Date: Fri, 13 Jul 2012 13:55:54 -0400 From: John Baldwin <jhb@freebsd.org> To: Scott Long <scott4long@yahoo.com> Cc: Peter Jeremy <peter@rulingia.com>, "current@freebsd.org" <current@freebsd.org> Subject: Re: Adding support for WC (write-combining) memory to bus_dma Message-ID: <201207131355.54432.jhb@freebsd.org> In-Reply-To: <201207121351.20951.jhb@freebsd.org> References: <201207121040.27116.jhb@freebsd.org> <1342111033.198.YahooMailNeo@web45716.mail.sp1.yahoo.com> <201207121351.20951.jhb@freebsd.org>
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On Thursday, July 12, 2012 1:51:20 pm John Baldwin wrote:
> On Thursday, July 12, 2012 12:37:13 pm Scott Long wrote:
> > Yup, this is a problem, and I like your fix; this kind of state is exactly what
> > belongs in the map.
>
> Why don't I break out the fix first as a separate patch.
Here is a patch to just fix this. I also mirrored the changes into powerpc
since it had copied the same code from x86 (albeit disabled). If you feel
the malloc stats via M_DEVBUF are important, I can restore those (probably
by adding a contigmalloc_attr() wrapper).
Index: powerpc/powerpc/busdma_machdep.c
===================================================================
--- powerpc/powerpc/busdma_machdep.c (revision 238365)
+++ powerpc/powerpc/busdma_machdep.c (working copy)
@@ -46,6 +46,8 @@
#include <sys/sysctl.h>
#include <vm/vm.h>
+#include <vm/vm_extern.h>
+#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
@@ -130,6 +132,7 @@
bus_dmamap_callback_t *callback;
void *callback_arg;
STAILQ_ENTRY(bus_dmamap) links;
+ int contigalloc;
};
static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
@@ -489,6 +492,7 @@
bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
bus_dmamap_t *mapp)
{
+ vm_memattr_t attr;
int mflags;
if (flags & BUS_DMA_NOWAIT)
@@ -500,6 +504,12 @@
if (flags & BUS_DMA_ZERO)
mflags |= M_ZERO;
+#ifdef NOTYET
+ if (flags & BUS_DMA_NOCACHE)
+ attr = VM_MEMATTR_UNCACHEABLE;
+ else
+#endif
+ attr = VM_MEMATTR_DEFAULT;
/*
* XXX:
@@ -511,7 +521,8 @@
*/
if ((dmat->maxsize <= PAGE_SIZE) &&
(dmat->alignment < dmat->maxsize) &&
- dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
+ dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
+ attr == VM_MEMATTR_DEFAULT) {
*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
} else {
/*
@@ -520,9 +531,10 @@
* multi-seg allocations yet though.
* XXX Certain AGP hardware does.
*/
- *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
- 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
- dmat->boundary);
+ *vaddr = (void *)kmem_alloc_contig(kernel_map, dmat->maxsize,
+ mflags, 0ul, dmat->lowaddr, dmat->alignment ?
+ dmat->alignment : 1ul, dmat->boundary, attr);
+ (*mapp)->contigalloc = 1;
}
if (*vaddr == NULL) {
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
@@ -531,11 +543,6 @@
} else if (vtophys(*vaddr) & (dmat->alignment - 1)) {
printf("bus_dmamem_alloc failed to align memory properly.\n");
}
-#ifdef NOTYET
- if (flags & BUS_DMA_NOCACHE)
- pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
- VM_MEMATTR_UNCACHEABLE);
-#endif
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, 0);
return (0);
@@ -548,18 +555,12 @@
void
bus_dmamem_free(bus_dma_tag_t dmat, void *vaddr, bus_dmamap_t map)
{
- bus_dmamap_destroy(dmat, map);
-#ifdef NOTYET
- pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, VM_MEMATTR_DEFAULT);
-#endif
- if ((dmat->maxsize <= PAGE_SIZE) &&
- (dmat->alignment < dmat->maxsize) &&
- dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
+ if (!map->contigalloc)
free(vaddr, M_DEVBUF);
- else {
- contigfree(vaddr, dmat->maxsize, M_DEVBUF);
- }
+ else
+ kmem_free(kernel_map, (vm_offset_t)vaddr, dmat->maxsize);
+ bus_dmamap_destroy(dmat, map);
CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
}
Index: x86/x86/busdma_machdep.c
===================================================================
--- x86/x86/busdma_machdep.c (revision 238365)
+++ x86/x86/busdma_machdep.c (working copy)
@@ -42,6 +42,8 @@
#include <sys/sysctl.h>
#include <vm/vm.h>
+#include <vm/vm_extern.h>
+#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
@@ -131,7 +133,7 @@
static STAILQ_HEAD(, bus_dmamap) bounce_map_waitinglist;
static STAILQ_HEAD(, bus_dmamap) bounce_map_callbacklist;
-static struct bus_dmamap nobounce_dmamap;
+static struct bus_dmamap nobounce_dmamap, contig_dmamap;
static void init_bounce_pages(void *dummy);
static int alloc_bounce_zone(bus_dma_tag_t dmat);
@@ -465,7 +467,7 @@
int
bus_dmamap_destroy(bus_dma_tag_t dmat, bus_dmamap_t map)
{
- if (map != NULL && map != &nobounce_dmamap) {
+ if (map != NULL && map != &nobounce_dmamap && map != &contig_dmamap) {
if (STAILQ_FIRST(&map->bpages) != NULL) {
CTR3(KTR_BUSDMA, "%s: tag %p error %d",
__func__, dmat, EBUSY);
@@ -490,6 +492,7 @@
bus_dmamem_alloc(bus_dma_tag_t dmat, void** vaddr, int flags,
bus_dmamap_t *mapp)
{
+ vm_memattr_t attr;
int mflags;
if (flags & BUS_DMA_NOWAIT)
@@ -512,6 +515,10 @@
}
if (flags & BUS_DMA_ZERO)
mflags |= M_ZERO;
+ if (flags & BUS_DMA_NOCACHE)
+ attr = VM_MEMATTR_UNCACHEABLE;
+ else
+ attr = VM_MEMATTR_DEFAULT;
/*
* XXX:
@@ -523,7 +530,8 @@
*/
if ((dmat->maxsize <= PAGE_SIZE) &&
(dmat->alignment < dmat->maxsize) &&
- dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem)) {
+ dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem) &&
+ attr == VM_MEMATTR_DEFAULT) {
*vaddr = malloc(dmat->maxsize, M_DEVBUF, mflags);
} else {
/*
@@ -532,9 +540,10 @@
* multi-seg allocations yet though.
* XXX Certain AGP hardware does.
*/
- *vaddr = contigmalloc(dmat->maxsize, M_DEVBUF, mflags,
- 0ul, dmat->lowaddr, dmat->alignment? dmat->alignment : 1ul,
- dmat->boundary);
+ *vaddr = (void *)kmem_alloc_contig(kernel_map, dmat->maxsize,
+ mflags, 0ul, dmat->lowaddr, dmat->alignment ?
+ dmat->alignment : 1ul, dmat->boundary, attr);
+ *mapp = &contig_dmamap;
}
if (*vaddr == NULL) {
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
@@ -543,9 +552,6 @@
} else if (vtophys(*vaddr) & (dmat->alignment - 1)) {
printf("bus_dmamem_alloc failed to align memory properly.\n");
}
- if (flags & BUS_DMA_NOCACHE)
- pmap_change_attr((vm_offset_t)*vaddr, dmat->maxsize,
- PAT_UNCACHEABLE);
CTR4(KTR_BUSDMA, "%s: tag %p tag flags 0x%x error %d",
__func__, dmat, dmat->flags, 0);
return (0);
@@ -560,18 +566,15 @@
{
/*
* dmamem does not need to be bounced, so the map should be
- * NULL
+ * NULL if malloc() was used and contig_dmamap if
+ * contigmalloc() was used.
*/
- if (map != NULL)
+ if (!(map == NULL || map == &contig_dmamap))
panic("bus_dmamem_free: Invalid map freed\n");
- pmap_change_attr((vm_offset_t)vaddr, dmat->maxsize, PAT_WRITE_BACK);
- if ((dmat->maxsize <= PAGE_SIZE) &&
- (dmat->alignment < dmat->maxsize) &&
- dmat->lowaddr >= ptoa((vm_paddr_t)Maxmem))
+ if (map == NULL)
free(vaddr, M_DEVBUF);
- else {
- contigfree(vaddr, dmat->maxsize, M_DEVBUF);
- }
+ else
+ kmem_free(kernel_map, (vm_offset_t)vaddr, dmat->maxsize);
CTR3(KTR_BUSDMA, "%s: tag %p flags 0x%x", __func__, dmat, dmat->flags);
}
@@ -662,7 +665,7 @@
vm_offset_t vaddr;
int seg, error;
- if (map == NULL)
+ if (map == NULL || map == &contig_dmamap)
map = &nobounce_dmamap;
if ((dmat->flags & BUS_DMA_COULD_BOUNCE) != 0) {
@@ -1139,7 +1142,7 @@
struct bounce_page *bpage;
KASSERT(dmat->bounce_zone != NULL, ("no bounce zone in dma tag"));
- KASSERT(map != NULL && map != &nobounce_dmamap,
+ KASSERT(map != NULL && map != &nobounce_dmamap && map != &contig_dmamap,
("add_bounce_page: bad map %p", map));
bz = dmat->bounce_zone;
--
John Baldwin
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