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/pgtable.h>
30 #include <asm/atarihw.h>
31 #include <asm/atari_stram.h>
32 #include <asm/io.h>
33
34
35 /*
36 * The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of
37 * configurable size, set aside on ST-RAM init.
38 * As long as this pool is not exhausted, allocation of real ST-RAM can be
39 * guaranteed.
40 */
41
42 /* set if kernel is in ST-RAM */
43 static int kernel_in_stram;
44
45 static struct resource stram_pool = {
46 .name = "ST-RAM Pool"
47 };
48
49 static unsigned long pool_size = 1024*1024;
50
51 static unsigned long stram_virt_offset;
52
atari_stram_setup(char * arg)53 static int __init atari_stram_setup(char *arg)
54 {
55 if (!MACH_IS_ATARI)
56 return 0;
57
58 pool_size = memparse(arg, NULL);
59 return 0;
60 }
61
62 early_param("stram_pool", atari_stram_setup);
63
64
65 /*
66 * This init function is called very early by atari/config.c
67 * It initializes some internal variables needed for stram_alloc()
68 */
atari_stram_init(void)69 void __init atari_stram_init(void)
70 {
71 int i;
72
73 /*
74 * determine whether kernel code resides in ST-RAM
75 * (then ST-RAM is the first memory block at virtual 0x0)
76 */
77 kernel_in_stram = (m68k_memory[0].addr == 0);
78
79 for (i = 0; i < m68k_num_memory; ++i) {
80 if (m68k_memory[i].addr == 0) {
81 return;
82 }
83 }
84
85 /* Should never come here! (There is always ST-Ram!) */
86 panic("atari_stram_init: no ST-RAM found!");
87 }
88
89
90 /*
91 * This function is called from setup_arch() to reserve the pages needed for
92 * ST-RAM management, if the kernel resides in ST-RAM.
93 */
atari_stram_reserve_pages(void * start_mem)94 void __init atari_stram_reserve_pages(void *start_mem)
95 {
96 if (kernel_in_stram) {
97 pr_debug("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n");
98 stram_pool.start = (resource_size_t)memblock_alloc_low(pool_size,
99 PAGE_SIZE);
100 if (!stram_pool.start)
101 panic("%s: Failed to allocate %lu bytes align=%lx\n",
102 __func__, pool_size, PAGE_SIZE);
103
104 stram_pool.end = stram_pool.start + pool_size - 1;
105 request_resource(&iomem_resource, &stram_pool);
106 stram_virt_offset = 0;
107 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
108 pool_size, &stram_pool);
109 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
110 stram_virt_offset);
111 }
112 }
113
114
115 /*
116 * This function is called as arch initcall to reserve the pages needed for
117 * ST-RAM management, if the kernel does not reside in ST-RAM.
118 */
atari_stram_map_pages(void)119 int __init atari_stram_map_pages(void)
120 {
121 if (!kernel_in_stram) {
122 /*
123 * Skip page 0, as the fhe first 2 KiB are supervisor-only!
124 */
125 pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n");
126 stram_pool.start = PAGE_SIZE;
127 stram_pool.end = stram_pool.start + pool_size - 1;
128 request_resource(&iomem_resource, &stram_pool);
129 stram_virt_offset = (unsigned long) ioremap(stram_pool.start,
130 resource_size(&stram_pool)) - stram_pool.start;
131 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
132 pool_size, &stram_pool);
133 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
134 stram_virt_offset);
135 }
136 return 0;
137 }
138 arch_initcall(atari_stram_map_pages);
139
140
atari_stram_to_virt(unsigned long phys)141 void *atari_stram_to_virt(unsigned long phys)
142 {
143 return (void *)(phys + stram_virt_offset);
144 }
145 EXPORT_SYMBOL(atari_stram_to_virt);
146
147
atari_stram_to_phys(void * virt)148 unsigned long atari_stram_to_phys(void *virt)
149 {
150 return (unsigned long)(virt - stram_virt_offset);
151 }
152 EXPORT_SYMBOL(atari_stram_to_phys);
153
154
atari_stram_alloc(unsigned long size,const char * owner)155 void *atari_stram_alloc(unsigned long size, const char *owner)
156 {
157 struct resource *res;
158 int error;
159
160 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
161
162 /* round up */
163 size = PAGE_ALIGN(size);
164
165 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
166 if (!res)
167 return NULL;
168
169 res->name = owner;
170 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
171 PAGE_SIZE, NULL, NULL);
172 if (error < 0) {
173 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
174 error);
175 kfree(res);
176 return NULL;
177 }
178
179 pr_debug("atari_stram_alloc: returning %pR\n", res);
180 return atari_stram_to_virt(res->start);
181 }
182 EXPORT_SYMBOL(atari_stram_alloc);
183
184
atari_stram_free(void * addr)185 void atari_stram_free(void *addr)
186 {
187 unsigned long start = atari_stram_to_phys(addr);
188 struct resource *res;
189 unsigned long size;
190
191 res = lookup_resource(&stram_pool, start);
192 if (!res) {
193 pr_err("atari_stram_free: trying to free nonexistent region "
194 "at %p\n", addr);
195 return;
196 }
197
198 size = resource_size(res);
199 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
200 release_resource(res);
201 kfree(res);
202 }
203 EXPORT_SYMBOL(atari_stram_free);
204
