linux/drivers/parisc/ccio-rm-dma.c
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   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#include <linux/gfp.h>
  42
  43#include <asm/uaccess.h>
  44
  45#include <asm/io.h>
  46#include <asm/hardware.h>
  47#include <asm/page.h>
  48
  49/* Only chose "ccio" since that's what HP-UX calls it....
  50** Make it easier for folks to migrate from one to the other :^)
  51*/
  52#define MODULE_NAME "ccio"
  53
  54#define U2_IOA_RUNWAY 0x580
  55#define U2_BC_GSC     0x501
  56#define UTURN_IOA_RUNWAY 0x581
  57#define UTURN_BC_GSC     0x502
  58
  59#define IS_U2(id) ( \
  60    (((id)->hw_type == HPHW_IOA) && ((id)->hversion == U2_IOA_RUNWAY)) || \
  61    (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == U2_BC_GSC))  \
  62)
  63
  64#define IS_UTURN(id) ( \
  65    (((id)->hw_type == HPHW_IOA) && ((id)->hversion == UTURN_IOA_RUNWAY)) || \
  66    (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == UTURN_BC_GSC))  \
  67)
  68
  69static int ccio_dma_supported( struct pci_dev *dev, u64 mask)
  70{
  71        if (dev == NULL) {
  72                printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
  73                BUG();
  74                return(0);
  75        }
  76
  77        /* only support 32-bit devices (ie PCI/GSC) */
  78        return((int) (mask >= 0xffffffffUL));
  79}
  80
  81
  82static void *ccio_alloc_consistent(struct pci_dev *dev, size_t size,
  83                                 dma_addr_t *handle)
  84{
  85        void *ret;
  86        
  87        ret = (void *)__get_free_pages(GFP_ATOMIC, get_order(size));
  88
  89        if (ret != NULL) {
  90                memset(ret, 0, size);
  91                *handle = virt_to_phys(ret);
  92        }
  93        return ret;
  94}
  95        
  96static void ccio_free_consistent(struct pci_dev *dev, size_t size,
  97                               void *vaddr, dma_addr_t handle)
  98{
  99        free_pages((unsigned long)vaddr, get_order(size));
 100}
 101
 102static dma_addr_t ccio_map_single(struct pci_dev *dev, void *ptr, size_t size,
 103                          int direction)
 104{
 105        return virt_to_phys(ptr);
 106}
 107
 108static void ccio_unmap_single(struct pci_dev *dev, dma_addr_t dma_addr,
 109                            size_t size, int direction)
 110{
 111        /* Nothing to do */
 112}
 113
 114
 115static int ccio_map_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
 116{
 117        int tmp = nents;
 118
 119        /* KISS: map each buffer separately. */
 120        while (nents) {
 121                sg_dma_address(sglist) = ccio_map_single(dev, sglist->address, sglist->length, direction);
 122                sg_dma_len(sglist) = sglist->length;
 123                nents--;
 124                sglist++;
 125        }
 126
 127        return tmp;
 128}
 129
 130
 131static void ccio_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
 132{
 133#if 0
 134        while (nents) {
 135                ccio_unmap_single(dev, sg_dma_address(sglist), sg_dma_len(sglist), direction);
 136                nents--;
 137                sglist++;
 138        }
 139        return;
 140#else
 141        /* Do nothing (copied from current ccio_unmap_single()  :^) */
 142#endif
 143}
 144
 145
 146static struct pci_dma_ops ccio_ops = {
 147        ccio_dma_supported,
 148        ccio_alloc_consistent,
 149        ccio_free_consistent,
 150        ccio_map_single,
 151        ccio_unmap_single,
 152        ccio_map_sg,
 153        ccio_unmap_sg,
 154        NULL,                   /* dma_sync_single_for_cpu : NOP for U2 */
 155        NULL,                   /* dma_sync_single_for_device : NOP for U2 */
 156        NULL,                   /* dma_sync_sg_for_cpu     : ditto */
 157        NULL,                   /* dma_sync_sg_for_device     : ditto */
 158};
 159
 160
 161/*
 162** Determine if u2 should claim this chip (return 0) or not (return 1).
 163** If so, initialize the chip and tell other partners in crime they
 164** have work to do.
 165*/
 166static int
 167ccio_probe(struct parisc_device *dev)
 168{
 169        printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME,
 170                        dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn",
 171                        dev->hpa.start);
 172
 173/*
 174** FIXME - should check U2 registers to verify it's really running
 175** in "Real Mode".
 176*/
 177
 178#if 0
 179/* will need this for "Virtual Mode" operation */
 180        ccio_hw_init(ccio_dev);
 181        ccio_common_init(ccio_dev);
 182#endif
 183        hppa_dma_ops = &ccio_ops;
 184        return 0;
 185}
 186
 187static struct parisc_device_id ccio_tbl[] = {
 188        { HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc },
 189        { HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc },
 190        { 0, }
 191};
 192
 193static struct parisc_driver ccio_driver = {
 194        .name =         "U2/Uturn",
 195        .id_table =     ccio_tbl,
 196        .probe =        ccio_probe,
 197};
 198
 199void __init ccio_init(void)
 200{
 201        register_parisc_driver(&ccio_driver);
 202}
 203
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