Fix two problems:

- In subr_ndis.c:ndis_allocate_sharemem(), create the busdma tags
  used for shared memory allocations with a lowaddr of 0x3E7FFFFF.
  This forces the buffers to be mapped to physical/bus addresses within
  the first 1GB of physical memory. It seems that at least one card
  (Linksys Instant Wireless PCI V2.7) depends on this behavior. I
  don't know if this is a hardware restriction, or if the NDIS
  driver for this card is truncating the addresses itself, but using
  physical/bus addresses beyong the 1GB limit causes initialization
  failures.

- Create am NDIS_INITIALIZED() macro in if_ndisvar.h and use it in
  if_ndis.c to test whether the device has been initialized rather
  than checking for the presence of the IFF_UP flag in if_flags.
  While debugging the previous problem, I noticed that bringing
  up the device would always produce failures from ndis_setmulti().
  It turns out that the following steps now occur during device
  initialization:

	- IFF_UP flag is set in if_flags
	- ifp->if_ioctl() called with SIOCSIFADDR (which we don't handle)
	- ifp->if_ioctl() called with SIOCADDMULTI
	- ifp->if_ioctl() called with SIOCADDMULTI (again)
	- ifp->if_ioctl() called with SIOCADDMULTI (yet again)
	- ifp->if_ioctl() called with SIOCSIFFLAGS

  Setting the receive filter and multicast filters can only be done
  when the underlying NDIS driver has been initialized, which is done
  by ifp->if_init(). However, we don't call ifp->if_init() until
  ifp->if_ioctl() is called with SIOCSIFFLAGS and IFF_UP has been
  set. It appears that now, the network stack tries to add multicast
  addresses to interface's filter before those steps occur. Normally,
  ndis_setmulti() would trap this condition by checking for the IFF_UP
  flag, but the network code has in fact set this flag already, so
  ndis_setmulti() is fooled into thinking the interface has been
  initialized when it really hasn't.

  It turns out this is usually harmless because the ifp->if_init()
  routine (in this case ndis_init()) will set up the multicast
  filter when it initializes the hardware anyway, and the underlying
  routines (ndis_get_info()/ndis_set_info()) know that the driver/NIC
  haven't been initialized yet, but you end up spurious error messages
  on the console all the time.

Something tells me this new behavior isn't really correct. I think
the intention was to fix it so that ifp->if_init() is only called
once when we ifconfig an interface up, but the end result seems a
little bogus: the change of the IFF_UP flag should be propagated
down to the driver before calling any other ioctl() that might actually
require the hardware to be up and running.

2 files changed, 17 insertions, 1 deletions

diff --git a/sys/compat/ndis/ndis_var.h b/sys/compat/ndis/ndis_var.h
index f2c3566..2c015a9 100644
--- a/sys/compat/ndis/ndis_var.h
+++ b/sys/compat/ndis/ndis_var.h
@@ -975,6 +975,8 @@ struct ndis_sc_element {
 typedef struct ndis_sc_element ndis_sc_element;
 
 #define NDIS_MAXSEG		32
+#define NDIS_BUS_SPACE_SHARED_MAXADDR	0x3E7FFFFF
+
 struct ndis_sc_list {
 	uint32_t		nsl_frags;
 	uint32_t		*nsl_rsvd;
diff --git a/sys/compat/ndis/subr_ndis.c b/sys/compat/ndis/subr_ndis.c
index 30def31..243c9dc 100644
--- a/sys/compat/ndis/subr_ndis.c
+++ b/sys/compat/ndis/subr_ndis.c
@@ -1297,8 +1297,22 @@ ndis_alloc_sharedmem(adapter, len, cached, vaddr, paddr)
 	if (sh == NULL)
 		return;
 
+	/*
+	 * When performing shared memory allocations, create a tag
+	 * with a lowaddr limit that restricts physical memory mappings
+	 * so that they all fall within the first 1GB of memory.
+	 * At least one device/driver combination (Linksys Instant
+	 * Wireless PCI Card V2.7, Broadcom 802.11b) seems to have
+	 * problems with performing DMA operations with physical
+	 * that lie above the 1GB mark. I don't know if this is a
+	 * hardware limitation or if the addresses are being truncated
+	 * within the driver, but this seems to be the only way to
+	 * make these cards work reliably in systems with more than
+	 * 1GB of physical memory.
+	 */
+
 	error = bus_dma_tag_create(sc->ndis_parent_tag, 64,
-	    0, BUS_SPACE_MAXADDR_32BIT, BUS_SPACE_MAXADDR, NULL,
+	    0, NDIS_BUS_SPACE_SHARED_MAXADDR, BUS_SPACE_MAXADDR, NULL,
 	    NULL, len, 1, len, BUS_DMA_ALLOCNOW, NULL, NULL,
 	    &sh->ndis_stag);