Date: Mon, 6 Sep 2010 13:04:18 +0530 From: "Jayachandran C." <c.jayachandran@gmail.com> To: freebsd-mips@freebsd.org Cc: gonzo@freebsd.org Subject: Re: busdma_machdep.c with more than 512M memory Message-ID: <AANLkTim2gqj=cbgM35rD5oyMD43rWFY1cjyY4A4CoR99@mail.gmail.com> In-Reply-To: <AANLkTimjmpOBOAncY9K9AhCodvp27t=XTQ9qZp4q8%2Bvv@mail.gmail.com> References: <AANLkTimjmpOBOAncY9K9AhCodvp27t=XTQ9qZp4q8%2Bvv@mail.gmail.com>
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[-- Attachment #1 --]
On Wed, Sep 1, 2010 at 12:37 PM, Jayachandran C.
<c.jayachandran@gmail.com> wrote:
> I was looking at a few crashes I see with PCI drivers, and I think it
> is caused by an issue in busdma_machdep.c where physical address is
> directly converted using MIPS_PHYS_TO_KSEG1. I have not looked at it
> in detail, but it looks obviously wrong.
>
> Any suggestions on how to fix thiis is welcome, it probably needs an
> uncached TLB entry. On 64bit we could use XKPHYS uncached.
>
>
> ---
> 632 if (newmap->flags & DMAMAP_UNCACHEABLE) {
> 633 void *tmpaddr = (void *)*vaddr;
> 634
> 635 if (tmpaddr) {
> 636 tmpaddr = (void
> *)MIPS_PHYS_TO_KSEG1(vtophys(tmpaddr));
> 637 newmap->origbuffer = *vaddr;
> 638 newmap->allocbuffer = tmpaddr;
> 639 mips_dcache_wbinv_range((vm_offset_t)*vaddr,
> 640 dmat->maxsize);
> 641 *vaddr = tmpaddr;
> 642 }
> ---
> 1361 bpage->busaddr = pmap_kextract(bpage->vaddr);
> 1362 bpage->vaddr_nocache =
> 1363 (vm_offset_t)MIPS_PHYS_TO_KSEG1(bpage->busaddr);
> 1364 mtx_lock(&bounce_lock);
Based on Juli's suggestion, I have a patch (attached) to switch the
calls to pmap_mapdev/pmap_unmapdev.
Seems to work for me now, please review.
Thanks,
JC.
[-- Attachment #2 --]
Index: sys/mips/mips/busdma_machdep.c
===================================================================
--- sys/mips/mips/busdma_machdep.c (revision 211984)
+++ sys/mips/mips/busdma_machdep.c (working copy)
@@ -620,6 +620,7 @@
0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
dmat->boundary);
}
+
if (*vaddr == NULL) {
if (newmap != NULL) {
_busdma_free_dmamap(newmap);
@@ -633,7 +634,8 @@
void *tmpaddr = (void *)*vaddr;
if (tmpaddr) {
- tmpaddr = (void *)MIPS_PHYS_TO_KSEG1(vtophys(tmpaddr));
+ printf("uncache mapping %p %lx\n", tmpaddr, (u_long)vtophys(tmpaddr));
+ tmpaddr = (void *)pmap_mapdev(vtophys(tmpaddr), dmat->maxsize);
newmap->origbuffer = *vaddr;
newmap->allocbuffer = tmpaddr;
mips_dcache_wbinv_range((vm_offset_t)*vaddr,
@@ -660,6 +662,9 @@
vaddr = map->origbuffer;
}
+ if (map->flags & DMAMAP_UNCACHEABLE)
+ pmap_unmapdev((vm_offset_t)map->allocbuffer, dmat->maxsize);
+
if (map->flags & DMAMAP_MALLOCUSED)
free(vaddr, M_DEVBUF);
else
@@ -1359,8 +1364,9 @@
break;
}
bpage->busaddr = pmap_kextract(bpage->vaddr);
- bpage->vaddr_nocache =
- (vm_offset_t)MIPS_PHYS_TO_KSEG1(bpage->busaddr);
+ bpage->vaddr_nocache = (vm_offset_t)pmap_mapdev(bpage->busaddr, PAGE_SIZE);
+ printf("bounce mapping %p %p\n", (void *)bpage->busaddr,
+ (void *)bpage->vaddr_nocache);
mtx_lock(&bounce_lock);
STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
total_bpages++;
help
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