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From: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
To: <linux-pci@vger.kernel.org>, <linuxppc-dev@lists.ozlabs.org>
Cc: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>,
	Bjorn Helgaas <helgaas@kernel.org>,
	linux@yadro.com
Subject: [PATCH v6 17/30] PCI: hotplug: movable BARs: Don't reserve IO/mem bus space
Date: Thu, 24 Oct 2019 20:12:15 +0300	[thread overview]
Message-ID: <20191024171228.877974-18-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20191024171228.877974-1-s.miroshnichenko@yadro.com>

A hotplugged bridge with many hotplug-capable ports may request
reserving more IO space than the machine has. This could be overridden
with the "hpiosize=" kernel argument though.

But when BARs are movable, there are no need to reserve space anymore:
new BARs are allocated not from reserved gaps, but via rearranging the
existing BARs. Requesting a precise amount of space for bridge windows
increases the chances of adding the new bridge successfully.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-bus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 675a612236d7..a68ec726010e 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1285,7 +1285,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 
 	case PCI_HEADER_TYPE_BRIDGE:
 		pci_bridge_check_ranges(bus);
-		if (bus->self->is_hotplug_bridge) {
+		if (bus->self->is_hotplug_bridge && !pci_can_move_bars) {
 			additional_io_size  = pci_hotplug_io_size;
 			additional_mem_size = pci_hotplug_mem_size;
 		}
-- 
2.23.0


  parent reply	other threads:[~2019-10-24 17:49 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-24 17:11 [PATCH v6 00/30] PCI: Allow BAR movement during hotplug Sergey Miroshnichenko
2019-10-24 17:11 ` [PATCH v6 01/30] PCI: Fix race condition in pci_enable/disable_device() Sergey Miroshnichenko
2019-10-25 14:33   ` Oxford Semiconductor Ltd OX16PCI954 - weird dmesg Carlo Pisani
2019-10-25 16:37     ` Bjorn Helgaas
2019-10-24 17:12 ` [PATCH v6 02/30] PCI: Enable bridge's I/O and MEM access for hotplugged devices Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 03/30] PCI: hotplug: Add a flag for the movable BARs feature Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 04/30] PCI: Define PCI-specific version of the release_child_resources() Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 05/30] PCI: hotplug: movable BARs: Fix reassigning the released bridge windows Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 06/30] PCI: hotplug: movable BARs: Recalculate all bridge windows during rescan Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 07/30] PCI: hotplug: movable BARs: Don't disable the released bridge windows Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 08/30] PCI: hotplug: movable BARs: Don't allow added devices to steal resources Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 09/30] PCI: Include fixed and immovable BARs into the bus size calculating Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 10/30] PCI: Prohibit assigning BARs and bridge windows to non-direct parents Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 11/30] PCI: hotplug: movable BARs: Try to assign unassigned resources only once Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 12/30] PCI: hotplug: movable BARs: Calculate immovable parts of bridge windows Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 13/30] PCI: hotplug: movable BARs: Compute limits for relocated " Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 14/30] PCI: Make sure bridge windows include their fixed BARs Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 15/30] PCI: Fix assigning the fixed prefetchable resources Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 16/30] PCI: hotplug: movable BARs: Assign fixed and immovable BARs before others Sergey Miroshnichenko
2019-10-24 17:12 ` Sergey Miroshnichenko [this message]
2019-10-24 17:12 ` [PATCH v6 18/30] PCI: hotplug: Configure MPS for hot-added bridges during bus rescan Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 19/30] PCI: hotplug: movable BARs: Ignore the MEM BAR offsets from bootloader Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 20/30] powerpc/pci: Fix crash with enabled movable BARs Sergey Miroshnichenko
2019-10-25  1:22   ` Alexey Kardashevskiy
2019-10-24 17:12 ` [PATCH v6 21/30] powerpc/pci: Access PCI config space directly w/o pci_dn Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 22/30] powerpc/pci: Create pci_dn on demand Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 23/30] powerpc/pci: hotplug: Add support for movable BARs Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 24/30] powerpc/powernv/pci: Suppress an EEH error when reading an empty slot Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 25/30] PNP: Don't reserve BARs for PCI when enabled movable BARs Sergey Miroshnichenko
2019-10-27 17:40   ` kbuild test robot
2019-10-24 17:12 ` [PATCH v6 26/30] PCI: hotplug: movable BARs: Enable the feature by default Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 27/30] nvme-pci: Handle movable BARs Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 28/30] PCI/portdrv: Declare support of " Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 29/30] PCI: pciehp: movable BARs: Trigger a domain rescan on hp events Sergey Miroshnichenko
2019-10-24 17:12 ` [PATCH v6 30/30] Revert "powerpc/powernv/pci: Work around races in PCI bridge enabling" Sergey Miroshnichenko

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