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 68static 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 81static 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 95static 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 101static 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 107static 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 114static 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 130static void ccio_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction) 131{ 132 /* Do nothing (copied from current ccio_unmap_single() :^) */ 133} 134 135 136static struct pci_dma_ops ccio_ops = { 137 ccio_dma_supported, 138 ccio_alloc_consistent, 139 ccio_free_consistent, 140 ccio_map_single, 141 ccio_unmap_single, 142 ccio_map_sg, 143 ccio_unmap_sg, 144 NULL, /* dma_sync_single_for_cpu : NOP for U2 */ 145 NULL, /* dma_sync_single_for_device : NOP for U2 */ 146 NULL, /* dma_sync_sg_for_cpu : ditto */ 147 NULL, /* dma_sync_sg_for_device : ditto */ 148}; 149 150 151/* 152** Determine if u2 should claim this chip (return 0) or not (return 1). 153** If so, initialize the chip and tell other partners in crime they 154** have work to do. 155*/ 156static int 157ccio_probe(struct parisc_device *dev) 158{ 159 printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME, 160 dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn", 161 dev->hpa.start); 162 163 164 hppa_dma_ops = &ccio_ops; 165 return 0; 166} 167 168static struct parisc_device_id ccio_tbl[] = { 169 { HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc }, 170 { HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc }, 171 { 0, } 172}; 173 174static struct parisc_driver ccio_driver = { 175 .name = "U2/Uturn", 176 .id_table = ccio_tbl, 177 .probe = ccio_probe, 178}; 179 180void __init ccio_init(void) 181{ 182 register_parisc_driver(&ccio_driver); 183} 184