From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: Bjorn Helgaas <bhelgaas@google.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>,
Mario.Limonciello@dell.com,
Michael Jamet <michael.jamet@intel.com>,
Yehezkel Bernat <yehezkel.bernat@intel.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Lukas Wunner <lukas@wunner.de>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: [PATCH RESEND v4 6/9] PCI: Move resource distribution for a single bridge outside of the loop
Date: Tue, 3 Apr 2018 17:52:22 +0300 [thread overview]
Message-ID: <20180403145225.22371-7-mika.westerberg@linux.intel.com> (raw)
In-Reply-To: <20180403145225.22371-1-mika.westerberg@linux.intel.com>
There is a special case where there is only single bridge on the bus. In
that case we just assign all resources to it. Currently this is done as
a part of the resource distribution loop but it does not have to be
there, and moving it outside actually improves readability.
While there we can add hotplug_bridges == 1 && normal_bridges == 0 to
the same block because they are dealt the same way.
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/pci/setup-bus.c | 28 +++++++++++++++++-----------
1 file changed, 17 insertions(+), 11 deletions(-)
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index f1e6172734f0..b5eefd20d78d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1951,6 +1951,22 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
mmio_start = mmio_res->start;
mmio_pref_start = mmio_pref_res->start;
+ /*
+ * There is only one bridge on the bus so it gets all available
+ * resources which it can then distribute to the possible
+ * hotplug bridges below.
+ */
+ if ((hotplug_bridges == 0 && normal_bridges == 1) ||
+ (hotplug_bridges == 1 && normal_bridges == 0)) {
+ 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);
+ }
+ return;
+ }
+
/*
* Go over devices on this bus and distribute the remaining
* resource space between hotplug bridges.
@@ -1963,17 +1979,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
if (!b)
continue;
- if (!hotplug_bridges && normal_bridges == 1) {
- /*
- * There is only one bridge on the bus (upstream
- * port) so it gets all available resources
- * which it can then distribute to the possible
- * hotplug bridges below.
- */
- pci_bus_distribute_available_resources(b, add_list,
- available_io, available_mmio,
- available_mmio_pref);
- } else if (dev->is_hotplug_bridge) {
+ if (dev->is_hotplug_bridge) {
resource_size_t io, mmio, mmio_pref;
/*
--
2.16.2
next prev parent reply other threads:[~2018-04-03 14:52 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-03 14:52 [PATCH RESEND v4 0/9] PCI: Fixes and cleanups for native PCIe and ACPI hotplug Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 1/9] PCI: Take all bridges into account when calculating bus numbers for extension Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 2/9] PCI: Take bridge window alignment into account when distributing resources Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 3/9] PCI: pciehp: Clear Presence Detect and Data Link Layer Status Changed on resume Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 4/9] ACPI / hotplug / PCI: Do not scan all bridges when native PCIe hotplug is used Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 5/9] ACPI / hotplug / PCI: Mark stale PCI devices disconnected Mika Westerberg
2018-04-03 14:52 ` Mika Westerberg [this message]
2018-04-10 15:01 ` [PATCH RESEND v4 6/9] PCI: Move resource distribution for a single bridge outside of the loop Rafael J. Wysocki
2018-04-03 14:52 ` [PATCH RESEND v4 7/9] PCI: Document return value of pci_scan_bridge() and pci_scan_bridge_extend() Mika Westerberg
2018-04-10 15:00 ` Rafael J. Wysocki
2018-04-03 14:52 ` [PATCH RESEND v4 8/9] PCI: Improve "partially hidden behind bridge" log message Mika Westerberg
2018-04-10 15:04 ` Rafael J. Wysocki
2018-04-11 9:40 ` Mika Westerberg
2018-04-03 14:52 ` [PATCH RESEND v4 9/9] ACPI / hotplug / PCI: Drop unnecessary parentheses Mika Westerberg
2018-04-10 15:05 ` Rafael J. Wysocki
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