1 /* $NetBSD: xen_bus_dma.c,v 1.34 2024/05/14 19:00:44 andvar 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 * 21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 __KERNEL_RCSID(0, "$NetBSD: xen_bus_dma.c,v 1.34 2024/05/14 19:00:44 andvar Exp $"); 36 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/kernel.h> 40 #include <sys/mbuf.h> 41 #include <sys/proc.h> 42 #include <sys/bus.h> 43 44 #include <machine/bus_private.h> 45 #include <machine/pmap_private.h> 46 47 #include <uvm/uvm.h> 48 49 #include "opt_xen.h" 50 51 /* No special needs */ 52 struct x86_bus_dma_tag xenbus_bus_dma_tag = { 53 ._tag_needs_free = 0, 54 ._bounce_thresh = 0, 55 ._bounce_alloc_lo = 0, 56 ._bounce_alloc_hi = 0, 57 ._may_bounce = NULL, 58 }; 59 60 #ifdef XENPV 61 62 extern paddr_t avail_end; 63 64 /* Pure 2^n version of get_order */ 65 static inline int get_order(unsigned long size) 66 { 67 int order = -1; 68 size = (size - 1) >> (PAGE_SHIFT - 1); 69 do { 70 size >>= 1; 71 order++; 72 } while (size); 73 return order; 74 } 75 76 static int 77 _xen_alloc_contig(bus_size_t size, bus_size_t alignment, 78 struct pglist *mlistp, int flags, bus_addr_t low, bus_addr_t high) 79 { 80 int order, i; 81 unsigned long npagesreq, npages, mfn; 82 bus_addr_t pa; 83 struct vm_page *pg, *pgnext; 84 int s, error; 85 struct xen_memory_reservation res; 86 87 /* 88 * When requesting a contiguous memory region, the hypervisor will 89 * return a memory range aligned on size. 90 * The only way to enforce alignment is to request a memory region 91 * of size max(alignment, size). 92 */ 93 order = uimax(get_order(size), get_order(alignment)); 94 npages = (1 << order); 95 npagesreq = (size >> PAGE_SHIFT); 96 KASSERT(npages >= npagesreq); 97 98 /* get npages from UVM, and give them back to the hypervisor */ 99 error = uvm_pglistalloc(((psize_t)npages) << PAGE_SHIFT, 100 0, avail_end, 0, 0, mlistp, npages, (flags & BUS_DMA_NOWAIT) == 0); 101 if (error) 102 return (error); 103 104 for (pg = mlistp->tqh_first; pg != NULL; pg = pg->pageq.queue.tqe_next) { 105 pa = VM_PAGE_TO_PHYS(pg); 106 mfn = xpmap_ptom(pa) >> PAGE_SHIFT; 107 xpmap_ptom_unmap(pa); 108 set_xen_guest_handle(res.extent_start, &mfn); 109 res.nr_extents = 1; 110 res.extent_order = 0; 111 res.mem_flags = 0; 112 res.domid = DOMID_SELF; 113 error = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &res); 114 if (error != 1) { 115 #ifdef DEBUG 116 printf("xen_alloc_contig: XENMEM_decrease_reservation " 117 "failed: err %d (pa %#" PRIxPADDR " mfn %#lx)\n", 118 error, pa, mfn); 119 #endif 120 xpmap_ptom_map(pa, ptoa(mfn)); 121 122 error = ENOMEM; 123 goto failed; 124 } 125 } 126 /* Get the new contiguous memory extent */ 127 set_xen_guest_handle(res.extent_start, &mfn); 128 res.nr_extents = 1; 129 res.extent_order = order; 130 res.mem_flags = XENMEMF_address_bits(get_order(high) + PAGE_SHIFT); 131 res.domid = DOMID_SELF; 132 error = HYPERVISOR_memory_op(XENMEM_increase_reservation, &res); 133 if (error != 1) { 134 #ifdef DEBUG 135 printf("xen_alloc_contig: XENMEM_increase_reservation " 136 "failed: %d (order %d mem_flags %d)\n", 137 error, order, res.mem_flags); 138 #endif 139 error = ENOMEM; 140 pg = NULL; 141 goto failed; 142 } 143 s = splvm(); /* XXXSMP */ 144 /* Map the new extent in place of the old pages */ 145 for (pg = mlistp->tqh_first, i = 0; pg != NULL; pg = pgnext, i++) { 146 pgnext = pg->pageq.queue.tqe_next; 147 pa = VM_PAGE_TO_PHYS(pg); 148 xpmap_ptom_map(pa, ptoa(mfn+i)); 149 xpq_queue_machphys_update(((paddr_t)(mfn+i)) << PAGE_SHIFT, pa); 150 } 151 /* Flush updates through and flush the TLB */ 152 xpq_queue_tlb_flush(); 153 splx(s); 154 /* now that ptom/mtop are valid, give the extra pages back to UVM */ 155 for (pg = mlistp->tqh_first, i = 0; pg != NULL; pg = pgnext, i++) { 156 pgnext = pg->pageq.queue.tqe_next; 157 if (i >= npagesreq) { 158 TAILQ_REMOVE(mlistp, pg, pageq.queue); 159 uvm_pagefree(pg); 160 } 161 } 162 return 0; 163 164 failed: 165 /* 166 * Attempt to recover from a failed decrease or increase reservation: 167 * if decrease_reservation failed, we don't have given all pages 168 * back to Xen; give them back to UVM, and get the missing pages 169 * from Xen. 170 * if increase_reservation failed, we expect pg to be NULL and we just 171 * get back the missing pages from Xen one by one. 172 */ 173 /* give back remaining pages to UVM */ 174 for (; pg != NULL; pg = pgnext) { 175 pgnext = pg->pageq.queue.tqe_next; 176 TAILQ_REMOVE(mlistp, pg, pageq.queue); 177 uvm_pagefree(pg); 178 } 179 /* remplace the pages that we already gave to Xen */ 180 s = splvm(); /* XXXSMP */ 181 for (pg = mlistp->tqh_first; pg != NULL; pg = pgnext) { 182 pgnext = pg->pageq.queue.tqe_next; 183 set_xen_guest_handle(res.extent_start, &mfn); 184 res.nr_extents = 1; 185 res.extent_order = 0; 186 res.mem_flags = XENMEMF_address_bits(32); 187 res.domid = DOMID_SELF; 188 if (HYPERVISOR_memory_op(XENMEM_increase_reservation, &res) 189 < 0) { 190 printf("xen_alloc_contig: recovery " 191 "XENMEM_increase_reservation failed!\n"); 192 break; 193 } 194 pa = VM_PAGE_TO_PHYS(pg); 195 xpmap_ptom_map(pa, ptoa(mfn)); 196 xpq_queue_machphys_update(((paddr_t)mfn) << PAGE_SHIFT, pa); 197 /* slow but we don't care */ 198 xpq_queue_tlb_flush(); 199 TAILQ_REMOVE(mlistp, pg, pageq.queue); 200 uvm_pagefree(pg); 201 } 202 splx(s); 203 return error; 204 } 205 206 207 /* 208 * Allocate physical memory from the given physical address range. 209 * Called by DMA-safe memory allocation methods. 210 * We need our own version to deal with physical vs machine addresses. 211 */ 212 int 213 _xen_bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, 214 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 215 int nsegs, int *rsegs, int flags, bus_addr_t low, bus_addr_t high) 216 { 217 bus_addr_t curaddr, lastaddr; 218 struct vm_page *m; 219 struct pglist mlist; 220 int curseg, error; 221 int doingrealloc = 0; 222 bus_size_t uboundary; 223 224 /* Always round the size. */ 225 size = round_page(size); 226 227 KASSERT((alignment & (alignment - 1)) == 0); 228 KASSERT((boundary & (boundary - 1)) == 0); 229 KASSERT(boundary >= PAGE_SIZE || boundary == 0); 230 231 if (alignment < PAGE_SIZE) 232 alignment = PAGE_SIZE; 233 234 /* 235 * Allocate pages from the VM system. 236 * We accept boundaries < size, splitting in multiple segments 237 * if needed. uvm_pglistalloc does not, so compute an appropriate 238 * boundary: next power of 2 >= size 239 */ 240 if (boundary == 0) 241 uboundary = 0; 242 else { 243 uboundary = boundary; 244 while (uboundary < size) 245 uboundary = uboundary << 1; 246 } 247 error = uvm_pglistalloc(size, 0, avail_end, alignment, uboundary, 248 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0); 249 if (error) 250 return (error); 251 again: 252 253 /* 254 * Compute the location, size, and number of segments actually 255 * returned by the VM code. 256 */ 257 m = mlist.tqh_first; 258 curseg = 0; 259 curaddr = lastaddr = segs[curseg].ds_addr = _BUS_VM_PAGE_TO_BUS(m); 260 if (curaddr < low || curaddr >= high) 261 goto badaddr; 262 segs[curseg].ds_len = PAGE_SIZE; 263 m = m->pageq.queue.tqe_next; 264 if ((segs[curseg].ds_addr & (alignment - 1)) != 0) 265 goto dorealloc; 266 267 for (; m != NULL; m = m->pageq.queue.tqe_next) { 268 curaddr = _BUS_VM_PAGE_TO_BUS(m); 269 if (curaddr < low || curaddr >= high) 270 goto badaddr; 271 if (curaddr == (lastaddr + PAGE_SIZE) && 272 (lastaddr & boundary) == (curaddr & boundary)) { 273 segs[curseg].ds_len += PAGE_SIZE; 274 } else { 275 curseg++; 276 if (curseg >= nsegs || 277 (curaddr & (alignment - 1)) != 0) { 278 if (doingrealloc) 279 return EFBIG; 280 else 281 goto dorealloc; 282 } 283 segs[curseg].ds_addr = curaddr; 284 segs[curseg].ds_len = PAGE_SIZE; 285 } 286 lastaddr = curaddr; 287 } 288 289 *rsegs = curseg + 1; 290 return (0); 291 292 badaddr: 293 if (doingrealloc == 0) 294 goto dorealloc; 295 if (curaddr < low) { 296 /* no way to enforce this */ 297 printf("_xen_bus_dmamem_alloc_range: no way to " 298 "enforce address range (0x%" PRIx64 " - 0x%" PRIx64 ")\n", 299 (uint64_t)low, (uint64_t)high); 300 uvm_pglistfree(&mlist); 301 return EINVAL; 302 } 303 printf("xen_bus_dmamem_alloc_range: " 304 "curraddr=0x%lx > high=0x%lx\n", 305 (u_long)curaddr, (u_long)high); 306 panic("xen_bus_dmamem_alloc_range 1"); 307 dorealloc: 308 if (doingrealloc == 1) 309 panic("_xen_bus_dmamem_alloc_range: " 310 "xen_alloc_contig returned " 311 "too much segments"); 312 doingrealloc = 1; 313 /* 314 * Too much segments, or memory doesn't fit 315 * constraints. Free this memory and 316 * get a contiguous segment from the hypervisor. 317 */ 318 uvm_pglistfree(&mlist); 319 for (curseg = 0; curseg < nsegs; curseg++) { 320 segs[curseg].ds_addr = 0; 321 segs[curseg].ds_len = 0; 322 } 323 error = _xen_alloc_contig(size, alignment, 324 &mlist, flags, low, high); 325 if (error) 326 return error; 327 goto again; 328 } 329 #endif /* XENPV */ 330
Indexes created Mon Sep 22 13:09:51 GMT 2025