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 /* Do nothing (copied from current ccio_unmap_single() :^) */ 134} 135 136 137static struct pci_dma_ops ccio_ops = { 138 ccio_dma_supported, 139 ccio_alloc_consistent, 140 ccio_free_consistent, 141 ccio_map_single, 142 ccio_unmap_single, 143 ccio_map_sg, 144 ccio_unmap_sg, 145 NULL, /* dma_sync_single_for_cpu : NOP for U2 */ 146 NULL, /* dma_sync_single_for_device : NOP for U2 */ 147 NULL, /* dma_sync_sg_for_cpu : ditto */ 148 NULL, /* dma_sync_sg_for_device : ditto */ 149}; 150 151 152/* 153** Determine if u2 should claim this chip (return 0) or not (return 1). 154** If so, initialize the chip and tell other partners in crime they 155** have work to do. 156*/ 157static int 158ccio_probe(struct parisc_device *dev) 159{ 160 printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME, 161 dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn", 162 dev->hpa.start); 163 164 165 hppa_dma_ops = &ccio_ops; 166 return 0; 167} 168 169static struct parisc_device_id ccio_tbl[] = { 170 { HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc }, 171 { HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc }, 172 { 0, } 173}; 174 175static struct parisc_driver ccio_driver = { 176 .name = "U2/Uturn", 177 .id_table = ccio_tbl, 178 .probe = ccio_probe, 179}; 180 181void __init ccio_init(void) 182{ 183 register_parisc_driver(&ccio_driver); 184} 185