1 /* 2 * arch/m68k/atari/stram.c: 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 #undef DEBUG 34 35 #ifdef DEBUG 36 #define DPRINTK(fmt,args...) printk( fmt, ##args ) 37 #else 38 #define DPRINTK(fmt,args...) 39 #endif 40 41 #if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC) 42 /* abbrev for the && above... */ 43 #define DO_PROC 44 #include <linux/proc_fs.h> 45 #endif 46 47 /* 48 * ++roman: 49 * 50 * New version of ST-Ram buffer allocation. Instead of using the 51 * 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000 52 * (1 MB granularity!), such buffers are reserved like this: 53 * 54 * - If the kernel resides in ST-Ram anyway, we can take the buffer 55 * from behind the current kernel data space the normal way 56 * (incrementing start_mem). 57 * 58 * - If the kernel is in TT-Ram, stram_init() initializes start and 59 * end of the available region. Buffers are allocated from there 60 * and mem_init() later marks the such used pages as reserved. 61 * Since each TT-Ram chunk is at least 4 MB in size, I hope there 62 * won't be an overrun of the ST-Ram region by normal kernel data 63 * space. 64 * 65 * For that, ST-Ram may only be allocated while kernel initialization 66 * is going on, or exactly: before mem_init() is called. There is also 67 * no provision now for freeing ST-Ram buffers. It seems that isn't 68 * really needed. 69 * 70 */ 71 72 /* Start and end (virtual) of ST-RAM */ 73 static void *stram_start, *stram_end; 74 75 /* set after memory_init() executed and allocations via start_mem aren't 76 * possible anymore */ 77 static int mem_init_done; 78 79 /* set if kernel is in ST-RAM */ 80 static int kernel_in_stram; 81 82 typedef struct stram_block { 83 struct stram_block *next; 84 void *start; 85 unsigned long size; 86 unsigned flags; 87 const char *owner; 88 } BLOCK; 89 90 /* values for flags field */ 91 #define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ 92 #define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */ 93 #define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ 94 95 /* list of allocated blocks */ 96 static BLOCK *alloc_list; 97 98 /* We can't always use kmalloc() to allocate BLOCK structures, since 99 * stram_alloc() can be called rather early. So we need some pool of 100 * statically allocated structures. 20 of them is more than enough, so in most 101 * cases we never should need to call kmalloc(). */ 102 #define N_STATIC_BLOCKS 20 103 static BLOCK static_blocks[N_STATIC_BLOCKS]; 104 105 /***************************** Prototypes *****************************/ 106 107 static BLOCK *add_region( void *addr, unsigned long size ); 108 static BLOCK *find_region( void *addr ); 109 static int remove_region( BLOCK *block ); 110 111 /************************* End of Prototypes **************************/ 112 113 114 /* ------------------------------------------------------------------------ */ 115 /* Public Interface */ 116 /* ------------------------------------------------------------------------ */ 117 118 /* 119 * This init function is called very early by atari/config.c 120 * It initializes some internal variables needed for stram_alloc() 121 */ 122 void __init atari_stram_init(void) 123 { 124 int i; 125 126 /* initialize static blocks */ 127 for( i = 0; i < N_STATIC_BLOCKS; ++i ) 128 static_blocks[i].flags = BLOCK_FREE; 129 130 /* determine whether kernel code resides in ST-RAM (then ST-RAM is the 131 * first memory block at virtual 0x0) */ 132 stram_start = phys_to_virt(0); 133 kernel_in_stram = (stram_start == 0); 134 135 for( i = 0; i < m68k_num_memory; ++i ) { 136 if (m68k_memory[i].addr == 0) { 137 /* skip first 2kB or page (supervisor-only!) */ 138 stram_end = stram_start + m68k_memory[i].size; 139 return; 140 } 141 } 142 /* Should never come here! (There is always ST-Ram!) */ 143 panic( "atari_stram_init: no ST-RAM found!" ); 144 } 145 146 147 /* 148 * This function is called from setup_arch() to reserve the pages needed for 149 * ST-RAM management. 150 */ 151 void __init atari_stram_reserve_pages(void *start_mem) 152 { 153 /* always reserve first page of ST-RAM, the first 2 kB are 154 * supervisor-only! */ 155 if (!kernel_in_stram) 156 reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT); 157 158 } 159 160 void atari_stram_mem_init_hook (void) 161 { 162 mem_init_done = 1; 163 } 164 165 166 /* 167 * This is main public interface: somehow allocate a ST-RAM block 168 * 169 * - If we're before mem_init(), we have to make a static allocation. The 170 * region is taken in the kernel data area (if the kernel is in ST-RAM) or 171 * from the start of ST-RAM (if the kernel is in TT-RAM) and added to the 172 * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel 173 * address space in the latter case. 174 * 175 * - If mem_init() already has been called, try with __get_dma_pages(). 176 * This has the disadvantage that it's very hard to get more than 1 page, 177 * and it is likely to fail :-( 178 * 179 */ 180 void *atari_stram_alloc(long size, const char *owner) 181 { 182 void *addr = NULL; 183 BLOCK *block; 184 int flags; 185 186 DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner); 187 188 if (!mem_init_done) 189 return alloc_bootmem_low(size); 190 else { 191 /* After mem_init(): can only resort to __get_dma_pages() */ 192 addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size)); 193 flags = BLOCK_GFP; 194 DPRINTK( "atari_stram_alloc: after mem_init, " 195 "get_pages=%p\n", addr ); 196 } 197 198 if (addr) { 199 if (!(block = add_region( addr, size ))) { 200 /* out of memory for BLOCK structure :-( */ 201 DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- " 202 "freeing again\n" ); 203 free_pages((unsigned long)addr, get_order(size)); 204 return( NULL ); 205 } 206 block->owner = owner; 207 block->flags |= flags; 208 } 209 return( addr ); 210 } 211 EXPORT_SYMBOL(atari_stram_alloc); 212 213 void atari_stram_free( void *addr ) 214 215 { 216 BLOCK *block; 217 218 DPRINTK( "atari_stram_free(addr=%p)\n", addr ); 219 220 if (!(block = find_region( addr ))) { 221 printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p " 222 "from %p\n", addr, __builtin_return_address(0) ); 223 return; 224 } 225 DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, " 226 "flags=%02x\n", block, block->size, block->owner, block->flags ); 227 228 if (!(block->flags & BLOCK_GFP)) 229 goto fail; 230 231 DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n", 232 get_order(block->size)); 233 free_pages((unsigned long)addr, get_order(block->size)); 234 remove_region( block ); 235 return; 236 237 fail: 238 printk( KERN_ERR "atari_stram_free: cannot free block at %p " 239 "(called from %p)\n", addr, __builtin_return_address(0) ); 240 } 241 EXPORT_SYMBOL(atari_stram_free); 242 243 244 /* ------------------------------------------------------------------------ */ 245 /* Region Management */ 246 /* ------------------------------------------------------------------------ */ 247 248 249 /* insert a region into the alloced list (sorted) */ 250 static BLOCK *add_region( void *addr, unsigned long size ) 251 { 252 BLOCK **p, *n = NULL; 253 int i; 254 255 for( i = 0; i < N_STATIC_BLOCKS; ++i ) { 256 if (static_blocks[i].flags & BLOCK_FREE) { 257 n = &static_blocks[i]; 258 n->flags = 0; 259 break; 260 } 261 } 262 if (!n && mem_init_done) { 263 /* if statics block pool exhausted and we can call kmalloc() already 264 * (after mem_init()), try that */ 265 n = kmalloc( sizeof(BLOCK), GFP_KERNEL ); 266 if (n) 267 n->flags = BLOCK_KMALLOCED; 268 } 269 if (!n) { 270 printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" ); 271 return( NULL ); 272 } 273 n->start = addr; 274 n->size = size; 275 276 for( p = &alloc_list; *p; p = &((*p)->next) ) 277 if ((*p)->start > addr) break; 278 n->next = *p; 279 *p = n; 280 281 return( n ); 282 } 283 284 285 /* find a region (by start addr) in the alloced list */ 286 static BLOCK *find_region( void *addr ) 287 { 288 BLOCK *p; 289 290 for( p = alloc_list; p; p = p->next ) { 291 if (p->start == addr) 292 return( p ); 293 if (p->start > addr) 294 break; 295 } 296 return( NULL ); 297 } 298 299 300 /* remove a block from the alloced list */ 301 static int remove_region( BLOCK *block ) 302 { 303 BLOCK **p; 304 305 for( p = &alloc_list; *p; p = &((*p)->next) ) 306 if (*p == block) break; 307 if (!*p) 308 return( 0 ); 309 310 *p = block->next; 311 if (block->flags & BLOCK_KMALLOCED) 312 kfree( block ); 313 else 314 block->flags |= BLOCK_FREE; 315 return( 1 ); 316 } 317 318 319 320 /* ------------------------------------------------------------------------ */ 321 /* /proc statistics file stuff */ 322 /* ------------------------------------------------------------------------ */ 323 324 #ifdef DO_PROC 325 326 #define PRINT_PROC(fmt,args...) len += sprintf( buf+len, fmt, ##args ) 327 328 int get_stram_list( char *buf ) 329 { 330 int len = 0; 331 BLOCK *p; 332 333 PRINT_PROC("Total ST-RAM: %8u kB\n", 334 (stram_end - stram_start) >> 10); 335 PRINT_PROC( "Allocated regions:\n" ); 336 for( p = alloc_list; p; p = p->next ) { 337 if (len + 50 >= PAGE_SIZE) 338 break; 339 PRINT_PROC("0x%08lx-0x%08lx: %s (", 340 virt_to_phys(p->start), 341 virt_to_phys(p->start+p->size-1), 342 p->owner); 343 if (p->flags & BLOCK_GFP) 344 PRINT_PROC( "page-alloced)\n" ); 345 else 346 PRINT_PROC( "??)\n" ); 347 } 348 349 return( len ); 350 } 351 352 #endif 353 354 355 /* 356 * Local variables: 357 * c-indent-level: 4 358 * tab-width: 4 359 * End: 360 */ 361