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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Simple allocator for internal RAM in ETRAX FS
   4  *
   5  * Copyright (c) 2004 Axis Communications AB.
   6  */
   7
   8 #include <linux/list.h>
   9 #include <linux/slab.h>
  10 #include <asm/io.h>
  11 #include <memmap.h>
  12
  13 #define STATUS_FREE 0
  14 #define STATUS_ALLOCATED 1
  15
  16 #ifdef CONFIG_ETRAX_L2CACHE
  17 #define RESERVED_SIZE 66*1024
  18 #else
  19 #define RESERVED_SIZE 0
  20 #endif
  21
  22 struct intmem_allocation {
  23         struct list_head entry;
  24         unsigned int size;
  25         unsigned offset;
  26         char status;
  27 };
  28
  29
  30 static struct list_head intmem_allocations;
  31 static void* intmem_virtual;
  32
  33 static void crisv32_intmem_init(void)
  34 {
  35         static int initiated = 0;
  36         if (!initiated) {
  37                 struct intmem_allocation* alloc;
  38                 alloc = kmalloc(sizeof *alloc, GFP_KERNEL);
  39                 INIT_LIST_HEAD(&intmem_allocations);
  40                 intmem_virtual = ioremap(MEM_INTMEM_START + RESERVED_SIZE,
  41                                          MEM_INTMEM_SIZE - RESERVED_SIZE);
  42                 initiated = 1;
  43                 alloc->size = MEM_INTMEM_SIZE - RESERVED_SIZE;
  44                 alloc->offset = 0;
  45                 alloc->status = STATUS_FREE;
  46                 list_add_tail(&alloc->entry, &intmem_allocations);
  47         }
  48 }
  49
  50 void* crisv32_intmem_alloc(unsigned size, unsigned align)
  51 {
  52         struct intmem_allocation* allocation;
  53         struct intmem_allocation* tmp;
  54         void* ret = NULL;
  55
  56         preempt_disable();
  57         crisv32_intmem_init();
  58
  59         list_for_each_entry_safe(allocation, tmp, &intmem_allocations, entry) {
  60                 int alignment = allocation->offset % align;
  61                 alignment = alignment ? align - alignment : alignment;
  62
  63                 if (allocation->status == STATUS_FREE &&
  64                     allocation->size >= size + alignment) {
  65                         if (allocation->size > size + alignment) {
  66                                 struct intmem_allocation* alloc;
  67                                 alloc = 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 = kmalloc(sizeof *tmp, GFP_ATOMIC);
  78                                         tmp->offset = allocation->offset;
  79                                         tmp->size = alignment;
  80                                         tmp->status = STATUS_FREE;
  81                                         allocation->offset += alignment;
  82                                         list_add_tail(&tmp->entry,
  83                                                 &allocation->entry);
  84                                 }
  85                         }
  86                         allocation->status = STATUS_ALLOCATED;
  87                         allocation->size = size;
  88                         ret = (void*)((int)intmem_virtual + allocation->offset);
  89                 }
  90         }
  91         preempt_enable();
  92         return ret;
  93 }
  94
  95 void crisv32_intmem_free(void* addr)
  96 {
  97         struct intmem_allocation* allocation;
  98         struct intmem_allocation* tmp;
  99
 100         if (addr == NULL)
 101                 return;
 102
 103         preempt_disable();
 104         crisv32_intmem_init();
 105
 106         list_for_each_entry_safe(allocation, tmp, &intmem_allocations, entry) {
 107                 if (allocation->offset == (int)(addr - intmem_virtual)) {
 108                         struct intmem_allocation *prev =
 109                           list_entry(allocation->entry.prev,
 110                                      struct intmem_allocation, entry);
 111                         struct intmem_allocation *next =
 112                           list_entry(allocation->entry.next,
 113                                      struct intmem_allocation, entry);
 114
 115                         allocation->status = STATUS_FREE;
 116                         /* Join with prev and/or next if also free */
 117                         if ((&prev->entry != &intmem_allocations) &&
 118                                         (prev->status == STATUS_FREE)) {
 119                                 prev->size += allocation->size;
 120                                 list_del(&allocation->entry);
 121                                 kfree(allocation);
 122                                 allocation = prev;
 123                         }
 124                         if ((&next->entry != &intmem_allocations) &&
 125                                         (next->status == STATUS_FREE)) {
 126                                 allocation->size += next->size;
 127                                 list_del(&next->entry);
 128                                 kfree(next);
 129                         }
 130                         preempt_enable();
 131                         return;
 132                 }
 133         }
 134         preempt_enable();
 135 }
 136
 137 void* crisv32_intmem_phys_to_virt(unsigned long addr)
 138 {
 139         return (void *)(addr - (MEM_INTMEM_START + RESERVED_SIZE) +
 140                 (unsigned long)intmem_virtual);
 141 }
 142
 143 unsigned long crisv32_intmem_virt_to_phys(void* addr)
 144 {
 145         return (unsigned long)((unsigned long )addr -
 146                 (unsigned long)intmem_virtual + MEM_INTMEM_START +
 147                 RESERVED_SIZE);
 148 }
 149
 150 static int __init crisv32_intmem_setup(void)
 151 {
 152         crisv32_intmem_init();
 153
 154         return 0;
 155 }
 156 device_initcall(crisv32_intmem_setup);
 157