Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) // Copyright (C) 2005-2017 Andes Technology Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) #include <linux/mman.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) #include <linux/shm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #define COLOUR_ALIGN(addr,pgoff)		\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 	 (((pgoff)<<PAGE_SHIFT) & (SHMLBA-1)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * We need to ensure that shared mappings are correctly aligned to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * avoid aliasing issues with VIPT caches.  We need to ensure that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * a specific page of an object is always mapped at a multiple of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * SHMLBA bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * We unconditionally provide this function for all cases, however
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  * in the VIVT case, we optimise out the alignment rules.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) unsigned long
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) arch_get_unmapped_area(struct file *filp, unsigned long addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 		       unsigned long len, unsigned long pgoff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 		       unsigned long flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	struct mm_struct *mm = current->mm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	struct vm_area_struct *vma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	int do_align = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	struct vm_unmapped_area_info info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	int aliasing = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	if(IS_ENABLED(CONFIG_CPU_CACHE_ALIASING))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 		aliasing = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	 * We only need to do colour alignment if either the I or D
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	 * caches alias.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	if (aliasing)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		do_align = filp || (flags & MAP_SHARED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	 * We enforce the MAP_FIXED case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	if (flags & MAP_FIXED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 		if (aliasing && flags & MAP_SHARED &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 		return addr;
^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) 	if (len > TASK_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	if (addr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		if (do_align)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 			addr = COLOUR_ALIGN(addr, pgoff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 			addr = PAGE_ALIGN(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 		vma = find_vma(mm, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 		if (TASK_SIZE - len >= addr &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		    (!vma || addr + len <= vm_start_gap(vma)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 			return addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 	info.flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	info.length = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	info.low_limit = mm->mmap_base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	info.high_limit = TASK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 	info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	info.align_offset = pgoff << PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 	return vm_unmapped_area(&info);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }