1 files changed, 32 insertions, 88 deletions

diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
index c4c8cd4c31d4..10e246f11271 100644
--- a/arch/arm64/mm/ioremap.c
+++ b/arch/arm64/mm/ioremap.c
@@ -1,108 +1,44 @@
-/*
- * Based on arch/arm/mm/ioremap.c
- *
- * (C) Copyright 1995 1996 Linus Torvalds
- * Hacked for ARM by Phil Blundell <philb@gnu.org>
- * Hacked to allow all architectures to build, and various cleanups
- * by Russell King
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
+// SPDX-License-Identifier: GPL-2.0-only
 
-#include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/vmalloc.h>
 #include <linux/io.h>
 
-#include <asm/fixmap.h>
-#include <asm/tlbflush.h>
-#include <asm/pgalloc.h>
+static ioremap_prot_hook_t ioremap_prot_hook;
 
-static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
-				      pgprot_t prot, void *caller)
+int arm64_ioremap_prot_hook_register(ioremap_prot_hook_t hook)
 {
-	unsigned long last_addr;
-	unsigned long offset = phys_addr & ~PAGE_MASK;
-	int err;
-	unsigned long addr;
-	struct vm_struct *area;
-
-	/*
-	 * Page align the mapping address and size, taking account of any
-	 * offset.
-	 */
-	phys_addr &= PAGE_MASK;
-	size = PAGE_ALIGN(size + offset);
+	if (WARN_ON(ioremap_prot_hook))
+		return -EBUSY;
 
-	/*
-	 * Don't allow wraparound, zero size or outside PHYS_MASK.
-	 */
-	last_addr = phys_addr + size - 1;
-	if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
-		return NULL;
+	ioremap_prot_hook = hook;
+	return 0;
+}
 
-	/*
-	 * Don't allow RAM to be mapped.
-	 */
-	if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
-		return NULL;
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   pgprot_t pgprot)
+{
+	unsigned long last_addr = phys_addr + size - 1;
 
-	area = get_vm_area_caller(size, VM_IOREMAP, caller);
-	if (!area)
+	/* Don't allow outside PHYS_MASK */
+	if (last_addr & ~PHYS_MASK)
 		return NULL;
-	addr = (unsigned long)area->addr;
-	area->phys_addr = phys_addr;
 
-	err = ioremap_page_range(addr, addr + size, phys_addr, prot);
-	if (err) {
-		vunmap((void *)addr);
+	/* Don't allow RAM to be mapped. */
+	if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
 		return NULL;
-	}
-
-	return (void __iomem *)(offset + addr);
-}
-
-void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
-{
-	return __ioremap_caller(phys_addr, size, prot,
-				__builtin_return_address(0));
-}
-EXPORT_SYMBOL(__ioremap);
-
-void __iounmap(volatile void __iomem *io_addr)
-{
-	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
 
 	/*
-	 * We could get an address outside vmalloc range in case
-	 * of ioremap_cache() reusing a RAM mapping.
+	 * If a hook is registered (e.g. for confidential computing
+	 * purposes), call that now and barf if it fails.
 	 */
-	if (is_vmalloc_addr((void *)addr))
-		vunmap((void *)addr);
-}
-EXPORT_SYMBOL(__iounmap);
-
-void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
-{
-	/* For normal memory we already have a cacheable mapping. */
-	if (pfn_valid(__phys_to_pfn(phys_addr)))
-		return (void __iomem *)__phys_to_virt(phys_addr);
+	if (unlikely(ioremap_prot_hook) &&
+	    WARN_ON(ioremap_prot_hook(phys_addr, size, &pgprot))) {
+		return NULL;
+	}
 
-	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
-				__builtin_return_address(0));
+	return generic_ioremap_prot(phys_addr, size, pgprot);
 }
-EXPORT_SYMBOL(ioremap_cache);
+EXPORT_SYMBOL(ioremap_prot);
 
 /*
  * Must be called after early_fixmap_init
@@ -111,3 +47,11 @@ void __init early_ioremap_init(void)
 {
 	early_ioremap_setup();
 }
+
+bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+				 unsigned long flags)
+{
+	unsigned long pfn = PHYS_PFN(offset);
+
+	return pfn_is_map_memory(pfn);
+}