drivers/parisc/ccio-rm-dma.c

   1 /*
   2  * ccio-rm-dma.c:
   3  *      DMA management routines for first generation cache-coherent machines.
   4  *      "Real Mode" operation refers to U2/Uturn chip operation. The chip
   5  *      can perform coherency checks w/o using the I/O MMU. That's all we
   6  *      need until support for more than 4GB phys mem is needed.
   7  *
   8  *      This is the trivial case - basically what x86 does.
   9  *
  10  *      Drawbacks of using Real Mode are:
  11  *      o outbound DMA is slower since one isn't using the prefetching
  12  *        U2 can do for outbound DMA.
  13  *      o Ability to do scatter/gather in HW is also lost.
  14  *      o only known to work with PCX-W processor. (eg C360)
  15  *        (PCX-U/U+ are not coherent with U2 in real mode.)
  16  *
  17  *
  18  * This program is free software; you can redistribute it and/or modify
  19  * it under the terms of the GNU General Public License as published by
  20  * the Free Software Foundation; either version 2 of the License, or
  21  * (at your option) any later version.
  22  *
  23  *
  24  * Original version/author:
  25  *      CVSROOT=:pserver:anonymous@198.186.203.37:/cvsroot/linux-parisc
  26  *      cvs -z3 co linux/arch/parisc/kernel/dma-rm.c
  27  *
  28  *      (C) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
  29  *
  30  *
  31  * Adopted for The Puffin Group's parisc-linux port by Grant Grundler.
  32  *      (C) Copyright 2000 Grant Grundler <grundler@puffin.external.hp.com>
  33  *
  34  */
  35
  36 #include <linux/types.h>
  37 #include <linux/init.h>
  38 #include <linux/mm.h>
  39 #include <linux/string.h>
  40 #include <linux/pci.h>
  41
  42 #include <asm/uaccess.h>
  43
  44 #include <asm/io.h>
  45 #include <asm/hardware.h>
  46 #include <asm/page.h>
  47
  48 /* Only chose "ccio" since that's what HP-UX calls it....
  49 ** Make it easier for folks to migrate from one to the other :^)
  50 */
  51 #define MODULE_NAME "ccio"
  52
  53 #define U2_IOA_RUNWAY 0x580
  54 #define U2_BC_GSC     0x501
  55 #define UTURN_IOA_RUNWAY 0x581
  56 #define UTURN_BC_GSC     0x502
  57
  58 #define IS_U2(id) ( \
  59     (((id)->hw_type == HPHW_IOA) && ((id)->hversion == U2_IOA_RUNWAY)) || \
  60     (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == U2_BC_GSC))  \
  61 )
  62
  63 #define IS_UTURN(id) ( \
  64     (((id)->hw_type == HPHW_IOA) && ((id)->hversion == UTURN_IOA_RUNWAY)) || \
  65     (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == UTURN_BC_GSC))  \
  66 )
  67
  68 static int ccio_dma_supported( struct pci_dev *dev, u64 mask)
  69 {
  70         if (dev == NULL) {
  71                 printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
  72                 BUG();
  73                 return(0);
  74         }
  75
  76         /* only support 32-bit devices (ie PCI/GSC) */
  77         return((int) (mask >= 0xffffffffUL));
  78 }
  79
  80
  81 static void *ccio_alloc_consistent(struct pci_dev *dev, size_t size,
  82                                  dma_addr_t *handle)
  83 {
  84         void *ret;
  85
  86         ret = (void *)__get_free_pages(GFP_ATOMIC, get_order(size));
  87
  88         if (ret != NULL) {
  89                 memset(ret, 0, size);
  90                 *handle = virt_to_phys(ret);
  91         }
  92         return ret;
  93 }
  94
  95 static void ccio_free_consistent(struct pci_dev *dev, size_t size,
  96                                void *vaddr, dma_addr_t handle)
  97 {
  98         free_pages((unsigned long)vaddr, get_order(size));
  99 }
 100
 101 static dma_addr_t ccio_map_single(struct pci_dev *dev, void *ptr, size_t size,
 102                           int direction)
 103 {
 104         return virt_to_phys(ptr);
 105 }
 106
 107 static void ccio_unmap_single(struct pci_dev *dev, dma_addr_t dma_addr,
 108                             size_t size, int direction)
 109 {
 110         /* Nothing to do */
 111 }
 112
 113
 114 static int ccio_map_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
 115 {
 116         int tmp = nents;
 117
 118         /* KISS: map each buffer separately. */
 119         while (nents) {
 120                 sg_dma_address(sglist) = ccio_map_single(dev, sglist->address, sglist->length, direction);
 121                 sg_dma_len(sglist) = sglist->length;
 122                 nents--;
 123                 sglist++;
 124         }
 125
 126         return tmp;
 127 }
 128
 129
 130 static void ccio_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
 131 {
 132 #if 0
 133         while (nents) {
 134                 ccio_unmap_single(dev, sg_dma_address(sglist), sg_dma_len(sglist), direction);
 135                 nents--;
 136                 sglist++;
 137         }
 138         return;
 139 #else
 140         /* Do nothing (copied from current ccio_unmap_single()  :^) */
 141 #endif
 142 }
 143
 144
 145 static struct pci_dma_ops ccio_ops = {
 146         ccio_dma_supported,
 147         ccio_alloc_consistent,
 148         ccio_free_consistent,
 149         ccio_map_single,
 150         ccio_unmap_single,
 151         ccio_map_sg,
 152         ccio_unmap_sg,
 153         NULL,                   /* dma_sync_single_for_cpu : NOP for U2 */
 154         NULL,                   /* dma_sync_single_for_device : NOP for U2 */
 155         NULL,                   /* dma_sync_sg_for_cpu     : ditto */
 156         NULL,                   /* dma_sync_sg_for_device     : ditto */
 157 };
 158
 159
 160 /*
 161 ** Determine if u2 should claim this chip (return 0) or not (return 1).
 162 ** If so, initialize the chip and tell other partners in crime they
 163 ** have work to do.
 164 */
 165 static int
 166 ccio_probe(struct parisc_device *dev)
 167 {
 168         printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME,
 169                         dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn",
 170                         dev->hpa.start);
 171
 172 /*
 173 ** FIXME - should check U2 registers to verify it's really running
 174 ** in "Real Mode".
 175 */
 176
 177 #if 0
 178 /* will need this for "Virtual Mode" operation */
 179         ccio_hw_init(ccio_dev);
 180         ccio_common_init(ccio_dev);
 181 #endif
 182         hppa_dma_ops = &ccio_ops;
 183         return 0;
 184 }
 185
 186 static struct parisc_device_id ccio_tbl[] = {
 187         { HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc },
 188         { HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc },
 189         { 0, }
 190 };
 191
 192 static struct parisc_driver ccio_driver = {
 193         .name =         "U2/Uturn",
 194         .id_table =     ccio_tbl,
 195         .probe =        ccio_probe,
 196 };
 197
 198 void __init ccio_init(void)
 199 {
 200         register_parisc_driver(&ccio_driver);
 201 }