| // SPDX-License-Identifier: GPL-2.0-only |
| * A generic version of devmem_is_allowed. |
| * Based on arch/arm64/mm/mmap.c |
| * Copyright (C) 2020 Google, Inc. |
| * Copyright (C) 2012 ARM Ltd. |
| #include <linux/ioport.h> |
| * devmem_is_allowed() checks to see if /dev/mem access to a certain address |
| * is valid. The argument is a physical page number. We mimic x86 here by |
| * disallowing access to system RAM as well as device-exclusive MMIO regions. |
| * This effectively disable read()/write() on /dev/mem. |
| int devmem_is_allowed(unsigned long pfn) |
| if (iomem_is_exclusive(PFN_PHYS(pfn))) |