include/asm-i386/pci.h

   1 #ifndef __i386_PCI_H
   2 #define __i386_PCI_H
   3
   4 #ifdef __KERNEL__
   5
   6 /* Can be used to override the logic in pci_scan_bus for skipping
   7    already-configured bus numbers - to be used for buggy BIOSes
   8    or architectures with incomplete PCI setup by the loader */
   9
  10 #define pcibios_assign_all_busses()     0
  11
  12 #define PCIBIOS_MIN_IO          0x1000
  13 #define PCIBIOS_MIN_MEM         0x10000000
  14
  15 void pcibios_set_master(struct pci_dev *dev);
  16 void pcibios_penalize_isa_irq(int irq);
  17
  18 /* Dynamic DMA mapping stuff.
  19  * i386 has everything mapped statically.
  20  */
  21
  22 #include <linux/types.h>
  23 #include <linux/slab.h>
  24 #include <asm/scatterlist.h>
  25 #include <linux/string.h>
  26 #include <asm/io.h>
  27
  28 struct pci_dev;
  29
  30 /* Allocate and map kernel buffer using consistent mode DMA for a device.
  31  * hwdev should be valid struct pci_dev pointer for PCI devices,
  32  * NULL for PCI-like buses (ISA, EISA).
  33  * Returns non-NULL cpu-view pointer to the buffer if successful and
  34  * sets *dma_addrp to the pci side dma address as well, else *dma_addrp
  35  * is undefined.
  36  */
  37 extern void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
  38                                   dma_addr_t *dma_handle);
  39
  40 /* Free and unmap a consistent DMA buffer.
  41  * cpu_addr is what was returned from pci_alloc_consistent,
  42  * size must be the same as what as passed into pci_alloc_consistent,
  43  * and likewise dma_addr must be the same as what *dma_addrp was set to.
  44  *
  45  * References to the memory and mappings associated with cpu_addr/dma_addr
  46  * past this call are illegal.
  47  */
  48 extern void pci_free_consistent(struct pci_dev *hwdev, size_t size,
  49                                 void *vaddr, dma_addr_t dma_handle);
  50
  51 /* Map a single buffer of the indicated size for DMA in streaming mode.
  52  * The 32-bit bus address to use is returned.
  53  *
  54  * Once the device is given the dma address, the device owns this memory
  55  * until either pci_unmap_single or pci_dma_sync_single is performed.
  56  */
  57 extern inline dma_addr_t pci_map_single(struct pci_dev *hwdev, void *ptr,
  58                                         size_t size, int direction)
  59 {
  60         if (direction == PCI_DMA_NONE)
  61                 BUG();
  62         return virt_to_bus(ptr);
  63 }
  64
  65 /* Unmap a single streaming mode DMA translation.  The dma_addr and size
  66  * must match what was provided for in a previous pci_map_single call.  All
  67  * other usages are undefined.
  68  *
  69  * After this call, reads by the cpu to the buffer are guarenteed to see
  70  * whatever the device wrote there.
  71  */
  72 extern inline void pci_unmap_single(struct pci_dev *hwdev, dma_addr_t dma_addr,
  73                                     size_t size, int direction)
  74 {
  75         if (direction == PCI_DMA_NONE)
  76                 BUG();
  77         /* Nothing to do */
  78 }
  79
  80 /* Map a set of buffers described by scatterlist in streaming
  81  * mode for DMA.  This is the scather-gather version of the
  82  * above pci_map_single interface.  Here the scatter gather list
  83  * elements are each tagged with the appropriate dma address
  84  * and length.  They are obtained via sg_dma_{address,length}(SG).
  85  *
  86  * NOTE: An implementation may be able to use a smaller number of
  87  *       DMA address/length pairs than there are SG table elements.
  88  *       (for example via virtual mapping capabilities)
  89  *       The routine returns the number of addr/length pairs actually
  90  *       used, at most nents.
  91  *
  92  * Device ownership issues as mentioned above for pci_map_single are
  93  * the same here.
  94  */
  95 extern inline int pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
  96                              int nents, int direction)
  97 {
  98         if (direction == PCI_DMA_NONE)
  99                 BUG();
 100         return nents;
 101 }
 102
 103 /* Unmap a set of streaming mode DMA translations.
 104  * Again, cpu read rules concerning calls here are the same as for
 105  * pci_unmap_single() above.
 106  */
 107 extern inline void pci_unmap_sg(struct pci_dev *hwdev, struct scatterlist *sg,
 108                                 int nents, int direction)
 109 {
 110         if (direction == PCI_DMA_NONE)
 111                 BUG();
 112         /* Nothing to do */
 113 }
 114
 115 /* Make physical memory consistent for a single
 116  * streaming mode DMA translation after a transfer.
 117  *
 118  * If you perform a pci_map_single() but wish to interrogate the
 119  * buffer using the cpu, yet do not wish to teardown the PCI dma
 120  * mapping, you must call this function before doing so.  At the
 121  * next point you give the PCI dma address back to the card, the
 122  * device again owns the buffer.
 123  */
 124 extern inline void pci_dma_sync_single(struct pci_dev *hwdev,
 125                                        dma_addr_t dma_handle,
 126                                        size_t size, int direction)
 127 {
 128         if (direction == PCI_DMA_NONE)
 129                 BUG();
 130         /* Nothing to do */
 131 }
 132
 133 /* Make physical memory consistent for a set of streaming
 134  * mode DMA translations after a transfer.
 135  *
 136  * The same as pci_dma_sync_single but for a scatter-gather list,
 137  * same rules and usage.
 138  */
 139 extern inline void pci_dma_sync_sg(struct pci_dev *hwdev,
 140                                    struct scatterlist *sg,
 141                                    int nelems, int direction)
 142 {
 143         if (direction == PCI_DMA_NONE)
 144                 BUG();
 145         /* Nothing to do */
 146 }
 147
 148 /* Return whether the given PCI device DMA address mask can
 149  * be supported properly.  For example, if your device can
 150  * only drive the low 24-bits during PCI bus mastering, then
 151  * you would pass 0x00ffffff as the mask to this function.
 152  */
 153 extern inline int pci_dma_supported(struct pci_dev *hwdev, dma_addr_t mask)
 154 {
 155         return 1;
 156 }
 157
 158 /* These macros should be used after a pci_map_sg call has been done
 159  * to get bus addresses of each of the SG entries and their lengths.
 160  * You should only work with the number of sg entries pci_map_sg
 161  * returns, or alternatively stop on the first sg_dma_len(sg) which
 162  * is 0.
 163  */
 164 #define sg_dma_address(sg)      (virt_to_bus((sg)->address))
 165 #define sg_dma_len(sg)          ((sg)->length)
 166
 167 #endif /* __KERNEL__ */
 168
 169 #endif /* __i386_PCI_H */