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From: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
To: <linux-pci@vger.kernel.org>, <linuxppc-dev@lists.ozlabs.org>
Cc: Bjorn Helgaas <helgaas@kernel.org>, <linux@yadro.com>,
	Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
Subject: [PATCH RFC v4 11/21] PCI: Release and reassign the root bridge resources during rescan
Date: Mon, 11 Mar 2019 16:31:12 +0300
Message-ID: <20190311133122.11417-12-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20190311133122.11417-1-s.miroshnichenko@yadro.com>

When the movable BARs feature is enabled, don't rely on the memory gaps
reserved by the BIOS/bootloader/firmware, but instead rearrange the BARs
and bridge windows starting from the root.

Endpoint device's BARs, after being released, are resorted and written
back by the pci_assign_unassigned_root_bus_resources().

The last step of writing the recalculated windows to the bridges is done
by the new pci_setup_bridges() function.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/pci.h       |  1 +
 drivers/pci/probe.c     | 22 ++++++++++++++++++++++
 drivers/pci/setup-bus.c | 11 ++++++++++-
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 224d88634115..e06e8692a7b1 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -248,6 +248,7 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 				struct list_head *realloc_head,
 				struct list_head *fail_head);
 bool pci_bus_clip_resource(struct pci_dev *dev, int idx);
+void pci_bus_release_root_bridge_resources(struct pci_bus *bus);
 
 void pci_reassigndev_resource_alignment(struct pci_dev *dev);
 void pci_disable_bridge_window(struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1cf6ec960236..692752c71f71 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3299,6 +3299,25 @@ static void pci_bus_rescan_done(struct pci_bus *bus)
 	pm_runtime_put(&bus->dev);
 }
 
+static void pci_setup_bridges(struct pci_bus *bus)
+{
+	struct pci_dev *dev;
+
+	list_for_each_entry(dev, &bus->devices, bus_list) {
+		struct pci_bus *child;
+
+		if (!pci_dev_is_added(dev) || pci_dev_is_ignored(dev))
+			continue;
+
+		child = dev->subordinate;
+		if (child)
+			pci_setup_bridges(child);
+	}
+
+	if (bus->self)
+		pci_setup_bridge(bus);
+}
+
 /**
  * pci_rescan_bus - Scan a PCI bus for devices
  * @bus: PCI bus to scan
@@ -3321,8 +3340,11 @@ unsigned int pci_rescan_bus(struct pci_bus *bus)
 		pci_bus_rescan_prepare(root);
 
 		max = pci_scan_child_bus(root);
+
+		pci_bus_release_root_bridge_resources(root);
 		pci_assign_unassigned_root_bus_resources(root);
 
+		pci_setup_bridges(root);
 		pci_bus_rescan_done(root);
 	} else {
 		max = pci_scan_child_bus(bus);
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index be7d4e6d7b65..36a1907d9509 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1584,7 +1584,7 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
 		pci_printk(KERN_DEBUG, dev, "resource %d %pR released\n",
 					PCI_BRIDGE_RESOURCES + idx, r);
 		/* keep the old size */
-		r->end = resource_size(r) - 1;
+		r->end = pci_movable_bars_enabled() ? 0 : (resource_size(r) - 1);
 		r->start = 0;
 		r->flags = 0;
 
@@ -1637,6 +1637,15 @@ static void pci_bus_release_bridge_resources(struct pci_bus *bus,
 		pci_bridge_release_resources(bus, type);
 }
 
+void pci_bus_release_root_bridge_resources(struct pci_bus *root_bus)
+{
+	pci_bus_release_bridge_resources(root_bus, IORESOURCE_IO, whole_subtree);
+	pci_bus_release_bridge_resources(root_bus, IORESOURCE_MEM, whole_subtree);
+	pci_bus_release_bridge_resources(root_bus,
+					 IORESOURCE_MEM_64 | IORESOURCE_PREFETCH,
+					 whole_subtree);
+}
+
 static void pci_bus_dump_res(struct pci_bus *bus)
 {
 	struct resource *res;
-- 
2.20.1


  parent reply index

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-11 13:31 [PATCH RFC v4 00/21] PCI: Allow BAR movement during hotplug Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 01/21] PCI: Fix writing invalid BARs during pci_restore_state() Sergey Miroshnichenko
2019-03-26 14:02   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 02/21] PCI: Fix race condition in pci_enable/disable_device() Sergey Miroshnichenko
2019-03-26 19:00   ` Bjorn Helgaas
2019-03-27 17:11     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 03/21] PCI: Enable bridge's I/O and MEM access for hotplugged devices Sergey Miroshnichenko
2019-03-26 19:13   ` Bjorn Helgaas
2019-03-27 17:13     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 04/21] PCI: Define PCI-specific version of the release_child_resources() Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 05/21] PCI: hotplug: Add a flag for the movable BARs feature Sergey Miroshnichenko
2019-03-26 19:24   ` Bjorn Helgaas
2019-03-27 17:16     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 06/21] PCI: Pause the devices with movable BARs during rescan Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 07/21] PCI: Wake up bridges during rescan when movable BARs enabled Sergey Miroshnichenko
2019-03-26 19:28   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 08/21] nvme-pci: Handle movable BARs Sergey Miroshnichenko
2019-03-26 20:20   ` Bjorn Helgaas
2019-03-27 17:30     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 09/21] PCI: Mark immovable BARs with PCI_FIXED Sergey Miroshnichenko
2019-03-26 20:28   ` Bjorn Helgaas
2019-03-27 17:03     ` David Laight
2019-03-27 17:39       ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 10/21] PCI: Fix assigning of fixed prefetchable resources Sergey Miroshnichenko
2019-03-26 20:37   ` Bjorn Helgaas
2019-03-11 13:31 ` Sergey Miroshnichenko [this message]
2019-03-26 20:41   ` [PATCH RFC v4 11/21] PCI: Release and reassign the root bridge resources during rescan Bjorn Helgaas
2019-03-27 17:40     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 12/21] PCI: Don't allow hotplugged devices to steal resources Sergey Miroshnichenko
2019-03-26 20:55   ` Bjorn Helgaas
2019-03-27 18:02     ` Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 13/21] PCI: Include fixed BARs into the bus size calculating Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 14/21] PCI: Don't reserve memory for hotplug when enabled movable BARs Sergey Miroshnichenko
2019-03-26 20:57   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 15/21] PCI: Allow the failed resources to be reassigned later Sergey Miroshnichenko
2019-03-26 20:58   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 16/21] PCI: Calculate fixed areas of bridge windows based on fixed BARs Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 17/21] PCI: Calculate boundaries for bridge windows Sergey Miroshnichenko
2019-03-26 21:01   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 18/21] PCI: Make sure bridge windows include their fixed BARs Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 19/21] PCI: Prioritize fixed BAR assigning over the movable ones Sergey Miroshnichenko
2019-03-11 13:31 ` [PATCH RFC v4 20/21] PCI: pciehp: Add support for the movable BARs feature Sergey Miroshnichenko
2019-03-26 21:11   ` Bjorn Helgaas
2019-03-11 13:31 ` [PATCH RFC v4 21/21] powerpc/pci: Fix crash with enabled movable BARs Sergey Miroshnichenko

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