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/memblock.h>
21 #include <linux/mount.h>
22 #include <linux/blkdev.h>
23 #include <linux/module.h>
24 #include <linux/ioport.h>
25
26 #include <asm/setup.h>
27 #include <asm/machdep.h>
28 #include <asm/page.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 */
42 static int kernel_in_stram;
43
44 static struct resource stram_pool = {
45 .name = "ST-RAM Pool"
46 };
47
48 static unsigned long pool_size = 1024*1024;
49
50 static unsigned long stram_virt_offset;
51
52 static 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
61 early_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 */
68 void __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 */
93 void __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)memblock_alloc_low(pool_size,
98 PAGE_SIZE);
99 if (!stram_pool.start)
100 panic("%s: Failed to allocate %lu bytes align=%lx\n",
101 __func__, pool_size, PAGE_SIZE);
102
103 stram_pool.end = stram_pool.start + pool_size - 1;
104 request_resource(&iomem_resource, &stram_pool);
105 stram_virt_offset = 0;
106 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
107 pool_size, &stram_pool);
108 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
109 stram_virt_offset);
110 }
111 }
112
113
114 /*
115 * This function is called as arch initcall to reserve the pages needed for
116 * ST-RAM management, if the kernel does not reside in ST-RAM.
117 */
118 static int __init atari_stram_map_pages(void)
119 {
120 if (!kernel_in_stram) {
121 /*
122 * Skip page 0, as the fhe first 2 KiB are supervisor-only!
123 */
124 pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n");
125 stram_pool.start = PAGE_SIZE;
126 stram_pool.end = stram_pool.start + pool_size - 1;
127 request_resource(&iomem_resource, &stram_pool);
128 stram_virt_offset = (unsigned long) ioremap(stram_pool.start,
129 resource_size(&stram_pool)) - stram_pool.start;
130 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
131 pool_size, &stram_pool);
132 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
133 stram_virt_offset);
134 }
135 return 0;
136 }
137 arch_initcall(atari_stram_map_pages);
138
139
140 void *atari_stram_to_virt(unsigned long phys)
141 {
142 return (void *)(phys + stram_virt_offset);
143 }
144 EXPORT_SYMBOL(atari_stram_to_virt);
145
146
147 unsigned long atari_stram_to_phys(void *virt)
148 {
149 return (unsigned long)(virt - stram_virt_offset);
150 }
151 EXPORT_SYMBOL(atari_stram_to_phys);
152
153
154 void *atari_stram_alloc(unsigned long size, const char *owner)
155 {
156 struct resource *res;
157 int error;
158
159 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
160
161 /* round up */
162 size = PAGE_ALIGN(size);
163
164 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
165 if (!res)
166 return NULL;
167
168 res->name = owner;
169 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
170 PAGE_SIZE, NULL, NULL);
171 if (error < 0) {
172 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
173 error);
174 kfree(res);
175 return NULL;
176 }
177
178 pr_debug("atari_stram_alloc: returning %pR\n", res);
179 return atari_stram_to_virt(res->start);
180 }
181 EXPORT_SYMBOL(atari_stram_alloc);
182
183
184 void atari_stram_free(void *addr)
185 {
186 unsigned long start = atari_stram_to_phys(addr);
187 struct resource *res;
188 unsigned long size;
189
190 res = lookup_resource(&stram_pool, start);
191 if (!res) {
192 pr_err("atari_stram_free: trying to free nonexistent region "
193 "at %p\n", addr);
194 return;
195 }
196
197 size = resource_size(res);
198 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
199 release_resource(res);
200 kfree(res);
201 }
202 EXPORT_SYMBOL(atari_stram_free);
203
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