Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Based on arch/arm/mm/mmap.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * Copyright (C) 2012 ARM Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/elf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/memblock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/shm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/personality.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/random.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <asm/cputype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)  * You really shouldn't be using read() or write() on /dev/mem.  This might go
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)  * away in the future.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) int valid_phys_addr_range(phys_addr_t addr, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	 * Check whether addr is covered by a memory region without the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	 * MEMBLOCK_NOMAP attribute, and whether that region covers the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	 * entire range. In theory, this could lead to false negatives
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	 * if the range is covered by distinct but adjacent memory regions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	 * that only differ in other attributes. However, few of such
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	 * attributes have been defined, and it is debatable whether it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	 * follows that /dev/mem read() calls should be able traverse
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	 * such boundaries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	return memblock_is_region_memory(addr, size) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	       memblock_is_map_memory(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)  * Do not allow /dev/mem mappings beyond the supported physical range.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 	return !(((pfn << PAGE_SHIFT) + size) & ~PHYS_MASK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #ifdef CONFIG_STRICT_DEVMEM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #include <linux/ioport.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)  * devmem_is_allowed() checks to see if /dev/mem access to a certain address
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)  * is valid. The argument is a physical page number.  We mimic x86 here by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)  * disallowing access to system RAM as well as device-exclusive MMIO regions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59)  * This effectively disable read()/write() on /dev/mem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) int devmem_is_allowed(unsigned long pfn)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 	if (iomem_is_exclusive(pfn << PAGE_SHIFT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	if (!page_is_ram(pfn))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) #endif