Linux kernel mirror (for testing)
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linux
1/*
2 * Functions for ST-RAM allocations
3 *
4 * Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/mm.h>
14#include <linux/kdev_t.h>
15#include <linux/major.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/vmalloc.h>
19#include <linux/pagemap.h>
20#include <linux/bootmem.h>
21#include <linux/mount.h>
22#include <linux/blkdev.h>
23#include <linux/module.h>
24
25#include <asm/setup.h>
26#include <asm/machdep.h>
27#include <asm/page.h>
28#include <asm/pgtable.h>
29#include <asm/atarihw.h>
30#include <asm/atari_stram.h>
31#include <asm/io.h>
32
33
34/*
35 * The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of
36 * configurable size, set aside on ST-RAM init.
37 * As long as this pool is not exhausted, allocation of real ST-RAM can be
38 * guaranteed.
39 */
40
41/* set if kernel is in ST-RAM */
42static int kernel_in_stram;
43
44static struct resource stram_pool = {
45 .name = "ST-RAM Pool"
46};
47
48static unsigned long pool_size = 1024*1024;
49
50static unsigned long stram_virt_offset;
51
52static int __init atari_stram_setup(char *arg)
53{
54 if (!MACH_IS_ATARI)
55 return 0;
56
57 pool_size = memparse(arg, NULL);
58 return 0;
59}
60
61early_param("stram_pool", atari_stram_setup);
62
63
64/*
65 * This init function is called very early by atari/config.c
66 * It initializes some internal variables needed for stram_alloc()
67 */
68void __init atari_stram_init(void)
69{
70 int i;
71
72 /*
73 * determine whether kernel code resides in ST-RAM
74 * (then ST-RAM is the first memory block at virtual 0x0)
75 */
76 kernel_in_stram = (m68k_memory[0].addr == 0);
77
78 for (i = 0; i < m68k_num_memory; ++i) {
79 if (m68k_memory[i].addr == 0) {
80 return;
81 }
82 }
83
84 /* Should never come here! (There is always ST-Ram!) */
85 panic("atari_stram_init: no ST-RAM found!");
86}
87
88
89/*
90 * This function is called from setup_arch() to reserve the pages needed for
91 * ST-RAM management, if the kernel resides in ST-RAM.
92 */
93void __init atari_stram_reserve_pages(void *start_mem)
94{
95 if (kernel_in_stram) {
96 pr_debug("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n");
97 stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
98 stram_pool.end = stram_pool.start + pool_size - 1;
99 request_resource(&iomem_resource, &stram_pool);
100 stram_virt_offset = 0;
101 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
102 pool_size, &stram_pool);
103 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
104 stram_virt_offset);
105 }
106}
107
108
109/*
110 * This function is called as arch initcall to reserve the pages needed for
111 * ST-RAM management, if the kernel does not reside in ST-RAM.
112 */
113int __init atari_stram_map_pages(void)
114{
115 if (!kernel_in_stram) {
116 /*
117 * Skip page 0, as the fhe first 2 KiB are supervisor-only!
118 */
119 pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n");
120 stram_pool.start = PAGE_SIZE;
121 stram_pool.end = stram_pool.start + pool_size - 1;
122 request_resource(&iomem_resource, &stram_pool);
123 stram_virt_offset = (unsigned long) ioremap(stram_pool.start,
124 resource_size(&stram_pool)) - stram_pool.start;
125 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
126 pool_size, &stram_pool);
127 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
128 stram_virt_offset);
129 }
130 return 0;
131}
132arch_initcall(atari_stram_map_pages);
133
134
135void *atari_stram_to_virt(unsigned long phys)
136{
137 return (void *)(phys + stram_virt_offset);
138}
139EXPORT_SYMBOL(atari_stram_to_virt);
140
141
142unsigned long atari_stram_to_phys(void *virt)
143{
144 return (unsigned long)(virt - stram_virt_offset);
145}
146EXPORT_SYMBOL(atari_stram_to_phys);
147
148
149void *atari_stram_alloc(unsigned long size, const char *owner)
150{
151 struct resource *res;
152 int error;
153
154 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
155
156 /* round up */
157 size = PAGE_ALIGN(size);
158
159 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
160 if (!res)
161 return NULL;
162
163 res->name = owner;
164 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
165 PAGE_SIZE, NULL, NULL);
166 if (error < 0) {
167 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
168 error);
169 kfree(res);
170 return NULL;
171 }
172
173 pr_debug("atari_stram_alloc: returning %pR\n", res);
174 return atari_stram_to_virt(res->start);
175}
176EXPORT_SYMBOL(atari_stram_alloc);
177
178
179void atari_stram_free(void *addr)
180{
181 unsigned long start = atari_stram_to_phys(addr);
182 struct resource *res;
183 unsigned long size;
184
185 res = lookup_resource(&stram_pool, start);
186 if (!res) {
187 pr_err("atari_stram_free: trying to free nonexistent region "
188 "at %p\n", addr);
189 return;
190 }
191
192 size = resource_size(res);
193 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
194 release_resource(res);
195 kfree(res);
196}
197EXPORT_SYMBOL(atari_stram_free);