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From: Pratyush Yadav <pratyush@kernel.org>
To: Mike Rapoport <rppt@kernel.org>,
	Pasha Tatashin <pasha.tatashin@soleen.com>,
	Pratyush Yadav <pratyush@kernel.org>,
	Alexander Graf <graf@amazon.com>,
	Muchun Song <muchun.song@linux.dev>,
	Oscar Salvador <osalvador@suse.de>,
	David Hildenbrand <david@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jason Miu <jasonmiu@google.com>,
	Jork Loeser <jloeser@linux.microsoft.com>
Cc: kexec@lists.infradead.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 05/18] kho: move all memory retrieval logic to kho_mem_retrieve()
Date: Fri,  5 Jun 2026 20:34:38 +0200	[thread overview]
Message-ID: <20260605183501.3884950-6-pratyush@kernel.org> (raw)
In-Reply-To: <20260605183501.3884950-1-pratyush@kernel.org>

From: "Pratyush Yadav (Google)" <pratyush@kernel.org>

The memory retrieval logic is spread out across kho_mem_retrieve() and
kho_memory_init(). The incoming scratch area is initialized at
kho_memory_init(), and the error handling is done there too.

Consolidate all this logic into kho_mem_retrieve() to make the code
cleaner.

Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
---
 kernel/liveupdate/kexec_handover.c | 31 ++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index 61e436f5077e..7e556afae283 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -1412,8 +1412,13 @@ int kho_retrieve_subtree(const char *name, phys_addr_t *phys, size_t *size)
 }
 EXPORT_SYMBOL_GPL(kho_retrieve_subtree);
 
-static int __init kho_mem_retrieve(const void *fdt)
+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
@@ -1421,8 +1426,16 @@ static int __init kho_mem_retrieve(const void *fdt)
 	 */
 	kho_in.radix_tree.root = kho_get_mem_map(fdt);
 	mutex_init(&kho_in.radix_tree.lock);
-	return kho_radix_walk_tree(&kho_in.radix_tree,
-				   kho_preserved_memory_reserve);
+
+	err = kho_radix_walk_tree(&kho_in.radix_tree, kho_preserved_memory_reserve);
+	if (err) {
+		/*
+		 * Failed to initialize preserved memory. Clear FDT and radix
+		 * so KHO users don't treat it as a KHO boot.
+		 */
+		kho_in.fdt_phys = 0;
+		kho_in.radix_tree.root = NULL;
+	}
 }
 
 static __init int kho_out_fdt_setup(void)
@@ -1626,16 +1639,10 @@ fs_initcall(kho_init);
 
 void __init kho_memory_init(void)
 {
-	if (kho_in.scratch_phys) {
-		kho_scratch = phys_to_virt(kho_in.scratch_phys);
-
-		if (kho_mem_retrieve(kho_get_fdt())) {
-			kho_in.fdt_phys = 0;
-			kho_in.radix_tree.root = NULL;
-		}
-	} else {
+	if (kho_in.scratch_phys)
+		kho_mem_retrieve();
+	else
 		kho_reserve_scratch();
-	}
 }
 
 void __init kho_populate(phys_addr_t fdt_phys, u64 fdt_len,
-- 
2.54.0.1032.g2f8565e1d1-goog



  parent reply	other threads:[~2026-06-05 18:35 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-05 18:34 [PATCH v2 00/18] kho: make boot time huge page allocation work nicely with KHO Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 01/18] kho: generalize radix tree APIs Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 02/18] kho: disallow wide keys in radix tree Pratyush Yadav
2026-06-05 22:06   ` Jork Loeser
2026-06-08  9:10     ` Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 03/18] kho: return virtual address of mem_map Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 04/18] kho: store incoming radix tree in kho_in Pratyush Yadav
2026-06-05 18:34 ` Pratyush Yadav [this message]
2026-06-05 18:34 ` [PATCH v2 06/18] kho: add a struct for radix callbacks Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 07/18] kho: add callback for table pages Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 08/18] kho: add data argument to radix walk callback Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 09/18] kho: allow early-boot usage of the KHO radix tree Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 10/18] kho: allow destroying " Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 11/18] kho: add kho_radix_init_tree() Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 12/18] kho: export kho_scratch_overlap() Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 13/18] kho: initialize kho_scratch pointer earlier in boot Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 14/18] memblock: use kho_scratch_overlap() to decide migratetype Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 15/18] kho: extend scratch Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 16/18] memblock: make HugeTLB bootmem allocation work with KHO Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 17/18] memblock: allow calculating reserved size by flags Pratyush Yadav
2026-06-05 18:34 ` [PATCH v2 18/18] kho: exclude hugetlb memory from scratch size calculation Pratyush Yadav

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