xref: /dragonfly/sys/dev/drm/linux_iomapping.c (revision 5ca0a96d)
1 /*
2  * Copyright (c) 2014-2019 François Tigeot <ftigeot@wolfpond.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <machine/pmap.h>
28 #include <vm/pmap.h>
29 #include <vm/vm.h>
30 
31 #include <linux/kernel.h>
32 #include <linux/slab.h>
33 #include <linux/bug.h>
34 #include <asm/page.h>
35 #include <asm/io.h>
36 
37 struct lock iomap_lock = LOCK_INITIALIZER("dlioml", 0, LK_CANRECURSE);
38 
39 SLIST_HEAD(iomap_list_head, iomap) iomap_list = SLIST_HEAD_INITIALIZER(iomap_list);
40 
41 void __iomem *
42 __ioremap_common(unsigned long phys_addr, unsigned long size, int cache_mode)
43 {
44 	struct iomap *imp;
45 
46 	/* Ensure mappings are page-aligned */
47 	BUG_ON(phys_addr & PAGE_MASK);
48 	BUG_ON(size & PAGE_MASK);
49 
50 	imp = kmalloc(sizeof(struct iomap), M_DRM, M_WAITOK);
51 	imp->paddr = phys_addr;
52 	imp->npages = size / PAGE_SIZE;
53 	imp->pmap_addr = pmap_mapdev_attr(phys_addr, size, cache_mode);
54 	lockmgr(&iomap_lock, LK_EXCLUSIVE);
55 	SLIST_INSERT_HEAD(&iomap_list, imp, im_iomaps);
56 	lockmgr(&iomap_lock, LK_RELEASE);
57 
58 	return imp->pmap_addr;
59 }
60 
61 void iounmap(void __iomem *ptr)
62 {
63 	struct iomap *imp, *tmp_imp;
64 	int found = 0;
65 	int indx;
66 	vm_paddr_t paddr_end;
67 
68 	SLIST_FOREACH_MUTABLE(imp, &iomap_list, im_iomaps, tmp_imp) {
69 		if (imp->pmap_addr == ptr) {
70 			found = 1;
71 			break;
72 		}
73 	}
74 
75 	if (!found) {
76 		kprintf("iounmap: invalid address %p\n", ptr);
77 		return;
78 	}
79 
80 	paddr_end = imp->paddr + (imp->npages * PAGE_SIZE) - 1;
81 	/* Is this address space range backed by regular memory ? */
82 	for (indx = 0; phys_avail[indx].phys_end != 0; ++indx) {
83 		vm_paddr_t range_start = phys_avail[indx].phys_beg;
84 		vm_paddr_t size = phys_avail[indx].phys_end -
85 				  phys_avail[indx].phys_beg;
86 		vm_paddr_t range_end = range_start + size - 1;
87 
88 		if ((imp->paddr >= range_start) && (paddr_end <= range_end)) {
89 			/* Yes, change page caching attributes */
90 			pmap_change_attr(imp->paddr, imp->npages, PAT_WRITE_BACK);
91 			break;
92 		}
93 
94 	}
95 
96 	pmap_unmapdev((vm_offset_t)imp->pmap_addr, imp->npages * PAGE_SIZE);
97 
98 	lockmgr(&iomap_lock, LK_EXCLUSIVE);
99 	SLIST_REMOVE(&iomap_list, imp, iomap, im_iomaps);
100 	lockmgr(&iomap_lock, LK_RELEASE);
101 
102 	kfree(imp);
103 }
104 
105 #include <sys/memrange.h>
106 
107 int
108 arch_io_reserve_memtype_wc(resource_size_t start, resource_size_t size)
109 {
110 	int act;
111 	struct mem_range_desc mrdesc;
112 
113 	mrdesc.mr_base = start;
114 	mrdesc.mr_len = size;
115 	mrdesc.mr_flags = MDF_WRITECOMBINE;
116 	act = MEMRANGE_SET_UPDATE;
117 	strlcpy(mrdesc.mr_owner, "drm", sizeof(mrdesc.mr_owner));
118 	return mem_range_attr_set(&mrdesc, &act);
119 }
120