Author: jhb
Date: Thu Jun 27 21:02:26 2013
New Revision: 252318
URL: http://svnweb.freebsd.org/changeset/base/252318
Log:
MFC 233662,233677-233678,250418,252166:
If the firmware/BIOS assigns conflicting ranges to BARs then leaving the
BARs alone could result in one device stealing mmio accesses intended to go
to a second device. Previously the PCI bus driver attempted to handle this
case by clearing the BAR to 0 depending on BARs based at 0 not decoding (which
is not guaranteed to be true). Now when a conflicting BAR is detected the
following steps are taken:
1) If hw.pci.realloc_bars (a new tunable) is enabled (default is disabled),
then ignore the current BAR setting from the firmware and attempt to
allocate a fresh resource range for the BAR.
2) If 1) failed (or was disabled), disable decoding for the relevant
BAR type (e.g. disable mem decoding for a memory BAR) and emit a
warning if booting verbose.
Modified:
stable/8/sys/dev/pci/pci.c
Directory Properties:
stable/8/sys/ (props changed)
stable/8/sys/dev/ (props changed)
stable/8/sys/dev/pci/ (props changed)
Modified: stable/8/sys/dev/pci/pci.c
==============================================================================
--- stable/8/sys/dev/pci/pci.c Thu Jun 27 20:35:39 2013 (r252317)
+++ stable/8/sys/dev/pci/pci.c Thu Jun 27 21:02:26 2013 (r252318)
@@ -295,6 +295,12 @@ SYSCTL_INT(_hw_pci, OID_AUTO, enable_io_
enable these bits correctly. We'd like to do this all the time, but there\n\
are some peripherals that this causes problems with.");
+static int pci_do_realloc_bars = 0;
+TUNABLE_INT("hw.pci.realloc_bars", &pci_do_realloc_bars);
+SYSCTL_INT(_hw_pci, OID_AUTO, realloc_bars, CTLFLAG_RW,
+ &pci_do_realloc_bars, 0,
+ "Attempt to allocate a new range for any BARs whose original
firmware-assigned ranges fail to allocate during the initial device scan.");
+
static int pci_do_power_nodriver = 0;
TUNABLE_INT("hw.pci.do_power_nodriver", &pci_do_power_nodriver);
SYSCTL_INT(_hw_pci, OID_AUTO, do_power_nodriver, CTLFLAG_RW,
@@ -2743,20 +2749,39 @@ pci_add_map(device_t bus, device_t dev,
*/
res = resource_list_alloc(rl, bus, dev, type, ®, start, end, count,
prefetch ? RF_PREFETCHABLE : 0);
+ if (pci_do_realloc_bars && res == NULL && (start != 0 || end != ~0ul)) {
+ /*
+ * If the allocation fails, try to allocate a resource for
+ * this BAR using any available range. The firmware felt
+ * it was important enough to assign a resource, so don't
+ * disable decoding if we can help it.
+ */
+ resource_list_delete(rl, type, reg);
+ resource_list_add(rl, type, reg, 0, ~0ul, count);
+ res = resource_list_alloc(rl, bus, dev, type, ®, 0, ~0ul,
+ count, prefetch ? RF_PREFETCHABLE : 0);
+ }
if (res == NULL) {
/*
- * If the allocation fails, clear the BAR and delete
- * the resource list entry to force
- * pci_alloc_resource() to allocate resources from the
- * parent.
+ * If the allocation fails, delete the resource list entry
+ * and disable decoding for this device.
+ *
+ * If the driver requests this resource in the future,
+ * pci_reserve_map() will try to allocate a fresh
+ * resource range.
*/
resource_list_delete(rl, type, reg);
- start = 0;
+ pci_disable_io(dev, type);
+ if (bootverbose)
+ device_printf(bus,
+ "pci%d:%d:%d:%d bar %#x failed to allocate\n",
+ pci_get_domain(dev), pci_get_bus(dev),
+ pci_get_slot(dev), pci_get_function(dev), reg);
} else {
start = rman_get_start(res);
+ pci_write_bar(dev, pm, start);
rman_set_device(res, bus);
}
- pci_write_bar(dev, pm, start);
return (barlen);
}
@@ -3732,7 +3757,7 @@ pci_describe_device(device_t dev)
if ((desc = malloc(strlen(vp) + strlen(dp) + 3, M_DEVBUF, M_NOWAIT)) !=
NULL)
sprintf(desc, "%s, %s", vp, dp);
- out:
+out:
if (vp != NULL)
free(vp, M_DEVBUF);
if (dp != NULL)
@@ -4008,7 +4033,7 @@ pci_alloc_map(device_t dev, device_t chi
count, *rid, type, rman_get_start(res));
map = rman_get_start(res);
pci_write_bar(child, pm, map);
-out:;
+out:
return (res);
}
@@ -4210,19 +4235,6 @@ pci_delete_resource(device_t dev, device
rman_get_start(rle->res));
return;
}
-
-#ifndef __PCI_BAR_ZERO_VALID
- /*
- * If this is a BAR, clear the BAR so it stops
- * decoding before releasing the resource.
- */
- switch (type) {
- case SYS_RES_IOPORT:
- case SYS_RES_MEMORY:
- pci_write_bar(child, pci_find_bar(child, rid), 0);
- break;
- }
-#endif
bus_release_resource(dev, type, rid, rle->res);
}
resource_list_delete(rl, type, rid);
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