1 files changed, 60 insertions, 2 deletions

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 4fa420faa780..4b95d8999120 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -357,7 +357,7 @@ static phys_addr_t __init alloc_pte_late(uintptr_t va)
 	unsigned long vaddr;
 
 	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
+	BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page((void *)vaddr)));
 
 	return __pa(vaddr);
 }
@@ -440,7 +440,7 @@ static phys_addr_t __init alloc_pmd_late(uintptr_t va)
 	unsigned long vaddr;
 
 	vaddr = __get_free_page(GFP_KERNEL);
-	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page(vaddr)));
+	BUG_ON(!vaddr || !pgtable_pmd_page_ctor(virt_to_page((void *)vaddr)));
 
 	return __pa(vaddr);
 }
@@ -1389,3 +1389,61 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 	return vmemmap_populate_basepages(start, end, node, NULL);
 }
 #endif
+
+#if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
+/*
+ * Pre-allocates page-table pages for a specific area in the kernel
+ * page-table. Only the level which needs to be synchronized between
+ * all page-tables is allocated because the synchronization can be
+ * expensive.
+ */
+static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end,
+					       const char *area)
+{
+	unsigned long addr;
+	const char *lvl;
+
+	for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
+		pgd_t *pgd = pgd_offset_k(addr);
+		p4d_t *p4d;
+		pud_t *pud;
+		pmd_t *pmd;
+
+		lvl = "p4d";
+		p4d = p4d_alloc(&init_mm, pgd, addr);
+		if (!p4d)
+			goto failed;
+
+		if (pgtable_l5_enabled)
+			continue;
+
+		lvl = "pud";
+		pud = pud_alloc(&init_mm, p4d, addr);
+		if (!pud)
+			goto failed;
+
+		if (pgtable_l4_enabled)
+			continue;
+
+		lvl = "pmd";
+		pmd = pmd_alloc(&init_mm, pud, addr);
+		if (!pmd)
+			goto failed;
+	}
+	return;
+
+failed:
+	/*
+	 * The pages have to be there now or they will be missing in
+	 * process page-tables later.
+	 */
+	panic("Failed to pre-allocate %s pages for %s area\n", lvl, area);
+}
+
+void __init pgtable_cache_init(void)
+{
+	preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc");
+	if (IS_ENABLED(CONFIG_MODULES))
+		preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules");
+}
+#endif