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
24unsigned long amiga_chip_size;
25EXPORT_SYMBOL(amiga_chip_size);
26
27static struct resource chipram_res = {
28	.name = "Chip RAM", .start = CHIP_PHYSADDR
29};
30static atomic_t chipavail;
31
32
33void __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
45void *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}
63EXPORT_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
73void *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
94void 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}
113EXPORT_SYMBOL(amiga_chip_free);
114
115
116unsigned 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}
123EXPORT_SYMBOL(amiga_chip_avail);
124
125