From 9db8dc6d0785225c42a37be7b44d1b07b31b8957 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Wed, 8 Jan 2020 14:32:08 -0700 Subject: PCI: Don't disable bridge BARs when assigning bus resources Some PCI bridges implement BARs in addition to bridge windows. For example, here's a PLX switch: 04:00.0 PCI bridge: PLX Technology, Inc. PEX 8724 24-Lane, 6-Port PCI Express Gen 3 (8 GT/s) Switch, 19 x 19mm FCBGA (rev ca) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0, IRQ 30, NUMA node 0 Memory at 90a00000 (32-bit, non-prefetchable) [size=256K] Bus: primary=04, secondary=05, subordinate=0a, sec-latency=0 I/O behind bridge: 00002000-00003fff Memory behind bridge: 90000000-909fffff Prefetchable memory behind bridge: 0000380000800000-0000380000bfffff Previously, when the kernel assigned resource addresses (with the pci=realloc command line parameter, for example) it could clear the struct resource corresponding to the BAR. When this happened, lspci would report this BAR as "ignored": Region 0: Memory at (32-bit, non-prefetchable) [size=256K] This is because the kernel reports a zero start address and zero flags in the corresponding sysfs resource file and in /proc/bus/pci/devices. Investigation with 'lspci -x', however, shows the BIOS-assigned address will still be programmed in the device's BAR registers. It's clearly a bug that the kernel lost track of the BAR value, but in most cases, this still won't result in a visible issue because nothing uses the memory, so nothing is affected. However, when an IOMMU is in use, it will not reserve this space in the IOVA because the kernel no longer thinks the range is valid. (See dmar_init_reserved_ranges() for the Intel implementation of this.) Without the proper reserved range, a DMA mapping may allocate an IOVA that matches a bridge BAR, which results in DMA accesses going to the BAR instead of the intended RAM. The problem was in pci_assign_unassigned_root_bus_resources(). When any resource from a bridge device fails to get assigned, the code set the resource's flags to zero. This makes sense for bridge windows, as they will be re-enabled later, but for regular BARs, it makes the kernel permanently lose track of the fact that they decode address space. Change pci_assign_unassigned_root_bus_resources() and pci_assign_unassigned_bridge_resources() so they only clear "res->flags" for bridge *windows*, not bridge BARs. Fixes: da7822e5ad71 ("PCI: update bridge resources to get more big ranges when allocating space (again)") Link: https://lore.kernel.org/r/20200108213208.4612-1-logang@deltatee.com [bhelgaas: commit log, check for pci_is_bridge()] Reported-by: Kit Chow Signed-off-by: Logan Gunthorpe Signed-off-by: Bjorn Helgaas --- drivers/pci/setup-bus.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index f279826204eb..591161ce0f51 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1803,12 +1803,18 @@ again: /* Restore size and flags */ list_for_each_entry(fail_res, &fail_head, list) { struct resource *res = fail_res->res; + int idx; res->start = fail_res->start; res->end = fail_res->end; res->flags = fail_res->flags; - if (fail_res->dev->subordinate) - res->flags = 0; + + if (pci_is_bridge(fail_res->dev)) { + idx = res - &fail_res->dev->resource[0]; + if (idx >= PCI_BRIDGE_RESOURCES && + idx <= PCI_BRIDGE_RESOURCE_END) + res->flags = 0; + } } free_list(&fail_head); @@ -2055,12 +2061,18 @@ again: /* Restore size and flags */ list_for_each_entry(fail_res, &fail_head, list) { struct resource *res = fail_res->res; + int idx; res->start = fail_res->start; res->end = fail_res->end; res->flags = fail_res->flags; - if (fail_res->dev->subordinate) - res->flags = 0; + + if (pci_is_bridge(fail_res->dev)) { + idx = res - &fail_res->dev->resource[0]; + if (idx >= PCI_BRIDGE_RESOURCES && + idx <= PCI_BRIDGE_RESOURCE_END) + res->flags = 0; + } } free_list(&fail_head); -- cgit From 3d67a2dbdbe9400523164d8557a7a5fb7ef83c7e Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:45:32 +0000 Subject: PCI: Remove unnecessary braces Remove unnecessary braces in pci_bus_distribute_available_resources(). No functional changes. Link: https://lore.kernel.org/r/PSXP216MB0438061CB4442460BB92A75F803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 591161ce0f51..16300ad5e277 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1908,11 +1908,10 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, */ if (hotplug_bridges + normal_bridges == 1) { dev = list_first_entry(&bus->devices, struct pci_dev, bus_list); - if (dev->subordinate) { + if (dev->subordinate) pci_bus_distribute_available_resources(dev->subordinate, add_list, available_io, available_mmio, available_mmio_pref); - } return; } -- cgit From 053eb5c150fd732624a1ea2f456337972d52b163 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Tue, 28 Jan 2020 14:59:23 -0600 Subject: PCI: Rename variables In pci_bus_distribute_available_resources(), rename: io => io_per_hp mmio => mmio_per_hp mmio_pref => mmio_pref_per_hp No functional change; this is just to make a subsequent patch smaller. [bhelgaas: extracted from https://lore.kernel.org/r/PSXP216MB0438587C47CBEDF365B1EA27803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM] Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 16300ad5e277..9d167d5b2235 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1873,6 +1873,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, unsigned int normal_bridges = 0, hotplug_bridges = 0; struct resource *io_res, *mmio_res, *mmio_pref_res; struct pci_dev *dev, *bridge = bus->self; + resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp; io_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0]; mmio_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1]; @@ -1956,7 +1957,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * resource space between hotplug bridges. */ for_each_pci_bridge(dev, bus) { - resource_size_t align, io, mmio, mmio_pref; + resource_size_t align; struct pci_bus *b; b = dev->subordinate; @@ -1969,22 +1970,25 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * account. */ align = pci_resource_alignment(bridge, io_res); - io = div64_ul(available_io, hotplug_bridges); - io = min(ALIGN(io, align), remaining_io); - remaining_io -= io; + io_per_hp = div64_ul(available_io, hotplug_bridges); + io_per_hp = min(ALIGN(io_per_hp, align), remaining_io); + remaining_io -= io_per_hp; align = pci_resource_alignment(bridge, mmio_res); - mmio = div64_ul(available_mmio, hotplug_bridges); - mmio = min(ALIGN(mmio, align), remaining_mmio); - remaining_mmio -= mmio; + mmio_per_hp = div64_ul(available_mmio, hotplug_bridges); + mmio_per_hp = min(ALIGN(mmio_per_hp, align), remaining_mmio); + remaining_mmio -= mmio_per_hp; align = pci_resource_alignment(bridge, mmio_pref_res); - mmio_pref = div64_ul(available_mmio_pref, hotplug_bridges); - mmio_pref = min(ALIGN(mmio_pref, align), remaining_mmio_pref); - remaining_mmio_pref -= mmio_pref; - - pci_bus_distribute_available_resources(b, add_list, io, mmio, - mmio_pref); + mmio_pref_per_hp = div64_ul(available_mmio_pref, + hotplug_bridges); + mmio_pref_per_hp = min(ALIGN(mmio_pref_per_hp, align), + remaining_mmio_pref); + remaining_mmio_pref -= mmio_pref_per_hp; + + pci_bus_distribute_available_resources(b, add_list, io_per_hp, + mmio_per_hp, + mmio_pref_per_hp); } } -- cgit From d555a50fd6e0280735cabf8581feff875f3f39d7 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:45:52 +0000 Subject: PCI: Pass size + alignment to pci_bus_distribute_available_resources() Change pci_bus_distribute_available_resources() arguments from resource_size_t to struct resource to add more information required to get the alignment correct for bridge windows with alignment >1M. We require (size, alignment), instead of just (size) which is what is currently available. The change from resource_size_t to struct resource does just that. Note that the struct resource arguments are passed by value and not by reference. We do not want to pass by reference and change the resource size of the parent bridge window. We only want the size information. No functional change intended. Link: https://lore.kernel.org/r/PSXP216MB0438587C47CBEDF365B1EA27803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM [bhelgaas: split parts to other patches to reduce the size of this one] Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 35 +++++++++++++++++++---------------- 1 file changed, 19 insertions(+), 16 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 9d167d5b2235..7fa7ad1c3407 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1865,10 +1865,11 @@ static void extend_bridge_window(struct pci_dev *bridge, struct resource *res, static void pci_bus_distribute_available_resources(struct pci_bus *bus, struct list_head *add_list, - resource_size_t available_io, - resource_size_t available_mmio, - resource_size_t available_mmio_pref) + struct resource io, + struct resource mmio, + struct resource mmio_pref) { + resource_size_t available_io, available_mmio, available_mmio_pref; resource_size_t remaining_io, remaining_mmio, remaining_mmio_pref; unsigned int normal_bridges = 0, hotplug_bridges = 0; struct resource *io_res, *mmio_res, *mmio_pref_res; @@ -1885,6 +1886,10 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * calculated in __pci_bus_size_bridges() which covers all the * devices currently connected to the port and below. */ + available_io = resource_size(&io); + available_mmio = resource_size(&mmio); + available_mmio_pref = resource_size(&mmio_pref); + extend_bridge_window(bridge, io_res, add_list, available_io); extend_bridge_window(bridge, mmio_res, add_list, available_mmio); extend_bridge_window(bridge, mmio_pref_res, add_list, @@ -1911,8 +1916,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, dev = list_first_entry(&bus->devices, struct pci_dev, bus_list); if (dev->subordinate) pci_bus_distribute_available_resources(dev->subordinate, - add_list, available_io, available_mmio, - available_mmio_pref); + add_list, io, mmio, mmio_pref); return; } @@ -1986,28 +1990,27 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, remaining_mmio_pref); remaining_mmio_pref -= mmio_pref_per_hp; - pci_bus_distribute_available_resources(b, add_list, io_per_hp, - mmio_per_hp, - mmio_pref_per_hp); + io.end = io.start + io_per_hp - 1; + mmio.end = mmio.start + mmio_per_hp - 1; + mmio_pref.end = mmio_pref.start + mmio_pref_per_hp - 1; + + pci_bus_distribute_available_resources(b, add_list, io, mmio, + mmio_pref); } } static void pci_bridge_distribute_available_resources(struct pci_dev *bridge, struct list_head *add_list) { - resource_size_t available_io, available_mmio, available_mmio_pref; - const struct resource *res; + struct resource available_io, available_mmio, available_mmio_pref; if (!bridge->is_hotplug_bridge) return; /* Take the initial extra resources from the hotplug port */ - res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0]; - available_io = resource_size(res); - res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1]; - available_mmio = resource_size(res); - res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2]; - available_mmio_pref = resource_size(res); + available_io = bridge->resource[PCI_BRIDGE_RESOURCES + 0]; + available_mmio = bridge->resource[PCI_BRIDGE_RESOURCES + 1]; + available_mmio_pref = bridge->resource[PCI_BRIDGE_RESOURCES + 2]; pci_bus_distribute_available_resources(bridge->subordinate, add_list, available_io, -- cgit From 7779385484dad7c95b624f7c9ee1aa07ab8cf43b Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Tue, 28 Jan 2020 15:57:09 -0600 Subject: PCI: Remove local variable usage in pci_bus_distribute_available_resources() In pci_bus_distribute_available_resources(), use resource_size() rather than the local available_io, etc. No functional change intended; this just makes the preceding patch smaller. [bhelgaas: extracted from https://lore.kernel.org/r/PSXP216MB0438587C47CBEDF365B1EA27803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM] Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 7fa7ad1c3407..336c96c1d2d5 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1886,14 +1886,10 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * calculated in __pci_bus_size_bridges() which covers all the * devices currently connected to the port and below. */ - available_io = resource_size(&io); - available_mmio = resource_size(&mmio); - available_mmio_pref = resource_size(&mmio_pref); - - extend_bridge_window(bridge, io_res, add_list, available_io); - extend_bridge_window(bridge, mmio_res, add_list, available_mmio); + extend_bridge_window(bridge, io_res, add_list, resource_size(&io)); + extend_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio)); extend_bridge_window(bridge, mmio_pref_res, add_list, - available_mmio_pref); + resource_size(&mmio_pref)); /* * Calculate how many hotplug bridges and normal bridges there @@ -1929,9 +1925,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * extra space reduced by the minimal required space for the * non-hotplug bridges. */ - remaining_io = available_io; - remaining_mmio = available_mmio; - remaining_mmio_pref = available_mmio_pref; + remaining_io = available_io = resource_size(&io); + remaining_mmio = available_mmio = resource_size(&mmio); + remaining_mmio_pref = available_mmio_pref = resource_size(&mmio_pref); for_each_pci_bridge(dev, bus) { const struct resource *res; -- cgit From f924c26e4ee651493f602da2a3d7ff628824e636 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:46:13 +0000 Subject: PCI: Consider alignment of hot-added bridges when assigning resources Change pci_bus_distribute_available_resources() to better handle bridges with different resource alignment requirements. The arguments io, mmio and mmio_pref represent the start and end addresses of resource, into which we must fit the current bridge window. The steps taken by pci_bus_distribute_available_resources(): - For io, mmio and mmio_pref, increase .start to align with the alignment of the current bridge window (otherwise the current bridge window may not fit within the available range). - For io, mmio and mmio_pref, adjust the current bridge window to the size after the above. - Count the number of hotplug bridges and normal bridges on this bus. - If the total number of bridges is one, give that bridge all of the resources and return. - If there are no hotplug bridges, return. - For io, mmio and mmio_pref, increase .start by the amount required for each bridge resource on the bus for non hotplug bridges, giving extra room to make up for alignment of those resources. - For io, mmio and mmio_pref, calculate the resource size per hotplug bridge which is available after the previous steps. - For io, mmio and mmio_pref, distribute the resources to each hotplug bridge, with the sizes calculated above. The motivation for fixing this is enabling devices that require greater than 1MB alignment. This fixes the case where the user hot-adds devices with BAR alignment >1MB and Linux fails to assign resources to it. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199581 Link: https://lore.kernel.org/r/PSXP216MB0438C2BFD0FD3691ED9C83F4803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Reported-by: Mika Westerberg Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 78 +++++++++++++++++++++++++++++-------------------- 1 file changed, 46 insertions(+), 32 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 336c96c1d2d5..d76674ec712c 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1869,17 +1869,32 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, struct resource mmio, struct resource mmio_pref) { - resource_size_t available_io, available_mmio, available_mmio_pref; - resource_size_t remaining_io, remaining_mmio, remaining_mmio_pref; unsigned int normal_bridges = 0, hotplug_bridges = 0; struct resource *io_res, *mmio_res, *mmio_pref_res; struct pci_dev *dev, *bridge = bus->self; - resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp; + resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp, align; io_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0]; mmio_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1]; mmio_pref_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2]; + /* + * The alignment of this bridge is yet to be considered, hence it must + * be done now before extending its bridge window. + */ + align = pci_resource_alignment(bridge, io_res); + if (!io_res->parent && align) + io.start = min(ALIGN(io.start, align), io.end + 1); + + align = pci_resource_alignment(bridge, mmio_res); + if (!mmio_res->parent && align) + mmio.start = min(ALIGN(mmio.start, align), mmio.end + 1); + + align = pci_resource_alignment(bridge, mmio_pref_res); + if (!mmio_pref_res->parent && align) + mmio_pref.start = min(ALIGN(mmio_pref.start, align), + mmio_pref.end + 1); + /* * Update additional resource list (add_list) to fill all the * extra resource space available for this port except the space @@ -1925,12 +1940,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * extra space reduced by the minimal required space for the * non-hotplug bridges. */ - remaining_io = available_io = resource_size(&io); - remaining_mmio = available_mmio = resource_size(&mmio); - remaining_mmio_pref = available_mmio_pref = resource_size(&mmio_pref); - for_each_pci_bridge(dev, bus) { - const struct resource *res; + resource_size_t used_size; + struct resource *res; if (dev->is_hotplug_bridge) continue; @@ -1940,24 +1952,39 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * bridge and devices below it occupy. */ res = &dev->resource[PCI_BRIDGE_RESOURCES + 0]; - if (!res->parent && available_io > resource_size(res)) - remaining_io -= resource_size(res); + align = pci_resource_alignment(dev, res); + align = align ? ALIGN(io.start, align) - io.start : 0; + used_size = align + resource_size(res); + if (!res->parent) + io.start = min(io.start + used_size, io.end + 1); res = &dev->resource[PCI_BRIDGE_RESOURCES + 1]; - if (!res->parent && available_mmio > resource_size(res)) - remaining_mmio -= resource_size(res); + align = pci_resource_alignment(dev, res); + align = align ? ALIGN(mmio.start, align) - mmio.start : 0; + used_size = align + resource_size(res); + if (!res->parent) + mmio.start = min(mmio.start + used_size, mmio.end + 1); res = &dev->resource[PCI_BRIDGE_RESOURCES + 2]; - if (!res->parent && available_mmio_pref > resource_size(res)) - remaining_mmio_pref -= resource_size(res); + align = pci_resource_alignment(dev, res); + align = align ? ALIGN(mmio_pref.start, align) - + mmio_pref.start : 0; + used_size = align + resource_size(res); + if (!res->parent) + mmio_pref.start = min(mmio_pref.start + used_size, + mmio_pref.end + 1); } + io_per_hp = div64_ul(resource_size(&io), hotplug_bridges); + mmio_per_hp = div64_ul(resource_size(&mmio), hotplug_bridges); + mmio_pref_per_hp = div64_ul(resource_size(&mmio_pref), + hotplug_bridges); + /* * Go over devices on this bus and distribute the remaining * resource space between hotplug bridges. */ for_each_pci_bridge(dev, bus) { - resource_size_t align; struct pci_bus *b; b = dev->subordinate; @@ -1969,29 +1996,16 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * hotplug-capable downstream ports taking alignment into * account. */ - align = pci_resource_alignment(bridge, io_res); - io_per_hp = div64_ul(available_io, hotplug_bridges); - io_per_hp = min(ALIGN(io_per_hp, align), remaining_io); - remaining_io -= io_per_hp; - - align = pci_resource_alignment(bridge, mmio_res); - mmio_per_hp = div64_ul(available_mmio, hotplug_bridges); - mmio_per_hp = min(ALIGN(mmio_per_hp, align), remaining_mmio); - remaining_mmio -= mmio_per_hp; - - align = pci_resource_alignment(bridge, mmio_pref_res); - mmio_pref_per_hp = div64_ul(available_mmio_pref, - hotplug_bridges); - mmio_pref_per_hp = min(ALIGN(mmio_pref_per_hp, align), - remaining_mmio_pref); - remaining_mmio_pref -= mmio_pref_per_hp; - io.end = io.start + io_per_hp - 1; mmio.end = mmio.start + mmio_per_hp - 1; mmio_pref.end = mmio_pref.start + mmio_pref_per_hp - 1; pci_bus_distribute_available_resources(b, add_list, io, mmio, mmio_pref); + + io.start += io_per_hp; + mmio.start += mmio_per_hp; + mmio_pref.start += mmio_pref_per_hp; } } -- cgit From 3d264da9b741fc6503ea54e3bb65c08a77dabca4 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:47:05 +0000 Subject: PCI: Rename extend_bridge_window() parameter In extend_bridge_window(), change "available" parameter name to "new_size". This makes more sense as this parameter represents the new size for the window. No functional change intended. Link: https://lore.kernel.org/r/PSXP216MB043853617ECA4118C472A417803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index d76674ec712c..85439adb747a 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1840,14 +1840,14 @@ void __init pci_assign_unassigned_resources(void) static void extend_bridge_window(struct pci_dev *bridge, struct resource *res, struct list_head *add_list, - resource_size_t available) + resource_size_t new_size) { struct pci_dev_resource *dev_res; if (res->parent) return; - if (resource_size(res) >= available) + if (resource_size(res) >= new_size) return; dev_res = res_to_dev_res(add_list, res); @@ -1855,10 +1855,10 @@ static void extend_bridge_window(struct pci_dev *bridge, struct resource *res, return; /* Is there room to extend the window? */ - if (available - resource_size(res) <= dev_res->add_size) + if (new_size - resource_size(res) <= dev_res->add_size) return; - dev_res->add_size = available - resource_size(res); + dev_res->add_size = new_size - resource_size(res); pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, &dev_res->add_size); } -- cgit From 1e58f4e1cb47de03988f8b14f07f6941acc7e669 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:47:26 +0000 Subject: PCI: Rename extend_bridge_window() to adjust_bridge_window() Rename extend_bridge_window() to adjust_bridge_window() to prepare for the fact that the window will be able to shrink. No functional change intended. Link: https://lore.kernel.org/r/PSXP216MB0438C47B3473D0C9DE531F18803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 85439adb747a..12fe926e32b4 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1838,7 +1838,7 @@ void __init pci_assign_unassigned_resources(void) } } -static void extend_bridge_window(struct pci_dev *bridge, struct resource *res, +static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, struct list_head *add_list, resource_size_t new_size) { @@ -1901,9 +1901,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, * calculated in __pci_bus_size_bridges() which covers all the * devices currently connected to the port and below. */ - extend_bridge_window(bridge, io_res, add_list, resource_size(&io)); - extend_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio)); - extend_bridge_window(bridge, mmio_pref_res, add_list, + adjust_bridge_window(bridge, io_res, add_list, resource_size(&io)); + adjust_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio)); + adjust_bridge_window(bridge, mmio_pref_res, add_list, resource_size(&mmio_pref)); /* -- cgit From ae4611f1d7e99eda6916bbc5fc8df26516edf95e Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:47:46 +0000 Subject: PCI: Set resource size directly in adjust_bridge_window() Change adjust_bridge_window() to set resource size directly instead of using additional resource lists. Because additional resource lists are optional resources, any algorithm that requires guaranteed allocation that uses them cannot be guaranteed to work. Remove the resource from add_list, as a zero-sized additional resource is redundant. Update comment in pci_bus_distribute_available_resources() to reflect the above changes. Link: https://lore.kernel.org/r/PSXP216MB04386BA48874B56BC5CB0292803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 12fe926e32b4..742055908656 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1842,7 +1842,7 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, struct list_head *add_list, resource_size_t new_size) { - struct pci_dev_resource *dev_res; + resource_size_t add_size; if (res->parent) return; @@ -1850,17 +1850,10 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, if (resource_size(res) >= new_size) return; - dev_res = res_to_dev_res(add_list, res); - if (!dev_res) - return; - - /* Is there room to extend the window? */ - if (new_size - resource_size(res) <= dev_res->add_size) - return; - - dev_res->add_size = new_size - resource_size(res); - pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, - &dev_res->add_size); + add_size = new_size - resource_size(res); + pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, &add_size); + res->end = res->start + new_size - 1; + remove_from_list(add_list, res); } static void pci_bus_distribute_available_resources(struct pci_bus *bus, @@ -1896,10 +1889,8 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, mmio_pref.end + 1); /* - * Update additional resource list (add_list) to fill all the - * extra resource space available for this port except the space - * calculated in __pci_bus_size_bridges() which covers all the - * devices currently connected to the port and below. + * Now that we have adjusted for alignment, update the bridge window + * resources to fill as much remaining resource space as possible. */ adjust_bridge_window(bridge, io_res, add_list, resource_size(&io)); adjust_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio)); -- cgit From 948675736a77cb951b40bcb646d22dd794f8ed14 Mon Sep 17 00:00:00 2001 From: Nicholas Johnson Date: Mon, 6 Jan 2020 15:48:06 +0000 Subject: PCI: Allow adjust_bridge_window() to shrink resource if necessary Remove checks for resource size in adjust_bridge_window(). This is necessary to allow pci_bus_distribute_available_resources() to function when the kernel parameter "pci=hpmemsize=nn[KMG]" is used to allocate resources. Because the kernel parameter sets the size of all hotplug bridges to be the same, there are problems when nested hotplug bridges are encountered. Fitting a downstream hotplug bridge with size X and normal bridges with non-zero size Y into parent hotplug bridge with size X is impossible, and hence the downstream hotplug bridge needs to shrink to fit into its parent. Add check for if bridge is extended or shrunken and reflect that in the call to pci_dbg(). Reset the resource if its new size is zero (if we have run out of a bridge window resource) to prevent the PCI resource assignment code from attempting to assign a zero-sized resource. Link: https://lore.kernel.org/r/PSXP216MB0438D3E2CFE64EBAA32AF691803C0@PSXP216MB0438.KORP216.PROD.OUTLOOK.COM Signed-off-by: Nicholas Johnson Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg --- drivers/pci/setup-bus.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 742055908656..f2461bf9243d 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1842,16 +1842,24 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, struct list_head *add_list, resource_size_t new_size) { - resource_size_t add_size; + resource_size_t add_size, size = resource_size(res); if (res->parent) return; - if (resource_size(res) >= new_size) + if (!new_size) return; - add_size = new_size - resource_size(res); - pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, &add_size); + if (new_size > size) { + add_size = new_size - size; + pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, + &add_size); + } else if (new_size < size) { + add_size = size - new_size; + pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res, + &add_size); + } + res->end = res->start + new_size - 1; remove_from_list(add_list, res); } -- cgit