1 /* $NetBSD: xen_bus_dma.c,v 1.27 2018/06/24 20:28:57 jdolecek 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 1.27 2018/06/24 20:28:57 jdolecek 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 43 #include <sys/bus.h> 44 #include <machine/bus_private.h> 45 46 #include <uvm/uvm.h> 47 48 extern paddr_t avail_end; 49 50 /* Pure 2^n version of get_order */ 51 static inline int get_order(unsigned long size) 52 { 53 int order = -1; 54 size = (size - 1) >> (PAGE_SHIFT - 1); 55 do { 56 size >>= 1; 57 order++; 58 } while (size); 59 return order; 60 } 61 62 static int 63 _xen_alloc_contig(bus_size_t size, bus_size_t alignment, 64 struct pglist *mlistp, int flags, bus_addr_t low, bus_addr_t high) 65 { 66 int order, i; 67 unsigned long npagesreq, npages, mfn; 68 bus_addr_t pa; 69 struct vm_page *pg, *pgnext; 70 int s, error; 71 struct xen_memory_reservation res; 72 73 /* 74 * When requesting a contigous memory region, the hypervisor will 75 * return a memory range aligned on size. 76 * The only way to enforce alignment is to request a memory region 77 * of size max(alignment, size). 78 */ 79 order = max(get_order(size), get_order(alignment)); 80 npages = (1 << order); 81 npagesreq = (size >> PAGE_SHIFT); 82 KASSERT(npages >= npagesreq); 83 84 /* get npages from UVM, and give them back to the hypervisor */ 85 error = uvm_pglistalloc(((psize_t)npages) << PAGE_SHIFT, 86 0, avail_end, 0, 0, mlistp, npages, (flags & BUS_DMA_NOWAIT) == 0); 87 if (error) 88 return (error); 89 90 for (pg = mlistp->tqh_first; pg != NULL; pg = pg->pageq.queue.tqe_next) { 91 pa = VM_PAGE_TO_PHYS(pg); 92 mfn = xpmap_ptom(pa) >> PAGE_SHIFT; 93 xpmap_ptom_unmap(pa); 94 set_xen_guest_handle(res.extent_start, &mfn); 95 res.nr_extents = 1; 96 res.extent_order = 0; 97 res.address_bits = 0; 98 res.domid = DOMID_SELF; 99 error = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &res); 100 if (error != 1) { 101 #ifdef DEBUG 102 printf("xen_alloc_contig: XENMEM_decrease_reservation " 103 "failed: err %d (pa %#" PRIxPADDR " mfn %#lx)\n", 104 error, pa, mfn); 105 #endif 106 xpmap_ptom_map(pa, ptoa(mfn)); 107 108 error = ENOMEM; 109 goto failed; 110 } 111 } 112 /* Get the new contiguous memory extent */ 113 set_xen_guest_handle(res.extent_start, &mfn); 114 res.nr_extents = 1; 115 res.extent_order = order; 116 res.address_bits = get_order(high) + PAGE_SHIFT; 117 res.domid = DOMID_SELF; 118 error = HYPERVISOR_memory_op(XENMEM_increase_reservation, &res); 119 if (error != 1) { 120 #ifdef DEBUG 121 printf("xen_alloc_contig: XENMEM_increase_reservation " 122 "failed: %d (order %d address_bits %d)\n", 123 error, order, res.address_bits); 124 #endif 125 error = ENOMEM; 126 pg = NULL; 127 goto failed; 128 } 129 s = splvm(); /* XXXSMP */ 130 /* Map the new extent in place of the old pages */ 131 for (pg = mlistp->tqh_first, i = 0; pg != NULL; pg = pgnext, i++) { 132 pgnext = pg->pageq.queue.tqe_next; 133 pa = VM_PAGE_TO_PHYS(pg); 134 xpmap_ptom_map(pa, ptoa(mfn+i)); 135 xpq_queue_machphys_update(((paddr_t)(mfn+i)) << PAGE_SHIFT, pa); 136 /* while here, give extra pages back to UVM */ 137 if (i >= npagesreq) { 138 TAILQ_REMOVE(mlistp, pg, pageq.queue); 139 uvm_pagefree(pg); 140 } 141 } 142 /* Flush updates through and flush the TLB */ 143 xpq_queue_tlb_flush(); 144 splx(s); 145 return 0; 146 147 failed: 148 /* 149 * Attempt to recover from a failed decrease or increase reservation: 150 * if decrease_reservation failed, we don't have given all pages 151 * back to Xen; give them back to UVM, and get the missing pages 152 * from Xen. 153 * if increase_reservation failed, we expect pg to be NULL and we just 154 * get back the missing pages from Xen one by one. 155 */ 156 /* give back remaining pages to UVM */ 157 for (; pg != NULL; pg = pgnext) { 158 pgnext = pg->pageq.queue.tqe_next; 159 TAILQ_REMOVE(mlistp, pg, pageq.queue); 160 uvm_pagefree(pg); 161 } 162 /* remplace the pages that we already gave to Xen */ 163 s = splvm(); /* XXXSMP */ 164 for (pg = mlistp->tqh_first; pg != NULL; pg = pgnext) { 165 pgnext = pg->pageq.queue.tqe_next; 166 set_xen_guest_handle(res.extent_start, &mfn); 167 res.nr_extents = 1; 168 res.extent_order = 0; 169 res.address_bits = 32; 170 res.domid = DOMID_SELF; 171 if (HYPERVISOR_memory_op(XENMEM_increase_reservation, &res) 172 < 0) { 173 printf("xen_alloc_contig: recovery " 174 "XENMEM_increase_reservation failed!\n"); 175 break; 176 } 177 pa = VM_PAGE_TO_PHYS(pg); 178 xpmap_ptom_map(pa, ptoa(mfn)); 179 xpq_queue_machphys_update(((paddr_t)mfn) << PAGE_SHIFT, pa); 180 TAILQ_REMOVE(mlistp, pg, pageq.queue); 181 uvm_pagefree(pg); 182 } 183 /* Flush updates through and flush the TLB */ 184 xpq_queue_tlb_flush(); 185 splx(s); 186 return error; 187 } 188 189 190 /* 191 * Allocate physical memory from the given physical address range. 192 * Called by DMA-safe memory allocation methods. 193 * We need our own version to deal with physical vs machine addresses. 194 */ 195 int 196 _xen_bus_dmamem_alloc_range(bus_dma_tag_t t, bus_size_t size, 197 bus_size_t alignment, bus_size_t boundary, bus_dma_segment_t *segs, 198 int nsegs, int *rsegs, int flags, bus_addr_t low, bus_addr_t high) 199 { 200 bus_addr_t curaddr, lastaddr; 201 struct vm_page *m; 202 struct pglist mlist; 203 int curseg, error; 204 int doingrealloc = 0; 205 bus_size_t uboundary; 206 207 /* Always round the size. */ 208 size = round_page(size); 209 210 KASSERT((alignment & (alignment - 1)) == 0); 211 KASSERT((boundary & (boundary - 1)) == 0); 212 KASSERT(boundary >= PAGE_SIZE || boundary == 0); 213 214 if (alignment < PAGE_SIZE) 215 alignment = PAGE_SIZE; 216 217 /* 218 * Allocate pages from the VM system. 219 * We accept boundaries < size, splitting in multiple segments 220 * if needed. uvm_pglistalloc does not, so compute an appropriate 221 * boundary: next power of 2 >= size 222 */ 223 if (boundary == 0) 224 uboundary = 0; 225 else { 226 uboundary = boundary; 227 while (uboundary < size) 228 uboundary = uboundary << 1; 229 } 230 error = uvm_pglistalloc(size, 0, avail_end, alignment, uboundary, 231 &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0); 232 if (error) 233 return (error); 234 again: 235 236 /* 237 * Compute the location, size, and number of segments actually 238 * returned by the VM code. 239 */ 240 m = mlist.tqh_first; 241 curseg = 0; 242 curaddr = lastaddr = segs[curseg].ds_addr = _BUS_VM_PAGE_TO_BUS(m); 243 if (curaddr < low || curaddr >= high) 244 goto badaddr; 245 segs[curseg].ds_len = PAGE_SIZE; 246 m = m->pageq.queue.tqe_next; 247 if ((segs[curseg].ds_addr & (alignment - 1)) != 0) 248 goto dorealloc; 249 250 for (; m != NULL; m = m->pageq.queue.tqe_next) { 251 curaddr = _BUS_VM_PAGE_TO_BUS(m); 252 if (curaddr < low || curaddr >= high) 253 goto badaddr; 254 if (curaddr == (lastaddr + PAGE_SIZE) && 255 (lastaddr & boundary) == (curaddr & boundary)) { 256 segs[curseg].ds_len += PAGE_SIZE; 257 } else { 258 curseg++; 259 if (curseg >= nsegs || 260 (curaddr & (alignment - 1)) != 0) { 261 if (doingrealloc) 262 return EFBIG; 263 else 264 goto dorealloc; 265 } 266 segs[curseg].ds_addr = curaddr; 267 segs[curseg].ds_len = PAGE_SIZE; 268 } 269 lastaddr = curaddr; 270 } 271 272 *rsegs = curseg + 1; 273 return (0); 274 275 badaddr: 276 if (doingrealloc == 0) 277 goto dorealloc; 278 if (curaddr < low) { 279 /* no way to enforce this */ 280 printf("_xen_bus_dmamem_alloc_range: no way to " 281 "enforce address range (0x%" PRIx64 " - 0x%" PRIx64 ")\n", 282 (uint64_t)low, (uint64_t)high); 283 uvm_pglistfree(&mlist); 284 return EINVAL; 285 } 286 printf("xen_bus_dmamem_alloc_range: " 287 "curraddr=0x%lx > high=0x%lx\n", 288 (u_long)curaddr, (u_long)high); 289 panic("xen_bus_dmamem_alloc_range 1"); 290 dorealloc: 291 if (doingrealloc == 1) 292 panic("_xen_bus_dmamem_alloc_range: " 293 "xen_alloc_contig returned " 294 "too much segments"); 295 doingrealloc = 1; 296 /* 297 * Too much segments, or memory doesn't fit 298 * constraints. Free this memory and 299 * get a contigous segment from the hypervisor. 300 */ 301 uvm_pglistfree(&mlist); 302 for (curseg = 0; curseg < nsegs; curseg++) { 303 segs[curseg].ds_addr = 0; 304 segs[curseg].ds_len = 0; 305 } 306 error = _xen_alloc_contig(size, alignment, 307 &mlist, flags, low, high); 308 if (error) 309 return error; 310 goto again; 311 } 312