arch/m68k/amiga/chipram.c

   1 /*
   2 **  linux/amiga/chipram.c
   3 **
   4 **      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
   5 **          - 64-bit aligned allocations for full AGA compatibility
   6 **
   7 **      Rewritten 15/9/2000 by Geert to use resource management
   8 */
   9
  10 #include <linux/config.h>
  11 #include <linux/types.h>
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/ioport.h>
  15 #include <linux/slab.h>
  16 #include <linux/string.h>
  17 #include <asm/page.h>
  18 #include <asm/amigahw.h>
  19
  20 unsigned long amiga_chip_size;
  21
  22 static struct resource chipram_res = {
  23     .name = "Chip RAM", .start = CHIP_PHYSADDR
  24 };
  25 static unsigned long chipavail;
  26
  27
  28 void __init amiga_chip_init(void)
  29 {
  30     if (!AMIGAHW_PRESENT(CHIP_RAM))
  31         return;
  32
  33 #ifndef CONFIG_APUS_FAST_EXCEPT
  34     /*
  35      *  Remove the first 4 pages where PPC exception handlers will be located
  36      */
  37     amiga_chip_size -= 0x4000;
  38 #endif
  39     chipram_res.end = amiga_chip_size-1;
  40     request_resource(&iomem_resource, &chipram_res);
  41
  42     chipavail = amiga_chip_size;
  43 }
  44
  45
  46 void *amiga_chip_alloc(unsigned long size, const char *name)
  47 {
  48     struct resource *res;
  49
  50     /* round up */
  51     size = PAGE_ALIGN(size);
  52
  53 #ifdef DEBUG
  54     printk("amiga_chip_alloc: allocate %ld bytes\n", size);
  55 #endif
  56     res = kmalloc(sizeof(struct resource), GFP_KERNEL);
  57     if (!res)
  58         return NULL;
  59     memset(res, 0, sizeof(struct resource));
  60     res->name = name;
  61
  62     if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
  63         kfree(res);
  64         return NULL;
  65     }
  66     chipavail -= size;
  67 #ifdef DEBUG
  68     printk("amiga_chip_alloc: returning %lx\n", res->start);
  69 #endif
  70     return (void *)ZTWO_VADDR(res->start);
  71 }
  72
  73
  74     /*
  75      *  Warning:
  76      *  amiga_chip_alloc_res is meant only for drivers that need to allocate
  77      *  Chip RAM before kmalloc() is functional. As a consequence, those
  78      *  drivers must not free that Chip RAM afterwards.
  79      */
  80
  81 void * __init amiga_chip_alloc_res(unsigned long size, struct resource *res)
  82 {
  83     unsigned long start;
  84
  85     /* round up */
  86     size = PAGE_ALIGN(size);
  87     /* dmesg into chipmem prefers memory at the safe end */
  88     start = CHIP_PHYSADDR + chipavail - size;
  89
  90 #ifdef DEBUG
  91     printk("amiga_chip_alloc_res: allocate %ld bytes\n", size);
  92 #endif
  93     if (allocate_resource(&chipram_res, res, size, start, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
  94         printk("amiga_chip_alloc_res: first alloc failed!\n");
  95         if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0)
  96             return NULL;
  97     }
  98     chipavail -= size;
  99 #ifdef DEBUG
 100     printk("amiga_chip_alloc_res: returning %lx\n", res->start);
 101 #endif
 102     return (void *)ZTWO_VADDR(res->start);
 103 }
 104
 105 void amiga_chip_free(void *ptr)
 106 {
 107     unsigned long start = ZTWO_PADDR(ptr);
 108     struct resource **p, *res;
 109     unsigned long size;
 110
 111     for (p = &chipram_res.child; (res = *p); p = &res->sibling) {
 112         if (res->start != start)
 113             continue;
 114         *p = res->sibling;
 115         size = res->end-start;
 116 #ifdef DEBUG
 117         printk("amiga_chip_free: free %ld bytes at %p\n", size, ptr);
 118 #endif
 119         chipavail += size;
 120         kfree(res);
 121         return;
 122     }
 123     printk("amiga_chip_free: trying to free nonexistent region at %p\n", ptr);
 124 }
 125
 126
 127 unsigned long amiga_chip_avail(void)
 128 {
 129 #ifdef DEBUG
 130         printk("amiga_chip_avail : %ld bytes\n", chipavail);
 131 #endif
 132         return chipavail;
 133 }