drivers/pci/iova.h

   1 /*
   2  * Copyright (c) 2006, Intel Corporation.
   3  *
   4  * This file is released under the GPLv2.
   5  *
   6  * Copyright (C) 2006 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   7  *
   8  */
   9
  10 #ifndef _IOVA_H_
  11 #define _IOVA_H_
  12
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/rbtree.h>
  16 #include <linux/dma-mapping.h>
  17
  18 /*
  19  * We need a fixed PAGE_SIZE of 4K irrespective of
  20  * arch PAGE_SIZE for IOMMU page tables.
  21  */
  22 #define PAGE_SHIFT_4K           (12)
  23 #define PAGE_SIZE_4K            (1UL << PAGE_SHIFT_4K)
  24 #define PAGE_MASK_4K            (((u64)-1) << PAGE_SHIFT_4K)
  25 #define PAGE_ALIGN_4K(addr)     (((addr) + PAGE_SIZE_4K - 1) & PAGE_MASK_4K)
  26
  27 /* IO virtual address start page frame number */
  28 #define IOVA_START_PFN          (1)
  29
  30 #define IOVA_PFN(addr)          ((addr) >> PAGE_SHIFT_4K)
  31 #define DMA_32BIT_PFN   IOVA_PFN(DMA_32BIT_MASK)
  32 #define DMA_64BIT_PFN   IOVA_PFN(DMA_64BIT_MASK)
  33
  34 /* iova structure */
  35 struct iova {
  36         struct rb_node  node;
  37         unsigned long   pfn_hi; /* IOMMU dish out addr hi */
  38         unsigned long   pfn_lo; /* IOMMU dish out addr lo */
  39 };
  40
  41 /* holds all the iova translations for a domain */
  42 struct iova_domain {
  43         spinlock_t      iova_alloc_lock;/* Lock to protect iova  allocation */
  44         spinlock_t      iova_rbtree_lock; /* Lock to protect update of rbtree */
  45         struct rb_root  rbroot;         /* iova domain rbtree root */
  46         struct rb_node  *cached32_node; /* Save last alloced node */
  47 };
  48
  49 struct iova *alloc_iova_mem(void);
  50 void free_iova_mem(struct iova *iova);
  51 void free_iova(struct iova_domain *iovad, unsigned long pfn);
  52 void __free_iova(struct iova_domain *iovad, struct iova *iova);
  53 struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size,
  54         unsigned long limit_pfn,
  55         bool size_aligned);
  56 struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
  57         unsigned long pfn_hi);
  58 void copy_reserved_iova(struct iova_domain *from, struct iova_domain *to);
  59 void init_iova_domain(struct iova_domain *iovad);
  60 struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
  61 void put_iova_domain(struct iova_domain *iovad);
  62
  63 #endif