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/config.h> 12 #include <linux/types.h> 13 #include <linux/kernel.h> 14 #include <linux/mm.h> 15 #include <linux/kdev_t.h> 16 #include <linux/major.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/vmalloc.h> 20 #include <linux/pagemap.h> 21 #include <linux/bootmem.h> 22 #include <linux/mount.h> 23 #include <linux/blkdev.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 #include <asm/semaphore.h> 33 34 #undef DEBUG 35 36 #ifdef DEBUG 37 #define DPRINTK(fmt,args...) printk( fmt, ##args ) 38 #else 39 #define DPRINTK(fmt,args...) 40 #endif 41 42 #if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC) 43 /* abbrev for the && above... */ 44 #define DO_PROC 45 #include <linux/proc_fs.h> 46 #endif 47 48 /* 49 * ++roman: 50 * 51 * New version of ST-Ram buffer allocation. Instead of using the 52 * 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000 53 * (1 MB granularity!), such buffers are reserved like this: 54 * 55 * - If the kernel resides in ST-Ram anyway, we can take the buffer 56 * from behind the current kernel data space the normal way 57 * (incrementing start_mem). 58 * 59 * - If the kernel is in TT-Ram, stram_init() initializes start and 60 * end of the available region. Buffers are allocated from there 61 * and mem_init() later marks the such used pages as reserved. 62 * Since each TT-Ram chunk is at least 4 MB in size, I hope there 63 * won't be an overrun of the ST-Ram region by normal kernel data 64 * space. 65 * 66 * For that, ST-Ram may only be allocated while kernel initialization 67 * is going on, or exactly: before mem_init() is called. There is also 68 * no provision now for freeing ST-Ram buffers. It seems that isn't 69 * really needed. 70 * 71 */ 72 73 /* Start and end (virtual) of ST-RAM */ 74 static void *stram_start, *stram_end; 75 76 /* set after memory_init() executed and allocations via start_mem aren't 77 * possible anymore */ 78 static int mem_init_done; 79 80 /* set if kernel is in ST-RAM */ 81 static int kernel_in_stram; 82 83 typedef struct stram_block { 84 struct stram_block *next; 85 void *start; 86 unsigned long size; 87 unsigned flags; 88 const char *owner; 89 } BLOCK; 90 91 /* values for flags field */ 92 #define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */ 93 #define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */ 94 #define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */ 95 96 /* list of allocated blocks */ 97 static BLOCK *alloc_list; 98 99 /* We can't always use kmalloc() to allocate BLOCK structures, since 100 * stram_alloc() can be called rather early. So we need some pool of 101 * statically allocated structures. 20 of them is more than enough, so in most 102 * cases we never should need to call kmalloc(). */ 103 #define N_STATIC_BLOCKS 20 104 static BLOCK static_blocks[N_STATIC_BLOCKS]; 105 106 /***************************** Prototypes *****************************/ 107 108 static BLOCK *add_region( void *addr, unsigned long size ); 109 static BLOCK *find_region( void *addr ); 110 static int remove_region( BLOCK *block ); 111 112 /************************* End of Prototypes **************************/ 113 114 115 /* ------------------------------------------------------------------------ */ 116 /* Public Interface */ 117 /* ------------------------------------------------------------------------ */ 118 119 /* 120 * This init function is called very early by atari/config.c 121 * It initializes some internal variables needed for stram_alloc() 122 */ 123 void __init atari_stram_init(void) 124 { 125 int i; 126 127 /* initialize static blocks */ 128 for( i = 0; i < N_STATIC_BLOCKS; ++i ) 129 static_blocks[i].flags = BLOCK_FREE; 130 131 /* determine whether kernel code resides in ST-RAM (then ST-RAM is the 132 * first memory block at virtual 0x0) */ 133 stram_start = phys_to_virt(0); 134 kernel_in_stram = (stram_start == 0); 135 136 for( i = 0; i < m68k_num_memory; ++i ) { 137 if (m68k_memory[i].addr == 0) { 138 /* skip first 2kB or page (supervisor-only!) */ 139 stram_end = stram_start + m68k_memory[i].size; 140 return; 141 } 142 } 143 /* Should never come here! (There is always ST-Ram!) */ 144 panic( "atari_stram_init: no ST-RAM found!" ); 145 } 146 147 148 /* 149 * This function is called from setup_arch() to reserve the pages needed for 150 * ST-RAM management. 151 */ 152 void __init atari_stram_reserve_pages(void *start_mem) 153 { 154 /* always reserve first page of ST-RAM, the first 2 kB are 155 * supervisor-only! */ 156 if (!kernel_in_stram) 157 reserve_bootmem (0, PAGE_SIZE); 158 159 } 160 161 void atari_stram_mem_init_hook (void) 162 { 163 mem_init_done = 1; 164 } 165 166 167 /* 168 * This is main public interface: somehow allocate a ST-RAM block 169 * 170 * - If we're before mem_init(), we have to make a static allocation. The 171 * region is taken in the kernel data area (if the kernel is in ST-RAM) or 172 * from the start of ST-RAM (if the kernel is in TT-RAM) and added to the 173 * rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel 174 * address space in the latter case. 175 * 176 * - If mem_init() already has been called, try with __get_dma_pages(). 177 * This has the disadvantage that it's very hard to get more than 1 page, 178 * and it is likely to fail :-( 179 * 180 */ 181 void *atari_stram_alloc(long size, const char *owner) 182 { 183 void *addr = NULL; 184 BLOCK *block; 185 int flags; 186 187 DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner); 188 189 if (!mem_init_done) 190 return alloc_bootmem_low(size); 191 else { 192 /* After mem_init(): can only resort to __get_dma_pages() */ 193 addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size)); 194 flags = BLOCK_GFP; 195 DPRINTK( "atari_stram_alloc: after mem_init, " 196 "get_pages=%p\n", addr ); 197 } 198 199 if (addr) { 200 if (!(block = add_region( addr, size ))) { 201 /* out of memory for BLOCK structure :-( */ 202 DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- " 203 "freeing again\n" ); 204 free_pages((unsigned long)addr, get_order(size)); 205 return( NULL ); 206 } 207 block->owner = owner; 208 block->flags |= flags; 209 } 210 return( addr ); 211 } 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 } 241 242 243 /* ------------------------------------------------------------------------ */ 244 /* Region Management */ 245 /* ------------------------------------------------------------------------ */ 246 247 248 /* insert a region into the alloced list (sorted) */ 249 static BLOCK *add_region( void *addr, unsigned long size ) 250 { 251 BLOCK **p, *n = NULL; 252 int i; 253 254 for( i = 0; i < N_STATIC_BLOCKS; ++i ) { 255 if (static_blocks[i].flags & BLOCK_FREE) { 256 n = &static_blocks[i]; 257 n->flags = 0; 258 break; 259 } 260 } 261 if (!n && mem_init_done) { 262 /* if statics block pool exhausted and we can call kmalloc() already 263 * (after mem_init()), try that */ 264 n = kmalloc( sizeof(BLOCK), GFP_KERNEL ); 265 if (n) 266 n->flags = BLOCK_KMALLOCED; 267 } 268 if (!n) { 269 printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" ); 270 return( NULL ); 271 } 272 n->start = addr; 273 n->size = size; 274 275 for( p = &alloc_list; *p; p = &((*p)->next) ) 276 if ((*p)->start > addr) break; 277 n->next = *p; 278 *p = n; 279 280 return( n ); 281 } 282 283 284 /* find a region (by start addr) in the alloced list */ 285 static BLOCK *find_region( void *addr ) 286 { 287 BLOCK *p; 288 289 for( p = alloc_list; p; p = p->next ) { 290 if (p->start == addr) 291 return( p ); 292 if (p->start > addr) 293 break; 294 } 295 return( NULL ); 296 } 297 298 299 /* remove a block from the alloced list */ 300 static int remove_region( BLOCK *block ) 301 { 302 BLOCK **p; 303 304 for( p = &alloc_list; *p; p = &((*p)->next) ) 305 if (*p == block) break; 306 if (!*p) 307 return( 0 ); 308 309 *p = block->next; 310 if (block->flags & BLOCK_KMALLOCED) 311 kfree( block ); 312 else 313 block->flags |= BLOCK_FREE; 314 return( 1 ); 315 } 316 317 318 319 /* ------------------------------------------------------------------------ */ 320 /* /proc statistics file stuff */ 321 /* ------------------------------------------------------------------------ */ 322 323 #ifdef DO_PROC 324 325 #define PRINT_PROC(fmt,args...) len += sprintf( buf+len, fmt, ##args ) 326 327 int get_stram_list( char *buf ) 328 { 329 int len = 0; 330 BLOCK *p; 331 332 PRINT_PROC("Total ST-RAM: %8u kB\n", 333 (stram_end - stram_start) >> 10); 334 PRINT_PROC( "Allocated regions:\n" ); 335 for( p = alloc_list; p; p = p->next ) { 336 if (len + 50 >= PAGE_SIZE) 337 break; 338 PRINT_PROC("0x%08lx-0x%08lx: %s (", 339 virt_to_phys(p->start), 340 virt_to_phys(p->start+p->size-1), 341 p->owner); 342 if (p->flags & BLOCK_GFP) 343 PRINT_PROC( "page-alloced)\n" ); 344 else 345 PRINT_PROC( "??)\n" ); 346 } 347 348 return( len ); 349 } 350 351 #endif 352 353 354 /* 355 * Local variables: 356 * c-indent-level: 4 357 * tab-width: 4 358 * End: 359 */ 360