1 /* $NetBSD: xen_bus_dma.c,v 1.5 2005/12/24 23:24:07 perry Exp $ */ 2 /* NetBSD bus_dma.c,v 1.21 2005/04/16 07:53:35 yamt Exp */ 3 4 /*- 5 * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace 10 * Simulation Facility, NASA Ames Research Center. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the NetBSD 23 * Foundation, Inc. and its contributors. 24 * 4. Neither the name of The NetBSD Foundation nor the names of its 25 * contributors may be used to endorse or promote products derived 26 * from this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 38 * POSSIBILITY OF SUCH DAMAGE. 39 */ 40 41 #include <sys/cdefs.h> 42 __KERNEL_RCSID(0, "$NetBSD: xen_bus_dma.c,v 1.5 2005/12/24 23:24:07 perry Exp $"); 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/malloc.h> 48 #include <sys/mbuf.h> 49 #include <sys/proc.h> 50 51 #include <machine/bus.h> 52 #include <machine/bus_private.h> 53 54 #include <uvm/uvm_extern.h> 55 56 extern paddr_t avail_end; 57 58 /* Pure 2^n version of get_order */ 59 static inline int get_order(unsigned long size) 60 { 61 int order = -1; 62 size = (size - 1) >> (PAGE_SHIFT - 1); 63 do { 64 size >>= 1; 65 order++; 66 } while (size); 67 return order; 68 } 69 70 static int 71 _xen_alloc_contig(bus_size_t size, bus_size_t alignment, bus_size_t boundary, 72 struct pglist *mlistp, int flags) 73 { 74 int order, i; 75 unsigned long npagesreq, npages, mfn; 76 bus_addr_t pa; 77 struct vm_page *pg, *pgnext; 78 struct pglist freelist; 79 int s, error; 80 81 TAILQ_INIT(&freelist); 82 83 /* 84 * When requesting a contigous memory region, the hypervisor will 85 * return a memory range aligned on size. This will automagically 86 * handle "boundary", but the only way to enforce alignment 87 * is to request a memory region of size max(alignment, size). 88 */ 89 order = max(get_order(size), get_order(alignment)); 90 npages = (1 << order); 91 npagesreq = (size >> PAGE_SHIFT); 92 KASSERT(npages >= npagesreq); 93 94 /* get npages from UWM, and give them back to the hypervisor */ 95 error = uvm_pglistalloc(npages << PAGE_SHIFT, 0, avail_end, 0, 0, 96 mlistp, npages, (flags & BUS_DMA_NOWAIT) == 0); 97 if (error) 98 return (error); 99 100 for (pg = mlistp->tqh_first; pg != NULL; pg = pg->pageq.tqe_next) { 101 pa = VM_PAGE_TO_PHYS(pg); 102 mfn = xpmap_ptom(pa) >> PAGE_SHIFT; 103 xpmap_phys_to_machine_mapping[ 104 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = INVALID_P2M_ENTRY; 105 if (HYPERVISOR_dom_mem_op(MEMOP_decrease_reservation, 106 &mfn, 1, 0) != 1) { 107 printf("xen_alloc_contig: MEMOP_decrease_reservation " 108 "failed!\n"); 109 return ENOMEM; 110 } 111 } 112 /* Get the new contiguous memory extent */ 113 if (HYPERVISOR_dom_mem_op(MEMOP_increase_reservation, 114 &mfn, 1, order) != 1) { 115 printf("xen_alloc_contig: MEMOP_increase_reservation " 116 "failed!\n"); 117 return ENOMEM; 118 } 119 s = splvm(); 120 /* Map the new extent in place of the old pages */ 121 for (pg = mlistp->tqh_first, i = 0; pg != NULL; pg = pgnext, i++) { 122 pgnext = pg->pageq.tqe_next; 123 pa = VM_PAGE_TO_PHYS(pg); 124 xpmap_phys_to_machine_mapping[ 125 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = mfn+i; 126 xpq_queue_machphys_update((mfn+i) << PAGE_SHIFT, pa); 127 /* while here, give extra pages back to UVM */ 128 if (i >= npagesreq) { 129 TAILQ_REMOVE(mlistp, pg, pageq); 130 uvm_pagefree(pg); 131 } 132 133 } 134 /* Flush updates through and flush the TLB */ 135 xpq_queue_tlb_flush(); 136 xpq_flush_queue(); 137 splx(s); 138 return 0; 139 } 140 141 142 /* 143 * Allocate physical memory from the given physical address range. 144 * Called by DMA-safe memory allocation methods. 145 * We need our own version to deal with physical vs machine addresses. 146 */ 147 int 148 _xen_bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, 149 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 150 int nsegs, int *rsegs, int flags, bus_addr_t low, bus_addr_t high) 151 { 152 paddr_t curaddr, lastaddr; 153 bus_addr_t bus_curaddr, bus_lastaddr; 154 struct vm_page *m; 155 struct pglist mlist; 156 int curseg, error; 157 int doingrealloc = 0; 158 159 /* Always round the size. */ 160 size = round_page(size); 161 162 KASSERT((alignment & (alignment - 1)) == 0); 163 KASSERT((boundary & (boundary - 1)) == 0); 164 if (alignment < PAGE_SIZE) 165 alignment = PAGE_SIZE; 166 if (boundary != 0 && boundary < size) 167 return (EINVAL); 168 169 /* 170 * Allocate pages from the VM system. 171 */ 172 error = uvm_pglistalloc(size, 0, avail_end, alignment, boundary, 173 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0); 174 if (error) 175 return (error); 176 again: 177 178 /* 179 * Compute the location, size, and number of segments actually 180 * returned by the VM code. 181 */ 182 m = mlist.tqh_first; 183 curseg = 0; 184 lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m); 185 segs[curseg].ds_len = PAGE_SIZE; 186 m = m->pageq.tqe_next; 187 if ((_BUS_PHYS_TO_BUS(segs[curseg].ds_addr) & (alignment - 1)) != 0) 188 goto dorealloc; 189 190 for (; m != NULL; m = m->pageq.tqe_next) { 191 curaddr = VM_PAGE_TO_PHYS(m); 192 bus_curaddr = _BUS_PHYS_TO_BUS(curaddr); 193 bus_lastaddr = _BUS_PHYS_TO_BUS(lastaddr); 194 if ((bus_lastaddr < low || bus_lastaddr >= high) || 195 (bus_curaddr < low || bus_curaddr >= high)) { 196 /* 197 * If machine addresses are outside the allowed 198 * range we have to bail. Xen2 doesn't offer an 199 * interface to get memory in a specific address 200 * range. 201 */ 202 printf("_xen_bus_dmamem_alloc_range: no way to " 203 "enforce address range\n"); 204 uvm_pglistfree(&mlist); 205 return EINVAL; 206 } 207 if (bus_curaddr == (bus_lastaddr + PAGE_SIZE)) { 208 segs[curseg].ds_len += PAGE_SIZE; 209 if ((bus_lastaddr & boundary) != 210 (bus_curaddr & boundary)) 211 goto dorealloc; 212 } 213 else { 214 curseg++; 215 if (curseg >= nsegs || 216 (bus_curaddr & (alignment - 1)) != 0) { 217 dorealloc: 218 if (doingrealloc == 1) 219 panic("_xen_bus_dmamem_alloc_range: " 220 "xen_alloc_contig returned " 221 "too much segments"); 222 doingrealloc = 1; 223 /* 224 * Too much segments. Free this memory and 225 * get a contigous segment from the hypervisor. 226 */ 227 uvm_pglistfree(&mlist); 228 for (curseg = 0; curseg < nsegs; curseg++) { 229 segs[curseg].ds_addr = 0; 230 segs[curseg].ds_len = 0; 231 } 232 error = _xen_alloc_contig(size, alignment, 233 boundary, &mlist, flags); 234 if (error) 235 return error; 236 goto again; 237 } 238 segs[curseg].ds_addr = curaddr; 239 segs[curseg].ds_len = PAGE_SIZE; 240 } 241 lastaddr = curaddr; 242 } 243 244 *rsegs = curseg + 1; 245 246 return (0); 247 } 248