Date: Thu, 27 Jun 2013 21:02:26 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r252318 - stable/8/sys/dev/pci Message-ID: <201306272102.r5RL2Q04078732@svn.freebsd.org>
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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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