xen_bus_dma.c revision 1.3.2.5
1 /* $NetBSD: xen_bus_dma.c,v 1.3.2.5 2006/09/16 11:18:59 ghen 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 1.3.2.5 2006/09/16 11:18:59 ghen 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 int s, error; 79 80 /* 81 * When requesting a contigous memory region, the hypervisor will 82 * return a memory range aligned on size. This will automagically 83 * handle "boundary", but the only way to enforce alignment 84 * is to request a memory region of size max(alignment, size). 85 */ 86 order = max(get_order(size), get_order(alignment)); 87 npages = (1 << order); 88 npagesreq = (size >> PAGE_SHIFT); 89 KASSERT(npages >= npagesreq); 90 91 /* get npages from UWM, and give them back to the hypervisor */ 92 error = uvm_pglistalloc(npages << PAGE_SHIFT, 0, avail_end, 0, 0, 93 mlistp, npages, (flags & BUS_DMA_NOWAIT) == 0); 94 if (error) 95 return (error); 96 97 for (pg = mlistp->tqh_first; pg != NULL; pg = pg->pageq.tqe_next) { 98 pa = VM_PAGE_TO_PHYS(pg); 99 mfn = xpmap_ptom(pa) >> PAGE_SHIFT; 100 xpmap_phys_to_machine_mapping[ 101 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = INVALID_P2M_ENTRY; 102 if (HYPERVISOR_dom_mem_op(MEMOP_decrease_reservation, 103 &mfn, 1, 0) != 1) { 104 #ifdef DEBUG 105 printf("xen_alloc_contig: MEMOP_decrease_reservation " 106 "failed!\n"); 107 #endif 108 xpmap_phys_to_machine_mapping[ 109 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = mfn; 110 error = ENOMEM; 111 goto failed; 112 } 113 } 114 /* Get the new contiguous memory extent */ 115 if (HYPERVISOR_dom_mem_op(MEMOP_increase_reservation, 116 &mfn, 1, order) != 1) { 117 #ifdef DEBUG 118 printf("xen_alloc_contig: MEMOP_increase_reservation " 119 "failed!\n"); 120 #endif 121 error = ENOMEM; 122 pg = NULL; 123 goto failed; 124 } 125 s = splvm(); 126 /* Map the new extent in place of the old pages */ 127 for (pg = mlistp->tqh_first, i = 0; pg != NULL; pg = pgnext, i++) { 128 pgnext = pg->pageq.tqe_next; 129 pa = VM_PAGE_TO_PHYS(pg); 130 xpmap_phys_to_machine_mapping[ 131 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = mfn+i; 132 xpq_queue_machphys_update((mfn+i) << PAGE_SHIFT, pa); 133 /* while here, give extra pages back to UVM */ 134 if (i >= npagesreq) { 135 TAILQ_REMOVE(mlistp, pg, pageq); 136 uvm_pagefree(pg); 137 } 138 139 } 140 /* Flush updates through and flush the TLB */ 141 xpq_queue_tlb_flush(); 142 xpq_flush_queue(); 143 splx(s); 144 return 0; 145 146 failed: 147 /* 148 * Attempt to recover from a failed decrease or increase reservation: 149 * if decrease_reservation failed, we don't have given all pages 150 * back to Xen; give them back to UVM, and get the missing pages 151 * from Xen. 152 * if increase_reservation failed, we expect pg to be NULL and we just 153 * get back the missing pages from Xen one by one. 154 */ 155 /* give back remaining pages to UVM */ 156 for (; pg != NULL; pg = pgnext) { 157 pgnext = pg->pageq.tqe_next; 158 TAILQ_REMOVE(mlistp, pg, pageq); 159 uvm_pagefree(pg); 160 } 161 /* remplace the pages that we already gave to Xen */ 162 s = splvm(); 163 for (pg = mlistp->tqh_first; pg != NULL; pg = pgnext) { 164 pgnext = pg->pageq.tqe_next; 165 if (HYPERVISOR_dom_mem_op(MEMOP_increase_reservation, 166 &mfn, 1, 0) != 1) { 167 printf("xen_alloc_contig: recovery " 168 "MEMOP_increase_reservation failed!\n"); 169 break; 170 } 171 pa = VM_PAGE_TO_PHYS(pg); 172 xpmap_phys_to_machine_mapping[ 173 (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = mfn; 174 xpq_queue_machphys_update((mfn) << PAGE_SHIFT, pa); 175 TAILQ_REMOVE(mlistp, pg, pageq); 176 uvm_pagefree(pg); 177 } 178 /* Flush updates through and flush the TLB */ 179 xpq_queue_tlb_flush(); 180 xpq_flush_queue(); 181 splx(s); 182 return error; 183 } 184 185 186 /* 187 * Allocate physical memory from the given physical address range. 188 * Called by DMA-safe memory allocation methods. 189 * We need our own version to deal with physical vs machine addresses. 190 */ 191 int 192 _xen_bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, 193 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 194 int nsegs, int *rsegs, int flags, bus_addr_t low, bus_addr_t high) 195 { 196 bus_addr_t curaddr, lastaddr; 197 struct vm_page *m; 198 struct pglist mlist; 199 int curseg, error; 200 int doingrealloc = 0; 201 202 /* Always round the size. */ 203 size = round_page(size); 204 205 KASSERT((alignment & (alignment - 1)) == 0); 206 KASSERT((boundary & (boundary - 1)) == 0); 207 if (alignment < PAGE_SIZE) 208 alignment = PAGE_SIZE; 209 if (boundary != 0 && boundary < size) 210 return (EINVAL); 211 212 /* 213 * Allocate pages from the VM system. 214 */ 215 error = uvm_pglistalloc(size, 0, avail_end, alignment, boundary, 216 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0); 217 if (error) 218 return (error); 219 again: 220 221 /* 222 * Compute the location, size, and number of segments actually 223 * returned by the VM code. 224 */ 225 m = mlist.tqh_first; 226 curseg = 0; 227 lastaddr = segs[curseg].ds_addr = _BUS_VM_PAGE_TO_BUS(m); 228 segs[curseg].ds_len = PAGE_SIZE; 229 m = m->pageq.tqe_next; 230 if ((segs[curseg].ds_addr & (alignment - 1)) != 0) 231 goto dorealloc; 232 233 for (; m != NULL; m = m->pageq.tqe_next) { 234 curaddr = _BUS_VM_PAGE_TO_BUS(m); 235 if ((lastaddr < low || lastaddr >= high) || 236 (curaddr < low || curaddr >= high)) { 237 /* 238 * If machine addresses are outside the allowed 239 * range we have to bail. Xen2 doesn't offer an 240 * interface to get memory in a specific address 241 * range. 242 */ 243 printf("_xen_bus_dmamem_alloc_range: no way to " 244 "enforce address range\n"); 245 uvm_pglistfree(&mlist); 246 return EINVAL; 247 } 248 if (curaddr == (lastaddr + PAGE_SIZE)) { 249 segs[curseg].ds_len += PAGE_SIZE; 250 if ((lastaddr & boundary) != 251 (curaddr & boundary)) 252 goto dorealloc; 253 } else { 254 curseg++; 255 if (curseg >= nsegs || 256 (curaddr & (alignment - 1)) != 0) { 257 dorealloc: 258 if (doingrealloc == 1) 259 panic("_xen_bus_dmamem_alloc_range: " 260 "xen_alloc_contig returned " 261 "too much segments"); 262 doingrealloc = 1; 263 /* 264 * Too much segments. Free this memory and 265 * get a contigous segment from the hypervisor. 266 */ 267 uvm_pglistfree(&mlist); 268 for (curseg = 0; curseg < nsegs; curseg++) { 269 segs[curseg].ds_addr = 0; 270 segs[curseg].ds_len = 0; 271 } 272 error = _xen_alloc_contig(size, alignment, 273 boundary, &mlist, flags); 274 if (error) 275 return error; 276 goto again; 277 } 278 segs[curseg].ds_addr = curaddr; 279 segs[curseg].ds_len = PAGE_SIZE; 280 } 281 lastaddr = curaddr; 282 } 283 284 *rsegs = curseg + 1; 285 286 return (0); 287 } 288
Indexes created Wed Oct 15 16:09:53 GMT 2025