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 24 #include <asm/setup.h> 25 #include <asm/machdep.h> 26 #include <asm/page.h> 27 #include <asm/pgtable.h> 28 #include <asm/atarihw.h> 29 #include <asm/atari_stram.h> 30 #include <asm/io.h> 31 #include <asm/semaphore.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); 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 } 211 212 void atari_stram_free( void *addr ) 213 214 { 215 BLOCK *block; 216 217 DPRINTK( "atari_stram_free(addr=%p)\n", addr ); 218 219 if (!(block = find_region( addr ))) { 220 printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p " 221 "from %p\n", addr, __builtin_return_address(0) ); 222 return; 223 } 224 DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, " 225 "flags=%02x\n", block, block->size, block->owner, block->flags ); 226 227 if (!(block->flags & BLOCK_GFP)) 228 goto fail; 229 230 DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n", 231 get_order(block->size)); 232 free_pages((unsigned long)addr, get_order(block->size)); 233 remove_region( block ); 234 return; 235 236 fail: 237 printk( KERN_ERR "atari_stram_free: cannot free block at %p " 238 "(called from %p)\n", addr, __builtin_return_address(0) ); 239 } 240 241 242 /* ------------------------------------------------------------------------ */ 243 /* Region Management */ 244 /* ------------------------------------------------------------------------ */ 245 246 247 /* insert a region into the alloced list (sorted) */ 248 static BLOCK *add_region( void *addr, unsigned long size ) 249 { 250 BLOCK **p, *n = NULL; 251 int i; 252 253 for( i = 0; i < N_STATIC_BLOCKS; ++i ) { 254 if (static_blocks[i].flags & BLOCK_FREE) { 255 n = &static_blocks[i]; 256 n->flags = 0; 257 break; 258 } 259 } 260 if (!n && mem_init_done) { 261 /* if statics block pool exhausted and we can call kmalloc() already 262 * (after mem_init()), try that */ 263 n = kmalloc( sizeof(BLOCK), GFP_KERNEL ); 264 if (n) 265 n->flags = BLOCK_KMALLOCED; 266 } 267 if (!n) { 268 printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" ); 269 return( NULL ); 270 } 271 n->start = addr; 272 n->size = size; 273 274 for( p = &alloc_list; *p; p = &((*p)->next) ) 275 if ((*p)->start > addr) break; 276 n->next = *p; 277 *p = n; 278 279 return( n ); 280 } 281 282 283 /* find a region (by start addr) in the alloced list */ 284 static BLOCK *find_region( void *addr ) 285 { 286 BLOCK *p; 287 288 for( p = alloc_list; p; p = p->next ) { 289 if (p->start == addr) 290 return( p ); 291 if (p->start > addr) 292 break; 293 } 294 return( NULL ); 295 } 296 297 298 /* remove a block from the alloced list */ 299 static int remove_region( BLOCK *block ) 300 { 301 BLOCK **p; 302 303 for( p = &alloc_list; *p; p = &((*p)->next) ) 304 if (*p == block) break; 305 if (!*p) 306 return( 0 ); 307 308 *p = block->next; 309 if (block->flags & BLOCK_KMALLOCED) 310 kfree( block ); 311 else 312 block->flags |= BLOCK_FREE; 313 return( 1 ); 314 } 315 316 317 318 /* ------------------------------------------------------------------------ */ 319 /* /proc statistics file stuff */ 320 /* ------------------------------------------------------------------------ */ 321 322 #ifdef DO_PROC 323 324 #define PRINT_PROC(fmt,args...) len += sprintf( buf+len, fmt, ##args ) 325 326 int get_stram_list( char *buf ) 327 { 328 int len = 0; 329 BLOCK *p; 330 331 PRINT_PROC("Total ST-RAM: %8u kB\n", 332 (stram_end - stram_start) >> 10); 333 PRINT_PROC( "Allocated regions:\n" ); 334 for( p = alloc_list; p; p = p->next ) { 335 if (len + 50 >= PAGE_SIZE) 336 break; 337 PRINT_PROC("0x%08lx-0x%08lx: %s (", 338 virt_to_phys(p->start), 339 virt_to_phys(p->start+p->size-1), 340 p->owner); 341 if (p->flags & BLOCK_GFP) 342 PRINT_PROC( "page-alloced)\n" ); 343 else 344 PRINT_PROC( "??)\n" ); 345 } 346 347 return( len ); 348 } 349 350 #endif 351 352 353 /* 354 * Local variables: 355 * c-indent-level: 4 356 * tab-width: 4 357 * End: 358 */ 359