Annotation of src/sys/arch/xen/x86/xen_bus_dma.c, Revision 1.1
1.1 ! bouyer 1: /* $NetBSD: bus_dma.c,v 1.21 2005/04/16 07:53:35 yamt 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: bus_dma.c,v 1.21 2005/04/16 07:53:35 yamt 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: /*
! 163: * Allocate pages from the VM system.
! 164: */
! 165: error = uvm_pglistalloc(size, 0, avail_end, alignment, boundary,
! 166: &mlist, nsegs, (flags & BUS_DMA_NOWAIT) == 0);
! 167: if (error)
! 168: return (error);
! 169: again:
! 170:
! 171: /*
! 172: * Compute the location, size, and number of segments actually
! 173: * returned by the VM code.
! 174: */
! 175: m = mlist.tqh_first;
! 176: curseg = 0;
! 177: lastaddr = segs[curseg].ds_addr = VM_PAGE_TO_PHYS(m);
! 178: segs[curseg].ds_len = PAGE_SIZE;
! 179: m = m->pageq.tqe_next;
! 180:
! 181: for (; m != NULL; m = m->pageq.tqe_next) {
! 182: curaddr = VM_PAGE_TO_PHYS(m);
! 183: bus_curaddr = _BUS_PHYS_TO_BUS(curaddr);
! 184: bus_lastaddr = _BUS_PHYS_TO_BUS(lastaddr);
! 185: if ((bus_lastaddr < low || bus_lastaddr >= high) ||
! 186: (bus_curaddr < low || bus_curaddr >= high)) {
! 187: /*
! 188: * If machine addresses are outside the allowed
! 189: * range we have to bail. Xen2 doesn't offer an
! 190: * interface to get memory in a specific address
! 191: * range.
! 192: */
! 193: printf("_xen_bus_dmamem_alloc_range: no way to "
! 194: "enforce address range\n");
! 195: return EINVAL;
! 196: }
! 197: if (bus_curaddr == (bus_lastaddr + PAGE_SIZE))
! 198: segs[curseg].ds_len += PAGE_SIZE;
! 199: else {
! 200: curseg++;
! 201: if (curseg >= nsegs) {
! 202: if (doingrealloc == 1)
! 203: panic("_xen_bus_dmamem_alloc_range: "
! 204: "xen_alloc_contig returned "
! 205: "too much segments");
! 206: doingrealloc = 1;
! 207: /*
! 208: * Too much segments. Free this memory and
! 209: * get a contigous segment from the hypervisor.
! 210: */
! 211: uvm_pglistfree(&mlist);
! 212: for (curseg = 0; curseg < nsegs; curseg++) {
! 213: segs[curseg].ds_addr = 0;
! 214: segs[curseg].ds_len = 0;
! 215: }
! 216: error = _xen_alloc_contig(size, alignment,
! 217: boundary, &mlist, flags);
! 218: if (error)
! 219: return error;
! 220: goto again;
! 221: }
! 222: segs[curseg].ds_addr = curaddr;
! 223: segs[curseg].ds_len = PAGE_SIZE;
! 224: }
! 225: lastaddr = curaddr;
! 226: }
! 227:
! 228: *rsegs = curseg + 1;
! 229:
! 230: return (0);
! 231: }
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