = folio_order(folio); - if (WARN_ON(kho_scratch_overlap(pfn << PAGE_SHIFT, PAGE_SIZE << order))) + if (IS_ENABLED(CONFIG_KEXEC_HANDOVER_DEBUG) && + WARN_ON(kho_scratch_overlap(pfn << PAGE_SHIFT, PAGE_SIZE << order))) return -EINVAL; return kho_radix_add_key(tree, kho_encode_radix_key(PFN_PHYS(pfn), @@ -1039,7 +1056,8 @@ int kho_preserve_pages(struct page *page, unsigned long nr_pages) unsigned long failed_pfn = 0; int err = 0; - if (WARN_ON(kho_scratch_overlap(start_pfn << PAGE_SHIFT, + if (IS_ENABLED(CONFIG_KEXEC_HANDOVER_DEBUG) && + WARN_ON(kho_scratch_overlap(start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT))) { return -EINVAL; } diff --git a/kernel/liveupdate/kexec_handover_debug.c b/kernel/liveupdate/kexec_handover_debug.c deleted file mode 100644 index 6efb696f5426..000000000000 --- a/kernel/liveupdate/kexec_handover_debug.c +++ /dev/null @@ -1,25 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * kexec_handover_debug.c - kexec handover optional debug functionality - * Copyright (C) 2025 Google LLC, Pasha Tatashin - */ - -#define pr_fmt(fmt) "KHO: " fmt - -#include "kexec_handover_internal.h" - -bool kho_scratch_overlap(phys_addr_t phys, size_t size) -{ - phys_addr_t scratch_start, scratch_end; - unsigned int i; - - for (i = 0; i < kho_scratch_cnt; i++) { - scratch_start = kho_scratch[i].addr; - scratch_end = kho_scratch[i].addr + kho_scratch[i].size; - - if (phys < scratch_end && (phys + size) > scratch_start) - return true; - } - - return false; -} diff --git a/kernel/liveupdate/kexec_handover_internal.h b/kernel/liveupdate/kexec_handover_internal.h index 0399ff107775..805d2a76c388 100644 --- a/kernel/liveupdate/kexec_handover_internal.h +++ b/kernel/liveupdate/kexec_handover_internal.h @@ -41,13 +41,4 @@ static inline void kho_debugfs_blob_remove(struct kho_debugfs *dbg, void *blob) { } #endif /* CONFIG_KEXEC_HANDOVER_DEBUGFS */ -#ifdef CONFIG_KEXEC_HANDOVER_DEBUG -bool kho_scratch_overlap(phys_addr_t phys, size_t size); -#else -static inline bool kho_scratch_overlap(phys_addr_t phys, size_t size) -{ - return false; -} -#endif /* CONFIG_KEXEC_HANDOVER_DEBUG */ - #endif /* LINUX_KEXEC_HANDOVER_INTERNAL_H */ diff --git a/tools/testing/memblock/internal.h b/tools/testing/memblock/internal.h index b6b1d147fd75..e86bb9000b22 100644 --- a/tools/testing/memblock/internal.h +++ b/tools/testing/memblock/internal.h @@ -66,4 +66,9 @@ static inline void init_deferred_page(unsigned long pfn, int nid) #define __SetPageReserved(p) ((void)(p)) +static inline bool kho_scratch_overlap(phys_addr_t phys, size_t size) +{ + return false; +} + #endif -- 2.55.0.571.g244d577d93-goog