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