arch/cris/arch-v32/mm/intmem.c

   1 /*
   2  * Simple allocator for internal RAM in ETRAX FS
   3  *
   4  * Copyright (c) 2004 Axis Communications AB.
   5  */
   6
   7 #include <linux/list.h>
   8 #include <linux/slab.h>
   9 #include <asm/io.h>
  10 #include <memmap.h>
  11
  12 #define STATUS_FREE 0
  13 #define STATUS_ALLOCATED 1
  14
  15 #ifdef CONFIG_ETRAX_L2CACHE
  16 #define RESERVED_SIZE 66*1024
  17 #else
  18 #define RESERVED_SIZE 0
  19 #endif
  20
  21 struct intmem_allocation {
  22         struct list_head entry;
  23         unsigned int size;
  24         unsigned offset;
  25         char status;
  26 };
  27
  28
  29 static struct list_head intmem_allocations;
  30 static void* intmem_virtual;
  31
  32 static void crisv32_intmem_init(void)
  33 {
  34         static int initiated = 0;
  35         if (!initiated) {
  36                 struct intmem_allocation* alloc =
  37                   (struct intmem_allocation*)kmalloc(sizeof *alloc, GFP_KERNEL);
  38                 INIT_LIST_HEAD(&intmem_allocations);
  39                 intmem_virtual = ioremap(MEM_INTMEM_START + RESERVED_SIZE,
  40                                          MEM_INTMEM_SIZE - RESERVED_SIZE);
  41                 initiated = 1;
  42                 alloc->size = MEM_INTMEM_SIZE - RESERVED_SIZE;
  43                 alloc->offset = 0;
  44                 alloc->status = STATUS_FREE;
  45                 list_add_tail(&alloc->entry, &intmem_allocations);
  46         }
  47 }
  48
  49 void* crisv32_intmem_alloc(unsigned size, unsigned align)
  50 {
  51         struct intmem_allocation* allocation;
  52         struct intmem_allocation* tmp;
  53         void* ret = NULL;
  54
  55         preempt_disable();
  56         crisv32_intmem_init();
  57
  58         list_for_each_entry_safe(allocation, tmp, &intmem_allocations, entry) {
  59                 int alignment = allocation->offset % align;
  60                 alignment = alignment ? align - alignment : alignment;
  61
  62                 if (allocation->status == STATUS_FREE &&
  63                     allocation->size >= size + alignment) {
  64                         if (allocation->size > size + alignment) {
  65                                 struct intmem_allocation* alloc =
  66                                         (struct intmem_allocation*)
  67                                         kmalloc(sizeof *alloc, GFP_ATOMIC);
  68                                 alloc->status = STATUS_FREE;
  69                                 alloc->size = allocation->size - size -
  70                                         alignment;
  71                                 alloc->offset = allocation->offset + size +
  72                                         alignment;
  73                                 list_add(&alloc->entry, &allocation->entry);
  74
  75                                 if (alignment) {
  76                                         struct intmem_allocation *tmp;
  77                                         tmp = (struct intmem_allocation *)
  78                                                 kmalloc(sizeof *tmp,
  79                                                         GFP_ATOMIC);
  80                                         tmp->offset = allocation->offset;
  81                                         tmp->size = alignment;
  82                                         tmp->status = STATUS_FREE;
  83                                         allocation->offset += alignment;
  84                                         list_add_tail(&tmp->entry,
  85                                                 &allocation->entry);
  86                                 }
  87                         }
  88                         allocation->status = STATUS_ALLOCATED;
  89                         allocation->size = size;
  90                         ret = (void*)((int)intmem_virtual + allocation->offset);
  91                 }
  92         }
  93         preempt_enable();
  94         return ret;
  95 }
  96
  97 void crisv32_intmem_free(void* addr)
  98 {
  99         struct intmem_allocation* allocation;
 100         struct intmem_allocation* tmp;
 101
 102         if (addr == NULL)
 103                 return;
 104
 105         preempt_disable();
 106         crisv32_intmem_init();
 107
 108         list_for_each_entry_safe(allocation, tmp, &intmem_allocations, entry) {
 109                 if (allocation->offset == (int)(addr - intmem_virtual)) {
 110                         struct intmem_allocation *prev =
 111                           list_entry(allocation->entry.prev,
 112                                      struct intmem_allocation, entry);
 113                         struct intmem_allocation *next =
 114                           list_entry(allocation->entry.next,
 115                                      struct intmem_allocation, entry);
 116
 117                         allocation->status = STATUS_FREE;
 118                         /* Join with prev and/or next if also free */
 119                         if ((prev != &intmem_allocations) &&
 120                                         (prev->status == STATUS_FREE)) {
 121                                 prev->size += allocation->size;
 122                                 list_del(&allocation->entry);
 123                                 kfree(allocation);
 124                                 allocation = prev;
 125                         }
 126                         if ((next != &intmem_allocations) &&
 127                                         (next->status == STATUS_FREE)) {
 128                                 allocation->size += next->size;
 129                                 list_del(&next->entry);
 130                                 kfree(next);
 131                         }
 132                         preempt_enable();
 133                         return;
 134                 }
 135         }
 136         preempt_enable();
 137 }
 138
 139 void* crisv32_intmem_phys_to_virt(unsigned long addr)
 140 {
 141         return (void *)(addr - (MEM_INTMEM_START + RESERVED_SIZE) +
 142                 (unsigned long)intmem_virtual);
 143 }
 144
 145 unsigned long crisv32_intmem_virt_to_phys(void* addr)
 146 {
 147         return (unsigned long)((unsigned long )addr -
 148                 (unsigned long)intmem_virtual + MEM_INTMEM_START +
 149                 RESERVED_SIZE);
 150 }
 151
 152 module_init(crisv32_intmem_init);
 153