xref: /openbmc/linux/arch/m68k/amiga/chipram.c (revision b2441318)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 **  linux/amiga/chipram.c
4 **
5 **      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
6 **          - 64-bit aligned allocations for full AGA compatibility
7 **
8 **	Rewritten 15/9/2000 by Geert to use resource management
9 */
10 
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/init.h>
15 #include <linux/ioport.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/module.h>
19 
20 #include <asm/atomic.h>
21 #include <asm/page.h>
22 #include <asm/amigahw.h>
23 
24 unsigned long amiga_chip_size;
25 EXPORT_SYMBOL(amiga_chip_size);
26 
27 static struct resource chipram_res = {
28 	.name = "Chip RAM", .start = CHIP_PHYSADDR
29 };
30 static atomic_t chipavail;
31 
32 
amiga_chip_init(void)33 void __init amiga_chip_init(void)
34 {
35 	if (!AMIGAHW_PRESENT(CHIP_RAM))
36 		return;
37 
38 	chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
39 	request_resource(&iomem_resource, &chipram_res);
40 
41 	atomic_set(&chipavail, amiga_chip_size);
42 }
43 
44 
amiga_chip_alloc(unsigned long size,const char * name)45 void *amiga_chip_alloc(unsigned long size, const char *name)
46 {
47 	struct resource *res;
48 	void *p;
49 
50 	res = kzalloc(sizeof(struct resource), GFP_KERNEL);
51 	if (!res)
52 		return NULL;
53 
54 	res->name = name;
55 	p = amiga_chip_alloc_res(size, res);
56 	if (!p) {
57 		kfree(res);
58 		return NULL;
59 	}
60 
61 	return p;
62 }
63 EXPORT_SYMBOL(amiga_chip_alloc);
64 
65 
66 	/*
67 	 *  Warning:
68 	 *  amiga_chip_alloc_res is meant only for drivers that need to
69 	 *  allocate Chip RAM before kmalloc() is functional. As a consequence,
70 	 *  those drivers must not free that Chip RAM afterwards.
71 	 */
72 
amiga_chip_alloc_res(unsigned long size,struct resource * res)73 void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
74 {
75 	int error;
76 
77 	/* round up */
78 	size = PAGE_ALIGN(size);
79 
80 	pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
81 	error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
82 				  PAGE_SIZE, NULL, NULL);
83 	if (error < 0) {
84 		pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
85 		       error);
86 		return NULL;
87 	}
88 
89 	atomic_sub(size, &chipavail);
90 	pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
91 	return ZTWO_VADDR(res->start);
92 }
93 
amiga_chip_free(void * ptr)94 void amiga_chip_free(void *ptr)
95 {
96 	unsigned long start = ZTWO_PADDR(ptr);
97 	struct resource *res;
98 	unsigned long size;
99 
100 	res = lookup_resource(&chipram_res, start);
101 	if (!res) {
102 		pr_err("amiga_chip_free: trying to free nonexistent region at "
103 		       "%p\n", ptr);
104 		return;
105 	}
106 
107 	size = resource_size(res);
108 	pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
109 	atomic_add(size, &chipavail);
110 	release_resource(res);
111 	kfree(res);
112 }
113 EXPORT_SYMBOL(amiga_chip_free);
114 
115 
amiga_chip_avail(void)116 unsigned long amiga_chip_avail(void)
117 {
118 	unsigned long n = atomic_read(&chipavail);
119 
120 	pr_debug("amiga_chip_avail : %lu bytes\n", n);
121 	return n;
122 }
123 EXPORT_SYMBOL(amiga_chip_avail);
124 
125