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/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 */
43static int kernel_in_stram;
44
45static struct resource stram_pool = {
46 .name = "ST-RAM Pool"
47};
48
49static unsigned long pool_size = 1024*1024;
50
51static unsigned long stram_virt_offset;
52
53static 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
62early_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 */
69void __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 */
94void __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 stram_pool.end = stram_pool.start + pool_size - 1;
101 request_resource(&iomem_resource, &stram_pool);
102 stram_virt_offset = 0;
103 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
104 pool_size, &stram_pool);
105 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
106 stram_virt_offset);
107 }
108}
109
110
111/*
112 * This function is called as arch initcall to reserve the pages needed for
113 * ST-RAM management, if the kernel does not reside in ST-RAM.
114 */
115int __init atari_stram_map_pages(void)
116{
117 if (!kernel_in_stram) {
118 /*
119 * Skip page 0, as the fhe first 2 KiB are supervisor-only!
120 */
121 pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n");
122 stram_pool.start = PAGE_SIZE;
123 stram_pool.end = stram_pool.start + pool_size - 1;
124 request_resource(&iomem_resource, &stram_pool);
125 stram_virt_offset = (unsigned long) ioremap(stram_pool.start,
126 resource_size(&stram_pool)) - stram_pool.start;
127 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
128 pool_size, &stram_pool);
129 pr_debug("atari_stram pool: stram_virt_offset = %lx\n",
130 stram_virt_offset);
131 }
132 return 0;
133}
134arch_initcall(atari_stram_map_pages);
135
136
137void *atari_stram_to_virt(unsigned long phys)
138{
139 return (void *)(phys + stram_virt_offset);
140}
141EXPORT_SYMBOL(atari_stram_to_virt);
142
143
144unsigned long atari_stram_to_phys(void *virt)
145{
146 return (unsigned long)(virt - stram_virt_offset);
147}
148EXPORT_SYMBOL(atari_stram_to_phys);
149
150
151void *atari_stram_alloc(unsigned long size, const char *owner)
152{
153 struct resource *res;
154 int error;
155
156 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
157
158 /* round up */
159 size = PAGE_ALIGN(size);
160
161 res = kzalloc(sizeof(struct resource), GFP_KERNEL);
162 if (!res)
163 return NULL;
164
165 res->name = owner;
166 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
167 PAGE_SIZE, NULL, NULL);
168 if (error < 0) {
169 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
170 error);
171 kfree(res);
172 return NULL;
173 }
174
175 pr_debug("atari_stram_alloc: returning %pR\n", res);
176 return atari_stram_to_virt(res->start);
177}
178EXPORT_SYMBOL(atari_stram_alloc);
179
180
181void atari_stram_free(void *addr)
182{
183 unsigned long start = atari_stram_to_phys(addr);
184 struct resource *res;
185 unsigned long size;
186
187 res = lookup_resource(&stram_pool, start);
188 if (!res) {
189 pr_err("atari_stram_free: trying to free nonexistent region "
190 "at %p\n", addr);
191 return;
192 }
193
194 size = resource_size(res);
195 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
196 release_resource(res);
197 kfree(res);
198}
199EXPORT_SYMBOL(atari_stram_free);