xref: /kernel/linux/linux-6.6/arch/xtensa/mm/highmem.c (revision 62306a36)
1/*
2 * High memory support for Xtensa architecture
3 *
4 * This file is subject to the terms and conditions of the GNU General
5 * Public License.  See the file "COPYING" in the main directory of
6 * this archive for more details.
7 *
8 * Copyright (C) 2014 Cadence Design Systems Inc.
9 */
10
11#include <linux/export.h>
12#include <linux/highmem.h>
13#include <asm/tlbflush.h>
14
15#if DCACHE_WAY_SIZE > PAGE_SIZE
16unsigned int last_pkmap_nr_arr[DCACHE_N_COLORS];
17wait_queue_head_t pkmap_map_wait_arr[DCACHE_N_COLORS];
18
19static void __init kmap_waitqueues_init(void)
20{
21	unsigned int i;
22
23	for (i = 0; i < ARRAY_SIZE(pkmap_map_wait_arr); ++i)
24		init_waitqueue_head(pkmap_map_wait_arr + i);
25}
26
27static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
28{
29	int idx = (type + KM_MAX_IDX * smp_processor_id()) * DCACHE_N_COLORS;
30
31	/*
32	 * The fixmap operates top down, so the color offset needs to be
33	 * reverse as well.
34	 */
35	return idx + DCACHE_N_COLORS - 1 - color;
36}
37
38enum fixed_addresses kmap_local_map_idx(int type, unsigned long pfn)
39{
40	return kmap_idx(type, DCACHE_ALIAS(pfn << PAGE_SHIFT));
41}
42
43enum fixed_addresses kmap_local_unmap_idx(int type, unsigned long addr)
44{
45	return kmap_idx(type, DCACHE_ALIAS(addr));
46}
47
48#else
49static inline void kmap_waitqueues_init(void) { }
50#endif
51
52void __init kmap_init(void)
53{
54	/* Check if this memory layout is broken because PKMAP overlaps
55	 * page table.
56	 */
57	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
58	kmap_waitqueues_init();
59}
60