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