[RFC PATCH 04/18] arm64: add arch callbacks for kernel replication

@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_NUMA_REPLICATION_H
+#define __ASM_NUMA_REPLICATION_H
+
+#ifdef CONFIG_KERNEL_REPLICATION
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+#include <asm/memory.h>
+#include <asm/mmu_context.h>
+#include <linux/mm.h>
+#include <linux/seq_file.h>
+
+#define PAGE_TABLE_REPLICATION_LEFT  ((max((u64)_end - SZ_2G, (u64)MODULES_VADDR)) & PGDIR_MASK)
+#define PAGE_TABLE_REPLICATION_RIGHT ((((u64)_end + SZ_2G) & PGDIR_MASK) + PGDIR_SIZE - 1)
+
+static inline pgd_t *numa_replicate_pgt_pgd(int nid)
+{
+	pgd_t *new_pgd;
+	struct page *pgd_page;
+
+	pgd_page = alloc_pages_node_noprof(nid, GFP_PGTABLE_KERNEL, 2);
+	BUG_ON(pgd_page == NULL);
+
+	new_pgd = (pgd_t *)page_address(pgd_page);
+	new_pgd += (PAGE_SIZE * 2 / sizeof(pgd_t)); //Extra pages for KPTI
+	copy_page(new_pgd, swapper_pg_dir);
+
+	return new_pgd;
+}
+
+static inline void numa_load_replicated_pgd(pgd_t *pgd)
+{
+	cpu_replace_ttbr1(pgd);
+	local_flush_tlb_all();
+}
+
+static inline ssize_t numa_cpu_dump(struct seq_file *m)
+{
+	seq_printf(m, "NODE: #%02d, CPU: #%04d, ttbr1_el1: 0x%p, COMM: %s\n",
+		numa_node_id(),
+		smp_processor_id(),
+		(void *)read_sysreg(ttbr1_el1),
+		current->group_leader->comm);
+	return 0;
+}
+
+static inline void numa_sync_text_replicas(unsigned long start, unsigned long end)
+{
+	caches_clean_inval_pou(start, end);
+	icache_inval_all_pou();
+}
+#endif /* CONFIG_KERNEL_REPLICATION */
+#endif /* __ASM_NUMA_REPLICATION_H */