]> xenbits.xensource.com Git - people/liuw/freebsd.git/commitdiff
x86/dma_bounce: revert r289834 and r289836
authorroyger <royger@FreeBSD.org>
Mon, 26 Oct 2015 14:50:35 +0000 (14:50 +0000)
committerroyger <royger@FreeBSD.org>
Mon, 26 Oct 2015 14:50:35 +0000 (14:50 +0000)
The new load_ma implementation can cause dereferences when used with
certain drivers, back it out until the reason is found:

Fatal trap 12: page fault while in kernel mode
cpuid = 11; apic id = 03
fault virtual address   = 0x30
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff808a2d22
stack pointer           = 0x28:0xfffffe07cc737710
frame pointer           = 0x28:0xfffffe07cc737790
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 13 (g_down)
trap number             = 12
panic: page fault
cpuid = 11
KDB: stack backtrace:
#0 0xffffffff80641647 at kdb_backtrace+0x67
#1 0xffffffff80606762 at vpanic+0x182
#2 0xffffffff806067e3 at panic+0x43
#3 0xffffffff8084eef1 at trap_fatal+0x351
#4 0xffffffff8084f0e4 at trap_pfault+0x1e4
#5 0xffffffff8084e82f at trap+0x4bf
#6 0xffffffff80830d57 at calltrap+0x8
#7 0xffffffff8063beab at _bus_dmamap_load_ccb+0x1fb
#8 0xffffffff8063bc51 at bus_dmamap_load_ccb+0x91
#9 0xffffffff8042dcad at ata_dmaload+0x11d
#10 0xffffffff8042df7e at ata_begin_transaction+0x7e
#11 0xffffffff8042c18e at ataaction+0x9ce
#12 0xffffffff802a220f at xpt_run_devq+0x5bf
#13 0xffffffff802a17ad at xpt_action_default+0x94d
#14 0xffffffff802c0024 at adastart+0x8b4
#15 0xffffffff802a2e93 at xpt_run_allocq+0x193
#16 0xffffffff802c0735 at adastrategy+0xf5
#17 0xffffffff80554206 at g_disk_start+0x426
Uptime: 2m29s

sys/dev/xen/blkfront/blkfront.c
sys/x86/x86/busdma_bounce.c

index 0a75d79b1d257c5cc1efcf047c22014af39fd107..fa8d479331b4fdfc119d56f1d73622f0435cf2dd 100644 (file)
@@ -293,12 +293,8 @@ xbd_queue_request(struct xbd_softc *sc, struct xbd_command *cm)
 {
        int error;
 
-       if (cm->cm_bp != NULL)
-               error = bus_dmamap_load_bio(sc->xbd_io_dmat, cm->cm_map,
-                   cm->cm_bp, xbd_queue_cb, cm, 0);
-       else
-               error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map,
-                   cm->cm_data, cm->cm_datalen, xbd_queue_cb, cm, 0);
+       error = bus_dmamap_load(sc->xbd_io_dmat, cm->cm_map, cm->cm_data,
+           cm->cm_datalen, xbd_queue_cb, cm, 0);
        if (error == EINPROGRESS) {
                /*
                 * Maintain queuing order by freezing the queue.  The next
@@ -358,6 +354,8 @@ xbd_bio_command(struct xbd_softc *sc)
        }
 
        cm->cm_bp = bp;
+       cm->cm_data = bp->bio_data;
+       cm->cm_datalen = bp->bio_bcount;
        cm->cm_sector_number = (blkif_sector_t)bp->bio_pblkno;
 
        switch (bp->bio_cmd) {
@@ -1011,7 +1009,7 @@ xbd_instance_create(struct xbd_softc *sc, blkif_sector_t sectors,
 
        sc->xbd_disk->d_mediasize = sectors * sector_size;
        sc->xbd_disk->d_maxsize = sc->xbd_max_request_size;
-       sc->xbd_disk->d_flags = DISKFLAG_UNMAPPED_BIO;
+       sc->xbd_disk->d_flags = 0;
        if ((sc->xbd_flags & (XBDF_FLUSH|XBDF_BARRIER)) != 0) {
                sc->xbd_disk->d_flags |= DISKFLAG_CANFLUSHCACHE;
                device_printf(sc->xbd_dev,
index db90e940784a42cfb06bd2c04a58c7be33939428..ebd6238ef820a9f1ffcc3531c41f5e5290876c42 100644 (file)
@@ -79,8 +79,8 @@ struct bounce_page {
        vm_offset_t     vaddr;          /* kva of bounce buffer */
        bus_addr_t      busaddr;        /* Physical address */
        vm_offset_t     datavaddr;      /* kva of client data */
+       vm_page_t       datapage;       /* physical page of client data */
        vm_offset_t     dataoffs;       /* page offset of client data */
-       vm_page_t       datapage[2];    /* physical page(s) of client data */
        bus_size_t      datacount;      /* client data count */
        STAILQ_ENTRY(bounce_page) links;
 };
@@ -135,8 +135,8 @@ static int alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages);
 static int reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
                                int commit);
 static bus_addr_t add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map,
-                                 vm_offset_t vaddr, bus_addr_t addr1,
-                                 bus_addr_t addr2, bus_size_t size);
+                                 vm_offset_t vaddr, bus_addr_t addr,
+                                 bus_size_t size);
 static void free_bounce_page(bus_dma_tag_t dmat, struct bounce_page *bpage);
 int run_filter(bus_dma_tag_t dmat, bus_addr_t paddr);
 static void _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map,
@@ -527,51 +527,6 @@ _bus_dmamap_count_pages(bus_dma_tag_t dmat, bus_dmamap_t map, pmap_t pmap,
        }
 }
 
-static void
-_bus_dmamap_count_ma(bus_dma_tag_t dmat, bus_dmamap_t map, struct vm_page **ma,
-    int ma_offs, bus_size_t buflen, int flags)
-{
-       bus_size_t sg_len, max_sgsize;
-       int page_index;
-       vm_paddr_t paddr;
-
-       if ((map != &nobounce_dmamap && map->pagesneeded == 0)) {
-               CTR4(KTR_BUSDMA, "lowaddr= %d Maxmem= %d, boundary= %d, "
-                   "alignment= %d", dmat->common.lowaddr,
-                   ptoa((vm_paddr_t)Maxmem),
-                   dmat->common.boundary, dmat->common.alignment);
-               CTR3(KTR_BUSDMA, "map= %p, nobouncemap= %p, pagesneeded= %d",
-                   map, &nobounce_dmamap, map->pagesneeded);
-
-               /*
-                * Count the number of bounce pages
-                * needed in order to complete this transfer
-                */
-               page_index = 0;
-               while (buflen > 0) {
-                       paddr = ma[page_index]->phys_addr + ma_offs;
-                       sg_len = PAGE_SIZE - ma_offs;
-                       max_sgsize = MIN(buflen, dmat->common.maxsegsz);
-                       sg_len = MIN(sg_len, max_sgsize);
-                       if (bus_dma_run_filter(&dmat->common, paddr) != 0) {
-                               sg_len = roundup2(sg_len,
-                                   dmat->common.alignment);
-                               sg_len = MIN(sg_len, max_sgsize);
-                               KASSERT((sg_len & (dmat->common.alignment - 1))
-                                   == 0, ("Segment size is not aligned"));
-                               map->pagesneeded++;
-                       }
-                       if (((ma_offs + sg_len) & ~PAGE_MASK) != 0)
-                               page_index++;
-                       ma_offs = (ma_offs + sg_len) & PAGE_MASK;
-                       KASSERT(buflen >= sg_len,
-                           ("Segment length overruns original buffer"));
-                       buflen -= sg_len;
-               }
-               CTR1(KTR_BUSDMA, "pagesneeded= %d\n", map->pagesneeded);
-       }
-}
-
 static int
 _bus_dmamap_reserve_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int flags)
 {
@@ -677,7 +632,7 @@ bounce_bus_dmamap_load_phys(bus_dma_tag_t dmat, bus_dmamap_t map,
                    map->pagesneeded != 0 &&
                    bus_dma_run_filter(&dmat->common, curaddr)) {
                        sgsize = MIN(sgsize, PAGE_SIZE - (curaddr & PAGE_MASK));
-                       curaddr = add_bounce_page(dmat, map, 0, curaddr, 0,
+                       curaddr = add_bounce_page(dmat, map, 0, curaddr,
                            sgsize);
                }
                sgsize = _bus_dmamap_addseg(dmat, map, curaddr, sgsize, segs,
@@ -746,7 +701,7 @@ bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
                    bus_dma_run_filter(&dmat->common, curaddr)) {
                        sgsize = roundup2(sgsize, dmat->common.alignment);
                        sgsize = MIN(sgsize, max_sgsize);
-                       curaddr = add_bounce_page(dmat, map, kvaddr, curaddr, 0,
+                       curaddr = add_bounce_page(dmat, map, kvaddr, curaddr,
                            sgsize);
                } else {
                        sgsize = MIN(sgsize, max_sgsize);
@@ -765,90 +720,6 @@ bounce_bus_dmamap_load_buffer(bus_dma_tag_t dmat, bus_dmamap_t map, void *buf,
        return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
 }
 
-static int
-bounce_bus_dmamap_load_ma(bus_dma_tag_t dmat, bus_dmamap_t map,
-    struct vm_page **ma, bus_size_t buflen, int ma_offs, int flags,
-    bus_dma_segment_t *segs, int *segp)
-{
-       vm_paddr_t paddr, next_paddr;
-       int error, page_index;
-       struct vm_page *page;
-       bus_size_t sgsize, max_sgsize;
-
-       if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
-               /*
-                * If we have to keep the offset of each page this function
-                * is not suitable, switch back to bus_dmamap_load_ma_triv
-                * which is going to do the right thing in this case.
-                */
-               error = bus_dmamap_load_ma_triv(dmat, map, ma, buflen, ma_offs,
-                   flags, segs, segp);
-               return (error);
-       }
-
-       if (map == NULL)
-               map = &nobounce_dmamap;
-
-       if (segs == NULL)
-               segs = dmat->segments;
-
-       if ((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) {
-               _bus_dmamap_count_ma(dmat, map, ma, ma_offs, buflen, flags);
-               if (map->pagesneeded != 0) {
-                       error = _bus_dmamap_reserve_pages(dmat, map, flags);
-                       if (error)
-                               return (error);
-               }
-       }
-
-       page_index = 0;
-       page = ma[0];
-       while (buflen > 0) {
-               /*
-                * Compute the segment size, and adjust counts.
-                */
-               page = ma[page_index];
-               paddr = page->phys_addr + ma_offs;
-               max_sgsize = MIN(buflen, dmat->common.maxsegsz);
-               sgsize = PAGE_SIZE - ma_offs;
-               if (((dmat->bounce_flags & BUS_DMA_COULD_BOUNCE) != 0) &&
-                   map->pagesneeded != 0 &&
-                   bus_dma_run_filter(&dmat->common, paddr)) {
-                       sgsize = roundup2(sgsize, dmat->common.alignment);
-                       sgsize = MIN(sgsize, max_sgsize);
-                       KASSERT((sgsize & (dmat->common.alignment - 1)) == 0,
-                           ("Segment size is not aligned"));
-                       /*
-                        * Check if two pages of the user provided buffer
-                        * are used.
-                        */
-                       if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
-                               next_paddr = ma[page_index + 1]->phys_addr;
-                       else
-                               next_paddr = 0;
-                       paddr = add_bounce_page(dmat, map, 0, paddr,
-                           next_paddr, sgsize);
-               } else {
-                       sgsize = MIN(sgsize, max_sgsize);
-               }
-               sgsize = _bus_dmamap_addseg(dmat, map, paddr, sgsize, segs,
-                   segp);
-               if (sgsize == 0)
-                       break;
-               KASSERT(buflen >= sgsize,
-                   ("Segment length overruns original buffer"));
-               buflen -= sgsize;
-               if (((ma_offs + sgsize) & ~PAGE_MASK) != 0)
-                       page_index++;
-               ma_offs = (ma_offs + sgsize) & PAGE_MASK;
-       }
-
-       /*
-        * Did we fit?
-        */
-       return (buflen != 0 ? EFBIG : 0); /* XXX better return value here? */
-}
-
 static void
 bounce_bus_dmamap_waitok(bus_dma_tag_t dmat, bus_dmamap_t map,
     struct memdesc *mem, bus_dmamap_callback_t *callback, void *callback_arg)
@@ -892,7 +763,6 @@ bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
 {
        struct bounce_page *bpage;
        vm_offset_t datavaddr, tempvaddr;
-       bus_size_t datacount1, datacount2;
 
        if ((bpage = STAILQ_FIRST(&map->bpages)) == NULL)
                return;
@@ -908,35 +778,17 @@ bounce_bus_dmamap_sync(bus_dma_tag_t dmat, bus_dmamap_t map,
                while (bpage != NULL) {
                        tempvaddr = 0;
                        datavaddr = bpage->datavaddr;
-                       datacount1 = bpage->datacount;
                        if (datavaddr == 0) {
                                tempvaddr =
-                                   pmap_quick_enter_page(bpage->datapage[0]);
+                                   pmap_quick_enter_page(bpage->datapage);
                                datavaddr = tempvaddr | bpage->dataoffs;
-                               datacount1 = min(PAGE_SIZE - bpage->dataoffs,
-                                   datacount1);
                        }
 
                        bcopy((void *)datavaddr,
-                           (void *)bpage->vaddr, datacount1);
+                           (void *)bpage->vaddr, bpage->datacount);
 
                        if (tempvaddr != 0)
                                pmap_quick_remove_page(tempvaddr);
-
-                       if (bpage->datapage[1] == 0)
-                               goto next_w;
-
-                       /*
-                        * We are dealing with an unmapped buffer that expands
-                        * over two pages.
-                        */
-                       datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
-                       datacount2 = bpage->datacount - datacount1;
-                       bcopy((void *)datavaddr,
-                           (void *)(bpage->vaddr + datacount1), datacount2);
-                       pmap_quick_remove_page(datavaddr);
-
-next_w:
                        bpage = STAILQ_NEXT(bpage, links);
                }
                dmat->bounce_zone->total_bounced++;
@@ -946,35 +798,17 @@ next_w:
                while (bpage != NULL) {
                        tempvaddr = 0;
                        datavaddr = bpage->datavaddr;
-                       datacount1 = bpage->datacount;
                        if (datavaddr == 0) {
                                tempvaddr =
-                                   pmap_quick_enter_page(bpage->datapage[0]);
+                                   pmap_quick_enter_page(bpage->datapage);
                                datavaddr = tempvaddr | bpage->dataoffs;
-                               datacount1 = min(PAGE_SIZE - bpage->dataoffs,
-                                   datacount1);
                        }
 
-                       bcopy((void *)bpage->vaddr, (void *)datavaddr,
-                           datacount1);
+                       bcopy((void *)bpage->vaddr,
+                           (void *)datavaddr, bpage->datacount);
 
                        if (tempvaddr != 0)
                                pmap_quick_remove_page(tempvaddr);
-
-                       if (bpage->datapage[1] == 0)
-                               goto next_r;
-
-                       /*
-                        * We are dealing with an unmapped buffer that expands
-                        * over two pages.
-                        */
-                       datavaddr = pmap_quick_enter_page(bpage->datapage[1]);
-                       datacount2 = bpage->datacount - datacount1;
-                       bcopy((void *)(bpage->vaddr + datacount1),
-                           (void *)datavaddr, datacount2);
-                       pmap_quick_remove_page(datavaddr);
-
-next_r:
                        bpage = STAILQ_NEXT(bpage, links);
                }
                dmat->bounce_zone->total_bounced++;
@@ -1138,7 +972,7 @@ reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)
 
 static bus_addr_t
 add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
-               bus_addr_t addr1, bus_addr_t addr2, bus_size_t size)
+               bus_addr_t addr, bus_size_t size)
 {
        struct bounce_zone *bz;
        struct bounce_page *bpage;
@@ -1168,16 +1002,12 @@ add_bounce_page(bus_dma_tag_t dmat, bus_dmamap_t map, vm_offset_t vaddr,
 
        if (dmat->common.flags & BUS_DMA_KEEP_PG_OFFSET) {
                /* Page offset needs to be preserved. */
-               bpage->vaddr |= addr1 & PAGE_MASK;
-               bpage->busaddr |= addr1 & PAGE_MASK;
-               KASSERT(addr2 == 0,
-       ("Trying to bounce multiple pages with BUS_DMA_KEEP_PG_OFFSET"));
+               bpage->vaddr |= addr & PAGE_MASK;
+               bpage->busaddr |= addr & PAGE_MASK;
        }
        bpage->datavaddr = vaddr;
-       bpage->datapage[0] = PHYS_TO_VM_PAGE(addr1);
-       KASSERT((addr2 & PAGE_MASK) == 0, ("Second page is not aligned"));
-       bpage->datapage[1] = PHYS_TO_VM_PAGE(addr2);
-       bpage->dataoffs = addr1 & PAGE_MASK;
+       bpage->datapage = PHYS_TO_VM_PAGE(addr);
+       bpage->dataoffs = addr & PAGE_MASK;
        bpage->datacount = size;
        STAILQ_INSERT_TAIL(&(map->bpages), bpage, links);
        return (bpage->busaddr);
@@ -1249,7 +1079,7 @@ struct bus_dma_impl bus_dma_bounce_impl = {
        .mem_free = bounce_bus_dmamem_free,
        .load_phys = bounce_bus_dmamap_load_phys,
        .load_buffer = bounce_bus_dmamap_load_buffer,
-       .load_ma = bounce_bus_dmamap_load_ma,
+       .load_ma = bus_dmamap_load_ma_triv,
        .map_waitok = bounce_bus_dmamap_waitok,
        .map_complete = bounce_bus_dmamap_complete,
        .map_unload = bounce_bus_dmamap_unload,