drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm_vm.c

   1 /*
   2  * Support for Medifield PNW Camera Imaging ISP subsystem.
   3  *
   4  * Copyright (c) 2010 Intel Corporation. All Rights Reserved.
   5  *
   6  * Copyright (c) 2010 Silicon Hive www.siliconhive.com.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  */
  23 /*
  24  * This file contains function for ISP virtual address management in ISP driver
  25  */
  26 #include <linux/kernel.h>
  27 #include <linux/types.h>
  28 #include <linux/mm.h>
  29 #include <linux/slab.h>
  30 #include <asm/page.h>
  31
  32 #include "atomisp_internal.h"
  33 #include "mmu/isp_mmu.h"
  34 #include "hmm/hmm_vm.h"
  35 #include "hmm/hmm_common.h"
  36
  37 static unsigned int vm_node_end(unsigned int start, unsigned int pgnr)
  38 {
  39         return start + pgnr_to_size(pgnr);
  40 }
  41
  42 static int addr_in_vm_node(unsigned int addr,
  43                 struct hmm_vm_node *node)
  44 {
  45         return (addr >= node->start) && (addr < (node->start + node->size));
  46 }
  47
  48 int hmm_vm_init(struct hmm_vm *vm, unsigned int start,
  49                 unsigned int size)
  50 {
  51         if (!vm)
  52                 return -1;
  53
  54         vm->start = start;
  55         vm->pgnr = size_to_pgnr_ceil(size);
  56         vm->size = pgnr_to_size(vm->pgnr);
  57
  58         INIT_LIST_HEAD(&vm->vm_node_list);
  59         spin_lock_init(&vm->lock);
  60         vm->cache = kmem_cache_create("atomisp_vm", sizeof(struct hmm_vm_node),
  61                                       0, 0, NULL);
  62
  63         return vm->cache != NULL ? 0 : -ENOMEM;
  64 }
  65
  66 void hmm_vm_clean(struct hmm_vm *vm)
  67 {
  68         struct hmm_vm_node *node, *tmp;
  69         struct list_head new_head;
  70
  71         if (!vm)
  72                 return;
  73
  74         spin_lock(&vm->lock);
  75         list_replace_init(&vm->vm_node_list, &new_head);
  76         spin_unlock(&vm->lock);
  77
  78         list_for_each_entry_safe(node, tmp, &new_head, list) {
  79                 list_del(&node->list);
  80                 kmem_cache_free(vm->cache, node);
  81         }
  82
  83         kmem_cache_destroy(vm->cache);
  84 }
  85
  86 static struct hmm_vm_node *alloc_hmm_vm_node(unsigned int pgnr,
  87                                              struct hmm_vm *vm)
  88 {
  89         struct hmm_vm_node *node;
  90
  91         node = kmem_cache_alloc(vm->cache, GFP_KERNEL);
  92         if (!node) {
  93                 dev_err(atomisp_dev, "out of memory.\n");
  94                 return NULL;
  95         }
  96
  97         INIT_LIST_HEAD(&node->list);
  98         node->pgnr = pgnr;
  99         node->size = pgnr_to_size(pgnr);
 100         node->vm = vm;
 101
 102         return node;
 103 }
 104
 105 struct hmm_vm_node *hmm_vm_alloc_node(struct hmm_vm *vm, unsigned int pgnr)
 106 {
 107         struct list_head *head;
 108         struct hmm_vm_node *node, *cur, *next;
 109         unsigned int vm_start, vm_end;
 110         unsigned int addr;
 111         unsigned int size;
 112
 113         if (!vm)
 114                 return NULL;
 115
 116         vm_start = vm->start;
 117         vm_end = vm_node_end(vm->start, vm->pgnr);
 118         size = pgnr_to_size(pgnr);
 119
 120         addr = vm_start;
 121         head = &vm->vm_node_list;
 122
 123         node = alloc_hmm_vm_node(pgnr, vm);
 124         if (!node) {
 125                 dev_err(atomisp_dev, "no memory to allocate hmm vm node.\n");
 126                 return NULL;
 127         }
 128
 129         spin_lock(&vm->lock);
 130         /*
 131          * if list is empty, the loop code will not be executed.
 132          */
 133         list_for_each_entry(cur, head, list) {
 134                 /* Add gap between vm areas as helper to not hide overflow */
 135                 addr = PAGE_ALIGN(vm_node_end(cur->start, cur->pgnr) + 1);
 136
 137                 if (list_is_last(&cur->list, head)) {
 138                         if (addr + size > vm_end) {
 139                                 /* vm area does not have space anymore */
 140                                 spin_unlock(&vm->lock);
 141                                 kmem_cache_free(vm->cache, node);
 142                                 dev_err(atomisp_dev,
 143                                           "no enough virtual address space.\n");
 144                                 return NULL;
 145                         }
 146
 147                         /* We still have vm space to add new node to tail */
 148                         break;
 149                 }
 150
 151                 next = list_entry(cur->list.next, struct hmm_vm_node, list);
 152                 if ((next->start - addr) > size)
 153                         break;
 154         }
 155         node->start = addr;
 156         node->vm = vm;
 157         list_add(&node->list, &cur->list);
 158         spin_unlock(&vm->lock);
 159
 160         return node;
 161 }
 162
 163 void hmm_vm_free_node(struct hmm_vm_node *node)
 164 {
 165         struct hmm_vm *vm;
 166
 167         if (!node)
 168                 return;
 169
 170         vm = node->vm;
 171
 172         spin_lock(&vm->lock);
 173         list_del(&node->list);
 174         spin_unlock(&vm->lock);
 175
 176         kmem_cache_free(vm->cache, node);
 177 }
 178
 179 struct hmm_vm_node *hmm_vm_find_node_start(struct hmm_vm *vm, unsigned int addr)
 180 {
 181         struct hmm_vm_node *node;
 182
 183         if (!vm)
 184                 return NULL;
 185
 186         spin_lock(&vm->lock);
 187
 188         list_for_each_entry(node, &vm->vm_node_list, list) {
 189                 if (node->start == addr) {
 190                         spin_unlock(&vm->lock);
 191                         return node;
 192                 }
 193         }
 194
 195         spin_unlock(&vm->lock);
 196         return NULL;
 197 }
 198
 199 struct hmm_vm_node *hmm_vm_find_node_in_range(struct hmm_vm *vm,
 200                                               unsigned int addr)
 201 {
 202         struct hmm_vm_node *node;
 203
 204         if (!vm)
 205                 return NULL;
 206
 207         spin_lock(&vm->lock);
 208
 209         list_for_each_entry(node, &vm->vm_node_list, list) {
 210                 if (addr_in_vm_node(addr, node)) {
 211                         spin_unlock(&vm->lock);
 212                         return node;
 213                 }
 214         }
 215
 216         spin_unlock(&vm->lock);
 217         return NULL;
 218 }