xref: /netbsd-src/sys/arch/xen/xen/xenmem.c (revision e5fbc36ada28f9b9a5836ecffaf4a06aa1ebb687)
1 /* $NetBSD: xenmem.c,v 1.5 2023/12/20 15:34:46 thorpej Exp $ */
2 /*
3  * Copyright (c) 2022 Manuel Bouyer.
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, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __KERNEL_RCSID(0, "$NetBSD: xenmem.c,v 1.5 2023/12/20 15:34:46 thorpej Exp $");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/extent.h>
33 #include <sys/kmem.h>
34 #include <uvm/uvm_physseg.h>
35 
36 #include <xen/xenmem.h>
37 
38 /*
39  * Xen physical space management
40  * The xenmem_ex extent manage the VM's pseudo-physical memory space.
41  * This contains the m�mory allocated to the VM, and is also used to allocate
42  * extra physical space used for XENMEM_add_to_physmap (in come cases)
43  * In the !XENPV case, the physical space is managed by bus_space, so
44  * we reuse the iomem_ex
45  */
46 
47 extern struct  extent *iomem_ex;
48 #define XENMEM_EX iomem_ex
49 
50 paddr_t
xenmem_alloc_pa(u_long size,u_long align,bool waitok)51 xenmem_alloc_pa(u_long size, u_long align, bool waitok)
52 {
53 	u_long result;
54 	int error;
55 
56 #ifdef _LP64
57 	/* allocate above the 4Gb range to not collide wit devices */
58 	error = extent_alloc_subregion(XENMEM_EX, 0x100000000UL, MAXIOMEM,
59 	    size, align, 0,
60 	    (waitok ? (EX_WAITSPACE | EX_WAITOK) : EX_NOWAIT) | EX_MALLOCOK,
61 	    &result);
62 #else
63 	error = extent_alloc(XENMEM_EX, size, align, 0,
64 	    (waitok ? (EX_WAITSPACE | EX_WAITOK) : EX_NOWAIT) | EX_MALLOCOK,
65 	    &result);
66 #endif
67 	if (error) {
68 		printf("xenmem_alloc_pa: failed %d\n", error);
69 		return 0;
70 	}
71 	return result;
72 }
73 
74 void
xenmem_free_pa(paddr_t start,u_long size)75 xenmem_free_pa(paddr_t start, u_long size)
76 {
77 	int error;
78 	error = extent_free(XENMEM_EX, start, size, EX_NOWAIT);
79 	if (error) {
80 		printf("WARNING: xenmem_alloc_pa failed: %d\n", error);
81 	}
82 }
83